METHOD AND APPARATUS FOR CONVERTING ORGANIC MATERIAL USING MICROWAVE EXCITATION

The present invention relates to methods and apparatus for converting an organic material into hydrocarbons and the resulting product thereof. The method relates in particular to methods and apparatus in which at least a part of the heating of the organic material is performed by microwave heating.

Background All kinds of waste are produced all over the world from factories, households etc., and as a result waste disposal has increased to an insuperable amount of waste over the last decades. Dumping of waste has become an increasingly problem and therefore a cheap effective dispose of waste has become increasingly more important.

Known methods of waste disposal is refuse incineration, which has been shown to develop toxic and ash. Though the developing of ash and toxic is more preferable than disposal of waste, both toxic and ash is not preferred. Refuse incineration is cheap but the method does not recycle any useful products besides the disposable products of toxic and ash. Other methods of waste disposal enable recycling of some usable products.

In view of this new methods have been developed. However these known methods are still very limited in regards to the kind of waste, which may be treated in the same apparatus and in regards to how much of the converted waste which is turned into recyclable products. Additionally, the energy of the organic material, which is converted into recyclable products are still very low compared to the amount of energy added to the method. Therefore in order to make conversion of organic material commercial interesting there is still a need of a more energy effective process.

Furthermore, known methods have shown that char and soot deposit inside the apparatus in such an amount that regular cleaning of the apparatus is needed. Such cleaning operations are time consuming and therefore expensive.

Corrosion of the materials used for making apparatus for the converting of organic material has in known methods been such a problem that the materials for these components had to be chosen in a more expensive group of materials. This problem of corrosion has increased the cost of the apparatus for the converting and therefore decreased the incentive for using converting of waste instead of refuse incineration.

In known methods of conversion of organic material a considerable amount of toxic is still developed. Therefore, there it is still need of converting methods, which develop less toxic and preferably also less ash.

Summary of the invention

An objective of the present invention is to provide an improved method and an improved apparatus for converting organic material, such as waste, sludge, biomass etc., into recyclable products, such as hydrocarbon fuel, which method at least partly overcome or at least mitigate the aforementioned problems and disadvantages.

Another objective of the present invention is to provide an improved recyclable product from the conversion of organic material, which improved product is reusable as some kind of energy.

Thus, the present invention relates in a first aspect to method for converting an organic material into hydrocarbon fuels, comprising the steps of: pressurising said organic material in a fluid to a pressure above 25 bar, such as above 225 bar, and heating said organic material in said fluid to a temperature above 150 ⁰ C, such as above 200 ⁰ C in the presence of a homogeneous catalyst comprising a compound of at least one element of group IA of the periodic table of elements, the heating being performed at least partly by microwave heating wherein the method further comprises the steps of: contacting said organic material in said fluid with a heterogeneous catalyst comprising a compound of at least one element of group IVB of the periodic table and/or alpha-alumina, and assuring that said fluid has initially a pH value of above 7, such as adjusting said fluid to a pH value above 7.

An improved method for converting organic material into recyclable products is hereby obtained. By contacting the organic material with a heterogeneous catalyst comprising a compound of at least one element of group IVB of the periodic table and/or alpha-alumina, the catalyst may be reused and a continuously converting of organic material is possible. Thereby the amount of catalyst spent for converting one amount of organic material is decreased whereby the cost for converting the material is considerable decreased. Additionally, the process time has been decreased considerably due to the fact that dividing the catalyst process into two separate processes increases the velocity of conversion.

Furthermore, by adjusting the fluid to above 7 the corrosion of the materials used for the involved components in the apparatus is considerably decreased. The corrosion of these materials has decreased to such an amount that cheap standard materials may be used for the construction of the apparatus.

In preferred embodiments of the present invention the method may comprise the step of maintaining the pH value of said fluid containing said organic material in the range 7-14, such as 7-12 and preferably in the range 7-10 such as in the range 8-10, such as in the range of 7-9.5. It is hereby obtained that when converting the organic material into hydrocarbon fuel the corrosion of the materials used for the involved components of the apparatus is substantial decreased to at least an insignificant amount of corrosion.

Furthermore, according to preferred embodiments of the present invention the method may comprise the step of pre-treating the organic material at a pressure of 4-15 bar at the temperature of 100-150 ⁰ C, such as of 100-170 ⁰ C for a period of 0.5-2 hours. By pre- treating the organic material at this pressure, the organic material is pre-converted whereby the subsequent conversion may be performed more quickly than without the pre- treatment.

The conversion temperature of the organic material heated by microwave heating may preferable and advantageously be the same as in the pre-treatment step, such as in the range of 110-150 ⁰ C.

Preferably, the maximum temperature of the organic material during its contact with the heterogeneous catalyst may be below 33O ⁰ C, preferable below 300 ⁰ C, such as below 275 ⁰ C, and preferably below 25O ⁰ C, such as below 225 ⁰ C, and event more preferably below 200 ⁰ C, such as below 175 ⁰ C.

Subsequently, the pre-treating step may in preferred embodiments of the invention comprise a step of size reducing the material such as a cutting, grinding, milling, or sieving step or a combination thereof. By such a size reduction the conversion process of the organic material is performed even more quickly than without the size reduction.

Additionally, the pre-treating step may comprise the step of adding additives to the fluid according to the present invention, whereby the conversion process is improved even further in regards to speed of the conversion time and in regards to the resulting product from the conversion of the organic material into hydrocarbon fuels. The product resulting from the conversion of the organic material may by adding these additives be regulated, so that the resulting product may have variable composition of oil, methanol, water, water

soluble organics, water soluble salts, etc. It is then possible to adjust the recyclable product in regards to the wishes of the subsequent use of the products.

In preferred embodiment of the present invention the step of pre-treating may comprise the step of adjusting the pH of said fluid comprising said organic material to above 7. It hereby obtained to adjustment of the pH value in the fluid comprising the organic material at an early stage of the conversion process, whereby the process time for the conversion is reduced. Preferably, the step of assuring that the fluid has initially a pH value of above 7 may comprise one or more of the following: adding a base to the fluid, mixing several feedstock fluid, of which at least one is alkaline, adding a chemical reactant to the fluid, which consumes acid during pre-treatment and thereby raising the pH value above 7.

By the step of pre-treating the fluid comprising the organic material it is possible to increase the amount of solid-state material in the fluid, which again leads to a higher rate of conversion and thereby a higher production capacity. This results in a more efficient and cost saving converting of organic material.

In preferred embodiments of the present invention the method may further comprise a step of separating particles from the fluid comprising the organic material. By separating particles before contacting the fluid comprising the organic material with the heterogeneous catalyst the product resulting from the conversion process, such as oil, is then substantially free of being bound to these particles and therefore much more reusable straight after this conversion process. A second process, such as a refinery is thereby dispensable.

In further embodiments of the present invention the method may further comprise a second step of heating the fluid. The temperature of fluid comprising the organic material is hereby adjustable just before contacting the heterogeneous catalyst, whereby the process is optimised, which leads to a reduced process time. Furthermore, by separating the particles away from the fluid at such an early stage a substantially amount of energy for transporting the separated particles is saved, which again decreases the amount of energy spend in the conversion process as a total.

Additionally, preferred embodiments of the method according to the invention may comprise a second separating of particles, which step is merely for safety reason in regards to the first step of separating particles. This step reduces for the same reasons as the first step of separating particles the total amount of energy spend for the conversion process.

Furthermore, the method may according to the invention comprise a first step of cooling the fluid after contacting with the heterogeneous catalyst. By cooling the fluid the resulting product from converting of the organic material may be optimized in relations to the composition of product.

Advantageously, the step of cooling may according to the present invention be performed by heat exchanging with the first step of heating and/or a step of pre-heating the fluid in the pre-treating step. It is hereby obtained to reuse the heat from the fluid, which needs to cool down before the second part of conversion into the recyclable products, in the fluid in the first part of conversion process before contacting the fluid with the heterogeneous catalyst. The total amount of energy for the converting of organic material is thereby kept to a minimum.

Said method may according to preferred embodiments of the present invention further comprise a step of separation gas from the fluid, such as fuel gas. By separating this gas one kind of recyclable product is obtained, which was an objective of the invention.

The method may according to preferred embodiments of the present invention further comprise a second step of heating the fluid, the heating in the second step of heating being performed at least partly by micro wave heating and/or wherein at least some of the hydrocarbon fuel, preferably in gas phase, is used for at least partly heating the fluid in the second heating step. Additionally or in combination thereto, the hydrocarbon fuel may in preferred embodiments be used to heat either alone or in combination with microwave heating during pre-treatment and/or in the first heater.

Furthermore, the method may according to the invention further comprise a step of filtrating the fluid, separating water and water soluble organics from oil and water soluble salts in membrane-filter(s). By this separation a recyclable products is obtained and a further converting into recyclable products is possible.

In preferred embodiments of the present invention, the water and water soluble organics are transformed into electricity in a direct methanol fuel cell. This is one way of using one of the recyclable products of the present invention. It may also be regarded as a subsequent step of converting the recycle products into a usable product in form of electricity.

