PREPARING PROCESS OF BIOFUEL FROM LIGNOCELLULOSIC BIOMASS AND PRODUCTS THEREOF

TECHNICAL FIELD

Mechanical Engineering in part relating to technology and sustainable energy and environment management.

SUMMARY OF INVENTION

This invention is related to biomass material preparation process used for biofuel obtained from lignocelluloses biomass material which consist of cellulose, hemicelluloses and lignin with important procedures are size reduction, soaking in water, oil elimination, moisture adjustment, structure decomposition within biomass, bearing out water and decomposed substance and drying in order to be clean fuel which can take to use replacing other fuels such as coal, oil and natural gas because clean fuel as mentioned reduce or remove various problems of taking biomass used as fuel such as case example of biomass using palm cluster as raw material from origin with heat value of 7.24 MJ/kg increasing to 21-23.77 MJ/kg, having ashes decreasing from 14.70% to 1.65-2 % with higher concentration of energy making reduce the price of transportation and storage area, having low moisture about 4-7%, decreasing on tar and slagging.From attributes as mentioned make to be able to reduce using fuel in industrial sector, i.e. this invention can help reducing the problems on environments from flare system causing air pollution and/or leaving natural biomass because it cannot bring them to be fuel due to have high moisture such as palm oil empty fruit bunch, rice straw, cassava rhizome and other biomass with this similar attributes or if there are recycle but bother to be increasing the way of life of rural agriculturists from helping reduce environmental problems and making increased income.

BACKGROUND ART

Now there is taking biomass from plants reimbursing fuel from fossil seriously and being more systematic from 2 pressures, firstly is on energy price getting from fossil fuel such as coal, oil and natural gas with higher price as market mechanism including fuel from fossil with reserve of world decrease due to human have dug for several years but it has to spent the time in occurring these fuels for million years. So occurring with use lack of balance which there is anticipating that oil and natural gas will run out of in a few ten years in the future. Secondly, that to be significant problem that general people giving precedence is global warming affecting from using fossil fuel causing to occur many natural disasters phenomenon all around the world such as flood, landslide, earthquake, falling rain not as season, long-term drought and coldness, etc. Both Impulsions as above make world society having more awareness in using energy by turning to use renewable energy which is clean and friendship with environments to be able to rebuild such as energies from wind, sunshine, water and energy obtained from biomass on lignocelluloses, etc., by biomass plants which human can take as fuel such as biomass from planting for example straw, corn, cassava, oil palm leaf and oil palm tree.

Biomass from processing of agricultural products such as bagasse from sugar industry, husk from milling, palm shell, palm leaf and oil palm fiber from palm oil extraction factory, cassava rhizome from flour mills, cornstalk from animals processing factory and including fast growing trees taking as fuel, sliver, sawdust from sawmill, etc.

When world fuel price has higher adjustment continuously, biomass as mentioned above was taken to use as fuel which mostly will take biomass to use directly without attribute reform or else just reforming for drying to reduce moisture or downsizing and utilization from biomass in earliest stage mostly used for fuel substitution in processing plant for that agricultural products which is unsophisticated use, that is, when there is downsizing and reducing moisture and then feeding into combustion to produce the heat or somewhere may not reduce size and moisture sending as fuel immediately without considering the expenses on high energy because it receives fuel from the residues from processing. When there is combustion fuel use to produce heat for a long time, it will find the problems and having to stop for production in order to frequently clean combustion system and heat exchange system more than fuel use from fossil, so it wastes the time and expenses in maintenance.

Besides, there is still various kinds of biomass being left without taking for combustion as fuel because of having high moisture and taking to combust and then arising many problems with heat production system because there are substances making slag, gum or having more ashes such as oil palm leaf, palm tree, bare palm cluster, cassava rhizome, rice straw, corn, etc. Later when biomass having more needs for using as fuel, transportation and storage for biomass is then important. With properties of most biomass have lightweight with approximate average of 100- 400 kg/m ³ with high moisture up to 10-87% depending on kind of biomass having average heat value at 5-16 MJ/kg and having ashes of 5-13% in order that parameter value will be different in each kind of biomass and processing process. When there is biomass transportation from production source to terminal using biomass, heat comparison per unit area or weight of biomass is then obstacle for taking biomass for use.

