Energy and exergy evaluation of product gas from coal/biomass blend gasification in a dual circulating fluidized bed reactor

Abstract

Product gas from coal/biomass blend gasification in a dual circulating fluidized bed reactor is studied from energy and exergy aspects. The energy and exergy values of product gases are analyzed, the effects of reactor temperature, steam/fuel ratio and biomass ratio are reported. The energy and exergy values of product gases from coal gasification and biomass gasification increase monotonously when the reactor temperature increases, whereas vary slightly and irregularly when the steam/fuel ratio increases. As the biomass ratio increases from 0 to 1, the energy and exergy values increase first and then decline. On the whole, the exergy values are lower than the corresponding energy values, and keep pace with the energy values. When the reactor temperature and steam/fuel ratio are the same, product gases from biomass gasification show higher energy and exergy values than those from coal gasification. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2012.