The method may also according to preferred embodiments of the present invention comprise a second step of filtering water soluble organics from the water, such as a

purification of methanol in a second membrane-filter. By this conversion step one recycle product is obtained.

Subsequently, said one or more membrane-filters may be selected from the group of 5 membrane processes comprising ultra-filtration, nano-filtration, reverse osmosis or pervaporation or a combination thereof. By this selection different kinds of recycle products are obtainable.

In preferred embodiments of the present invention, the water and water soluble organics 10 after the second filtering step may be transformed into drinkable water in a process of reverse osmosis or similar water purification technology. By the method comprising the process of reverse osmosis one very usable recyclable product is obtained.

In preferred embodiments of the present invention, the water soluble organic product is 15 re-circulated to the pre-treating step. A further optimization of the converting method is hereby obtained, and the converted product of up-concentrated methanol is reused.

Additionally, the method may according to preferred embodiments of the invention comprise a phase separator or similar oil/water separation equipment, whereby separation 20 of oil as product is obtained.

In preferred embodiments of the present invention, the step of contacting the organic material in the fluid with a heterogeneous catalyst may be performed while the temperature is kept substantially constant. By keeping the temperature constant in the

25 contacting step the contacting of the fluid with the heterogeneous catalyst is kept in the same condition and the conversion is therefore constant throughout the contacting step. A further advantage is that the equilibriums and reaction rates of the chemical reactions involved in the conversion are kept constant throughout the contacting step, thereby ensuring uniformity in the products formed by the conversion.

30

The temperature in the step of contacting may in preferred embodiments be in the range 150-650°C, such as in the range 150-450°C, and preferably in the range 150-374°C, and even more preferably in the range 150-374°C, such as in the range 150-300°C. Furthermore, the temperature in the step of contacting may preferably be in the range of

35 200-650°C, such as in the range of 200-450°C, and preferably in the range 200-374°C, and even more preferably in the range of 250-374°C, such as in the range of 275-350°C. By keeping these low temperatures the conversion process is using less energy in converting the same amount of organic material than at higher temperatures. A low temperature

together with a pH value above 7 decreases the corrosion of the materials used for the apparatus in which the present method is performed.

A low temperature in the contacting step increases the fraction of the organic material being converted into hydrocarbon fuels, and thereby the oil production capacity of the contacting step. At such low temperatures the solubility of salts is high compared to higher temperature whereby the conversion process is further advantageous due to almost no salts depositing occurs inside the apparatus. Furthermore, at such low temperatures the organic material is less converted into soot and tar, which products are not very recyclable. Finally such low temperature allows construction of the apparatus from less corrosion resistant materials, further improving the competitive.

Preferably, the pressure for said conversion may be in the range 25-600 bars, such as in the range 25-400 bars and preferably in the range 25-350 bars, such as in the range 25-200 bars. Furthermore, the pressure for said conversion may preferably be in the range of 225-600 bars, such as in the range of 225-400 bars and preferably in the range of 225-350 bars, such as in the range of 240-300 bars. By using pressures inside these ranges it is obtained that standard components and equipment may be used for the present method whereby the cost of the conversion process and apparatus is substantially decreased compared to the same at higher pressures.

Furthermore, the method may according to the invention further comprise the step of contacting the fluid with the heterogeneous catalyst in less than 30 minutes, such as less than 20 minutes, preferably less 10 minutes, such as less than 7.5 minutes, and even more preferably in the range 0.5-6 minutes, such as in the range 1-5 minutes. By contacting the fluid at in a short period the conversion process time is decreased without decreasing the conversion processing of organic material substantially.

Additionally, the compound of at least one element of group IVB of the periodic table used as heterogeneous catalyst may comprise zirconium and/or titanium according preferred embodiments of the present invention. By using zirconium and/or titanium as a heterogeneous catalyst the conversion process time is decreased without decreasing the conversion processing of organic material.

The compound of at least one element of group IVB of the periodic table may preferably be on an oxide and/or hydroxide form or a combination of the two. By using the heterogeneous catalyst on an oxide and/or hydroxide form the conversion process time is decreased without decreasing the conversion processing of organic material.

Advantageously and preferably, the compound of at least one element of group IVB of the periodic table is at least partly on a sulphate or sulphide form according to another embodiment of the present invention. By using the heterogeneous catalyst on a sulphate or sulphide form the conversion process time is decreased without decreasing the conversion processing of organic material.

The heterogeneous catalyst may preferably further comprise at least one element selected from the group consisting of Fe, Ni, Co, Cu, Cr, W, Mn, Mo, V, Sn, Zn, Si in an amount up to 20 % by weight, such as an amount up to 10 % by weight, preferably in an amount up to 5 % by weight, such as up to 2.5 % by weight. By using the aforementioned heterogeneous catalyst together with one or more elements of this group the conversion process time is substantially decreased without decreasing the conversion processing of organic material.

Furthermore, these elements may preferably be on an oxide and/or hydroxide form, whereby the conversion process time is further decreased without decreasing the conversion processing of organic material.

Said heterogeneous catalyst may in preferred embodiments be in the form of suspended particles, tablets, pellets, rings, cylinders, a honey comb structure, a fibrous structure and/or a combination of these. The advantage of said heterogeneous catalyst structures is to control the flow distribution of the organic material stream being contacted with the catalyst, while ensuring reasonable pressure drop and contact to all of the catalyst surface.

Additionally, said heterogeneous catalyst may at least partly be contained in a reactor according to preferred embodiments of the present invention. It is hereby possible to reuse that part of the catalyst, which is inside the reactor.

Advantageously, said reactor is a fixed bed reactor according to preferred embodiments of the present invention. By using a fixed bed reactor, it is hereby possible to even more easily reuse that part of the catalyst, which is inside the reactor.

Said heterogeneous catalyst may preferably have a BET surface area of at least 10 m2/g, such as 25 m2/g, and preferably at least 50 m2/g, such as 100 m2/g, and even more preferably at least 150 m2/g, such as at least 200 m2/g. By having this BET surface area, the conversion process time is further decreased without decreasing the quality of the conversion process, as sufficient catalytic active surface area is ensured.

In preferred embodiments of the present invention, said heterogeneous catalyst may

comprise at least one surface area stabilizer selected from the group consisting of Si, La, Y or Ce or a combination thereof. By having this surface stabilizer, the catalyst service lifetime time is further expanded without decreasing the quality of the conversion process.

Advantageously, said heterogeneous catalyst may according to preferred embodiments of the present invention comprise said at least one surface area stabilizer in an effective amount up to 20 % by weight, such as an effective amount up to 10 % by weight, preferably said surface area stabilizers in an effective amount up to 7.5 % by weight, such as surface stabilizers in an effective amount up to 5 % by weight, and more preferably said surface stabilizers are present in an effective amount from 0.5-5 % by weight, such as 1-3 % by weight. By having this surface stabilizer in up to 20 % by weight, the catalyst service lifetime is further expanded without decreasing the quality of the conversion process.

Preferably, the heterogeneous catalyst may have a BET surface area of at least 10 m2/g after 1000 hours of use, such as BET surface area of at least 25 m2/g after 1000 hours of use, and preferably a BET surface area of at least 50 m2/g after 1000 hours of use, such as a BET surface area of at 100 m2/g after 1000 hours of use, and even more preferably a BET surface area of at least 150 m2/g after 1000 hours in use, such as at a BET surface area of least 200 m2/g after 1000 hours in use. By having this BET surface area of at least 10 m2/g after 1000 hours of use, the conversion process time is further decreased without decreasing the quality of the conversion process, as sufficient catalytic active surface area is ensured.

Furthermore, said heterogeneous catalyst may preferably and advantageously be produced from red mud according to preferred embodiments of the present invention. It is hereby obtained to use waste product in the converting of the organic material, which also is a waste product.

Additionally, the method may according to the invention further comprise the step of recycling carbonates and/or hydrogen carbonates. By re-circulating carbonates and/or hydrogen carbonates the method is reusing products resulting from the conversion method and an optimizing of the method is hereby obtained.

The concentration of said carbonates and/or hydrogen carbonates may according to preferred embodiments of the invention be at least 0.5 % by weight, such as at least 1 % by weight, and preferably at least 2 % by weight, such as at least 3 % by weight, and more preferably at least 4 % by weight, such as at least 5 % by weight. The carbonates and bi-carbonates are important activators in the catalytic conversion performed by the

homogenous catalyst.

Furthermore, the method may according to the invention further comprise the step of recycling at least one alcohol. By re-circulating at least one alcohol the method is reusing products resulting from the conversion method and an optimizing of the method is hereby obtained.

According to preferred embodiments of the present invention, the at least one alcohol may comprise methanol, whereby a very usable recyclable product is reused in optimizing the method.

Preferably, the methanol content in the fluid may be at least 0.05 % by weight, such as at least 0.1 % by weight, and preferably at least 0.2 % by weight, such as at least 0.3 % by weight, and even more preferably at least 0.5 % methanol by weight, such as at least 1 % by weight. Methanol is involved in the chemical reactions responsible for producing the oil product, and in the chemical reactions destroying the radicals otherwise responsible for formation of soot and tar during the decomposition of the organic material.

