Use of the Steam as Gasifying Agent in Fluidized Bed Gasifier

Biomass energy is the oldest energy source used by humans. Biomass has evolved as one of the most promising sources of fuel for the future1. This has spurred the growth of research and development efforts in both federal and private sectors. This impetus is motivated by several factors; dwindling fossil fuels and thus an increased need of energy security, environmental concerns and promotion of socioeconomic benefits to rural areas. Another important fact is the somewhat uniformly distributed nature of biomass worldwide which means it is available locally and is helpful in reducing dependence on fossil fuel1. Biomass is potentially an attractive feedstock for producing transportation fuels as its use contributes little or no net carbon dioxide to the atmosphere2. Renewable biomass resources include short-rotation woody crops, herbaceous biomass, and agricultural residues. Biomass is available for exploitation for conversion to bio-fuels as well as for power generation applications. There are various conversion technologies that can convert biomass resources into power, heat, and fuels for potential use in UEMOA countries3. In view of this a variety of processes exists for biomass conversions. The most used of these are thermal conversions, bio-chemical and chemical conversions and direct combustion. The thermal conversion processes consist of fast and slow pyrolysis and biomass gasification. Biomass gasification is considered as one of the most promising routes for syngas or combined heat and power production because of the potential for higher efficiency cycles Gasification is a process for converting carbonaceous materials into a combustible or synthetic gas (H2, CO, CO2, CH4) 4. In general, gasification involves the reaction of carbon with air, oxygen, steam, carbon dioxide, or a mixture of these gases at 700 °C or higher to produce a gaseous product that can be used to provide electric power and heat or as a raw material for the synthesis of chemicals, liquid fuels, or other gaseous fuels such as hydrogen1.