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Title:
COMBINED PROCESSES FOR UTILIZING SYNTHESIS GAS AT LOW CO2 EMISSION AND HIGH ENERGY OUTPUT
Document Type and Number:
WIPO Patent Application WO/2011/021944
Kind Code:
A1
Abstract:
By combining energy from an oxygen-based combustion of organic material with gasification and pyrolysis as well as any other process using synthesis gas (e.g. methanation, methanol production, ammonia production, urea production, Fischer-Tropsch synthesis, etc.) usable energy may be extracted from the total process, e.g. in the form of electrical energy or products that may be combusted for liberating energy from the produced compounds.

Inventors:
FAREID ERIK (NO)
FAREID LARS ERIK (NO)
PEDERSEN SKULE (NO)
SCHIERNING TOMMY (NO)
Application Number:
PCT/NO2010/000310
Publication Date:
February 24, 2011
Filing Date:
August 19, 2010
Export Citation:
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Assignee:
EICPROC AS (NO)
FAREID ERIK (NO)
FAREID LARS ERIK (NO)
PEDERSEN SKULE (NO)
SCHIERNING TOMMY (NO)
International Classes:
C10G2/00; C01B3/02; C10B49/02; C10J3/00
Domestic Patent References:
WO2009091325A12009-07-23
WO2009091325A12009-07-23
Foreign References:
US20060112639A12006-06-01
US5584255A1996-12-17
US20070129449A12007-06-07
US20080250714A12008-10-16
US20090145028A12009-06-11
NO2007000387W2007-11-02
US7087651B22006-08-08
US6972119B22005-12-06
US6958136B22005-10-25
US6838071B12005-01-04
US5584255A1996-12-17
US20070129449A12007-06-07
Other References:
JIANJUN GUO; HUI LOU; HONG ZHAO; DINGFENG CHAI; XIAOMING ZHENG: "Dry reforming of methane over nickel catalysts supported on magnesium aluminate spines", APPLIED CATALYSIS A: GENERAL, vol. 273, no. 1-2, 8 October 2004 (2004-10-08), pages 75 - 82
M. WISNIEWSKI; A. BEREAVE; P. GELIN: "Catalytic C02 reforming of methane over Ir/Ce0.9Gd0.1O2-x", CATALYSIS COMMUNICATIONS, vol. 6, no. 9, September 2005 (2005-09-01), pages 596 - 600
MASAYA MATSOUKA; MASAAKI KITANO; MASATO TAKEUCHI; KOICHIRO TSUJIMARU; MASAKAZU ANPO; JOHN M. THOMAS: "Photocatalysis for new energy production. Recent advances in photo catalytic water splitting reactions for hydrogen production", CATALYSIS TODAY, 6 March 2007 (2007-03-06)
U. (BALU) BALACHANDRAN; T.H.LEE; S.E.DORRIS: "Hydrogen production by water dissociation using mixed conducting dense ceramic membranes", INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 32, no. 4, March 2007 (2007-03-01), pages 451 - 456, XP005912195, DOI: doi:10.1016/j.ijhydene.2006.05.010
DANIEL M. GINOSAR; LUCIA M. PETKOVIC; ANNE W. GLENN; KYLE C. BURCH: "Stability of supported platinum sulfuric acid decomposition catalysts for use in thermo chemical water splitting cycles", INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 32, no. 4, March 2007 (2007-03-01), pages 482 - 488
T. SANO; M. KOJIMA; N. HASEGAWA; M. TSUJI; Y. TAMAURA: "Thermo chemical water-splitting by a carbon-bearing Ni(II) ferrite at 300°C", INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 21, no. 9, September 1996 (1996-09-01), pages 781 - 787
S.K.MOHAPATRA; M.MISRA; V.K.MAHJAN; K.S.RAJA: "A novel method for the synthesis of titania nano tubes using sono electro chemical method and its application for photo electro chemical splitting of water", JOUIRNAL OF CATALYSIS, vol. 246, no. 2, 10 March 2007 (2007-03-10), pages 362 - 369
S.K.MOHAPATRA; M.MISRA; V.K.MAHAJAN; K.S.RAJA: "A novel method for the synthesis of titania nano tubes using sono electro chemical method and its application for photo electro chemical splitting of water", JOURNAL OF CATALYSIS, vol. 246, no. 2, 10 March 2007 (2007-03-10), pages 362 - 369
MENG NI; MICHAEL K.H. LEUNG; DENNIS Y.C.LEUNG; K. SUMATHY: "A review and recent developments in photo-catalytic water-splitting using Ti02 for hydrogen production", RENEWABLE AND SUSTAINABLE ENERGY REVIEWS, vol. 11, no. 3, April 2007 (2007-04-01), pages 401 - 425
WENFENG SHANGGUAN: "Hydrogen evolution from water splitting on nano composite photo-catalysts", SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, vol. 8, no. 1-2, January 2007 (2007-01-01), pages 76 - 81
SENG SING TAN; LINDA ZOU; ERIC HU: "Photosynthesis of hydrogen and methane as key components for clean energy system", SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, vol. 8, no. 1-2, January 2007 (2007-01-01), pages 89 - 92, XP005911510, DOI: doi:10.1016/j.stam.2006.11.004
Attorney, Agent or Firm:
OSLO PATENTKONTOR AS (Oslo, NO)
Download PDF:
Claims:
C l a i m s

1. Process for combustion of organic material by way of using an oxygen-containing gas producing combustion gases, and in particular CO, CO2 and H2O, wherein at least the formed carbon monoxide and carbon dioxide and water is passed into a two-step gas reactor that in its first step includes a reactor forming hydrogen and CO by gasification and in its second step a catalyst that hydrogenates CO and CO2.