Using raw biomass in the present time which still has no biomass arrangement or reform process before using as fuel or only having reform for creasing weight per area unit such as pellet or pelletizing cannot solve the huge problem arising from using as fuel, that is, when there is biomass combustion, each kind of plant will release chemicals within biomass and making trouble to combustion system and heat exchange system such as alkaline metals, for example potassium (K), sodium (Na) and alkaline earth metals, for example magnesium (Mg), calcium (Ca) and chlorine or some kinds of biomass such as husk with silicon (Si) in high content which may be up to 10-14% of weight which various substances above arising from activities in plants growing that agriculturists add into them such as from fertilizer to stimulate plants growing and from minerals being in natural soil will be accumulated within structure of such biomass.

When there are more needs for biomass, it then has development to reduce some limitations such as reducing moisture value by exposing to the sun or drying and then taking to pelletize, chunk or piece in order to increase weight per area unit from the first for pellet fuel. Reducing the size per unit area or unit volume will affect well to the cost of transportation which make to be able to transport per time increasingly, so it is time and expenses saving including to be able to reduce the area in storage affecting well in overall of the cost on fuel management receiving biomass but in order that there is still has issue arising from use because structure of inner composition of pelletized biomass or briquette is still all the same, so when taking to be combustion fuel comparing between raw fuel and pelletized fuel will have no different properties in aspect of the result of combustion. Sample of equipment invention for pressing plant biomass and process of pressing plant biomass as Thai patent document with publication of request No. 0901002633 mentioned on reforming properties of plant biomass, kinds of lignocelluloses with cellulose, hemi-cellulose and lignin as composition which process as mentioned can reduce the flaws of transportation and storage including reducing odor but composition of inner structure of biomass still have bare change or do not change really. Another sample of biomass development for using fuel with high energy density is properties reform within structure of biomass for use as fuel. As Thai patent document with publication of request No. 0801001355, patent as above has the goal to develop biomass material with higher density of heat value by using hydrothermal technique which technique as above use hot water with high pressure in reaction that has much high cost using energy and being dangerous. Besides, properties reform of plant biomass for using as fuel especially ethanol production as patent as Thai patent document with publication of request No.1001001243 on pretreatment of plant biomass that mentioned on technique using hot water under high pressure to reform the properties of biomass which had to high energy and being dangerous.

Development on taking fuel obtained from plants used as fuel has been developed for a long time that seen as products near us such as taking raw wood used as fuel in early era that human began to utilize from fire to produce the heat, light and cooking all the time until now taking wood or plant used as fuel has less development by beginning using fresh wood with high moisture used as fuel, the outcomes received making the smoke, soot and in area of use being dirty, low heat value and having high ashes. Later there was reducing the flaws as above by taking fresh wood to be dried and then burned in area limiting air or having less air which is called that carbonization which meant decomposition of wood or biomass by pyrolysis process in order to receive charcoal used as fuel which spent several days.

The products obtained from adjusting inner composition structure of plant biomass using the heat in area without air or less air will receive 3 products, namely gas, oil and charcoal which ratio will depend on various conditions such as size of supplied material, temperature used, time material receiving heat, etc. which in general carbonization will give average product approximately 25 - 35% from starting material weight which ratio as above has to be under control condition, air, temperature and reaction time as defined making charcoal to be expensive. In earliest stage that forest was still abundant, there were widely wood cutting until affecting for making forest area reduce. Later governments in several countries declared to forbid for wood cutting except being rapid growing woods grown for this purpose especially biomass obtained from by- product of agriculturists. Using technique for biomass combustion in incinerator to produce charcoal still release the smoke to outside atmosphere and causing follow- up environmental pollutions, so it is not desired of surrounding communities. From Thai patent document with publication of request No.0501001849 revealed treatment for white charcoal production from tropical woods and revealed period of time used including various steps in making charcoal with smoke and environmental pollution in production process.

