Thermochemical Conversion of Biomass to Power and Fuels ( Presentation by Group 1 )

1. Thermochemical Conversion of Biomass to Power and Fuels(Presentation by Group 1)

2. Group members • Lau Kok Chun • Najeeb Abdul Khalid • NurulAsyiqin Abdul Halim • Wan Munirah Wan Mat Zin • SyazwaniSalehudin

3. Biomass characterization Moisture content Proximate analysis Ultimate analysis Bulk density Alkali metal content

4. Moisture content

5. Moisture content of the biomass

6. Moisture Content (MCw) of Different Biomass Fuel Sources Sources : Atchison, J.E. and Hettenhaus,J.R.,Innovative methods for corn stover collecting, handling, storing and transporting, Subcontractor report NREL/SR-510-33893, National Renewable Energy Laboratory, Golden, CO, 2004; Klass,D., Biomass For Renewable Energy, Fuels And Chemicals, Academic Press, San Diego, CA, 1998; McKendry, P., Bioresources Technol., 83,37,2002a; Quaak, P. et al., Energy From Biomass: A Review Of Combustion And Gassification Technologies, World Bank Technical.

7. Proximate analysis

8. Process of proximate analysis

9. Table 2: Proximate Analysis (%Wt,db) Of Different Biomass Fuel Sources Sources: Data from Brown, R., Renewable Resources: Engineering New Products From Agriculture, Blackwell Publishing, Ames, IA, 2003; Guar, S. and Reed, T., Thermal Data For Natural And Synthetic Fuels, Marcel Decker, new york, 1998; McKendry, P., Bioresources technol., 83, 37, 2002a; McKendry, P., Bioresources Technol., 83, 47, 2002b; McKendry, P., Bioresources Technol. 83, 55, 200a.

10. Volatile matter in biomass

11. Ash content in wood

12. Ultimate analysis (elemental composition)

13. Table 3 : Ultimate Analysis (%Wt,db) Of Different Biomass Fuel Sources Sources : data from Brown, R., Renewable Resources: Engineering New Products from Agriculture, Blackwell Publishing, Ames, IA, 2003; Guar, S. and Reed, T., Thermal Data for Natural and Synthetic Fuels, Marcel Decker, New York, 1998; Hiler, E.A. and Stout, B.A., Biomass Energy: A Monograph, 1stedn., Texas A&M University Press, College Station, TX, 1985; McKendry,P., Bioresources Technol., 83, 37, 2002a; McKendry,P., Bioresources Technol., 83,47,2002b; McKendry, P., Bioresources Technol., 83, 55, 2002c; Reed, T.B, Encyclopedia Of Biomass Thermal Conversion: The Principle And Technology Of Pyrolysis, Gassification & Combustion, 3rdEdn., Biomass Energy Foundation Press, Golden, CO, 2002.

14. Heating value

15. Heating value

17. Table 4: Heating Value (Dry) Of Different Biomass Fuel Sources Sources : Data from Brown, R., Renewable Resources: Engineering New Products from Agriculture, Blackwell Publishing, Ames, IA, 2003; Guar, S. and Reed, T., Thermal Data for Natural and Synthetic Fuels, Marcel Decker, New York,1998.

18. Bulk density

19. Bulk density

20. Table 5: typical bulk densities (wet basis) of different biomass fuel Sources: Data from Brown, R., Renewable Resources: Engineering New Products from Agriculture, Blackwell Publishing, Ames, IA, 2003; Quaak, P. et., Energy from Biomass: A Review of Combustion and Gasification Technologies, World Bank Technical Paper No. 422, The World Bank, Washington, DC, 1999; Scurlock, J., Bioenergy feed-stock characteristics, Oak Ridge National Laboratory, Bioenergy Feedstock Developmet Programs, Available from http://bioenergy.ornl.gov/papers/misc/biochar_factsheet.html,2008.

21. Alkali metal content

22. Biomass storage

23. Biomass storage

24. Biomass storage

25. Overview of conversion technologies

26. COMBUSTION

27. OBJECTIVE : • Release all of the chemical energy stored in a fuels while minimizing losses due to incomplete combustion. Carried out in: PRODUCE HEAT FUEL is directly burned TYPES OF INDUSTRIAL BIOMASS COMBUSTION CAN BURN: • WOOD • AGRICULTURAL RESIDUE • WOOD PULPING LIQUOR low moisture content is preferred • MUNICIPAL SOLID WASTE • REFUSED DERIVED FUEL BOILER FURNACE STOVE

28. 3 tS (REQUIREMENT) OF COMBUSTION: • High temperature (ignition) • Sufficient turbulence (mix all the components with the oxidant) • Time Fundamental of combustion( 4 steps):

29. Steps in the conversion of biomass in boiler • Drying and pyrolysis use energy and flame and char combustion are exothermic

30. Combustion equipment • Combustors convert chemical energy of fuels into high temperature exhaust gases. • These gases can be used for; space heating, drying, or power generation. • Boiler is made up of a furnace. • The overall efficiency is defined by the following • nboiler= • Combustion systems can be classified as fixed bed or fluidized bed. • Fixed bed systems used method for burning biomass. • schematic of a dutch oven boiler

31. Schematic of biomass boiler • Combustion system are classsified as fixed bed and fluidized bed. • Types of fixed bed system(Dutch ovens, grate burner and suspension fired furnaces) schematic of a biomass boiler

32. FIXED BED • The grates(where the fuel burn) form the furnace floor, provide a surface on which the larger particle burn • The furnace provide volume in.so that; • The fuel can be burned completely • Provides for the absorption of sufficient heat to cool the flue gas to a temperature. 25%-75% air required, used to dry the fuel, promote the release of the volatiles and combust the devolatalized char resting on the grate. from 25%-75% of the total air required and provides air for the combustion of the volatiles and mixing.