2. Process according to claim 1, wherein the combustion gas (CO + CO2) is combined with hydrogen (preferably originating from water) for producing organic molecules (e.g. methane) and energy, and wherein the process combines (1) the production of energy from the combustion of organic fuels, with (2) the process of gasification and/or pyrolysis and with (3) any process of utilizing synthesis gas, such as methanation, methanol production, ammonia production, urea production, Fischer-Tropsch synthesis and any other utilization of the above in the production of energy and energy-harboring compounds. 3. Process according to claim 1 or 2, wherein gasification is performed within the temperature range of 500-2000°C, preferably within the temperature interval 800- 1200°C, e.g. within the temperature intervals 500-800°C, 700-1000°C, 900-1100°C, 850-1150°C, 1000-1200°C or 1 100-1200°C.

4. Process according to claim 1 - 3, wherein the gasification is performed within the pressure range 0,5 bar to 10 bar.

5. Process according to any of the preceding claims, wherein the temperature of the oxygen-containing gas and water for the gasification of the organic material lies within the temperature interval 500-2000°C, preferably within the temperature interval 800- 1200°C, e.g. within the temperature intervals 500-800°C, 700-1000°C, 900-1100°C, 850-1 150°C, 1000- 12000C or 1 100- 1200°C.

6. Process according to any of the preceding claims, wherein the process of utilizing the synthesis gas is methanation, and wherein said methanation is conducted at a

temperaure between aboutl50 and 600 0C.

7. Process according to claim 6, wherein the methanation is conducted at a pressure of 1 - 50 bar.

8. Process according to any of the claims 1 - 5, wherein the process of utilizing the synthesis gas is methanol synthesis.

9. Process according to claim 8, wherein the methanol synthesis is conducted at pressures between about 50-100 bar, and at temperatures not exceeding about 570K. 10. Process according to any of the claims 1 - 5, wherein the process utilizing the synthesis gas includes a Fischer-Tropsch reaction.

11. Process according to claim 10, wherein the Fischer-Tropsch reaction is conducted with one or more catalysts including e.g. a mixture of Co and Ni or pure Co or pure Ni optionally including support materials like carbon nanofibers or carbon nanotubes or Al2O3 or TiO2.

12. Process according to claim 10 or 11, wherein the Fischer-Tropsch reactor is a multitubular fixed-bed, riser or slurry reactor.

13. Process according to claim 12, wherein the reactor operates within a temperature up to 570 K, alternatively up to 530 K.

Description:
COMBINED PROCESSES FOR UTILIZING SYNTHESIS GAS AT LOW CO 2 EMISSION AND HIGH ENERGY OUTPUT

Disclosure.

With today's focus on human-produced CO 2 and the effect this substance has on pollution and global heating, it is of great importance to reduce or re-use and recirculate CO 2 .

One of the items of the present invention is to present a chemical process for providing energy in the form of electrical energy or synthesized products which may be combusted releasing usable chemical energy. The process according to the present invention combines combustion gas (CO + CO 2 ) with hydrogen (preferably originating from water) for producing organic molecules (e.g. methane) and energy. The process according to the present invention combines the processes of (1) power production from any combustion of organic fuels, (2) the process of gasification and or pyrolysis and (3) any process of utilizing synthesis gas, such as methanation, methanol production, ammonia production, urea production, Fischer-Tropsch synthesis and any other utilization of the above in the production of energy and energy-harboring compounds. In the present process the excess heat from the exhaust gas from the power production together with any heat from the synthesis gas utilization will supply all or parts of the heat necessary to gasify the organic substances to synthesis gas. Though this process it is possible to gasify organic/Bio waste as the CO 2 from these wastes are neutral.

In this connection the term "neutral" concerning emitted CO 2 means that the carbon involved neither increases nor reduces the total carbon emission to the atmosphere. One example of this is biofuels where plants assimilate the same amount of carbon from the atmosphere (in the form of CO 2 ) storing it in the form of e.g. cellulose and sugars, as the amount emitted to the atmosphere when combusting these materials, making the total carbon balance to the atmosphere zero.

Prior art.