Advantageously, the method may in preferred embodiments of the present invention comprise the step of re-circulating a fluid containing hydrogen. By recycling a fluid containing hydrogen the method is reusing products resulting from the conversion method and an optimizing of the method is hereby obtained.

The hydrogen content of said fluid may in preferred embodiments corresponds to at least 0.001 % by weight of the amount of said organic material to be treated, such as at least 0.01 % by weight of the amount of said organic material to be treated, and preferably 0.1 % by weight of the amount of said organic material to be treated, such as 0.2 % by weight of the amount of said organic material to be treated, and even more preferably the hydrogen content of the fluid is at least 0.5 % by weight of the amount of said organic material to be treated, such as at least 1 % by weight of the amount of said organic material to be treated. Hydrogen is involved in the chemical reactions producing saturated oil compounds, and in the reactions destroying free radicals, otherwise leading to formation of soot and tar during the thermal decomposition of the organic material during the conversion.

The method may according to the invention preferably further comprise the step of re- circulating at least one carboxylic acid. By re-circulating at least one carboxylic acid the method is reusing products resulting from the conversion method and an optimizing of the

method is hereby obtained.

Additionally, said at least one carboxylic acid may preferably comprise at least one carboxylic acid having a chain length corresponding to 1-4 carbon atoms. The at least one 5 carboxylic acid corresponding to 1-4 carbon atoms is involved in the chemical chain formation reactions producing the oil product.

Furthermore, the at least one carboxylic acid may preferably comprise formic acid and/or acetic acid according to preferred embodiments of the present invention. The at least one 10 carboxylic acid corresponding to 1-4 carbon atoms is involved in the chemical chain formation reactions producing the oil product.

Advantageously, the concentration of said carboxylic acid(s) in said fluid may according to the present invention preferably be at least 100 part per million by weight, such as at least 15 250 part per million by weight, and preferably at least 400 parts per million by weight, such as at least 500 parts per million by weight. At this concentration level the oil product producing chemical reactions rates are sufficient to ensure conversion of the organic material to said oil product.

20 In preferred embodiments of the present invention the method may comprise the step of recycling at least one aldehyde and/or at least one ketone. By re-circulating at least one aldehyde and/or at least one ketone the method is reusing products resulting from the conversion method and an optimizing of the method is hereby obtained.

25 Preferably, at least one aldehyde and/or at least one ketone comprises at least one aldehyde and/or at least one ketone having a chain length corresponding to 1-4 carbon atoms. The said at least one aldehyde or ketone corresponding to 1-4 carbon atoms is involved in the chemical chain formation reactions producing the oil product.

30 Preferably, at least one aldehyde and/or at least one ketone comprises formaldehyde and/or acetaldehyde. The at least one aldehyde or ketone corresponding to 1-4 carbon atoms is involved in the chemical chain formation reactions producing the oil product.

According to preferred embodiments of the present invention, the concentration of said at 35 least one aldehyde and/or at least one ketone in said fluid may be at least 100 part per million by weight, such as at least 250 part per million by weight, and preferably at least 400 parts per million by weight, such as at least 500 parts per million by weight. At this concentration level the oil product producing chemical reactions rates are sufficient to ensure conversion of the organic material to said oil product.

Advantageously, the homogeneous catalyst may preferably comprise potassium and/or sodium according to preferred embodiments of the present invention. By using potassium and/or sodium as a homogeneous catalyst the conversion process time is decreased 5 without decreasing the conversion processing of organic material, and the rates chemical reactions involved in the oil product formation are enhanced to facilitate production of said oil product.

Furthermore, according to preferred embodiments of the present invention the 10 homogeneous catalyst may comprise one or more water soluble salts selected from the group consisting of KOH, K ₂ CO ₃ , KHCO ₃ , NaOH, Na ₂ CO ₃ or NaHCO ₃ or a combination thereof. In combination with the carbon dioxide formed as part of the conversion of the organic material said salts are converted into the carbonate involved in the chemical reactions as activator. 15

The concentration of the homogeneous catalyst may preferably be at least 0.5 % by weight, such as at least 1 % by weight, and preferably at least 1.5 % by weight, such as at least 2.0 % by weight, and even more preferably above 2.5 % by weight, such as at least 4 % by weight. At this concentration level the oil product producing chemical 20 reactions rates are sufficient to ensure conversion of the organic material to said oil product.

Additionally, said fluid comprises water according to preferred embodiments of the present invention. Water is a cheap and very frequent fluid and therefore by using water the cost 25 to method of converting organic material is kept to a minimum and the method may be used in all areas of the world.

The water may preferably have a concentration of at least 5 % by weight, such as at least 10 % by weight, and preferably at least 20 % by weight, such as at least 30 % by weight, 30 and even more preferably at least 40 % by weight. The organic material to be converted must be pumpable.

The concentration of said water in said fluid may in preferred embodiments of the present invention be up to 99.5 % by weight, such as up to 98 % by weight, and preferably up to 35 95 % by weight, such as up to 90 % by weight, and even more preferably up to 85 % by weight, such as up to 80 % by weight. By decreasing the water content the heat value of the feedstock is increased, leading to increased oil production capacity at constant processing cost, without sacrificing the pumpability of the organic material to be

converted.

In preferred embodiments of the present invention the at least one carbonate and/or at least one hydrogen carbonate and/or at least one alcohol and/or at least one carboxylic acid and/or at least one aldehyde and/or at least one ketone may at least partly be produced by the conversion of said organic material. By reusing a product resulting from the conversion process, the conversion process time is decreased without decreasing the conversion processing of organic material. Furthermore expenses for treating an effluent stream are saved.

The least one carbonate and/or at least one hydrogen carbonate and/or at least one alcohol and/or at least one carboxylic acid and/or at least one aldehyde and/or at least one ketone may preferably be re-circulated after the step of contacting the fluid with the heterogeneous catalyst. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

Furthermore, at least part of a stream of said recirculation may according to preferred embodiments of the present invention be mixed in a ratio with a feed stream of said fluid comprising said homogeneous catalyst and organic material to be converted before entering the catalytic reactor. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

Additionally, the ratio of the re-circulating stream to the feed stream of said fluid may according to preferred embodiments of the present invention be in the range 1-20, such as 1-10, and preferably within the range 1.5-7.5, such as in the range 2-6, and more preferably in the range 2-4. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

Advantageously, the conversion of said organic material may according to preferred embodiments of the present invention be at least 90 %, such as at least 95 %, and preferably above 97.5 %, such as above 99 %, and even more preferably above 99.5 %, such as above 99.9 %. The high conversion leads to maximization of the oil production capacity, and minimizes or eliminates the content of unconverted organic material in oil product and mineral product, thereby eliminating the need for a purification step.

According to preferred embodiments of the present invention the reactor with

heterogeneous catalyst may be subjected to a treatment with hot pressurised water at pre-selected intervals.

The treatment with hot pressurised water may preferably have a duration of less than 12 hours, such as a duration of less than 6 hours, preferably a duration of less than 3 hours, such as a duration of less than 1 hour.

The interval between such treatment with hot pressurised water may preferably be at least 6 hours, such as at least 12 hours, preferably said interval between such treatment with hot pressurised water is at least 24 hours, such as at least one week.

By treating or flushing the reactor with hot pressurised water, the life time of the reactor is increased and the cost of the method is thereby substantially decreased.

Preferably, the organic material may be selected from the group consisting of sludge, such as sewage sludge, liquid manure, corn silage, clarifier sludge, black liquor, residues from fermentation, residues from juice production, residues from edible oil production, residues from fruit and vegetable processing, residues from food and drink production, leachate or seepage water, biomass or a combination thereof.

According to preferred embodiments of the present invention, the organic material may comprise a lignocelulotic material, selected from the group consisting of biomass, straw, grasses, stems, wood, bagasse, wine trash, sawdust, wood chips or energy crops or a combination thereof.

According to preferred embodiments of the present invention, the organic material may comprise a waste, such as house hold waste, municipal solid waste, paper waste, auto shredder waste, plastics, polymers, rubbers, scrap tires, cable wastes, CCA treated wood, halogenated organic compounds, PCB bearing transformer oils, electrolytic capacitors, halones, medical waste, risk material from meat processing, meat and bone meal, liquid streams, such as process or waste water streams containing dissolved and/or suspended organic material.

Advantageously, said sludge may according to preferred embodiments of the present invention be sludge from a biological treatment process.

The organic material may preferably be sludge from a waste water treatment process.

In preferred embodiments of the present invention said biological treatment process may be part of a waste water treatment process.

Furthermore, the biological water treatment process may according to preferred embodiments of the present invention be an aerobic process.

Additionally, the biological water treatment process may be an anaerobic process according to preferred embodiments of the present invention.

