Combustors for agricultural waste fuels are predominantly
grate-fired systems, suspension burners or fluidized
bed systems. All these types of combustors are being used in
industry. Grate-fired combustors were the most versatile
units in the mid-1980s [17] but the fluidized bed systems
have become serious competitors in the last decade. Because
of the heat recovery systems being largely identical to those
associated with fossil fuels, only the combustors are
reviewed below.