It is previously known different materials and methods for methanation and production of hydrogen. Examples of such prior art is represented by the following publications: PCT/NO2007/000387 may be summarized as a catalytic gas reactor including a catalyzer or process creating hydrogen and oxygen by splitting of water and a process with catalyzer creating methane from reactions wherein CO, CO 2 and hydrogen participate. Jianjun Guo, Hui Lou, Hong Zhao, Dingfeng Chai and Xiaoming Zheng: "Dry reforming of methane over nickel catalysts supported on magnesium aluminate spines" Applied Catalysis A: General, Volume 273, no. 1-2, 8. October 2004, page 75-82;

M. Wisniewski, A. Boreave and P. Gelin: "Catalytic CO 2 reforming of methane over Ir/Ceo .9 Gdo . i0 2 . x " Catalysis Communications, Volume 6, nbo.9, September 2005, page 596-600;

Masaya Matsouka, Masaaki Kitano, Masato Takeuchi, Koichiro Tsujimaru, Masakazu Anpo and John M. Thomas: "Photocatalysis for new energy production. Recent advances in photo catalytic water splitting reactions for hydrogen production" Catalysis Today, 6. March 2007; U. (BaIu) Balachandran, T.H.Lee and S.E.Dorris: "Hydrogen production by water dissociation using mixed conducting dense ceramic membranes" International Journal of Hydrogen Energy, Volume 32, no. 4, March 2007, page 451-456;

Daniel M. Ginosar, Lucia M. Petkovic, Anne W. Glenn and Kyle C. Burch: "Stability of supported platinum sulfuric acid decomposition catalysts for use in thermo chemical water splitting cycles" International Journal of Hydrogen Energy, Volume 32, no. 4, March 2007, page 482-488;

T. Sano, M. Kojima, N. Hasegawa, M. Tsuji and Y. Tamaura: "Thermo chemical water- splitting by a carbon-bearing Ni(II) ferrite at 300 0 C" International Journal of Hydrogen Energy, Volume 21, no. 9, September 1996, page 781-787; S.K.Mohapatra, M.Misra, V.K.Mahjan and K.S.Raja: "A novel method for the synthesis of titania nano tubes using sono electro chemical method and its application for photo electro chemical splitting of water" Jouirnal of Catalysis, Volume 246, no. 2, 10. March 2007, page 362-369;

S.K.Mohapatra, M.Misra, V.K.Mahajan and K.S.Raja: "A novel method for the synthesis of titania nano tubes using sono electro chemical method and its application for photo electro chemical splitting of water" Journal of Catalysis, Volume 246, no. 2, 10. March 2007, page 362-369;

Meng Ni, Michael K.H. Leung, Dennis Y.C.Leung and K. Sumathy: "A review and recent developments in photo-catalytic water-splitting using TiO 2 for hydrogen production", Renewable and Sustainable Energy Reviews, Volume 11, no. 3, April 2007, page 401-425;

Wenfeng Shangguan: "Hydrogen evolution from water splitting on nano composite photo-catalysts" Science and Technology of Advanced Materials, Volume 8, no. 1-2, January-March 2007, page 76-81 , APNF International Symposium on Nanotechnology in Environmental Protection and Pollution (ISNEPP2006);

Seng Sing Tan, Linda Zou and Eric Hu: "Photosynthesis of hydrogen and methane as key components for clean energy system" Science and Technology of Advanced Materials, Volume 8, no. 1-2, January-March 2007, page 89-92, APNF International Symposium on Nanotechnology in Environmental Protection and Pollution

(ISNEPP2006);

US patent 7.087.651 (Lee.Tuffnell et al., 8 th August 2006) "Process and apparatus for steam-methane reforming";

US patent 6.972.119 (Taguchi et al., December 6, 2005) "Apparatus for forming hydrogen"; US patent 6.958.136 (Chandran et al., October 25, 2005) "Process for the treatment of waste streams";

US patent 6.838.071 (Olsvik et al., January 4, 2005) "Process for preparing a H 2 -rich gas and a CO 2 -rich gas at high pressure".

WO 2009/091325 Al (Boson Energy SA, January 14, 2008) "A biomass gasification method and apparatus for production of syngas with a rich hydrogen content".

US patent 5584255 (Norman G. et al., June 7, 1995) "Method and apparatus for gasifying organic materials and vitrifying residual ash". US patent application 2007/0129449 Al (Norbert Topf et al., June 7, 2007) "Method and installation for producing liquid energy carriers from a solid carbon carrier".

General disclosure of the present invention.

As mentioned supra the present invention combines the processes of (1) power production from any combustion of organic fuels, with (2) the process of gasification and or pyrolysis with (3) any process of utilizing synthesis gas, such as methanation, methanol production, ammonia production, urea production, Fischer-Tropsch synthesis and any other utilization of the above in energy production. The excess heat from the exhaust gas from the power production together with any heat from the synthesis gas utilization will supply all or parts of the heat necessary to gasify the organic substances to synthesis gas. Though this process it is possible to gasify organic/Bio waste as the CO 2 from these wastes are neutral. By combining said chemical reactions it is possible to create a "reaction loop" wherein the recapture of the reaction energy provides usable energy in the form of electrical or chemical energy in the form of a gas that may be combusted directly or that harbours large amounts of potential chemical energy.

