Production Process Wood Pellet From Wood Biomass


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Production Process Wood Pellet From Wood Biomass. Indonesia is the highest biomass potential in ASEAN countries so that the chances of developing wood pellet industry is huge.

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  • Global markets for wood pellets are projected to grow by 200 to 300% from 2012 to 2020 – from 16 million tonnes to 40-50 million tonnes. Link :
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  • Korea looks to Indonesia for wood pellets
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Production Process Wood Pellet From Wood Biomass

  1. 1. Wood Pellet Production Process of From Wood Biomass Eko SB Setyawan
  2. 2. Overview Pellet Various types of pellets (wood pellet, torrefied wood pellet & charcoal pellet) Biomass decomposition regimes -White pellet = wood pellet are made of sawdust or planer shavings without bark -Brown pellet = wood pellet are made of bark containing raw materials -Black pellet = torrefied wood pellet Wood pellet : Property class A1 represents the highest quality level that is particularly relevant for private end users. In property class A2, the limiting values for the ash content, the NCV, the nitrogen and chlorine content and the ash melting behaviour are less strict. This property class is mainly relevant for commercial users operating pellet boilers with higher nominal capacity. Pellets according to property class B are relevant as industrial Pellets. The main factors distinguishing : calorific value, ash content and ash chemistry Pellets made from bark containing wood fractions such as forest wood chips, industrial wood chips with bark and short rotation coppice (SRC) would comply with A2 pellet class. That’s mean Calliandra Pellet is A2 Pellet.
  3. 3. Overview Pellet Usually brightly colored pellets from softwood and the dark one from hardwood. But pellets are made of soft wood from all parts of the tree ("whole tree") including bark will make darker pellets. So it is difficult to determine the quality of wood pellets of color alone. The length of pellets on the market varies from different manufacturers. Production of wood pellets requires consistent length and minimize the variation. Wood pellet diameter varies from 6 mm to 20 mm. Diameter of 6 mm is commonly used for home heating, whereas the 8 mm diameter upwards commonly used by industry and power plants. Generally hardwood pellets are preferred, especially for the stove and fireplace because it naturally has a lower water content, denser, longer burning and heat such as coal. Standard grade fuel is usually up to 3% ash content, while premium grade is less than 1 percent. Premium pellets are usually produced from hardwood or softwood sawdust containing no tree bark.
  4. 4. Overview Pellet Wood * Proksimate and ultimate analysis to determine the compounds and chemical elementsof wood pellets can also be done to complete product knowledge and commercialization
  5. 5. A. Process Technology of WoodA. Process Technology of Wood Pellet Production
  6. 6. Essence of Wood Pellet Making Process • Essence / Philosophy of wood pellet manufacturing process is compaction (densification) of biomass to facilitate handling, transportation and utilization such as combustion, pyrolysistransportation and utilization such as combustion, pyrolysis and gasification. In order produced a quality product (standard and stable) it is necessary to the selection of raw materials, preparation of raw materials such as particle size uniformity and the dryness, conditioning, add adhesive and so on before compacted (pelletizing). Raw materials are categorized wood waste or woody biomass that worth as wood waste.
  7. 7. Process Variables • Raw Material Type • Size of Raw Material • Moisture Content• Moisture Content • Hardness • Density • Product Size (Wood Pellet) • Ash Content • Raw material chemistry • Ash Chemistry • Contaminant etc.. These variables have tended to make pelleting more of an “art” than a “science”, through significant strides are being made in the sophistication of this process, bringing these variables under more control.
