A transition of a domestic boiler from coal to biomass – Emissions from combustion of raw and torrefied Palm Kernel shells (PKS)

Abstract This paper presents experimental results obtained during combustion of raw and torrefied PKS in a domestic scale boiler. The aim of the performed investigation was to assess if raw and torrefied PKS, without grinding and pelletizing, could be used in a domestic boiler, originally designed for coal. Introduction section of this paper presents a mini-review of the research performed so far on the torrefaction of Palm Kernel Shells (PKS) as well as on the combustion of torrefied biomass in small (mostly domestic) scale boilers. Section dedicated to materials and methods describes both the rig, where PKS was torrefied, as well as the domestic scale boiler used for combustion tests. Results presented in the paper consist of the operational parameters of the boiler and emissions, measured during combustion tests of both raw and torrefied PKS. Some operational issues, such as sintering and fouling of the heating surfaces of the boiler are highlighted. The extent of fouling was significantly smaller for the case of combustion of torrefied PKS, which should be a subject of a further investigation.