AIR POLLUTION ASPECTS OF BIOMASS ENERGY UTILIZATION

Abstract

Associated with conventional energy sources renewable energy sources are much advocated.Out of the renewable energy technologies biomass and biofuel represent perhaps the largestpotential commercial energy source. The interest in biomass energy generation over the years isattributed to the production surpluses in the agricultural sector and the reduced CO2 and S02emissions, which is important for combating the green house effect and acid rain with the use ofbiomass.

"Biofuels industry" consists of several unrelated industries such as the fuel ethanol industry andthe landfill methane-recovery industry, each of which is well established and whose biofuelshave different end-use applications. In terms of envi-cnmental aspects, each of these has specificadvantages and limitations. As most of the advantages offered by biomass energy generation areon air pollution aspects, this paper examines whether all of the different biofuel technologieshave this advantage.

Most stoves and boilers particularly those used in developing countries are not equipped with aircontrol devices and are not efficient enough to permit complete combustion resulting inconsiderable health impacts to the user due to the release of numerous toxic gases. In fact, someauthors claim that when compared with the combustion offossil fuels, the emission of pollutantsfrom wood combustion is higher. Gasification of biomass also results in similar emissions.Ethanol, derived from fermentation of biomass is a clean-burning fuel if completely combusted,because only CO2 and water are emitted. However, in automobiles not equipped with catalyticconverters aldehyde emissions is a concern.

Municipal waste which, is a freely available biomass energy source if burnt in an uncontrolledmanner to generate heat, release toxic gases and par.iculate matter directly into the atmosphere.Controlled incineration at extremely high temperatures reduces these effects to a certain extent.However, air pollution persists as the major concern for incinerator technologies and airpollution control mechanisms are deemed essential for incinerators.

On the other hand, biogas production from municipal solid waste and other biomass sources andmethane recovery from municipal solid waste landfills release minimum amounts of airpollutants into the atmosphere.

This paper emphasizes the dilemma in labelling all biomass energy conversion technologies asenvironment friendly and that proper conversion technologies and pollution control devices mustbe used to minimize air pollution.