Value Chain Analysis of Biocarbon Utilisation in Residential Pellet Stoves

Abstract

Biocarbon production is a thermochemical conversion process, which transfers biomass into solid fuels characterized with superior handling, grinding and combustion properties. Biocarbon can be potentially utilized as a high quality fuel in small-scale heating applications, as charcoal, powder, briquettes or pellets. However, there are only few studies on the use of biocarbon in residential stoves. Charcoal based modern residential stoves can achieve high thermal efficiency and low emissions. In this study, the main objectives were to assess the energy efficiency of the whole value chain for utilization of carbonized wood for small-scale biocarbon pellet based stoves and to evaluate the overall heat production cost of the whole value chain by a techno-economic approach, under Norwegian conditions. The carbonization temperature did not affect the stove thermal efficiency significantly. However, at higher carbonization temperatures higher biocarbon pellet production cost and higher overall heat production cost were obtained when standalone pellet production was considered. In the case of pellet and district heat coproduction, the pellet production cost was always lower than the corresponding one without district heat production.