The method is capable of converting many kinds of organic material as mentioned above. Even though the method is performed at a relatively low temperature and a relatively low pressure the temperature and pressure is still sufficient to disinfect the resulting product. Which means regardless what organic material the resulting products is usable without infecting risk, e.g. residues from food production, such as meat from a cow or a veal will not result in the spreading of the disease BSE. Likewise will virus, bacteria etc. from the organic material not be spread in a subsequent use of the resulting products.

Advantageously, said organic material may have been subjected to a mechanical dewatering according to preferred embodiments of the present invention. By dewatering the organic material the heat value of the feedstock is increased, leading to increased oil production capacity at constant processing cost, without sacrificing the pumpability of the organic material to be converted.

Furthermore, the mechanically dewatered organic material may according to preferred embodiments of the present invention have a dry solid content of at least 10 % by weight, preferably at least 15 % by weight, more preferably at least 20 % by weight, such as at least 25 %, most preferred 30 % by weight.

By the pre-treatment step of the method it is obtained to increase the dry solid content, which again decreases the conversion process time.

Additionally, the organic material may according to preferred embodiments of the present invention comprise a mixture of sludge, lignocelulotic materials or waste.

In preferred embodiments of the present invention the concentration of said organic material in said fluid may be at least 5 % by weight, such as at least 10 % by weight, preferably the concentration of said organic material is at least 15 % by weight, such as at least 200 % by weight, and more preferably the concentration of said organic material is at least 30 % by weight, such as at least 50 % by weight.

Advantageously, the elements of group IA of the periodic table may preferably be ash obtained from combustion of biomass or ash from coal firing.

5 By mixing the different organic materials it is obtained that less catalyst has to be used in the further processing and/or that the rate of the processing time is increased.

In a second aspect, the present invention relates to a method for converting organic material into hydrocarbon fuels, comprising the steps of:

10 - pressurizing said organic material being in a fluid to a pressure of above 25 bar, such as above 150 bar - heating said material to a temperature of above HO ⁰ C at least partly microwave heating.

Preferably, the microwave heating of the organic material in the fluid to a temperature 15 above HO ⁰ C is performed in the presence of a homogeneous catalyst comprising a compound of at least one element of group IA of the periodic table of elements.

In preferred embodiments, the method may further comprise contacting the organic material in the fluid with a heterogeneous catalyst comprising a compound of at least one 20 element of group IVB of the periodic table and/or alpha-alumina and/or a zeolite.

The method may preferably further comprise the step of pre-treating the organic material at a pressure of 4-15 bar at the temperature of 100-170 ⁰ C for a period of 0.5-2 hours.

25 Preferably, the temperature of the organic material after being heated at least partly by microwaves is substantially the same as the temperature of the material in the pretreatment step, preferably in the range of 110-150°C, such as in the range 100-150 ⁰ C.

In preferred embodiments, the maximum temperature may be below 300 ⁰ C such as below 30 275 ⁰ C, and preferably below 25O ⁰ C such as below 225 ⁰ C, and even more preferably below 200 ⁰ C, such as below 175 ⁰ C.

In third aspect, the present invention further relates to the product obtained by the aforementioned methods. Said product may according to the present invention comprise 35 hydrocarbon in the form of oil. A resulting product which is very usable is hereby obtained in that oil is presently a very demanded product all over the world. A product such as oil is possible to obtain in that the method is performed at very low temperatures.

In preferred embodiments of the present invention the fluid may have a feed carbon content and a feed hydrocarbon content, where the hydrocarbon oil product comprises at least 20 % of the feed carbon content, such as at least 35 % of the feed hydrocarbon content, preferably comprises said hydrocarbon oil product at least 50 % of the feed 5 carbon content, such as at least 65 % of the feed carbon content and more preferably said hydrocarbon oil product comprises at least 80 % of the feed carbon content.

At least 20 % of a energy content in the feed stream may preferably be recovered in said hydrocarbon oil product, such as at least 35 % of the energy content, preferably is at least 10 50 % of the energy content in the feed recovered in said hydrocarbon oil product, such as at least 65 % of the feed energy content and even more preferable at least 80 % of said feed energy content is recovered in said hydrocarbon oil product.

Furthermore, said hydrocarbon oil product may preferably comprise hydrocarbons with 12 15 to 16 carbon atoms according to preferred embodiments of the present invention.

Advantageously, said hydrocarbon oil product may be substantially free of sulphur according to preferred embodiments of the present invention.

20 Additionally, said hydrocarbon oil product may be substantially free of halogens according to preferred embodiments of the present invention.

By the method according to the present invention a hydrocarbon oil product free of sulphur and/or halogens is hereby obtained. Such oils free of sulphur and/or halogens are very 25 recyclable into new forms of energy without polluting the surroundings with reactions caused by sulphur and/or halogens.

The hydrocarbon oil product may according to preferred embodiments of the present invention comprise fatty acid esters and/or fatty acid methyl esters. The oxygen content of 30 the fatty acid esters and methyl esters is known to improve the properties of the hydrocarbon oil as transportation fuel, due to the reduced particle emission from the combustion of the fuel.

The hydrocarbon oil product may have diesel-like properties according to preferred 35 embodiments of the present invention. The diesel-like hydrocarbon fuel might be mixed directly into conventional diesel oil, thereby saving the cost of refining the oil product.

Furthermore, the hydrocarbon oil product may have an oxygen content in the range 0.1-30 % according to preferred embodiments of the present invention. The oxygen

content of the hydrocarbon fuel is known to improve the properties as transportation fuel, due to the reduced particle emission from the combustion of the fuel.

Additionally, the hydrocarbon oil product may be adsorbed on the surface of a mineral product according to preferred embodiments of the present invention. This oil containing mineral product is an improved starting material for molten mineral processing processes.

The hydrocarbon product may also comprise methanol according to preferred embodiments of the present invention. By further purification a purified methanol product might be obtained, which is preferred fuel for fuel cells or additive to gasoline for production of sustainable transportation fuels.

In further preferred embodiments of the present invention, the hydrocarbon product comprising methanol may comprise at least 20 % of the feed carbon content, such as at least 35 % of the feed carbon content, preferably comprises said methanol product at least 50 % of the feed carbon content, such as at least 65 % of the feed carbon content and more preferably comprises said methanol product at least 80 % of the feed carbon content. By further purification a purified methanol product might be obtained, which is preferred fuel for fuel cells or additive to gasoline for production of sustainable transportation fuels.

In yet further preferred embodiments of the present invention at least 20 % of the energy content in the feed may be recovered in said hydrocarbon product comprising methanol, such as at least 35 % of the energy content in the feed is recovered in said hydrocarbon product comprising methanol, preferably is at least 50 % of the energy content in the feed recovered in said hydrocarbon product comprising methanol, such as at least 65 % of the feed energy content is recovered in said hydrocarbon product comprising methanol and more preferably is at least 80 % of said feed energy content recovered in said hydrocarbon product comprising methanol. By further purification a purified methanol product might be obtained, which is preferred fuel for fuel cells or additive to gasoline for production of sustainable transportation fuels.

Preferable, the present invention further relates to the use of the aforementioned product for driving an engine or a generator, for power production in an oil fired power plant, for process heating or domestic heating. These are all means of producing energy from a sustainable source, yet without having to replace or renew the hardware installations or infrastructure established for energy production from fossil fuels.

Furthermore, the present invention relates preferably to the use of the aforementioned product as a blending component in petrodiesel or gasoline or in a suspension fired system or in a process for molten mineral processing. These are all means of producing energy from a sustainable source, yet without having to replace or renew the hardware installations or infrastructure established for energy production from fossil fuels.

Additionally, the present invention preferably relates to the use of the aforementioned for producing a product for use in a suspension fired system, in a process for molten mineral process, a fertilizer product or for producing clean water stream. Said clean water stream may furthermore have drinking water quality.

In a fourth aspect, the present invention relates to an apparatus for converting an organic material into hydrocarbons, comprising: a conversion system and a product recovery system, said conversion system comprises

- a first heating unit for heating a feed of fluid comprising organic material

- a catalyst reactor for contacting the feed of fluid comprising organic material, and

- an adjusting unit for adjusting the fluid to have a pH value of above 7, the conversion system being adapted to heat preferably in one or more steps the organic material and preferably before contacting the catalyst reactor at least partly by use of micro waves, and said product recovery system comprises

- membrane-filter for separating a first stream of oils and water soluble salts in from a second stream of water and water soluble organics.

In the present context, the conversion system may also be referred to a pre-conversion system.

In preferred embodiments of the present invention, the conversion system may further comprise a storage for feeding organic material to the fluid in a feeding direction.

Furthermore, the conversion system may further comprise a pre-treating unit situated after the feedstock and before the first heating unit in the feeding direction, according to preferred embodiments of the present invention. By pre-treating the fluid comprising the organic material it is possible to increase the amount of solid-state material in the fluid, which again leads to a higher rate of conversion and thereby a higher production capacity. This results in a more efficient and cost saving converting of organic material.

In preferred embodiments of the present invention, the pre-treating unit may preferably comprise a micro wave source for at least partly heating organic material present in the pre-treating unit.

