Chlorine Release from Co-Pyrolysis of Corn Straw and Lignite in Nitrogen and Oxidative Pyrolysis

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 moderate-temperature pyrolysis, O2 promoted HCl release, when compared with pyrolysis under a N2 atmosphere.

On Line Dirt Based Soot Blowing System using Fuzzy Logic for Utility Boilers

Soot is a byproduct of burning coal in thermal power plants. The soot accumulates in the boilers tubes. It gradually spoils the heating surface which reduces the heating efficiency. Hence it has to be cleaned. This process is called soot blowing. The existing soot blower control system in the old boiler is composed of relays, timers and contactors which are not efficient. In order to improve the efficiency, an intelligent system is proposed which estimates the dirt in the boiler tube periodically and initiates soot blowing process to improve the thermal efficiency. Simulation results demonstrate the superiority of the proposed scheme when compared to relay logics.