Assessment of Biomass Gasification: A Review of Basic Design Considerations

The essence of a gasification process is the conversion of solid carbon fuels into carbon monoxide and hydrogen mainly; by a complex thermo chemical process. Other products of the biomass conversion are gases which contain carbon dioxide, methane and nitrogen. The history of gasification dates back to the seventeenth century. Since the conception of the idea, gasification has passed through several phases of development. Authors across the world have conducted studies and researches on the design of gasifiers, performed modeling and simulation of biomass gasification. Various energy crisis and technological advancements have influenced the development of gasifiers for different fuels, configurations and applications other than wood and charcoal. The economic success of a biomass gasification plant depend on the understanding of the basic principles involved, knowledge of the steps to be taken while designing and the hitch free running of the plant. This paper reviews the fundamentals and basic formulae adopted while designing a biomass gasifier for energy production. Aspects such as: the elemental composition, ash content and energy density of the biomass were considered. The gasification process physical and chemical characteristics were reviewed too. Design considerations were reviewed with special emphasis on the reactor and blower such as: the type of reactor, cross-sectional area of the reactor, height of the reactor, thickness of the fuel bed, fan airflow and pressure, insulation for the reactor, location of firing the fuel, size and location of the char chamber, intended uses as well as safety considerations