Terms.

In the context of the present invention the term "organic fuels" is to mean materials comprising any number carbon atoms and hydrogen atoms in their structure that may be converted to or processed to a fluid or gaseous form or which may remain in a solid form, and which in their solid, fluid or gaseous form may be combusted with oxygen to form karbonmonoxide and/or carbondioxide and/or methane (see the reaction equations infra). In the context of the present invention the term "organic fuel" is to include any carbonaceous material that may react through combustion for producing energy.

In the context of the present invention the term "combustion" is to mean any reaction involving a reaction between oxygen and a carbonaceous material within the temperature intervals indicated infra.

In the context of the present invention the term "gasification" is to mean the evaporation and/or combustion of organic fuel.

In the context of the present invention the term "chemical energy" refers to the latent or potential energy of a compound that may be released through a chemical process that lowers the potential energy of the relevant compound forming one or more reaction products with a lower net potential energy and releasing the energy difference between the original compound(s) and the product(s).

In the context of the present invention the term "electrical energy" refers to energy that may be utilized by an electrical storage unit (battery, condenser, etc.) or be converted to other forms of energy, e.g. mechanical energy, through the use of an electrical appliance.

In the context of the present invention the term "large amounts of energy" refers to energy within the range 10-50 MJ/kg

In the context of the present invention the term "about" refers to a relative deviation from the indicated amount of up to + 10%, i.e. an interval of one unit per ten units of the relevant number. The deviation may also be smaller, e.g. 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% or any number in between or any interval combination thereof.

Possible realizations.

One of the possibilities realized by the present invention is through energy recapture to provide usable energy as well as providing a gas that may be combusted or that contains large amounts of chemical energy.

With "large amounts" of chemical energy in the context of the present invention is meant an energy difference between the original and product compounds that represents at least 15% of the chemical energy of the original compound(s) The waste from power production based on combustion of organic fuels may have a temperature in the range of 100-2000°C. Examples of possible temperature intervals in such a combustion are 200-1800°C, 30O-150O°C, 400-1300 0 C, 500-1250 0 C, 550- 1200 0 C, 600-1100 0 C, 700-1000 0 C or any combination of said intervals.

In step (2) of the present invention there may be used gasifiers for providing gas from the organic combustion material.

Examples of gasifiers that are currently available for commercial use include: counter- current fixed bed gasifisers; co-current fixed bed gasifisers, fluidized bed gasifiers and entrained flow gasifers. The counter-current fixed bed ("up draft") gasifier includes a fixed bed of carbonaceous fuel (e.g. coal or biomass) through which the "gasification agent" (steam, oxygen and/or air) flows in counter-current configuration.

The co-current fixed bed ("down draft") gasifier is similar to the counter-current type, but the gasification agent gas flows in co-current configuration with the fuel (downwards, hence the name "down draft gasifier").

In the fluidized bed reactor, the fuel is fluidized in oxygen and steam or air. The ash is removed dry or as heavy agglomerates that defluidize. The temperatures are relatively low in dry ash gasifiers, so the fuel must be highly reactive; low-grade coals are particularly suitable. The agglomerating gasifiers have slightly higher temperatures, and are suitable for higher rank coals. Fuel throughput is higher than for the fixed bed, but not as high as for the entrained flow gasifier.

In the entrained flow gasifier a dry pulverized solid, an atomized liquid fuel or a fuel slurry is gasified with oxygen (much less frequent: air) in co-current flow. The gasification reactions take place in a dense cloud of very fine particles. Most coals are suitable for this type of gasifier because of the high operating temperatures and because the coal particles are well separated from one another.

Gasifiers used in the present invention gasify organic waste into gaseous organic material to be further combusted into CO and/or CO 2 included in the combined process according to the present invention. Gasification of organic material in the process according to the present invention is preferably performed at low amounts of O 2 present, i.e. at O 2 concentrations of the inlet gas in the range of 0,5-15% O 2 (v/v). The gasification of the organic material in the gasifiers is conveniently done in a temperature interval of 500-2000 0 C, preferably within the temperature interval 800-1200°C, e.g. within the temperature intervals 500-800°C, 700-1000°C, 900-1 100°C, 850-1150°C, 1000-1200°C or 1 100-1200°C. These gasifiers can be run under the following pressure ranges: 0,5 bar to 10 bar. The use of external exhaust gas containing CO 2 and H 2 O will increase the production of synthesis gas by the reaction C + CO 2 = 2CO and C + H 2 O = CO + H 2 In step (3) of the process according to the present invention a methanation reaction is one of the reactions for utilizing the synthesis gas. The methanation reaction may be performed with the catalysts infra with different compositions depending on the condition of the gas that is to be treated, but all methanation catalysts may be used in the temperature interval 150 to 600 0 C;

Ni/NiO (nickel/nickel oxide) catalyst

- Ru (ruthenium) catalyst

Cu (copper) catalyst

Pt (platinum)

Rh (rhodium)

Ag (silver)

- Co (cobalt)

W (tungsten)

All other catalysts alone or together with one or more of the metals mentioned supra.

