Biomass Energy Technology
Wood Energy Data
Direct Combustion
Direct combustion is one of the main processes used to convert biomass into usefull energy. The heat and/or steam which is produced during this process can be used to provide process heat for (domestic) cooking, industrial processes or can be used to generate electricity. The following gives an overview of the various technologies used for this purpose in Asia.
Heat Generation - Electricity Generation - Co-generation
Heat Generation
Stoves - Furnaces - Boilers - Kilns
Stoves
Small-scale use of direct combustion is mainly used for domestic cooking and space heating purposes. There exists a wide range of stove types in Asia. In this overview a distinction is made between traditional cookstoves (CS) and Improved Cook Stoves (ICS). Note that figures about dissemination of stoves should be used with care as it is not said that installed stoves are really used by the users. RWEDP has published two country specific compendiums (China, India) and a development manual about Improved Cook Stoves. Additional information on institutional stoves is available at the stoves page.
| Stoves | ||||||
| Country | Year | Type | Efficiency | Cost | # Stoves | Note/Source |
| (%) | ($/unit) | ('000) | ||||
| Bangladesh | 1990 | ICS | 1.33 | 108 | stoves locally made from mud; APDC, 1993 | |
| Bhutan | 1990 | CS(open fire) | 5-16 | 22.5 | fuelwood as fuel input; HES, 1990, WET, 1996 | |
| Bhutan | 1990 | CS(Chulla) | 15-17 | 3-5 | 52 | fuelwood as fuel input; HES, 1990, WET, 1996 |
| Bhutan | 1990 | ICS | 22-24 | 75-150 | 12 | eff. and cost for Bhumtang type; HES, 1990, WET, 1996 |
| China | 1990 | ICS | 10 | 120,000 | 100% locally made; APDC, 1993 | |
| China | 1991 | ICS | 35-53.44 | 8-70 | 140,840 | extensive info available in RWEDP, 1993 |
| China | 1995 | ICS | 25-30 | 158,000 | efficiency of traditional stoves 10-15%; ICIMOD, 1999 | |
| China | 1998 | ICS | 180,000 | fuelwood and coal as fuel input; REW, 1999 | ||
| India | 1985 | ICS | 3,000 | ratio of ICS to family numbers 2.6%; ESCAP, 1991 | ||
| India | 1990 | ICS | 8-50 | 2-13.5 | 6,300 | extensive info available in RWEDP, 1993b; APDC, 1993 |
| India | 1993 | ICS | 14,505 | TIDE, 1995 | ||
| India | 1995 | ICS | 20-25 | 19,611 | ICIMOD, 1999 | |
| India | 1998 | ICS | 28,500 | REW, 1999 | ||
| Indonesia | 1985 | ICS | 25 | ratio of ICS to family numbers 0.1%; ESCAP, 1991 | ||
| Indonesia | 1990 | ICS | 10 | 100% locally made; APDC, 1993 | ||
| Indonesia | 1995 | ICS(ceramic) | 7.7-13.8 | fuel input:peat charcoal, milled peat; RWEDP, 1998 | ||
| Indonesia | 1995 | ICS(metal) | 17.6-33.8 | fuel input: peat charcoal, milled peat; RWEDP, 1998 | ||
| Myanmar | ICS(A-1)) | 30.7-43.6 | fuel input: fuelwood, charcoal, capacity 0.98-2.29 kW; RWEDP, 1998 | |||
| Myanmar | ICS(Pathein) | 26.1-46.9 | fuel input: fuelwood, charcoal,capacity 0.55-1.12 kW; RWEDP, 1998 | |||
| Nepal | 1985 | ICS | 30 | ratio of ICS to family numbers 1.2%; ESCAP, 1991 | ||