Additionally, the conversion system may according to preferred embodiments of the present invention further comprise a first particle separating unit situated after the first heating unit in the feeding direction. By separating particles before contacting the fluid comprising the organic material with the heterogeneous catalyst the product resulting from the conversion process, such as oil, is then substantially free of being bound to these particles and therefore much more reusable straight after this conversion process. A second process, such as a refinery is thereby dispensable.

Said conversion system may according to preferred embodiments of the present invention further comprise a second heating unit situated after the first particle separating unit and before the catalyst reactor in the feeding direction. The second heating unit may preferably comprise a micro wave source for at least partly heating organic material present in the second heating unit. It is hereby possible to optimize the temperature before entering the fluid into the reactor and thereby an optimization of the conversion process.

In preferred embodiments of the present invention the conversion system may further comprise a second particle separation unit after the catalyst reactor in the feeding direction. This particle separating unit is for the same reason as above advantageous.

In yet further preferred embodiments of the present invention the conversion system may further comprise means for re-circulating part of the feed of fluid after the catalyst reactor into the feed of fluid before the second heating unit in the feeding direction. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

Furthermore, the first heating unit may according to preferred embodiments of the present invention comprise a first heat exchanger, which besides heating cools the fluid from conversion system before entering the product recovery system. It is hereby obtained to reuse energy inside the apparatus and thereby same energy in the total amount of energy used in converting the organic material.

Alternatively or in combination thereto the first heating unit may according to preferred embodiments of the present invention comprise a micro wave source for at least partly heating organic material present in the first heating unit.

Additionally, the pre-treating unit may according to preferred embodiments of the invention further comprise a heat exchanger, which besides heating the fluid in the pre- treating system cools the fluid from conversion system before entering the product recovery system. This heat exchanger is for the same reason as above advantageous

The pre-treating unit may preferably further comprise a first expansion unit, which is situated between the first heat exchanger and the second heat exchanger. Gas production, such as fuel gas, is hereby obtained.

In preferred embodiments of the present invention the product recovery system may further comprise a gas separating unit for separation of gas, such as fuel gas, the gas separating unit is situated after the second heat exchanger and before the first membrane- filter in the feeding direction. Separation of the aforementioned gas, such as fuel gas from the rest of the fluid is hereby obtained.

In preferred embodiments of the present invention the product recovery system may further comprise means for re-circulating said gas, such as fuel gas for heating the fluid in the second heating unit. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

In preferred embodiments of the present invention the product recovery system may further comprise a second expansion unit situated after the first membrane-filter in the feeding direction.

Furthermore, the product recovery system may according to preferred embodiments of the present invention further comprise a phase separator unit for separation of oil from the first stream, the phase separator unit is situated after the membrane-filter in the feeding direction. It is herby obtained to separate oil from the fluid.

Additionally, the product recovery system may according to preferred embodiments of the present invention further comprises means for re-circulating part of the first stream into the pre-treating unit of the conversion system. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

Advantageously, the product recovery system may according to preferred embodiments of the present invention further comprise direct methanol fuel cell for generating electricity from the second stream.

According to preferred embodiments of the present invention the product recovery system may further comprise one or more membrane-filters preferably selected from the group of membrane processes comprising ultra-filtration, nano-filtration, reverse osmosis or pervaporation or a combination thereof.

Furthermore, the product recovery system may according to preferred embodiments of the invention further comprise the second membrane-filter for separating a purified methanol compound from the second stream.

In preferred embodiments of the present invention the product recovery system may further comprise means for re-circulating the purified methanol compound from the second stream to the pre-treating unit of the conversion system. It is hereby obtained that some of the resulting products from the conversion process is reused and that the conversion process time is decreased without decreasing the conversion processing of organic material.

In a fifth aspect, the present invention further relates to a plant comprising the aforementioned apparatus, for producing the aforementioned product by using one of the aforementioned methods.

In preferred embodiments of the present invention the plant may comprise means for supplying organic material to the apparatus and means for removal of the products from the apparatus. The plant may preferably further comprise a refinery.

In a sixth aspect, the present invention relates to a heterogeneous catalyst for use in a methods, apparatus and/or plants for converting an organic material into hydrocarbons according to the present invention. The catalyst comprises a compound of at least one element of group IVB of the periodic table and/or alpha-alumina.

Additionally, the compound of at least one element of group IVB of the periodic table may preferably comprise zirconium and/or titanium.

Furthermore, the compound of at least one element of group IVB of the periodic table -may preferably be on an oxide and/or hydroxide form or a combination of the two.

Advantageously, the compound of at least one element of group IVB of the periodic table may preferably be at least partly on a sulphate or sulphide form.

In preferred embodiment of the present invention the heterogeneous catalyst may further comprise at least one of element selected from group of Fe, Ni, Co, Cu, Cr, W, Mn, Mo, V, Sn, Zn, Si in an amount up to 20 % by weight, such as an amount up to 10 % by weight, preferably in an amount up to 5 % by weight, such as up to 2.5 % by weight.

Furthermore, these elements may preferably be on an oxide and/or hydroxide form.

Additionally, the heterogeneous catalyst may preferably be in the form of suspended particles, tablets, pellets, rings, cylinders, a honeycomb structure and/or a combination of these.

In yet other preferred embodiments of the present invention the heterogeneous catalyst may have a BET surface area of at least 10 m2/g, such as 25 m2/g, and preferably at least 50 m2/g, such as 100 m2/g, and even more preferably at least 150 m2/g, such as at least 200 m2/g.

Advantageously, the heterogeneous catalyst may preferably further comprise at least one surface area stabilizer selected from the group of Si, La, Y and/or Ce.

Subsequently, the heterogeneous catalyst may according to preferred embodiment of the present invention comprise said at least one surface area stabilizer in an effective amount up to 20 % by weight, such as an effective amount up to 10 % by weight, preferably said surface area stabilizers in an effective amount up to 7.5 % by weight, such as surface stabilizers in an effective amount up to 5 % by weight, and more preferably said surface stabilizers are present in an effective amount from 0.5-5 % by weight, such as 1-3 % by weight.

In other preferred embodiments of the present invention the heterogeneous catalyst may have a BET surface area of at least 10 m2/g after 1000 hours of use, such as BET surface area of at least 25 m2/g after 1000 hours of use, and preferably a BET surface area of at least 50 m2/g after 1000 hours of use, such as a BET surface area of at 100 m2/g after 1000 hours of use, and even more preferably a BET surface area of at least 150 m2/g after 1000 hours in use, such as at a BET surface area of least 200 m2/g after 1000 hours in use.

Finally, the heterogeneous catalyst may preferably be produced from red mud.

Detailed description of the invention

The present invention, and in particular preferred embodiments thereof, will in the following be described with reference to the accompanying drawings, in which:

Fig. 1 show schematic drawing of laboratory scale set-up,

Fig. 2 shows a general process flow sheet conversion of organic material according to the present invention, fig. 2a shown details of a micro wave based trimheater according to the present invention,

Fig. 3 shows one embodiment of product recovery according to the present invention,

Fig. 4 shows another embodiment of product recovery according to the present invention,

Fig. 5 shows yet another embodiment of product recovery according to the present invention,

Fig. 6 shows yet another embodiment of product recovery according to the present invention, and

Fig. 7 shows a process flow sheet of an embodiment for conversion of organic material according to the present invention.

The drawings are schematically and shown for the purpose of illustration.

Fig. 1 is a schematic drawing of the laboratory set-up used for the tests given in the examples. The set-up of fig. 1 is shown without the use of micro waves for heating the organic material and shows the potential of the method and apparatus according to the present invention. It should be clear to the skilled person that the heating performed in the set-up of fig. 1 can be done by use of microwaves. In fig. 2 an embodiment of a system and method for converting organic material is disclosed and in this example micro waves are disclosed for heating. The heater utilising micro waves and disclosed in connection with fig. 2 is applicable for performing heating in the embodiment shown in fig. 1, although the heating in connection with fig. 1 is disclosed as being performed by heat exchangers.

In fig. 1, the pre-treated fluid containing the homogeneous catalysts and organic material to be converted is supplied to the system at the position A. The fluid is pressurized by

means of the pump 1 and is heated to approximately 23O ⁰ C in the heater 2 comprising a heat exchanger and a temperature controller TIC. While heating is disclosed as being performed by utilizing a heat exchanger, heating may alternatively or in combination thereto be performed by exposing the stream to microwave. A device suitable for heating by microwaves is disclosed in connection with fig. 2a.

A second fluid being water is supplied to the system at position B. This stream is pressurized by means of the pump 3 and heated in the heater 4 to the temperature necessary to obtain the desired conversion temperature of the mixed fluid streams at position 4, the heater 4 comprising a heat exchanger and a temperature controller TIC.

While heating is disclosed as being performed by utilizing heat exchangers 2 and 4, heating may alternatively or in combination thereto be performed by exposing the stream to microwaves. A device suitable for heating by microwaves is disclosed in connection with fig. 2a.