  8. 8. Process Technology of Wood Pellet Production Plant • Standard Process of Large-Scale Wood Pellet Plant *Optional • The highest cost components at: -RawMaterial-RawMaterial -Drying
  9. 9. Comparison of Wood Pellet Plant A typical of large scale wood pellet plant. Left: 750rb TPY-Georgia, U.S.; Right: 5 TPH - Tenesse, U.S. A typical of small scale wood pellet plant. Left : 500kg/h- China; Central: 500kg / h - Argentina; Left: 350kg / h; China
  10. 10. Statistic of World Wood Pellet Production • Russia's total production 3,093 million tonnes / year by the largest plant in Leningrad capacity of 900,000 tonnes / year, the smallest in Galway 2500 tons / year (2011). • Total U.S. production of 5.481 million tons / year, with the largest plant in Georgia a capacity of 750,000 tonnes / year, the smallest of 10,000 tons / year is found in many places (2011). • The total production of Canada 2.958 million• The total production of Canada 2.958 million tons / year; China's total production of 792 000 tonnes / year; Japan's total production of 110,000 tons / year; total Indonesian production of 80,000 tons / year (2012). • Prediction of wood pellet demand continues to increase. In 2010 the global consumption of 16 million tons / year; 2015 predicted 37 million tons / year and in 2020 predicted 59 million tons / year.
  11. 11. Wood Pellets Export Ports
  12. 12. Logistic of Large-Scale Wood Pellets Marketing (Reference of Canada)
  13. 13. Biomass Potential of Southeast Asia Indonesia is the highest biomass potential in ASEAN countries so that the chances of developing wood pellet industry is huge.
  14. 14. Raw Material The level of dryness (MC) holds a vital role in the production process of wood pellets. Waste from processed wood such as furniture industry in general is dry, while the forest or plantation is still wet, so it needs drying before being processed into wood pellets.
  15. 15. Drying Process The Raw Material • Judging from its use; timber can be divided into: 1. carpentry and wood crafts; 2. timber industry; 3. firewood. All require drying before use. • Wood holds moisture in two ways: as free water in the cell cavities and bound water in cellwalls. The definition of free water is water that is contained within the cell cavity, which is easily in and out of the water, (hygroscopic). While water is bound water contained in the cell wall, where the water is rather slow exit and entry. • The variables that affect the wood drying process: 1. Wood, 2. moisture content, 3. heat, 4. carrier medium heat, 5. air circulation, 6. air temperature, 7. humidity, 8. dryer equipment (machine) , 9. drying technique and 10.time. •Wood drying process will run faster if the air temperature is higher, the lower theair humidity and velocity of air circulation around the surface of the wood morequickly. •Lighter wood in general will dry faster than heavier wood, because light woodporosity higher than the heavy woodporosity. •Drying techniques are used to optimize the process variables, such as: raising the air temperature, the humidity of air (using dry air), increase the velocity of circulation of dry air, extending the contact between the wood dried with dry air, in order to get dry wood withthe times relatively fast. •Drying by the sun with a relatively low temperature (40-60 C) also minimizes emissionsof organic compounds (VOC = Volatile Organic Compound) smelled of wood.
  16. 16. B. Effects of Moisture Content in Wood Pellet Production Process
  17. 17. Size Reduction Stage
  18. 18. Size Reduction Stage • Woodcrusher (sawdust maker) hammer mill type are generally only able to work on the moisture content max. 20%. • Timber harvest generally have a high moisture content of about 50% that need drying prior to being fed into a hammer mill. content of about 50% that need drying prior to being fed into a hammer mill. • Calliandra or gliricidia rod size can be fed is small average only 5-10 cm enough with 1-step process type hammer mill. However if the size is more than it can use a combination of wood chipper crusher and hammer mill or drum-type cutter.
  19. 19. Illustration of Wood Crusher Equipment Hammer Mill Wood chipper and hammer mill Hammer Mill
  20. 20. Pelletizing Stage
  21. 21. Various Types of Pelletiser For pelletizing highly fibrous biomass L/D = 8,5-9 : 1 For pelletizing wood L/D = 8-10 :1 For small capacity <500kg/hour For medium and large capacity; the most popular rarely used, laboratory scale application For flat die machine the length of of hole is shorter than ring die machine, that’s mean durability of pellets from ring die machine is better than flat die machine rarely used, laboratory scale application
  22. 22. Commercial Pelletiser Commercial Pelletiser: there are two kinds, namely the flat die and ring die. Flat die: high operational cost (rapid equipment wear and more maintenance), used for animal feed wood pellets or small-scale (<500kg/day), the price of FlatDie Ring Die (<500kg/day), the price of equipment is cheap . Ring die: low operational cost, the equipment (not quickly wear out and a bit of care), a popular and widely used wood pellet production capacity for medium to large (> 500kg/hour), the price is expensive.