In step (3) of the process according to the present invention another of the possible reactions is methanol production. Most synthesis gas for methanol production is produced by team reforming of natural gas. The ideal synthesis gas composition for this application in the process according to the present invention has a H 2 /CO ratio of about 2. A small amount of CO 2 (about 5%) increases the catalyst activity using a catalyst comprising the elements Cu/ZnO/Al 2 O 3 . The main reactions for the formation of methanol from synthesis gas are: CO + 2H 2 = CH 3 OH CO 2 + 3H 2 = CH 3 OH + H 2 O

The two methanol forming reactions are coupled by the water-gas shift reaction: CO + H 2 O = CO 2 + H 2 During CO hydrogenation to produce methanol other products may be formed such as higher alcohols and hydrocarbons. The selectivity of modern catalysts (Cu/ZnO/Al 2 θ 3 ) is over 99%. Modern methanol synthesis is operated at pressures between 50-100 bar, while the temperature usually does note exceed 570K due to rapid catalyst deactivation above said temperature interval. Modern methanol synthesis plants have plant capacities ranging from 150 to 6000 tons/day, although plants using remote natural gas may have a capacity as large as 10000 tons/day. The plants differ mainly in reactor design, and, interrelated with this, in the way the heat of the reaction is removed.

Adjustment of such parameters to be used in the process according to the present invention lies within the knowledge of he average practitioner within this field. In step (3) of the process according to the present invention another of the possible ways to convert synthesis gas to a wide range of hydrocarbons and/or alcohols is through the Fisher-Tropsch (F-T) process. The F-T process was discovered in 1923 but it is in the recent years that it has been perceived as a possible way to convert natural gas into liquid fuels. Although the chemistry behind the F-T process is rather complex, the fundamental aspects can be represented by he major overall reactions in the Fischer-Tropsch synthesis:

Alkanes: nCO + (2n + 1 ) H 2 = C n H 2n+2 + nH 2 0

Alkenes: nCO + 2nH 2 = C 2 H 2n + nH 2 O Water-gas shift: CO + H 2 O = CO 2 + H 2

Alcohols* : nCO + 2nH 2 = H(-CH 2 -) n OH + (n- 1 )H 2 O

Bouoduard reaction* : 2CO = C + CO 2 * = side reactions

A characteristic of the F-T reactions is their high exothermicity. For example, the formation of 1 mol of -CH 2 - is accompanied by a heat release of 165 kJ/mol. From the overall reactions it can be seen that both hydrocarbons and alcohols can be formed. Therefore, the choice of catalyst and process conditions is very important. The hydrocarbons are formed by a chain-growth process, with the length of the chain being determined by the catalyst selectivity and the reaction conditions. Selecting such conditions lies, however, within the competence of the person skilled in the art or requires no unreasonable amount of experimentation to determine. Suitable catalysts for performing the F-T reaction include e.g. a mixture of Co and Ni or pure Co or pure Ni optionally including support materials like carbon nanofibers or carbon nanotubes or Al 2 O 3 or TiO 2 .

Efficient removal of the heat of reaction is a major consideration in the selection/design of suitable Fischer-Tropsch reactors. The currently used reactors are multi-tubular fixed-bed, riser and slurry reactors. These three reactor types yield rather different product distributions. As a result of the relatively low temperature, up to about 530 K, in the fixed-bed and up to about 570 K in the slurry reactor, the selectivity towards heavy products (waxes) in these reactors is high. The low H 2 /CO ratio in the slurry reactor results in a relatively high selectivity towards liquid products. In the riser reactor, which has to operate at much higher temperatures, lying usually within the temperature interval of above 570 K, gasoline is the major product. In addition, the riser reactor produces a larger quantity of light products such as methane.

In one step of the process according to the present invention CO 2 is transformed to methane through the aid of hydrogen and may consequently be used again as a fuel or as a raw material for a number of other processes. Some of these processes may be the production of methane, methanol, ammonia, urea, nitric acid, ammonium nitrate, NPK, PVC, etc.

The present invention may be used in all forms of gases wherein fossil or biological fuel is used.

In addition the present invention solves the problem with emission of VOC (volatile organic compounds), NOx (nitrogen oxides), N 2 O (laughing gas), NH 3 (ammonia) and other greenhouse and in other ways polluting gases.

Combustion/gasification of organic fuels (e.g. bio-waste) produces nitrogen-containing gases, NOx-gases (e.g. from combusted proteins). Such NOx-gases are treated by

SNCR (selective non-catalytic reduction), SCR (selective catalytic reduction) and other NOx-reducing processes according to procedures known to the skilled artisan.