The heterogeneous catalyst is located in the tubular catalytic reactor 5. After contact with the heterogeneous catalyst, the fluid containing the converted organic material is cooled to ambient temperature in the cooler 6, and filtered in the filter 7 for separation and collection of suspended particles. Subsequently the fluid is expanded to ambient pressure over the valve 8. The system pressure is maintained by controlling the flow through the valve 8, utilising the pressure controller PIC. The temperature of the expanded fluid is measured with a temperature transmitter 9. The liquid fraction of the stream is collected in a liquid trap 10, and the gas vented off from the trap at position G. The flow rate of the produced gas is continuously measured by a gas meter (not shown) placed at H. The composition of the gas is analysed by gas chromatography (not shown) of a small sample taken through I at controlled pressure established by the flow valve 11 and the pressure controller (PIC).

Fig. 2 shows a schematic drawing of a preferred embodiment of a method according to the present invention. Organic material for conversion is received in a feed storage (not shown on the figure). Said organic material may comprise a wide range of biomass and wastes, and may also comprise fossil fuels such coal, shale, orimulsion, heavy fractions of crude oil etc. Many embodiments according to the present invention involve treatment of organic material from a mixture of different sources of material as just mentioned.

The feed storage will typically have a capacity corresponding to three days of plant operation. The feed storage is preferably a concealed and agitated silo, such as an agitated

concrete silo. A fluid containing the organic material is pumped to the pre-treatment step 1 at position A.

The first part of the pre-treatment comprises in this embodiment a size reduction of the feed e.g. by cutting, grinding, milling and/or sieving the material. This size reduction may be an integral part of feeding pump (not shown). During the feeding operation to the pre- treatment the pressure of the fluid containing the organic material to be treated is increased to a pressure in the range 4-15 bars. In the second part of the pre-treatment the fluid containing said organic material is typically maintained in a pre-treatment vessel for a period of 0.5-2 hours. The pre-treatment vessel is preferably an agitated vessel, which is maintained at a temperature of 100-170 ⁰ C, and preferably in the range 110 to 14O ⁰ C. The energy for this pre-heating of said fluid comprising said organic material to be converted is preferably supplied, by recovering heat from one of the process streams to be cooled. In the figure this is illustrated by integrating the heat exchanger 2 in the pre- treatment vessel 1 for recovery of heat from the process stream D.

Also in this situation, the fluid in the pre-treatment vessel may be heated - or heated in combination with a heat exchanger - by use of microwaves typically by using a suitable microwave device such as the one disclosed in connection with fig. 2a.

The pH in the pre-treatment vessel is adjusted to a value above 7, and preferable in the range 8-10. This pH adjustment is in many embodiments according to the present invention performed by adding additives to the vessel either directly into the pre-treatment vessel and/or through its inlet, e.g. by adding a base, which may also comprise an element of group IA of the periodic table. Non-limiting examples of such additives are KOH, NaOH, K ₂ CO ₃ , Na ₂ CO ₃ , ash from biomass or coal combustion. Such additives may be added to the vessel through a stream S (not show) either streaming into stream A or streaming directly into the vessel 1. Feed of the stream S may be provided by a feeding pump (not shown).

During the residence in the pre-treatment vessel larger molecules such as cellulose, hemicellulose and lignin are hydrolyzed, and cells from biomass addition are opened facilitating the release of cell contents, such as salts. For a number of potential feedstock this cell opening involve release of catalysts such as potassium from the feedstock itself, thereby allowing for a very efficient process. A number of other additives may also enhance the conversion of the organic material and are further advantageous for the subsequent processing. Such other additives include alcohols, such as methanol, carboxylic acids, aldehydes, and/or ketones. In a preferred embodiment of the invention a number of such additives being utilized in the pre-treatment, are produced in-situ in the process and re-circulated to the pre-treatment step as shown by the streams E and F. Typical

compositions of these recirculation streams is further described in relation to the figures 3-5.

A fluid stream containing pre-converted organic material is withdrawn from pre-treatment vessel by the feed pump 3, and pressurized to the operating pressure e.g. 250 bars. The feed pump may comprise a plunger pump.

After pressurization the fluid containing the pre-converted organic material, the homogeneous catalyst and other additives is heated in the first heating step 4 by heat exchange with the hot converted product stream from the catalytic reactor. Also in this case, heating by use of micro waves may be used in combination with or as an alternative to the heat exchanger 4 by a suitable microwave device such as the one shown in fig. 2a. The temperature of the fluid containing the pre-converted organic material will in many applications according to the present invention be in the order of 20-30°C below the operating temperature of the catalytic reactor. During this first heating step the organic material in the feed is further thermally decomposed. A number of undesirable side reactions may proceed during this thermal decomposition, such soot and char formation. Besides reducing the overall efficiency of the process, this may lead to operational problems such as plugging or reduced efficiency of heat exchanger, and deposition on downstream equipment. The aforementioned additives reduce these undesirable side reactions and enhance further the conversion of the organic material into desirable products.

From the heat exchanger 4, the fluid containing said pre-converted organic material may pass a first particle separation device 5 for collection of suspended particles, which may be formed during said conversion during heat-up. This particles separation device 5 may comprise any conventional means for particle separation, e.g. a cyclone, a filter, a gravimetric settling chamber etc. Particles collected are withdrawn from the process shown by the stream B.

After the first particle separation device 5 the fluid containing said pre-converted organic material is mixed with a re-circulating stream from the catalytic reactor. This mixing will typically increase the temperature of the mixed fluid with 10-20 ⁰ C , such as with 10-200 ⁰ C, and the recirculation will further introduce desirable compounds for the further conversion into the feed.

After mixing with the re-circulation stream the mixed fluid passes to a trimheater (second heating unit) 6, wherein the temperature is raised to the operating temperature of the catalytic reactor 7.

The trimheater 6 is shown schematically in fig. 2a. The trimheater 6 comprises a high pressure flow cell 6a, designed to withstand the process conditions of the process. The flow cell 6a is equipped with a microwave transparent high pressure window 6b. Microwaves are generated in the microwave generator (MW), transferred through the wave guide 6c and introduced through the window 6b into the flow cell where the energy of the microwaves is dissipated into the liquid flowing through the cell 6a. The dissipated energy results in a temperature increase in the liquid, and also acceleration of the chemical reactions taking place in the liquid. Of particular interest is the microwave acceleration of the catalytic reactions involving the homogeneous catalyst, as these reactions are important elements in the conversion of organic material.

Although the trimheater 6 is disclosed as using only microwave for heating, this heating may be combined with a gas or oil fired heater. Such gas or oil fired heater may preferably be at least partly fuelled by re-circulating gas and/or other fuel products produced in the process. In a preferred embodiment, such additional heater is fuelled by re-circulating the produced gas denoted I in fig. 3. The re-circulation of said produced gas I may include a purification step.

In the catalytic reactor 7, the fluid containing homogeneous catalyst, additives, and pre- converted organic material is contacted with the heterogeneous catalyst. The heterogeneous catalyst will typically be contained in a tubular fixed bed, and the catalytic reactor may comprise multiple tubular fixed beds. During the conversion a dissolved fuel gas, a water soluble organics and an oil is generally produced. The product distribution is adjustable within a wide range of concentration of resulting products as shown in the examples below, and may be controlled by selecting a suitable combination of residence time, re-circulation flow rate, reaction temperature, and concentration of homogeneous catalyst and additives.

In fig. 2 the trimheater 6 and catalytic reactor 7 is disclosed as two separate units.

However, these two units may be built into one unit having a common pressure shell.

Typically, the microwave heating will in such a unit be carried out in an atrium of the unit in order to avoid negative effects of exposing the heterogeneous catalyst to microwaves.

Such negative effects could be that a major part or all energy of the microwave will be absorbed in the first catalytic particle encountered by the wave, resulting in local overheating. Another effect could be that the heterogeneous catalyst reflects the microwaves resulting in destruction of the micro wave generator.

Part of the product stream from the catalytic reactor is re-circulated by the pump 8, and mixed with the fluid containing the pre-converted organic material as described above. The remaining part corresponding to the mass flow of the fluid containing the pre- converted organic material before mixing with the re-circulating stream is withdrawn to the second particle separation device 9. As for the first particle separation device this second particles separation device may comprise any conventional means for particle separation e.g. a cyclone, a filter, a gravimetric settling chamber etc. The main feature is to provide a hot separation of potential suspended particles produced oil prior to cooling and expansion to avoid adsorption of the oil to the suspended particles. However, in a number of applications of the present invention e.g. for feedstock with a low ash content this particle separation device may be optional. Particles collected in the second particle separation device are withdrawn from the process shown by the stream C.

Subsequent to the passage of the second particle separation device the fluid stream is cooled in by heat exchange with the feed stream in the heat exchanger 4, and in the heat exchanger 2 and expanded to a pressure in the range 1-225 bars over the expansion valve 10, and separated in the product recovery system 11. Some of the separated fluid stream from the product recovery system 11, such as the streams F and/or E may be re-circulated to the pre-treatment step as described above. The product recovery system 11 is further illustrated and described below in the figures 3-6.

