Monday, January 14, 2008

Biomass in China

The biomass energy resources in China include the residue from agriculture and forestry processing, covering solid residue, the concentrated organic waste water from the agriculture products processing, crop straw and stalk burned as fuel, fuelwood, human and animal excreta, and urban residential refuse.

Traditionally, biomass was a major energy source in China but with the huge escalation of fossil-fuel generating capacity in the last 15 years, it is now dwarfed. 80% of biomass energy is rural, the principal biomass resource being crop residue, which accounts for over 52% of total biomass energy, followed by dung with 20% and firewood with 10%. Currently, 61% of rural household energy in China comes from traditional use of biomass. This means that each year approximately four billion tons of crop residues and woodfuel are burnt using stoves.

Among the extensive agricultural residues in China, the straw and stalk output alone reaches about 604 million tons. Calculated with a collection rate of 85%, the available amount of straw and stalk is 513.4 million tons, equal to 205 million tons of carbon equivalent (tce). Much of the 513.4 million tons of straw and stalk are presently used for cooking and heating in rural households. Other uses include forage, industrial raw material for paper production, and organic fertiliser. Presently, most of it is used at low efficiency. For example, in domestic cooking stoves the conversion efficiency is only 10-20%. The remainder of the straw is either dumped or burned in the field.

City refuse accounts for 18%. Crop and forest residues are mainly used as fuels for cooking food and/or heating by means of direct burning.


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