The present invention produces also energy far more effectively than similar processes today, and has far lower CO 2 emission per kWh than contemporary processes with CO 2 harvesting. Other advantages of the present process versus others are apparent from table 1 infra. Table 1 infra is presented as an comparative example presenting parameters and cost-effectiveness of the process according to the present invention. Table 1. Comparison between the present invention and a similar power plant (LM Ericsson 2500 gas turbine) with and without CO 2 collection. All numbers* are relative to today's without CO 2 collection:

• All numbers are guiding As a consequence of the development of the present invention, the present invention may be used within the general area OfCO 2 purification, collection and sequestering.

The processes according to the present invention may be performed within a reactor providing ways of controlling the physical and chemical parameters involved in the following reaction equations: CO + H 2 O = CO 2 + H 2 Shift reaction 1.

CO + 3H 2 = CH 4 + H 2 O Methanation reaction 2.

CO 2 + 4H 2 = CH 4 + 2H 2 O Methanation reaction 3. CO 2 + H 2 = CO + H 2 O Reverse shift reaction 4.

C + H 2 O = H 2 + CO Gasification reaction 5*.

C x H y + (x + y/4)O 2 = xCO 2 + (y/2)H 2 O Combustion reaction 6.

* Where C describes any organic substance like but not limited to biomass or organic waste The assembly, design and operating parameters of such reactors lies within the knowledge of the person skilled in the art, and will be realized by the skilled person when reading the disclosure of the present invention.

The present reactions are also disclosed as the application of specific reactor designs providing catalytic and physical characteristics allowing and emphasizing the hydrogenation of CO and CO 2 to CH 4 (methane).

The present invention may be considered as a triple one, the one part producing hydrogen and CO according to reaction 5. The second part will take advantage of the produced hydrogen from the first part, but may also individually produce hydrogen from reaction 1. The produced hydrogen will in the third part react with CO and CO 2 according to reaction 2 and 3 and produce methane.

The produced methane may either be re-circulated and combusted in a continuous loop or the methane may be separated out and be used as a raw material for producing other chemicals. The produced hydrogen and CO may be used as raw materials for other uses and processes. Part 1 of the present invention may contain combustion and/or oxidation processes where fossil or organic substances are used as fuel. Part 2 of the present invention may contain catalysts and other devices making it possible to produce synthesis gas. Synthesis gas contains hydrogen and carbon monoxide, however synthesis gas may also contain carbon doxide, water, nitrogen and methane. Part 3 of the present invention is to contain a catalyst being suited for performing the methanation reaction, reactions 2 and 3, and suppressing the reverse shift reaction, reaction 4.

Part 1 , part 2 and part 3 may be integrated with each other or may be separate entities.

Part 1 is the section where the organic or fossil fuel is combusted and/or oxidized and is described by the well known reaction 6.

Part 2 is the section wherein the gasification is performed. Gasification is an energy demanding process. This energy may be taken from Part 3 developing large amounts of energy or the energy may be provided from external sources, or part 1.

The organic substances may be split into hydrogen and CO according to reaction 5 through several different processes. As mentioned supra, some of these may be:

The counter-current fixed bed ("up draft") gasifier consists of a fixed bed of carbonaceous fuel (e.g. coal or biomass) through which the "gasification agent" (steam, oxygen and/or air) flows in counter-current configuration.

The co-current fixed bed ("down draft") gasifier is similar to the counter-current type, but the gasification agent gas flows in co-current configuration with the fuel (downwards, hence the name "down draft gasifier").

In the fluidized bed reactor, the fuel is fluidized in oxygen and steam or air. The ash is removed dry or as heavy agglomerates that defluidize. The temperatures are relatively low in dry ash gasifiers, so the fuel must be highly reactive; low-grade coals are particularly suitable. The agglomerating gasifiers have slightly higher temperatures, and are suitable for higher rank coals. Fuel throughput is higher than for the fixed bed, but not as high as for the entrained flow gasifier. In the entrained flow gasifier a dry pulverized solid, an atomized liquid fuel or a fuel slurry is gasified with oxygen (much less frequent: air) in co-current flow. The gasification reactions take place in a dense cloud of very fine particles. Most coals are suitable for this type of gasifier because of the high operating temperatures and because the coal particles are well separated from one another.

In Part 3 the transforming of CO 2 with hydrogen to methane is performed in a reactor with a catalyst. The heat being developed may be used for heating Part 2 or in any other way. The shape of the catalyst is not essential and may inter alia comprise coated monoliths, different nano materials and other types and forms of carriers. The carriers may be selected from e.g. TiO 2 , Al 2 O 3 , cordierite, Gd-doped CeO and other types of carrier materials. The catalytic material may also be present in any form as a "pure" catalyst material. The form and composition of the reactor and the catalyst will depend on which emission gas it is wanted to purify. An impure exhaust gas with large amounts of dust (from the combustion of coal) may have a monolithic catalyst carrier whereas a pure exhaust gas (from a natural gas turbine) may have a catalyst in the form of pellets. All types of exhaust gases from all types of combustions of organic material may be treated.

