FLUE GAS CHEMISTRY OF NO AND KCL DURING INJECTION OF AMMONIUM SULPHATE - AN EXPERIMENTAL INVESTIGATION IN A BIOMASS FIRED BFB BOILER

摘要

Sulphate containing additives, such as ammonium sulphate (AS), are used for sulphation of KCl duringrnbiomass combustion. Another aspect with injection of AS is that a significant NOx reduction is achieved but it mayrnalso have an impact on other flue gas components. Operating parameters such as the air excess ratio and the presencernof combustibles could also have an effect on the flue gas chemistry involving NO and KCl. This paper is based onrnresults obtained from a measurement campaign during combustion of demolition wood in a 63 MWth BubblingrnFluidised Bed (BFB) boiler. Ammonium sulphate was injected for simultaneous reduction of NO and KCl at twornpositions in the boiler i.e. in the upper part of the combustion chamber and in the empty pass. The impact of AS onrnthe flue gas chemistry was investigated at different operating conditions. Several measurement tools including, IACMrn(on-line measurements of gaseous alkali chlorides) and gas analysis were applied. The position for injection of AS asrnwell as the operating parameters had a great impact on the flue gas chemistry for NO and KCl.