The application of furniture manufacturing residues in wood pellets: Assessment of the combustion efficiency

Abstract

The European Union aims to fulfill 20% of the primary energy consumption with renewable energy sources, by 2020. Biomass has a great potential for domestic and industrial heating applications and these are amongst the most promising uses for biomass as they combine high efficiency and ease of use. Pellets are a good method for biomass distribution due to its quality standards and energy density which make them attractive to distribution and handling. In addition to the traditional use of sawdust as a raw material, there has been a growing interest in the incorporation of residues from industry processing such as the furniture sector. This paper reports the application of pellets made of residues from the furniture industry as a fuel source in domestic heating applications. Pellets were characterized according to their chemical and physical composition. They were subsequently burned in an automatic boiler rated at 15 kW. A probe in the exhaust chimney was used to continuously analyze the flue gases. In addition, the ashes chemical composition was also analyzed. The results show that these pellets have a good thermal efficiency in domestic boilers, releasing however large emissions of NOx, originated from the high concentration of nitrogen in its chemical composition. The ash analysis confirms the slagging and fouling prediction, and these problems were verified in the grate, chamber combustion and heat exchanger. In conclusion, these pellets can be explored for industrial applications, with better control of its chemical composition. For domestic boilers however, these can cause serious ash problems.