The methanation reaction may be performed with the catalyzers infra with different compositions depending on the condition of the gas that is to be treated, but all methanation catalyst may be used in the temperature interval 150 to 600 0 C. Examples of usable catalysts are:

Ni/NiO (nickel/nickel oxide) catalyst

Ru (ruthenium) catalysts

Cu (copper) catalysts

- Pt (platinum)

Rh (rhodium)

Ag (silver)

Co (cobolt)

W (tungsten)

- All other catalysts alone or together with one or more of the metals mentioned supra.

When a methanation reaction is selected in the combined process according to the present invention, such a methantion reaction is conducted according to standard procedus, taking into account e.g. the efficiency and optimal operating conditions of the catalysts used, but the methanation reaction is normally conducted at temperatures indicated supra and at pressures in the range of about. 1 to 50 bar.

When re-circulating the methane for further combustion and production of electricity or other forms of energy, the CO having been produced at the gasification may be used as a source for other applications e.g. for producing energy or as a starting material for the production of more hydrogen.

Another possibility for using of the formed synthesis gas (hydrogen and CO) may be to produce methanol as disclosed supra. This production may conceivably happen according to commercial processes being available today, and the methanol may have several areas of use such as e.g. fuel for transportation vehicles.

This process may be realized in the following way: Fuel is combusted with air in a burner. Electricity, being another form of energy, is taken out from the combustion process in a conventional manner. The CO 2 produced is used, as disclosed in the present invention, for producing methane. The methane is recirculated while the hydrogen and CO produced by the gasification is used for producing methanol.

The present invention is not limited to these two fields, but may be used in all processes wherein natural gas or other hydrocarbons and organic compounds are one of the raw materials. The present invention also produces energy far more efficiently than comparable processes today, and has a far lower CO 2 emission per kWh than today's processes with capture of CO 2 . The other advantages of the present process as compare to others are observed in the table infra (being equal to table 1 supra, but emphasizing other aspects of the present invention). Table 1. Comparison between the present invention and comparable power plants with and without capture of CO 2 . All numbers a relative to today's without capture of CO 2 :

All numbers are guiding.

A small part of the exhaust gas may be emitted to avoid accumulation of certain trace elements. This exhaust gas consists mainly of CO 2 and water. This composition makes it very simple to capture CO 2 without using chemicals (e.g. amines and others), since the water may be condensed out while the CO 2 still is in a gaseous state. CO 2 may then be used for other purposes or may be stored. The cost for capture and optionally storage of such CO 2 then becomes very small. The CO 2 may be captured and used or stored in any possible way described. The disclosed reactions (see reactions below) are common reactions (equilibrium reactions) happening in the production of ammonia over different catalytic layers and in the gasification of the organic compounds.

The shift reaction happens in the LT (low temperature being known to the person skilled in the art) or HT (high temperature being known to the person skilled in the art) shift reactors wherein carbon monoxide reacts to produce carbon dioxide and hydrogen over an iron oxide/chromium oxide respectively a copper oxide/zinc oxide catalyst may be used.

The methanation reaction happens in a methane reactor (operating under the conditions temperature up to 600 °C, pressure 1 to 50 bar, space velocity 10 000 h '1 ) wherein carbon monoxide and carbon dioxide is reacted into methane and water over a nickel, ruthenium, tungsten or other metal-containing catalyst according to several total reactions (equilibrium reactions), inter alia:

CO + H 2 O = CO 2 + H 2 Shift reaction 1. CO + 3H 2 = CH 4 + H 2 O Methanation reaction 2.

CO 2 + 4H 2 = CH 4 + 2H 2 O Methanation reaction 3.

Since the ammonia process is a process for producing ammonia via hydrogen from methane and nitrogen from air, the reactions 2. and 3. disclosed supra are reactions that are not wanted and which give losses of in the production of ammonia. In the present invention all of these reactions are wanted since they produce methane being a product or intermediates participating in producing methane.

The waste gases may contain different types of contaminants. These contaminants may be, but are not limited to N 2 O, NO, NO 2 , volatile compounds (VOCs), SO 2 , etc.

Ordinary destruction of these contaminants happens with CO 2 present in the combustion gas. An ordinary concentration of CO 2 in the combustion gas is about 1 -20 % by volume. When CO 2 is removed prior to the other contaminants the catalyst volume and the addition of chemicals will be reduced dramatically, partly on account of the lowered volume, and partly on account of the inhibitor effect of CO 2 if this is present. Any process solution may be used for removing these contaminants, and this lies within the competence of the person skilled in the art.

Some of the relevant reactions involved in the process according to the present invention may be summarized by the following items: A combustion/oxidizing process, a process producing synthesis gas by

gasification/pyrolysis, e.g. by organic material, and a process producing methane from reactions wherein CO, CO 2 , water, oxygen and hydrogen participate according to a methanation reaction scheme as follows:

CO + H 2 O = CO 2 + H 2 Shift reaction 1. CO + 3H 2 = CH 4 + H 2 O Methanation reaction 2.

CO 2 + 4H 2 = CH 4 + 2H 2 O Methanation reaction 3.