Charcoal obtained from woods or briquette biomass and burned can lightly reduce the flaws of using fresh biomass from plants such as usable time with less smoke, having less gum causing substance, higher heat value but remained problem is less weight per unit area so there is development taking charcoal to be briquetted in order to make more weight per unit area for solving problem as above. From using raw woods to be charcoal and then developed to be charcoal with high density, of course production cost is higher, so it is not popular using in industrial sector but for service sector such as restaurant and household sector still use because of some properties of charcoal better than using other fuel providing heat such as electricity or gas which quality of charcoal will depend on material used and combustion technique that has to control various factors as above with suitability. When having more needs in using energy because of world development depending on fossil energy having limitedly, so it drives the costs of energy coming from fossil such as mineral, oil and natural gas have higher adjustment continuously accompanying global environmental problems with more awareness in energy use. In industrial sector turn to depend on energy from raw biomass as first generation fuel being nature without reforming inner composition structure such as sawdust, husk, rubber slab, coconut shell, bagasse, corncob, etc. Later there is some properties to reduce obstacle on transportation and storage by making as pellet or briquette with limitations and still has problems as above that is second generation fuel but it can stop or retard using biomass from plants until affecting higher fuel price from plant biomass as demand of market.

However, until now development in reforming properties of biomass from plants still has limitedly because it is stage starting for development that can conclude methods using to reform biomass from plants as fuel and combustion problem solving with various techniques as follows:

1. Cutting wood as little pieces (Wood Chip)

2. Pellet or Briquette

3. Carbonization or Slow or Fast Pyrolysis

4. Steam Explosion

5. Hydrothermal or Hydrothermal Carbonization

6. Torrefaction

7. Additive for Slagging problem in incineration and deposit problem solving.

And by technology as above, all of them have different merits and flaws. Using the same technology cannot solve all problems, so it is cause of this invention which is developed fuel or called that third generation fuel.

DESCRIPTION OF THE INVENTION

This invention is properties reform of biomass from plants with cellulose, hemicellulose and lignin as main compositions in order to use as fuel such as bare palm cluster, palm leaf, palm, rice straw, husk, corn, corncobs, bagasse, cassava rhizome, rapid growing tree, rubber wood and other plants with compositions as above which process consist of procedures as follows: Step 1: is step downsizing of biomass material in order to be easy and convenient, rapid to 1 reaction in next step that is soaking step and biomass structural decomposition step with good size of downsized materials of 0.1-5 centimeters, preferably better downsized between 0.1- 3 centimeters and best downsize between 0.1-2 centimeters by using a small hack consisting of blade held with at least one rotated disc and driving rotated disc with electrical motor or mechanical power and having at least one blade held with fixed steel frame. Downsizing machine as above will has input port for filling biomass for digestion and having output port for biomass to be downsized as needed. This step has necessity for biomass with big pieces such as bare palm cluster, palm leaf, palm, rice straw, husk, corn, bagasse, cassava rhizome, rapid growing tree but it may be not necessary if they are small biomass or being equal to value as defined such as sawdust, rice bran, animal faeces, etc.

Step 2: is using water as various substances and elements separator including the dirt such as soil, stone, sand and various metals attaching to biomass out of biomass by using water with pH 5.5-8 at ratio of dry biomass: water volume that should be at 100 gram/ 1-5 liter, temperature of water at 20-50°C and then soaking biomass to be downsized as step 1 which period of time in soaking in this step depend on kind of biomass such as from oil palm empty fruit bunch spending time of 0.5-24 hour depending on state of palm oil empty fruit bunch how much there is moisture and dirt. While biomass soaked in Water in this step 2, it will make some elements such as potassium (K), calcium (Ca), sodium (Na), sulfur (S), silicon (Si), chlorine (CI) in biomass including various dirt such as soil, stone, sand, metal, various elements out of biomass as well and it will fuel through this invention process having more cleanliness in combustion step.

