The reduction of emissions from the combustion of biomass for domestic heating applications

While biofuels are an attractive proposition as an alternative to fossil fuels for heating fuel purposes, both for the reason of their neutral effect on atmospheric CO2 levels and for their relative availability in many areas of Europe. there remains the problem that their use will result in the emission of other pollutants such as volatile organic compounds, tar, soot and carbon monoxide. Each of these pollutants represent unburnt gases that escape an appliance as a result of incomplete combustion. For fuels intended for use in domestic heating appliances, the reduction of these emissions must be affordable and robust. This paper describes research carried out by the authors into two potential methods for emissions reduction. The first concerns improved combustor design, whereby the pollutants are consumed in a secondary combustion chamber within the appliance. The second concerns the use of a catalytic flue gas cleaning system of a type suitable for domestic heating appliances. The results presented show good reductions of emissions in both cases. Both options appear to be both technically and economically viable and have an excellent potential for exploitation. Appliances with these technologies can be expected to reach the market place in the short term.