C + H 2 O = H 2 + CO Gasification reaction 5*.

C x H y + (x + y/4)O 2 = xC0 2 + (y/2)H 2 O Combustion reaction 6.

* Where C describes any organic substance like but not limited to biomass or organic waste.

Brief account of the figures.

Figure 1: Gasification of biomass with flue gas.

Figure 2: Biomass heat exchanged with flue gas.

Figure 3: Conventional gasification process

Legend to figures.

Figure 1 : Gasification of biomass with flue gas.

The figure shows air and fossil fuel (e.g. methane) being fed to a combustion unit (2). The flue gas from the combustion is mixed with biomass and fed to the gasification reactor (4). In the gasification reactor the biomass together with the oxygen and water in the flue gas is converted to synthesis gas. The synthesis gas is heat exchanged (if necessary in 5) and either used as raw material and converted to the synthesis gas conversion (6) unit, or burned to generate energy.

Figure 2: Biomass heat exchanged with flue gas.

The figure shows biomass, air and water being heat exchanged (3) with hot flue gas from a combustion unit (1) before entering a gasification reactor (4). The reactants are converted to synthesis gas, and the synthesis gas is heat exchanged (in necessary in 5) and either used as raw material and converted in the synthesis gas conversion unit (6) or burned to generate energy.

Figure 3: Conventional gasification process.

The figure shows a conventional gasification process where biomass, air and water is mixed and heated (if necessary in 2) before entering a gasification reactor (3). The synthesis gas is heat exchanged (if necessary in 4) and either used as raw material and converted in the synthesis gas conversion unit (5), or burned to generate energy. Detailed use of the invention.

Figure 1. The figure shows air and fossil fuel (e.g. methane) being fed to a combustion unit (2). The flue gas from the combustion is mixed with biomass and fed to the gasification reactor (4). In the gasification reactor the biomass together with the oxygen and water in the flue gas is converted to synthesis gas. The synthesis gas is heat exchanged (if necessary in 5) and either used as raw material and converted in the synthesis gas conversion (6) unit, or burned to generate energy.

Figure 2. The figure shows biomass, air and water being heat exchanged (3) with hot flue gas from a combustion unit (1) before entering a gasification reactor (4). The reactants are converted to synthesis gas, and the synthesis gas is heat exchanged (if necessary in 5) and either used as raw material and converted in the synthesis gas conversion unit (6), or burned to generate energy.

Figure 3. The figure shows a conventional gasification process where biomass, air and water is mixed and heated (if necessary in 2) before entering a gasification reactor (3). The synthesis gas is heat exchanged (if necessary in 4) and either used as raw material and converted in the synthesis gas conversion unit (5), or burned to generate energy.

CO 2 may be compressed and stored in a suitable way. Example 1 of gasification combined with methanation.

Using the source of heat, water and oxygen from a combustion unit, as described in Figure 1, gasification for H 2 and CO production based on entrained flow gasifier may be used in a combined process with water dissociation and CO 2 methanation. It consists of three chemical steps:

C + H 2 O = H 2 + CO Gasification reaction 5*.

CO + H 2 O = CO 2 + H 2 Shift reaction 1.

CO 2 + 4H 2 = CH 4 + 2H 2 O Methanation reaction 3.

* Where C describes any organic substance like but not limited to biomass or organic waste.

The hydrogen recovery step is performed in any type of gasification reactor in the temperature range 300-1200 0 C but according to this example the gasification reactor is an entrained flow gasifier with the following operating conditions: temperature 1600 - 2200 K, atmospheric pressure. The gases that are developed are hydrogen, carbon monoxide and carbon dioxide. The carbon monoxide may be reacted with water to further develop more hydrogen in the water-gas shift reaction. The water-gas shift reaction is carried out using to adiabatic fixed-bed reactors with cooling between the two reactors. The first reactor (High Temperature Shift) operates at high temperature (350 "C) and contains a classical catalyst (iron oxide promoted with chromium oxide). The second reactor contains a more active catalyst (copper on a mixed support of zinc oxide and aluminum oxide) and operates at lower temperature (Low Temperature Shift, 190 - 210 "C). The hydrogen will be used together with the CO 2 -containing exhaust gas and reacted over a methanation catalyst being specifically in the present example Nickel on aluminum oxide support for providing methane and water. The parameters under which this methanation catalyst operates are: Temperature: 350 0 C and atmospheric pressure.

Including the energy in the produced methane, the electrical efficiency for the whole set up may be as high as 70%

Example 2 of gasification combined with methanation. Large amounts of hydrogen and CO may be produced at moderate temperatures (300- 1200 0 C). The Hydrogen and CO may be used as described in example 1 or the gas mixture can be used to produce other chemicals like, but not limited to, methanol ethanol and diesel fuels. In all examples the excess of heat from the Sabatier reaction (methanation of CO 2 and hydrogen for providing methane and water) will be used either to heat the gasification or for creating any type of energy. The heat from the waste- or flue-gases will also assist in heating the gasification process.