| Nepal | 1990 | ICS | 130 | 100% locally made; APDC, 1993 | ||
| Nepal | 1995 | ICS | 90 | ICIMOD, 1999 | ||
| Nepal | 1998 | ICS | 250 | REW, 1999 | ||
| Pakistan | 1985 | ICS | 14-28 | ICS made from mix of clay, animal dung, straw and water, efficiency of CS 6.5%; ICIMOD, 1999 | ||
| Pakistan | 1990 | ICS | 3 | 100% locally made; APDC, 1993 | ||
| Pakistan | 1998 | ICS | 68 | mainly fuelwood as fuel input; REW, 1999 | ||
| Philippines | CS | 7.6-21.5 | more specific info in RWEDP, 1986 | |||
| Sri Lanka | 1985 | ICS | 119 | ratio ICS to family numbers 4.78%; ESCAP, 1991 | ||
| Sri Lanka | 1990 | ICS | 10 | 350 | mainly fuelwood as fuel input, 100% locally made; APDC, 1993 | |
| Thailand | 1990 | ICS | 4 | mainly charcoal as fuel input; APDC, 1993 | ||
| Thailand | 1998 | ICS | 12-23 | 500 | mainly charcoal as fuel input; RWEDP, 1998, REW, 1999 | |
| Vietnam | 1990 | ICS | 12-20 | 1-4 | fuel input: ricehusk, coal, fuelwood; SED, APDC, 1993 | |
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| Note: # Stoves refers to number of stoves installed up to reference year. | ||||||
Furnaces
Improved stoves can be used for domestic use as well as for small and medium scale industrial use. For medium- and large scale industries, specialized furnaces and boilers have been developed which can burn various types of biomass. Equipment is commercially available in various sizes and capacities.
The types of furnaces commonly used for the production of process heat can be classified into three major groups: grate burners, suspension burners and fluidized bed. Suspended burners and fluidized bed systems both have considerable energy demands, making them less attractive for small-scale applications. Grate burners appear in a number of configurations: step grate, sloping grate and horizontal grate. The most common of these systems in developing countries is the horizontal burner type. These furnaces range from very basic units which do not employ any draught control with low efficiencies (as low as 10-20%) to more efficient units.
Boilers
Furnace and heat exchanger together are known as a boiler. The heat generated by a boiler can be used to drive a steam turbine or steam engine. Boilers can be classified into: shell, fire-tube and water-tube. The shell boiler has largely been replaced by the other two types. The simplest systems (up to 100 kW) operate on an open cycle requiring a continuous supply of clean water for the boiler. Boilers based on a closed cycle generally have higher efficiencies. The smallest available systems of this type are 200 kW.
Kilns
Kilns are used to provide process heat for a number of industrial activities. Brick making, lime burning, tobacco curing and sugar making are among these industrial activities. One can distinguish two basic types of kilns: batch-type intermittent kilns and continuous types. Most of the following data is obtained from RWEDP's publications on traditional biomass energy using industries and the brick industry.
