ABSTRACT
This chapter addresses the design of a biomass gasifier, particularly a downdraft gasifier, including the basic calculations and specific sizing reported in the literature. Biomass-derived synthesis gas has attracted much attention in recent years because of its versatility and greenhouse gas neutrality. It plays an important role in replacing fossil fuels in terms of utilizing the existing downstream technologies with some modifications, such as replacing the diesel and gasoline fuels used in internal combustion engines and gas turbines. A downdraft gasifier uses concurrent flows of fuel and air streams. A downdraft gasifier can be operated by either pressurized or suction operations, with suction gasifiers being more practical because they clean up the gas train. Imbert-type downdraft gasifier was designed by an inventor named Imbert. It is characterized by a constricted hearth or throat at the lower half of the gasifier. Tar reduction and gasifier efficiency improvement are key factors in developing the gasifier design.
