Combustion behavior and pollutant emission characteristics of polymers and biomass in a bubbling fluidized bed reactor

Abstract

The paper presents the results of combustion of polymers and biomass in a bubbling fluidized bed reactor. It was determined that 850 °C is the minimum temperature at which the combustion process should be carried out. To simulate bubbles’ chemical composition in a hot fluidized bed, TG analysis coupled with FTIR analysis was performed under pyrolysis conditions. Recorded IR spectra were deconvoluted to determine the composition of fuel bubbles in the fluidized bed. It was shown that a uniform access to oxygen is necessary for the combustion of complex gas mixtures. The combustion processes were conducted in two ways. The materials were burned autothermally and in the process of co-combustion together with auxiliary fuel. Inorganic and organic substances were identified in the flue gases. The latter contained mainly short-chain aliphatic hydrocarbons. The detailed emission characteristics of gaseous products during the combustion of the polymeric materials in the bubbling fluidized bed was investigated. The increase of the combustion temperature intensifies the oxidation of the fuel-bound nitrogen and the NO conversion to N2 on the surface of the char. The obtained values of emission coefficients for different polymers will be useful in the choice of appropriate method of combustion of alternative fuels.