Energy Conversion and Management, Vol.87, 1162-1169, 2014
Physico-chemical characteristics of eight different biomass fuels and comparison of combustion and emission results in a small scale multi-fuel boiler
This study describes the results from the investigation of 7 different biomass fuel types produced on a farm, and a commercial grade wood pellet, for their physical, chemical, thermo-gravimetric and combustion properties. Three types of short rotation coppice (SRC) willow, two species of conifers, forest residues (brash), commercially produced wood-pellets and a chop harvested energy grass crop Miscanthus giganteus spp., (elephant grass) were investigated. Significant differences (p < 0.05) were found in most of the raw fuel parameters examined using particle distribution, Thermogravimetric, Ultimate and Proximate analysis. Combustion tests in a 120 kW multi-fuel boiler revealed differences, some significant, in the maximum output, energy conversion efficiency, gaseous emission profiles and ash residues produced from the fuels. It was concluded that some of the combustion results could be directly correlated with the inherent properties of the different fuels. Ash production and gaseous emissions were the aspects of performance that were clearly and significantly different though effects on energy outputs were more varied and less consistent. The standard wood pellet fuel returned the best overall performance and miscanthus produced the largest amount of total ash and clinker after combustion in the boiler. (C) 2014 Elsevier Ltd. All rights reserved.