Emission Profiles of Major Gaseous Pollutants from Unmodified and Paper and Starch Modified Briquettes Made from Agro-Derived Wastes

Abstract

Energy use in rural areas in Nigeria is largely dependent on firewood and other biomass sources. Biomass fuel is domestically used daily for cooking and lighting. Continuous use of this energy resource has negative impact on both the environment and human health, especially on users. Many pulmonary problems have been associated with continuous exposure to smoke arising from burning of these materials. The use of briquetting is a more sustainable alternative to raw burning of biomass as briquettes burn with little or no smoke. However, there is scarcity of data on the emission profiles of major gaseous pollutants arising from many biomass briquettes. This study therefore, investigated the emission profiles of carbon monoxide (CO), carbon dioxide (CO2), sulphur dioxide (SO2) nitrogen dioxide (NO2) and particulate matter (PM2.5) from the combustion of unmodified as well as starch and paper modified briquettes made from four commonly used agro-based wastes namely, wood (control), sawdust (SD), rice husk (RH), coconut shell (CS) and corncob (CC). The gaseous pollutants emitted from combusting 0.5kg of each briquette were measured using appropriate devices. The mean concentrations (ppm) of gaseous emissions and particulates from all briquettes ranged as follows: CO: 35.4 - 79.0, CO2: 500 - 852, NO2: 0.09-0.50 and SO2: bdl - 2.13. All briquettes indicated higher PM2.5 concentrations than control (5190 μg/m3) except SD-paper modified briquettes (3305 μg/m3). CC-paper modified briquettes and RH-starch modified briquettes showed highest concentrations of 21003μg/m3 and 16362μg/m3, respectively. CS-paper modified briquettes emitted the least concentration of PM2.5. This suggests it could be considered as the safest and most ecofriendly of the briquette types.