33. FLUIDIZED-BED COMBUSTORS • Used to burn biomass fuel in a hot bed granular material, such as sand. • Injection of air into the bed creates turbulence, resembling a boiling liqiud. • This design increases heat transfer and allows for operating temperature below 972ºC, reducing nitrogen oxide emissions, allows for improved fuel flexibility, which enables the combustion of high fouling and low-energy fuels. • The principle of fluidization is shown below;

34. The fluidization medium consists of an inert material, like sand, and air is injected into the botttom through a distributor plate. • The air flows through the particles bed, and at the critical, or minimum, fluidization velocity, the upward drag forces will equal the gravitational forces of the particles, and the particles will become suspended in the fluid medium. • As the velocity increased, the height of the fluidized bed increases and some of the bed particles will leave through the top, which create a circulating fluidized bed.

35. Many of the new biomass boilers being built today are circulating fluidized boilers. The advsantages is: • The ability to burn low-grade fuels, due to high thermal inertia and high turbulence of the fluidized bed. • High combustion efficiencies, due to the turbulence mixing of the fluidized bed and the long residence time of the fuel in the furnace. • Low S02 emissions, which are made possible by the reaction of limestone to sulfur in the fuel at relatively low temperatures(850ºC-900ºC) • Low CO and CXHy emissions, due to the turbulence, long residence time, and mixing in the cyclone. • Good cycling and load-following capability, due to the heat transfer being approximately proportional to the load.

36. Uses of combustion The steam produced can be used as; Source of mechanical power to drive a shaft Produce power as elecricity

37. BOILER EMISSIONS • Biomass boiler must meet the stringent environmental requirements imposed by governments. • Emissions from a boiler can either be solid, thermal or air. • Air emissions are of the greatest concern and are mainly by-products of the combustion process. • Air emission can be as follow; • Particulates • CO • NOX • SOX • Volatile organic compound

38. Liquefaction

39. Source: Demirbas, A. (2010)

40. Process of conversion of biomass to liquefied products through a complex sequence of physical structure and chemical changes. The feedstock is usually wet matter. Two types of liquefaction: Direct liquefaction Indirect liquefaction Liquefaction

41. The amount of solids residue increases in proportion to the lignin content. Liquefaction process involves solvolysis, depolymerization, decarboxylation, hydrogenolysis and hydrogenation. Solvolysis-biomass is in micellar-like substructures which leads to rearrangements through hydrogenation and decarboxylation.

42. Involves rapid pyrolysis to produce liquid tars and oils and/or condensable organic vapors. Hydrothermal liquefaction is one of the direct liquefaction types. Direct liquefaction

43. Hydrothermal liquefaction (HTL) (hydropyrolysis) used high temperatures and pressures to decompose complex organic material, including biomass. HTL include pyrolysis, gasification and torrefaction. Hydrothermal liquefaction

44. The differences that separate HTL from other TCC processes are: 1) Allows for the processing of a wet biomass, such as swine or some cattle manures, without a preliminary drying step (Ocfemia et al., 2006). 2)The conversion process transforms the manure solids into oil and gas products that can be separated from the water effluent, thereby reducing the potential environmental impact of the manure through the removal of solids (Zhang et al., 1999). 3) It produces a high energy bio oil, which has potential commercial applications both as a liquid bio fuel and as a feedstock for the development of other specialty chemical applications, such as bio-asphalt (Jena and Das, 2011)). 4) The high temperature and pressure destroys the pathogens present within the manure (Ocfemia et al., 2006).

45. The volatile or organic components of the manure solids can be converted to bio oil via HTL. Feedstock that are higher in protein and lipid concentrations lead to a higher oil product yield, while those higher in fibrous material lead to the higher biochar yields. The moisture content is one of the critical feedstock characteristics that needs to be considered in HTL processing of manure. HTL processing works best with solids contents in the starting feedstock that are around 20-35 wt %. Feedstock with moisture contents that below 20% difficult to handle, due to higher viscosities. However, manure that is too dilute will decrease the efficiency of oil production, as there will be low concentrations of volatile solids available for conversion and may require larger system sizes for conversion, increasing costs. Feedstock characteristics

46. Source: Demirbas, A. (2010)

47. Operating condition

48. The differences between hydrothermal liquefaction with other thermochemical conversion technologies

49. Involves the use of catalysts to convert non-condensable, gaseous products of pyrolysis or gasification into liquid products. Alkali salts such as sodium carbonate, potassium carbonate acts as catalysts for the hydrolysis of cellulose and hemicellulose into smaller fragments. This process continued by depolymerization and deoxygenation. Two routes have commercial significance in indirect liquefaction are: Methanol synthesis; Fischer-Tropsch synthesis. Indirect liquefaction

50. Fischer-Tropsch (FT) diesel is a synthetic fuel produced from the conversion of natural gas into a diesel fuel. Developed in 1925 by Franz Fischer and Hans Tropsch which developed a catalyst that converted CO and H2 at 1 atm and 250 to 300 C into liquid hydrocarbons. The fuel thus formed is superior to crude oil based diesel in certain ways, principally the high cetane number and the zero sulfur content. Also known as GTL diesel, where the acronym refers to “gas to liquid” conversion. Mainly been used during disruptions to crude oil supply. Fischer-Tropsch synthesis.