Step 3: is using hot water separating oil out of biomass. For the case biomass having slick whether at surface or within biomass, it will affect the damage in step of composition degradation of cellulose, hemicellulose and lignin that is reducing agent on efficiency of composition degradation as above because it make oil attaching biomass to be dry slag attaching to the wall or surface of biomass and reactor wall making to be hard for doing the cleanliness and as reducing agent on efficiency of heat transfer of reactor which biomass is processed taking off oil for example biomass from oil palm such as bare palm cluster, palm fiber, etc. which here do not only limit to be biomass from palm, but also include any other biomass with oil mixing with that biomass. In this step hot water is taken as main substance in oil decomposition out of water which water use temperature in range of 50-80°C, preferably better at 65-80°C depending on oil content attaching to biomass. Hot water will be filled in tank with checking system for hot water, temperature and period of time using this step will be controlled with set of temperature measurement, set of measuring water level, set of time control and instruction set for filling hot water and heating automatically in order to be related to feed biomass because water content and biomass content will have to have relative ratio for efficiency of oil removal out of biomass. In this step, hot water will discharge oil in both surface and within biomass fiber seeing that water and oil will have stratification because density of water has more than oil, oil will upraise on water surface which can stratify water and oil by centrifugation in order to increase efficiency taking off oil from biomass and stratifying oil out of hot water and the dirt being out of hot water and rotating hot water passing for oil and dirt removal such as soil, stone, sand, various metals attaching to biomass that hot water used for decomposition can take to recycle in order that heat energy used in increasing temperature obtained residual convection of system to give the heat for energy saving which the time used in step of oil removal from biomass will depend on state of mass which is processed, for example bare palm cluster just being processed for separating palm fruits out of cluster in standard palm extraction plant will spent the time about 1-60 minutes. In this step not only important step in decomposing oil out of biomass, but also is structure preparation of biomass to be ready entering to structural decomposition step of lignocelluloses. Due to biomass passed hot soaking, it will make any hot water permeate in fiber.

Step 4: Propermoisture state adjustment. When biomass was then passed step for oil decomposition, biomass passed step as mentioned, biomass fiber will absorb any water which water being in biomass is necessary to squeeze some water in order to make sufficient reaction and fitting in reactor invented in step 5 which necessary water or moisture and should have in biomass that entering to biomass decomposition, it should be in range of 100-400%, preferably better range between 100-300% and best range between 100-200%) of dry biomass weight. In this stage 4 is state adjustment to biomass with proper water and moisture in reaction in reactor decomposing structure of biomass in step 5

Biomass state adjustment in this step 4 provides state adjustment in order to provide proper moisture that may provide with squeezing, compression, centrifugation or discharging moisture with natural heat making water separating from biomass in order to receive the last value as defined.

Step 5: is important step in adjusting biomass state with decomposing or degrading composition of biomass in order to degrade cellulose, hemicelluloses and lignin. In this step provides reactor set that can tolerate high pressure no less than 100-150 km/cm ² and tolerate high temperature no less than 300-500 °C made with mild steel being the same kind used in making boiler and being coated in inner surface to protect rust with thickness no less than 15 mm. which reactor set as above can make higher temperature with heat source such as electricity, gas, direct flame from material combustion with carbon as composition, hot wind, hot oil, superheated steam or microwave or providing the heat more than 1 kind. Reactor set as above will be covered tank closely without air leaking while working. Reactor set as above while working will have ratio of controlled heat in range of 1-10 °C/min. Reactor system will have temperature increase from outside heat source. Pressure within tank will adjust as defined mechanism which ratio increasing pressure used in reaction of reactor should be in range of 0.5 -1 kg/cm ² /min. in order to accelerate decomposition reaction of cellulose, hemicelluloses and lignin to be proper and absolute. Reaction tank as this step has characteristic as long circular cylinder or sphere that can be placed in horizon or vertical and covering closely head and tail having no pressure leaking with gateway for filling biomass passed structure decomposition at least one channel. Reactor as above also consists of set providing the heat inside tank or outside tank. Tank as above also consists of temperature control set inside and outside reactor tank of measurement set and pressure control set, safety set in case of excess pressure which has relation in working all system automatically.