| Kilns | ||||||
| Country | Activity | Kiln type | Capacity | SEC | Investm. | Note/Source |
| (MJ/kg) | (US$) | |||||
| Brick making | Scove | 5,000-100,000 br./firing | 2.0-8.0 | RWEDP, 1993c | ||
| Brick making | Vertical Chinese | 4,000-30,000 br./day | 0.8-0.9 | >4,000 | RWEDP, 1993c | |
| Brick making | Scotch | 5,000-40,000 br./firing | 2.0-8.0 | <5,000 | RWEDP, 1993c | |
| Brick making | Downdraft | 10,000-40,000 br./firing | 2.0 - 6.0 | <20,000 | RWEDP, 1993c | |
| Brick making | High Draught | 20,000-40,000 br./day | 1.2-1.8 | >15,000 | RWEDP, 1993c | |
| Brick making | Tunnel | 50,000-150,000 br./day | 1.2 - 2.5 | >1,000,000 | RWEDP, 1993c | |
| Brick making | Clamp | 5,000-1,000,000 br./firing | 2.0-8.0 | RWEDP, 1993c | ||
| Bangladesh | Brick making | typical | 1,000,000 br./yr | 1.5 - 4.3 | >3,000 brick units in 1991; RWEDP, 1993c, RWEDP, 1997 | |
| China | Brick making | Hofmann | 2,000-24,000 br./day | 1.5 - 2.8 | >80,000 | RWEDP, 1993c, RWEDP, 1997 |
| China | Brick making | Single-shaft VSBK | 0.97 | RWEDP, 1997 | ||
| China | Brick making | Double-shaft VSBK | 0.915 | RWEDP, 1997 | ||
| Indonesia | Brick making | Intermittent updraft | 20,000-200,000 br./yr | 3.14 | >45,000 brick units in 1987; RWEDP, 1993c, RWEDP, 1997 | |
| Nepal | Brick making | Double-shaft VSBK | 1.03 | 442 brick units in 1989 (formal sector only); RWEDP, 1997 | ||
| Pakistan | Brick making | Bull's Trench | 10,000-48,000 br./day | 1.5-2.8 | >7,000 | >3,000 brick units in 1991; RWEDP, 1993c, RWEDP, 1997 |
| Pakistan | Brick making | Double-shaft VSBK | 1.13 | >3,000 brick units in 1991; RWEDP, 1997 | ||
| Thailand | Lime production | batch process | 1-3 ton/day | > 10 | very low | fuel input: wood/lignite; Dankers, 1992 |
| Thailand | Lime production | vertical shaft(KVIC) | 4-10 ton/day | 5.65 | very low | Dankers, 1992 |
| Thailand | Tobacco curing | 1,300,000 kg/yr | 1 m3/194 kg | typical figures, fuel input: fuelwood, about 956 plants in 1992; RWEDP, 1998a | ||
| Thailand | Ceramic production | 1,250,000 items/yr | 1 m3/360 items | typical figures, fuel input: fuelwood, about 88 plants in 1992; RWEDP, 1998a | ||
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| Notes: SEC= specific energy consumption; VSBK= Vertical Shaft Brick Kiln; br.= bricks | ||||||
Electricity Generation
Biomass-fired power plants have been installed in a number of countries in Asia. These plants have the option to deliver electricity to the grid, utilize the electricity to satisfy the power demand of a stand-alone production proces(ses) or a combination of both. Dedicated plantations for the sole purpose of electricity generation in power plants, so called dendro power, has been applied on a limited scale. RWEDP prepared a publication on modern applications of biomass energy.
| Biomass Power plants | |||||||
| Country | Year | Type | Inst.Cap. | Cap. | Investm. | PBT | Note/Source |
| (MW) | (MW/unit) | ('000 $) | yr. | ||||
| India | 1990 | Power gen. | 5.5 | total number of 600 plants; APDC, 1993 | |||
| India | 1998 | Power gen. | 132.75 | REW, 1999 | |||
| Indonesia | 1998 | Power gen. | 178 | REW, 1999 | |||
| Indonesia | 1998 | Power gen. | 5.55 | 4,488 | 3.6 | demo project at wood complex, steam boiler: 40tph,30bar,385C; RWEDP, 1998b | |
| Indonesia | 1998 | Power gen. | 1,600 | 2.4 | demo project at plymill, steam boiler: 35tph,35bar,380C; RWEDP, 1998b | ||
| Malaysia | 1990 | Power gen. | 1.5 | municipal waste-based power plant, APDC, 1993 | |||
