Chlorine release from co‐pyrolysis of corn straw and lignite in nitrogen and oxidative pyrolysis

Abstract

Elevated emissions of hydrogen chloride (HCl) from the combustion of biomass in utility boilers are a major issue because they can cause corrosion problems and deposit molten alkali chloride salts on boilers’ water tubes, resulting in further corrosion. Pyrolysis is a good pre‐treatment for solving this problem. This work conducted pyrolysis and co‐pyrolysis of pulverized corn straw and lignite coal in a horizontal muffle furnace, with compositions typical of power plant combustion effluents (5% O2, 15% CO2, 80% N2) at different temperatures. Cl compounds were monitored in fuel, flue gas, and solid production of pyrolysis. The co‐pyrolysis significantly affected Cl release from fuel. Cl release from corn straw into fuel gas was reduced during biomass co‐pyrolysis with lignite. Co‐pyrolysis had little influence on the release of organic Cl and KCl. Furthermore, at mod-erate‐temperature pyrolysis, O2 promoted HCl release, when compared with pyrolysis under a N2 atmosphere.