The separation system, illustrated in figure 3, comprises a gas-liquid separator 12, separating the gas products in stream I and the liquid products in stream J. In the embodiment shown in fig. 2 the gas-liquid separator 12 is integrated with the product recovery system 11 and in this case, the stream I (not shown in fig. 2 but in fig.3) streams out of product recovery system 11 and is used as fuel internally for heating or externally as commercial product.

In an embodiment the gas product is used internally for fuelling the trimheater 6 in combination with the micro wave heating. The liquid products are further separated in a first membrane filter 13. The membrane filtration separation is pressure driven, and in many applications applying a nano- or ultrafiltration membrane. The filtration retentate in stream L includes parts of the feed water, the oil product and the dissolved inorganic compounds, e.g. salts from the feedstock and the homogenous catalyst. The oil product is separated from stream L in an oil separator (phase separator unit) 14 operating at atmospheric conditions, and forming the oil product stream H. The remaining water and dissolved inorganic compounds forms stream O. The main part of stream O is recycled to the conversion 1, 2 in stream E, thereby recycling the homogenous catalyst, while a purge stream P is discharged to balance the inorganic compound input from the feedstock.

The further processing of the membrane filtration permeate, denoted stream K, is illustrated in figure 4 - 6. Stream K contains smaller water soluble organics like C 1 - 4 alcohols and carboxylic acids. 5

In one embodiment illustrated in fig. 4 stream K is fed to a separation unit (membrane filter) 15, producing pure water of drinking water quality in stream G and a stream of water soluble organics in stream F. The separation unit 15 is in an embodiment of the invention a reverse osmosis membrane unit, comprising a multitude of membrane 10 modules. The retained water soluble organics in stream F are recycled to the conversion step 1, 2.

In a further embodiment, illustrated in fig. 5, stream K is split into a concentrated water soluble organics stream F and an organics depleted water stream Q. The separation unit 15 16 involved is in many applications a membrane separation driven by temperature or concentration gradients, like membrane distillation or pervaporation.

The water stream Q is further purified in a polishing step 17, producing the pure water stream G. The polishing step 17 is preferably an activated carbon filter or like means for 20 absorption of very low concentrations of impurities from a water stream.

In an embodiment illustrated in fig. 6 the water soluble organic stream K is fed to a direct methanol fuel cell 18, producing electricity and a process water stream R. The direct methanol fuel cell 18 might include feed stream and effluent conditioning steps.

25

Fig. 7 shows a further embodiment according to the present invention. The embodiment is disclosed in connection with conversion of organic material in sludge from waste water treatment at a dairy farm. However, the embodiment is applicable for conversion of other types of organic materials as well.

30

Sludge from waste water treatment at a dairy farm has been found to contain 10 % dry matter, of which 90 % by weight is organic (fat and proteins) and 10 % by weight is inorganic, mainly salts, and this particular sludge is converted in a plant as shown in figure 7.

35

The sludge is preheated to 9O ⁰ C and mixed with 1.5 % by weight potassium carbonate in a feed pre-treatment vessel (not shown in fig. 7). The feed flow T of 20 kg/h preheated sludge is pressurized to 250 bar in the feed pump 20, and heated to 200 ⁰ C in the feed heater 21. The net effect of said feed heater is 2.78 kW and is utilizing microwaves as

energy source. The heated feed flow U is mixed with the recycle flow V (60 kg/h, 35O ⁰ C). A mixing temperature of 319 ⁰ C is established in the mixed flow W (80 kg/h), which is introduced into the high pressure microwave flow cell 22. This microwave flow cell 22 is similar to the one shown in fig. 2a. The sludge is heated at constant pressure from 319 to 35O ⁰ C by microwave absorption. The applied microwave frequency is 2.45 GHz and the net effect of the microwave heater is 4.7 kW. The heated sludge X is introduced into the heterogeneous catalytic reactor 23, in which the organic content of the sludge is converted into oil and gas fuels. The reactor residence time is 5 minutes. Upon contact with the heterogeneous catalyst a part of the liquid Y (20 kg/h) is removed from the recycle loop and cooled in the primary feed cooler 24 and depressurized through a pressure control valve 25 to form the product mixture Z. The remaining liquid V (60 kg/h) is mixed with the incoming feed flow by means of the recycle pump 26.

The product mixture Z may be subjected to a treatment similar to the treatment of stream D in fig. 2.

Complete conversion of the organic sludge may be achieved. The oil product is virtually sulphur and chlorine free, has an oxygen content of 5-15 % by weight and may account for up to 90 % of the carbon content in the feedstock.

Examples

In the following examples on processes according to the present invention are presented.

Illustrative example 1: Conversion of sewage sludge

Anaerobic digested sewage sludge below was converted according to the method of the present invention in the laboratory scale plant shown in fig. 1.

The dry matter content of the sewage sludge was 5 %. The main components of the dry matter in weight % were:

> C = 28.3 %

> H = 4.33 % > N = 3.55 %

> O = 28.4 %

> P = 4.49 %

> Al = 7.77 %

> Si = 7.44 %

> Ca = 6.95 %

> Fe = 3.17 %

> K = 1.62 %

5 An elemental analysis of sewage sludge dry matter was further analyzed by induced coupled plasma (ICP) revealing the following composition:

C [%] O [%] Al [%] H [%] Ca [%] Si [%] N [%] P [%] K [%]

30.9 30.5 6. 15 5 2 5.03 4. 98 4. 66 4 62 2.36

C [%] S [%] Fe i [%] Na [%] Mg [%] Zn [%] Ti [%] Ba [%] Mn [%]

1. 13 1. 09 1. 04 0 938 0.875 0. 226 0. 195 0 0652 0.0375

The combustible fraction amounts to 58 % of the dry matter content, with a heat value of 10 22.2 MJ/kg, which translates into a calorific value of 476 KJ/kg in the sewage sludge as received.

Prior to the test the sewage sludge was pre-treated by sizing to less than 1 mm by cutting longer particles by a Seepex macerator (type 25/15-I-I-F12-2) and milling by a colloid mill

15 (Probst und Class, type N100/E), and filtered by a screen basket filter (mesh width lmm).

Subsequently 1.5 % by weight of potassium in the form of potassium carbonate was added to the resulting slurry. The pH value of the slurry was 9.0.

20 125 ml of ZrO ₂ heterogeneous catalyst stabilized with 2.2 atomic mole % of Si. The catalyst in the form of cylindrical pellets of 3 mm length and a diameter of 3 mm was added to the tubular reactor.

63 g/h of the pre-treated sewage sludge was pressurized to 250 bars and heated to 23O ⁰ C 25 in the pre-heating step. This stream was mixed with 393 g/h of pressurized water heated to a temperature so as to obtain a substantially constant temperature of 360 ± 5 ⁰ C after mixing.

The mixed flow was subsequently contacted with the heterogeneous catalyst in the 30 reactor. The feed to water ratio translates into a water to feed ratio of 6: 1, and the total flow of 456 g/h translates into a contact time of approximately 4 minutes.

After to the contact with the heterogeneous catalyst, the fluid containing the converted organic material is cooled to ambient temperature, filtered through a particle filter for collection of suspended particles, and expanded to ambient pressure. The liquid fraction on the stream was collected in a liquid trap, and the gas is vented off.

The experiment resulted in three product streams, a gas, an aqueous product and a solid precipitate. Samples for analysis were collected for a period of 15.5 hours.

Gas analysis

The flow rate and composition of the produced gas was measured continuously by a gas meter with sampling. The composition was measured by gas chromatography.

The analysis of the gas phase revealed the following results:

Liquid analysis

The liquid product was contained suspended particles. The filtered liquid was analyzed by ion chromatography, Induced Plasma Emission (ICP) and high temperature total carbon analyzers and mass spectrometry.

The analysis of the liquid phase revealed the following results:

The inorganic carbon content in the liquid was found primarily to be due to the presence of carbonate.

Solid analysis

The solid fractions were analyzed by means of a total carbon analyzer and by elemental analysis by an induced coupled plasma analyzer (ICP). An organic phase was found to be adsorbed to the inorganic particles under the experimental conditions used.

This organic phase was extracted prior to the solid analysis using CH ₂ CI ₂ . The extractable fraction of the organic carbon was found to be an oil phase, primarily consisting of saturated hydrocarbons with a chain length of 12 to 16 carbon atoms, and there for comparable to fuel or diesel oil. The oil contained 2-hexadecanone, heptadecane, 6,10- dimethyl-2-undecanone, hexadecane, 3-methyl-indole, 2-tridecanone and other compounds. A sulphur and halogen analysis performed at the extracted oil, showed that the oil was essentially free of sulphur and halogen compounds. The total amount of oil extracted from the solids was 3.86 g and the total amount of carbon found in the oil phase was equivalent to 3.28 g.

No carbon was detected in the solid product after extraction of adsorbed oil, indicating 100 % conversion of the organic material in the feed. The same result can be concluded from the carbon balance below:

Carbon balance

Energy balance:

Illustrative example 2: Conversion of sewage sludge

Anaerobic digested sewage sludge with characteristics as given above in example was preheated and converted using the same catalyst and experimental set-up.

