COMBUSTION OF AGRICULTURAL BIOMASS - ISSUES AND SOLUTIONS

Biomass is one of the oldest energy source known to mankind. Progress made so far in understanding of a rather complex direct combustion process allowed for a constant technology development. Increasingly stringent environmental requirements of the EU, especially in terms of the pollutant emissions, require development of new design solutions of the combustion system for residential hot water boilers fuelled by some form of solid biomass. The emissions are becoming even greater problem if, various residues from agricultural production are used instead of a wooden biomass, as they are becoming more desirable fuel due to their lower cost. In this paper, various issues related to the combustion of agricultural biomass are discussed. Attention is given to the problems associated with high volatile matter contents, presence of nitrogen, sulphur, chlorine and low ash melting temperatures. At the end, novel design modifications of a conventional residential biomass combustion system are proposed, as the well-known methodologies for combustion and emissions control applied in industrial-scale boilers are in most cases not suitable for small-scale units.