EVALUATION OF THE IMPACT OF CO-COMBUSTION ON ASH UTILIZATION, FOULING, AND CORROSION BY LARGE SCALE CO-FIRING OF SRF IN A CFB BOILER

摘要

An important aspect of co-combustion is the impact of the secondary fuels inorganic matter on the quality of the residues. Co-combustion should not diminish the quality of residues, or aggravate some of the fouling and corrosion events associated with combustion processes. The chemical composition of secondary fuels and their ash forming elements influence ash utilization or ash disposal options as well as problematic deposit formation. This work performed for the referenced demonstration activity focused on the one hand on the detailed analyses of long and short term measurements including fly ash samples from superheater and ESP, whilst on the other hand on the detailed characterisation of the fuel input streams. The innovation in this paper is the evaluation of co-firing lignite with a solid recovered fuel (SRF) from two positions into a boiler along with sewage sludge at another position. This provides information on the quality of the fly ash obtained and on the tendency of the materials to deposit from a co-combustion scheme that is not regularly practiced, which may assist in the goal of increasing the share of renewable sources of energy used in coal fired and other industrial furnaces.