Biomass Gas, also known as biomass gasified gas(BGG), refers to the combustible gas produced in a gasifier by means of high-temperature pyrolysis or gasification decomposition of agricultural & forestry wastes, municipal refuse, livestock manure and other biomass resources as the raw material after collection, crushing and briquetting. The biomass gas includes woody syngas formed by gasification of wood chips, shrubs, sawdust, cotton stalks, etc., fruit shell gas, straw gas, rice husk gas, garbage gas, and the like of these.
Gasifier is the main equipment of biomass gasification reaction. According to the operation mode of gasifier, it can be divided into three types: Fixed bed, Fluidized bed and Rotating packed bed. At present, the main gasifiers used in biomass gasification process are fixed bed gasifier and fluidized bed gasifier. Gasifiers are widely used for gasification, heating and power generation of various agricultural and forestry waste, straw, rice husks, peat, coal powder and municipal solid waste. The heat value of a single system is 5-20MJ, and the power generation capacity is 100kW-2MW. Gasifier well solved the environmental problem.
Biomass gasification technology is suitable for conversion of wood processing waste and hard raw materials such as rice husk and cotton stalk. Compared with the adaptability of raw material of anaerobic fermentation technology, it can be found that there are obvious differences between biomass gasification technology and anaerobic fermentation technology in the adaptability of raw materials. The biomass which is not suitable for anaerobic fermentation treatment is just suitable for the fuel of gasification equipment.
Fluidized bed gasification system
Fixed Bed Gasification system
Crude gas was manufactured by pyrolysis and gasification of biomass, through purification and composition modulation, high quality synthetic gas can be obtained. It can be used as an ideal fuel for power generation.
The composition and content of biomass gas are different with different gasification methods and raw materials. The purified biomass gas is consisted of CO (content of 15.5%), H2 (6.7%), CH4 (6.2%), N2 (54%), CO2 (15.3%), O2 (1%), and CnHm(1.3%), whose combustible gases include H2, CO and a small amount of low molecular carbon hydrogen gas, and else of which are such as N2, CO2 and H2O that cannot be burned.
Gas requirement of Biomass Gas：● Gas temperature ≤ 40 ℃. ● Gas pressure 2.5～10 kPa. ● Pressure change rate ≤ 1 kPa/min . ● Calorific value ≥ 4.0 MJ/Nm³, moisture content ≤ 40 g/Nm³, no free water. ● Impurity content ≤ 30 mg/Nm³. ● Impurity size ≤ 5 μm. ● Tar content ≤ 50 mg/Nm³. ● H2S ≤ 50 mg/Nm³. ● Total sulfur content ≤ 100 mg/Nm³. ● NH3 ≤ 20 mg/Nm³. ● Cl ≤ 50 mg/Nm³. ● H2 ≤ 50%. ● O2 ≤ 1%.