| Malaysia | 1990 | Power self-gen. | 10 | wood waste-based power plant; APDC, 1993 | |||
| Malaysia | 1990 | Power self-gen. | 36 | paper waste-based power plant; APDC, 1993 | |||
| Malaysia | 1998 | Power gen. | 200 | REW, 1999 | |||
| Malaysia | 1998 | Power gen. | 10 | 7,045 | 3.1 | demo project at wood complex, RWEDP, 1998b | |
| Malaysia | 1998 | Power gen. | 5,630 | 3.5 | demo project at MDF factory, 22Gcal/hr, steam boiler: 5tph,12.3bar,193C; RWEDP, 1998b | ||
| Malaysia | 1998 | Power gen. | 274.8 | 2.9 | demo project at sawmill, steam boiler: 5tph,12.3bar,193C; RWEDP, 1998b | ||
| Philippines | 1989 | Dendro-power | 15.7 | total number of 5 power plants, ESCAP, 1991 | |||
| Thailand | 1988 | Dendro-power | 100 | 117,300 | figures based on feasibility study in ESCAP, 1991 | ||
| Thailand | 1988 | Dendro-power | 30 | 44,800 | figures based on feasibility study in ESCAP, 1991 | ||
| Thailand | 1988 | Dendro-power | 3.2 | 6,400 | figures based on feasibility study in ESCAP, 1991 | ||
| Thailand | 1998 | Power gen. | 229 | REW, 1999 | |||
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| Notes: Inst.Cap.= total installed capacity; Cap.= Capacity per plant; Investm.= Investment; PBT= Pay Back Time | |||||||
Co-generation
Co-generation of both heat and power is increasingly being applied in various wood and agro-processing industries. In Asia, co-generation is practised in three main agricultural industries: sugar, palm oil and rice mills. These industries have the potential to produce electricity in excess of their normal heat and power demand which can be fed to the grid.
| Cogen plants | ||||||
| Country | Year | Inst.Cap. | Cap. | Investm. | PBT | Note/Source |
| (MW) | (MW/unit) | (US$/unit) | (yr) | |||
| India | 1995 | 775-1,000 $/kW | operation costs 75-100 $/MWh; TIDE, 1995 | |||
| Malaysia | 1990 | 2 bagasse-based cogen plants; APDC, 1993 | ||||
| Malaysia | 1990 | 0.7 | 2 rice-husk based cogen plants; APDC, 1993C | |||
| Malaysia | 1998 | 1.2 | 693,300 | 3.7 | demo project at palm-oil mill, boiler:35tph,23bar,saturated; RWEDP, 1998b | |
| Malaysia | 1998 | 1.5 | 1,611,000 | 3.5 | demo project at wood complex, boiler:16tph,22bar,280C; RWEDP, 1998b | |
| Malaysia | 1998 | 1.65 | 1,994,000 | 3.1 | demo project at wood complex, boiler:30tph,30bar,saturated; RWEDP, 1998b | |
| Philippines | 1988 | 21 | total installed capacity of 6 plants in wood sector; DOE, 1996 | |||
| Philippines | 1988 | 50 | total installed capacity of 1 plant in pulp and paper sector; DOE, 1996 | |||
| Philippines | 1988 | 122.97 | total installed capacity of 28 plants in sugar sector; DOE, 1996 | |||
| Philippines | 1988 | 230.247 | total installed capacity 43 cogen plants in Philippines; DOE, 1996 | |||
| Philippines | 1990 | 230.25 | total installed capacity of 86 plants in Philippines; APDC, 1993 | |||
| Thailand | 1998 | 0.6 | 102,000 | 1.4 | demo project at paper mill, turbine: back pressure (20bar,5bar); RWEDP, 1998b | |
| Thailand | 1998 | 48.6 | 39,395,000 | 6.1 | demo project at palm oil mill, boiler: 179tph,62bar,482C; RWEDP, 1998b | |
| Thailand | 1998 | 2.5 | 3,865,000 | 3.6 | demo project at rice mill, boiler:17tph,35bar,420C; RWEDP, 1998b | |
| Thailand | 1998 | 2.5 | 2,187,000 | 2.9 | demo project at rubberwood complex, boiler:21tph,24bar,320C; RWEDP, 1998b | |
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| Notes: Inst.Cap.= total installed capacity; Cap.= Capacity per plant; Investm.= Investment; PBT= Pay Back Time | ||||||
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© FAO-RWEDP, 31/12/02