Role of Pulverized Coal Ash against Agglomeration, Fouling, and Corrosion in Circulating Fluidized-Bed Boilers Firing Challenging Biomass

Abstract

The rising use of agricultural residues (agros) aggravates some of the well-known challenges of biomass combustion in plants, such as agglomeration, fouling, and corrosion (AFC). Several countermeasures have been devised to contain AFC problems in biomass plants, some of which are broadly effective but somewhat costly, while others may be ineffective or harmful if deployed on unsuitable agros. The use of additives often falls in the first category, having broad applicability, high efficiency, high reliability, but high procurement costs. However, ash discarded from combustion plants firing coal can be a convenient exception, because its cost is negligible or even negative. Ash coming from pulverized fuel plants firing coal (PC-ash) was tested in a bench-scale reactor and a 1 MWth circulating fluidized-bed (CFB) pilot to assess its beneficial effects against agglomeration when firing the most demanding agro biomass. PC-ash was procured from different plants based on different PC technologies and firing div...