140 g/h of the pretreated sewage sludge was pressurized to 250 bar and heated to 23O ⁰ C in the pre-heating step. This stream was mixed with 414 g/h of pressurized water heated to a temperature so as to obtain a substantially constant temperature of 300 ± 5 ⁰ C after mixing.

The mixed flow was subsequently contacted with the heterogeneous catalyst in the reactor. The feed to water ratio translates into a water to feed ratio of 3: 1, and the total flow of 545 g/h translates into a contact time of 3.3 minutes.

After to the contact with the heterogeneous catalyst, the fluid containing the converted organic material is cooled to ambient temperature, filtered through a particle filter for collection of suspended particles, and expanded to ambient pressure. The liquid fraction on the stream is collected in a liquid trap, and the gas is vented off.

The experiment resulted in three product streams, a gas, an aqueous product and a solid precipitate. Samples for analysis were collected for a period of 10.5 hours.

Gas analysis

The analysis of the gas phase revealed the following results:

Liquid analysis

The analysis of the liquid phase revealed the following results:

The inorganic carbon content in the liquid was found primarily to be due to the presence of carbonate.

Solid analysis

The solid fractions were analyzed by means of a total carbon analyzer. An organic phase was found to be adsorbed to the inorganic particles under the experimental conditions used.

This organic phase was extracted prior to the solid analysis using CH ₂ CI ₂ . The extractable fraction of the organic carbon was found to be an oil phase, primarily consisting of saturated hydrocarbons with a chain length of 12 to 16 carbon atoms, and there for comparable to fuel or diesel oil. The oil contained 2-hexadecanone, heptadecane, 6,10- dimethyl-2-undecanone, hexadecane, 3-methyl-indole, 2-tridecanone and other compounds. The total amount of oil extracted from the solids was 12.73 g and the total amount of carbon found in the oil phase was equivalent to 10.83 g.

No carbon was detected in the solid product after extraction of adsorbed oil, indicating 100 % conversion of the organic material in the feed.

Carbon balance:

Energy balance:

Illustrative example 3: Conversion of Corn Silage

Corn silage was pretreated and converted using the same catalyst and experimental set-up as described above in example 1 and 2.

Prior to the test the sewage sludge was pretreated by sizing to less than 1 mm by cutting longer particles by a Seepex macerator (type 25/15-I-I-F12-2) and milling by a colloid mill (Probst und Class, type N100/E), and filtered by a screen basket filter (mesh width lmm).

Subsequently 1.5 % by weight of potassium in the form of potassium carbonate was added to the resulting slurry. The pH value of the slurry was 9.6.

The characteristics of the corn silage after the pretreatment were the following:

¹ Based on 18 MJ/kg heat of combustion for the organic fraction of the dry matter.

5 The inorganic content of the dry matter was mainly the added potassium carbonate, accounting for approximately % of the dry matter inorganic compounds. GC-MS analysis of the corn silage feedstock revealed numerous compounds, but all were present in concentrations too low for identification. Particularly aromatics like phenols were not found in any significant amount.

10

The dry matter content of the corn silage feedstock was analyzed, revealing the following composition:

15 140 g/h of the pretreated sewage sludge was pressurized to 250 bar and heated to 23O ⁰ C in the pre-heating step. This stream was mixed with 377 g/h of pressurized water heated to a temperature so as to obtain a substantially constant temperature of 350 ± 5 ⁰ C after mixing.

The mixed flow was subsequently contacted with the heterogeneous catalyst in the reactor. The feed to water ratio translates into a water to feed ratio of 3.75: 1, and the total flow of 517 g/h translates into a contact time of 3.3 minutes.

After the contact with the heterogeneous catalyst, the fluid containing the converted organic material was cooled to ambient temperature, filtered through a particle filter for collection of suspended particles, and expanded to ambient pressure. The liquid fraction on the stream is collected in a liquid trap, and the gas is vented off.

The experiment resulted in four product streams, a gas, an aqueous product, a free oil phase and a solid precipitate. Samples for analysis were collected for a period of 16 hours.

Gas analysis

The analysis of the gas phase revealed the following results:

Liquid analysis

The analysis of the liquid phase revealed the following results:

The inorganic carbon content in the liquid was found primarily to be due to the presence of carbonate.

Solid analysis

The solid fractions were analyzed by means of a total carbon analyzer. An organic phase was found to be adsorbed to the inorganic particles under the experimental conditions used.

This organic phase was extracted prior to the solid analysis using CH ₂ CI ₂ . The extractable fraction of the organic carbon was found to be an oil phase, primarily consisting of saturated hydrocarbons with a chain length of 12 to 16 carbon atoms, and there for comparable to fuel or diesel oil. The oil contained phenol, toluene, 4-ethyl-phenol, 4-ethyl- 3-methylphenol, cyclopent-2-ene-l-one 2,3,4 trimethyl , 2-methyl-l-penten-3-yne and other compounds. A sulphur analysis of the oil showed that the oil phase was essentially free of sulphur. A similar analysis for halogen compounds showed that the oil phase was essentially free of halogen. The total amount of oil extracted from the solids was 14.76 g and the total amount of carbon found in the oil phase was equivalent to 12.55 g.

No carbon was detected in the solid product after extraction of adsorbed oil, indicating 100 % conversion of the organic material in the feed. The same result can be concluded from the carbon balance below:

Carbon balance:

Energy balance:

Illustrative example 4:

Use of microwave heating in a catalytic liquid conversion process

Preferred embodiment according to the present invention for conversion of organic material in high pressure water is given in the figures 1-7 and disclosed in details above. As disclosed above, an advantageous alternative to e.g. fueling the heat exchangers by a burnable fuel, is in many applications according to the present invention, to use of microwave heating for at least part of the heating process.

Such heating typically combines existing microwave generators (known from kitchen microwave ovens) with high pressure cells comprising a transparent window may have one or more of the following advantages compared to conventional heaters based on electrical heat and/or superheated steam and/or other heat transfer fluids:

a. Improved heat transfer efficiency b. Extremely short response time c. Very accurate process control d. Hot spots are avoided e. High temperature heat transfer surfaces is avoided f. Less thermal cracking of the organic content g. Higher conversion rates h. High temperature uniformity i. Increased conversion capacity j. Increased energy efficiency of the overall process k. Reduction of temperature needed for conversion

I. Reduction the size of heat exchangers and cost of heat recovery in general m. Reduced chemical consumption and/or allow other catalysts to be used n. Simplification of the overall process and/or the related capital and/or operating costs o. Smaller foot print

Such microwave heating generally involve heating by magnetron systems operating within the frequency domain of microwaves and/or hyper-frequencies such as frequencies in the range from 300 MHz to 300 GHz such as in the range 500 MHz to 5 GHz. A microwave heating system may comprise multiple magnetrons, which may increase the overall microwave efficiency by reducing the thermal losses.

Different frequencies may initiate different energy transfer mechanisms within the materials being treated, which may be used to impact on reaction thermodynamics or product quality.

A further attractive effect of the microwave heating may be the opportunity to significantly reduce the temperature needed for a given conversion of organics according to the present invention. Hence, in a preferred embodiment of the present invention the maximum temperature in the process is below 300 ⁰ C such as below 275 ⁰ C, and preferably below 25O ⁰ C such as below 225 ⁰ C, and even more preferably below 175 ⁰ C. Depending on the

specific materials being converted the temperature may be as low as 15O ⁰ C such as in the range 110-150 ⁰ C.

In a particularly preferred embodiment the maximum temperature is substantially the same as in said pretreatment step according o the present invention.

Additionally the following definitions are used in the description of the present invention.

The term hydrocarbon fuel is in the present invention intended to define all hydrocarbon based fuels, which may or may not comprise other elements than carbon and hydrogen, e.g. some of said hydrocarbons may comprise oxygen and other elements e.g. in the form of groups of alcohols, aldehydes, ketones, carboxylic acid, ester, esthers etc. and reaction products thereof.

The membrane processes of the present invention is well known in the prior art (e.g. W. S. HO et al, "Membrane Handbook", Van Nordstrand Reinhold, p. 103-132,p.263-446, 1992, ISBN 0-442-23747-2, K. Scott, "Handbook of Industrial Membranes" Elsevier Science Publishers, 1995, p. 3-163, p. 331-355, p.575-630, ISBN 1 85617 233 3).

The surface areas referred to throughout this specification and claims are the nitrogen BET surface areas determined by the method described in the article by Brunauer, P. Emmett and E. Teller, J. Am. Chem. Soc, Vol. 60, p. 309 (1938). This method depends on the condensation of nitrogen into the pores, and is effective for measuring pores with pore diameters in the range of 10 A to 600 A. The volume of nitrogen adsorbed is related to the surface area per unit weight of the support.

It is well known that the activity of a catalyst is proportional to the surface area (BET), and that catalysts may show a significant activity drop over time, when subjected to e.g. hydrothermal conditions as used in relation to the present invention. In order to minimize such potential activity loss a surface area stabilizer is incorporated into the heterogeneous catalyst.

Red Mud is a waste product of bauxite processing via the Bayer process. It comprises oxides and hydroxides of mainly aluminium, iron, titanium, silicon, and sodium.