  23. 23. Analogy Flat Die Vs Ring Die = Motorcycle Vs Car Vs xxIn the context of a conveyance with a particular load: Motorcycle engines are generally small cc (100-500 cc) so that the payload capacity is also small, whereas when a large engine capacity 1500 cc and above example, it is more suitable to be installed or made cars for effectiveness the transport efficiency, aesthetics, handling, safety and so on rather than made a big motorcycle.
  24. 24. - Carbon steel alloy: strongest die, cheapest price, not corrosion resistant, rugged die surface friction and thus greater compression so that the wood pelletsproduced harder. Material Die Almost all manufacturers of wood pellet line also ring die and roller production, and there are also that specifically sell as below : -Stainless steel alloy: corrosion resistant, the price is-Stainless steel alloy: corrosion resistant, the price is more expensive, because the die surface is more smooth, then the depth of the die takes longer to produce hard wood pellet. - High chrome alloy: highest corrosion resistance, start- ups easier, because the die is smoother, then the depth of the die tajes longer to produce hard woor wood pellet, the price is the most expensive.
  25. 25. Characteristics Raw Materials Requires Different Shapes and Sizes of Die Each die (mold) suitable for one type of raw material !!! Die can not "generic" for all biomass
  26. 26. Pelleting Stage • Too high or too low levels of moisture in the wood in pelleting process will cause• Too high or too low levels of moisture in the wood in pelleting process will cause the failure of this process. • Toget good quality pellets, the average temperature on the die 125 C; Canada requires maintaining a temperature of 85 C for a minimum temperature of the die. The higher the temperature the better the quality of the pellets. • Efficiency wood pellet plant that can be accepted is 130-200 kWh / ton, without drying system. • Fuels that are used during pellet production may produce a maximum greenhouse gas (GHG) emission of 100 kg CO2 per tonne of pellets. This value can be achieved as long as biomass fuels are used for raw material drying and can be lower if use sun drying.
  27. 27. Pelletisation Process # 1 Phenomena in Ring Die Pelletiser Close up at Die Channel, Pelletiser
  28. 28. Pelletisation Process # 2 Thermographic View in Die Pelletiser Source : Serrano et al 2011 Elsevier
  29. 29. When Raw Material Too Wet • Too high moisture content (too wet) will cause the pressure (compression) is very high on the die. This makes the temperature rise and produce steam in large quantities. The high pressure will make the motor work too heavy and also potential to make die clogged. This condition also affects the bearing in the roller. Thecondition also affects the bearing in the roller. The resulting pellets will also be very soft and easily broken. Despite high compression but adequate temperature which makes the lignin out as the adhesive is not reached. Because of the high moisture content, the pellets will expand and release moisture, consequently pellet surface is not smooth and cylindrical as it should.
  30. 30. When Raw Material Too Wet Wood pellets are soft and easily broken when using raw materials too wet (high moisture content). Wood Pellet will be damaged or destroyed on Cooling stage when the moisture level is too high (too wet). Scheme wood pellet cooling with aircounter flow
  31. 31. When Raw Material Too Dry • Because the raw material has a low density and lack of moisture content (too dry) then the roller is not able to perform an adequate compression in the die. The lack of pressure also resulted in a lack of heat and lignin are not able toheat and lignin are not able to come out as an adhesive in the pellet. Because the raw materials can not generate enough friction and tension / compression of the material will be slide freely inside the die and consequently does not form pellet. Pellet was not formed when using raw material is too dry (low moisture content)
  32. 32. Cooling Mechanism When wood pellets out of pelletiser then the temperature is very hot, soft and generate steam. Before pellets can be stored and used then the condition to be cool and dry. The simplest way of cooling of wood pellets is so cold in the room laid it by itself at room temperature. Counter flow cooler is cooling type that common used in wood pellet industry currently with use the direction of the air and product of wood pellets in opposing directions. Cooling gradually will improve quality, reduce cracks in the surface and "fine". Wood pellet out of the cooler with moisture content to about 8% at temperatures ranging 5-10 C from room temperature. Almost all coolers fitted screen to filter "fine" / "powder" of wood pellets. "Fine" / "Powder" is then returned to the pelletiser to bewood pellets. "Fine" / "Powder" is then returned to the pelletiser to be used as raw material again. Left: Schematic of the equipment counter flow cooler; Middle: photo commercial cooler; Right: the fancy wood pellets cooled sufficiently smooth and shiny surface.