In working of step on structural decomposition of biomass consisting of cellulose, hemicelluloses and lignin begins from feeding biomass passed step as above into reactor set for structural decomposition of biomass. When it is obtained as defined, closing inlet filled with biomass tightly in order to protect air being not in and out and then increasing the heat to reactor set with acceleration rate of increasing of temperature and pressure as defined. While temperature increasing over 100°C, hemicelluloses and lignin will begin decompose at 180-250°

C which they will decompose better at 200-230°C and the best decomposition at 205-220°C in order that the pressure having relation with temperature in range as above is pressure range at 15-25 kg/cm . When it reaches fixed temperature, reaction in reactor will have the most perfection for 0.5-3 hours. While temperature reaches to specific level, it still keeps constant pressure, reaction will be absolute. When it is time to reaction of reactor set as specific time, providing pressure in order to take heat and pressure as above to utilize in step of biomass arrangement before entering to process in order to be energy saving or other utilization or discharging to atmosphere. When level of pressure then reduce to 0 kg/cm ² (Atmospheric pressure), taking biomass passed structural decomposition out of reactor to next process. From methods above, pressure and temperature used in catalysis for structural decomposition of biomass obtained from step 4, increasing of temperature in order to obtain sufficient pressure value in reaction in reactor can build by nitrogen or air compressions for receiving pressure at about 15-25 kg/cm ² by providing the heat to reactor like method above.

Step 6: Remove water being in biomass fiber and hemicelluloses and lignin including various minerals in biomass decomposed in step of reaction in reactor from biomass in step 5, which this step 6 provides with taking various substances and water attaching in step 1 before taking biomass to decompose in reactor that decomposed from biomass out of that biomass can make by compression, centrifugation, water suction with reducing pressure lower than vacuum by any method or several methods together in order to obtain moisture in fiber no more than 50% of weight of dry biomass or less than that that make saving energy in step of drying.

Step 7: Biomass passing water decomposition and various substances decomposition, in step 6 can be dried by taking for solarisation or natural airing to reduce moisture being in biomass which it spend time and using location or using the heat by using autoclave at 80-170°C for 1-2 minutes to help activating time of evaporation of water in biomass for making to be dry. Biofuel obtained from biomass which pass step 1 to step 7 abovementioned will have properties as illustrated as figure 1-5 to compare oil palm empty fruit bunch called briefly that EFB that pass or do not pass this invention treatment which fuel processed as invention steps will have specific attributes as follows:

Heating Value is higher than crude biomass with heat value in range of 20-23.77MJ/Kg as figure 1 Low ash content which has value in range of 1.65-2% and having low moisture value is in 4.92 - 6 % as figure 2, Having high hydrogen value 7.05-10 % as figure 3, Having composition within biomass such as low hemicelluloses in range of 5-10 % as figure 4 And at most for separating the difference between processed biomass and crude biomass as this invention is having specific characteristic which can see with naked eyes that any biomass product is processed or is not processed that can observe from color, that is, color of processed biomass as this invention will have darkened color with dark brown tone to black which is the best reaction stage that can measure color value by presenting as light value according to standard of showing color image for vision by combination of 3 colors, namely Red (R) Green( G) and Blue (B) which color of product obtained from this invention can look with naked eyes to be dark brown tone to black that can measure light value RGB in range from R44G37B9 to R47G37B12 which is equal to 10 color value in mode CMYK that is from range C62M61Y83K72 to C60M63Y82K72 as illustrated comparative color value in figure 5 Biofuel product as attributes abovementioned, can be used as fuel directly through combustion with sufficient air (Direct combustion) to provide direct heat or combustion in limited air content (Gasification) to produce synthesis gas for using heat or being fuel with engine for electricity production or using for vehicles including it also can take to pyrolysis to produce liquid fuel or biodiesel and if require transportation from source producing fuel to the place where will use work as fuel, product as this invention can downsize making saving area in transportation or storage by forming as form as needed in order to increase efficiency in transportation and working.

BRIEF DESCRIPTION OF THE DRAWINGS

Figurel shows heating value comparing between crude biomass (A) and processed biomass (B)

Figure 2 shows proximate analysis of crude biomass (A) and processed biomass (B) Figure 3 shows ultimate analysis of crude biomass (A) and processed biomass (B)

Figure 4 shows composition of crude biomass (A) and processed biomass (B)

Figure 5 compares color intensity between crude biomass (A) and processed biomass (B) by comparing color value of charcoal (C)