  33. 33. C. Pelletiser Characteristics and Maintenance The Equipment Including Pelletiser
  34. 34. 6 Considerations as a Success Key of Pelleting Success Pelleting = Quality Pellet 1. The relationship between the quality of raw material, capacity of machines and pelleting processes(pelleting operating conditions) must be synchronized. 2. Capacity friction on the die. The greater the friction the higher the density of the pellets. 3. Material and surface of the die and roller. Die of stainless steel has a smooth surface and corrosion resistance so that the start up easier than die from carbon steel, but increase friction then deepened the depth of the hole (die hole).friction then deepened the depth of the hole (die hole). 4.The ratio of length and diameter of the holes inthe die. 5.The thickness of raw material layer on the die and thus the thickness of the material is pressed into thedie. The optimum thickness is generally 1 mm 6. Compression frequency (rotationalspeed).
  35. 35. The Height of Roller and Carpet Carpet is a thin layer of material that is pressed, which is located at the top surface of the die. When the incoming raw materials to pelletiser it will be driven by the roller and forming carpet. The more materials put into pelletiser it will further add to the carpet. Carpet is then pressed into die hole and produce pellets. So for material that can form a pellet, initially to be able to form a carpet. 1 mmGap Generally carpet with a thickness of 1 mm is the optimum condition between pellet quality, energy consumption and equipment wear rates. >1mmGap Enlarge the gap between the roller and die, will increase the energy requirements needed. If the roller is set above 1 mm, then it is likely that the pressure generated will not be sufficient between the die and roller. Without enough pressure thenwill not be sufficient between the die and roller. Without enough pressure then there is no heat, so no adhesive is removed and the carpet is not formed, so that the pellet is not formed. Only in very special conditions so it is rarely applied to> 1 mm gap in the production of pellets. < 1mmGap When the roller and the die contact means no space to form a carpet, so the material is pressed directly into the luabng die, resulting in pellet quality will decline. More importantly, when the inter-metal contact occurs it will significantly reduce the life of the roller and die. Tip: When setting up the roller gap, the characteristics of raw materials need to be considered, for example the density of the material and gluing capabilities. 1mm gap is recommended for almost all the materials but try variations of the gap would be beneficial. All pellet production is a matter of reducing the need for energy and equipment wear rates while simultaneously improving quality and productivity pellets. This is why the quality of production of pellets requires special skills.
  36. 36. Gluing Characteristic In Wood Pellet Production • Variables including raw materials and moisture content, particle size, shape, and distribution, hardness and lignin content has a major influence on pellet quality and selection of adequate process conditions. The presence of a liquid such as moisture for generating pelleting style interface (interfacial forces) and capillary pressure, thereby increasing the bonding of particles.capillary pressure, thereby increasing the bonding of particles. • There are 3 stages in the compaction of biomass, including pellets. Stage 1: formation of particles arrange themselves to form a solid enough. Stage 2: particles push each other and form properties such as plastic and elastic deformation, thus enhancing the contact between the particles significantly; particles become bound by van der Waal's electrostatic force. Stage 3: a significant decline in volume due to the high pressure / compression so that the density pellets can be achieved.
  37. 37. Deformation Mechanisms of Biomass Powder Particles Under Compression #1
  38. 38. Deformation Mechanisms of Biomass Powder Particles Under Compression #2 Compression curve of biomass powder particles. Compaction process can be separated into several stages: particle rearrangement, elastic and plastic deformation, and hardening.
  39. 39. Susunan Cellulose, Hemicelullose dan Lignin Pada Biomasa
  40. 40. Gluing Characteristic In Wood Pellet Production #1 Compaction of biomass such as pellets with a pressure / high compression will increase the mechanical interlocking and adhesion between particles, thus forming bondsparticles, thus forming bonds between the molecules in the contact area. On raw materials such as wood biomass adhesion mechanisms can be divided into styles adhesion and cohesion, attractive forces between the particles and bonds interlocking.
  41. 41. Gluing Characteristic In Wood Pellet Production #2 Display of broken surfaces on pellets with a scanning microscope electrone (SEM) a. Typical surface fractures on the pellet, which indicates strong adhesion b. Typical surface fractures on the pellet which indicates a weak adhesion
  42. 42. Gluing Characteristic In Wood Pellet Production #3 Display light microscopy which showed the polymer melting and interlocking the fibers (biomass)
  43. 43. Gluing and Quality of Wood Pellet Particles "Fines" (Powder) formed due to the lack of adhesion during pellet formation So that the performance of pelletiser and the finished product affect to the percent fines. Pellet very strong when pressed vertically but easily broken when pressed horizontally. Poor quality pellets made crushed / broken into pieces and generate a lot of powder. Depending on the target market, the percentage of "fine" that forms need to be declared or not. Premium quality wood pellets at a target of fines should be less than 1%. CEN European standard specifications of the percentage of "fines" that is allowed and in many cases a percentage of the fine should be stated when sold. Packaging capacity also affects the occurrence percentage of the fine, the smaller the container will create a smaller percentage of fine.
  44. 44. Characteristic of Pelletiser • Each material has different qualities and characteristics. The parameter is the moisture content, density and quality of the gluing. • When the quality of the raw material for wood pellets has the appropriate quality, then after entering pelletiser and contact with the roller and get the appropriate heat and pressure then the pellets will exit. The blades can be added to set the length of pellets. And after cooled pellets will be hard and ready for use.
  45. 45. Characteristic of Pelletiser • Selection of quality raw materials greatly affect the quality of wood pellet, and setting pelletiser include material thickness and die, pressing time, pressing temperature and pressure also helps improve the quality of wood pellet. Pressure can be set by selecting the die, the die material and the distance by roller. So for the production of wood pellet from many variety of raw materials need to change feed speed to pelletiser andof raw materials need to change feed speed to pelletiser and selection the pelletiser die. Ideally, the selection is also related die compression ratio, for example, processing of raw materials of softwood requires die thicker than hardwood processing, for the same quality results pelleting. • There is a difference between just making wood pellets with making a quality wood pellet with minimum energy consumption and maximum roller and die life.
  46. 46. Maintenance Equipment Including Pelletiser Equipment used for wood pellet production exposed high temperature and pressure, so that adequate maintenance be essential to maximize the life of equipment and reduce energy consumption. A. Bearing maintenance Particular equipment such as crusher type hammer millParticular equipment such as crusher type hammer mill and pelletiser have much bearing, which reach high temperatures during operation. Periodically check the bearings needed to maintain the performance and life of the equipment. Some equipment are equipped with automatic lubrication for bearings.
  47. 47. Maintenance Equipment Including Pelletiser B. Maintain Minimum Energy Consumption Check the hammer mill and pelletiser can operate without resistance will keep the energy needs minimum. For example checking that there is no material cause additional friction around pelletiser and roller. C. What to Do At the End of Production When the end of the production is very important to include oily materials to pelletiser so production will be started When the end of the production is very important to include oily materials to pelletiser so production will be started easily again for example bran with cooking oil. If the raw materials are processed left in the die, then die cold so the raw material in the die cold too and will harden. If it happens then it is very difficult to start up production again and may need to be drilled the clogged die.
  48. 48. Photos Some Equipments that Need Maintenance Includes Pelletiser
  49. 49. Receiving Station • The raw material is received at the plant will calculated by : 1. Volume. Calculate the volume of wood in a car or truck tub then multiplied by average density wood (100-150 kg/m3) 2. Weighing. Wood can be put in a sack and weighed with scales or wood with truck minus weight of the truck with a truck load scales. Estimated price of 10 thousand dollars. Method 1 is cheaper and practical, but accuracy is not as good as the method 2.
  50. 50. Packing Wood Pellet • It is advisable to pack wood pellets to the large size, so if it does not use packing machine-for example, directly from the cooler is not a problem, because small amounts. • Jumbo bag packing models with capacity 1 ton or 500 kg can be applied. Generally, small scale of wood pellet plant in Indonesia use direct packing from cooler. 500 kg jumbo bag for wood pellet Jumbo bag for 1 ton wood pellet
  51. 51. Packing / Bagging A. Semi-Manual B. Full Automatic
  52. 52. D. Wood Pellet Plant ConfigurationD. Wood Pellet Plant Configuration
  53. 53. Product Storage • Wood pellet product storage in a dry air-vents. Highly recommended to use a pallet to keep the product dry. Some other guidelines such as the adjacent column.
  54. 54. Safety in Wood Pellet Plant • The things that need to be considered in the area of plant : Based on USData - Wearing masks, boots, gloves and helmets. - Avoid burning trash and the like that cause fire. - No smoking. - The electric motor and relay equipment must be protected. - Be careful when welding and cutting metal in many areas of dry sawdust potentiallymany areas of dry sawdust potentially dangerous. - Avoid contact hot surfaces with dry sawdust, as it could potentially cause a spark. - Wood pellets should not be stored longer without an adequate temperature monitoring* - Beware against friction, collision and sparks arising from hot bearings, moving parts, etc. that cause accidents with dry sawdust. * microbial activity will raise the temperature to 90 C of wood pellets which then could cause a fire when oxidized. High moisture content and production process so that the raw materials are not exposed to temperatures> 100 C will stimulate microbial activity.
  55. 55. E. Promotional Use of Wood Pellet for Indonesia and AsiaIndonesia and Asia
  56. 56. Affecting Factors
  57. 57. Comparison of Wood Pellet With Coal No. Factors WoodPellet Coal 1. CalorificValue 4000 kcal/kg andup 5000-5500kcal/kg 2. AshContent <4% 20 to40% 3. Pollution/Poisonous effluentSmoke No Smoke NoSulphur Sulphur, phosphorousfumes 4. Moisture 8 %(max) 20 to35% 5. Efficiency ofboiler 75% 75% 6. Wastages/Loss 8-10% 15-20% 7. Labourusage Single person isenough Require two persons7. Labourusage Single person isenough Require two persons 8. Boilerefficiency Normal Fly ash deposit ontubes High wear &tear 9. Handling Easy because of packedmaterial Toughmaterial 10. Type ofFuel CarbonNeutral CarbonPositive -Various advantages of wood pellets can be used as a bargaining postion sale price of wood pellets for coal substitution in industry. -For comparison: in the U.S. almost all the wood pellets used for household heating with pellet stove, while the majority of wood pellets in Asia are used for co-firing with in coal powerplant. -Most wood pellet production process also with debarking (remove the bark from the wood) for reducing the ash content. Because consumers of wood pellets in Indonesia and Asia is an industry that is generally more tolerant to higher ash content then there is not a problem without debarking.
  58. 58. F. How to Get Raw Material Supply with large volumeswith large volumes
  59. 59. Cultivation of Short Rotation Coppice (SRC) with Energy Forests / Plantations
  60. 60. Comparison the SRC Productivity Between Indonesia and Europe / America Productivity of woody biomass for 1 year Calliandra in Indonesia (tropical countries) = 4 years Willow in sub-tropical countries. (Calliandra)
  61. 61. Availability of Land in Indonesia Source : YETTI RUSLI PRESENTATION
  62. 62. International Price of Wood Pellet
  63. 63. Thank you Eko SB Setyawan Mobile :+62 8132 884 1805 Biomass to EnergyEntrepreneur @ekosbs