The quantification of greenhouse gases emissions from charcoal making activities and biomass burning cook stoves in developing countries: the case of Dar es Salaam, Tanzania

Abstract

The Assessment of Greenhouse Gases (GHG) from charcoal making activities and from charcoal, fuel wood and sawdust usage in Dar es Salaam city has been carried out. Gaseous pollutants CO, CO₂ and NO_x were measured using combustion analyzer CA-6200-CALc, while the velocity of polluted air was measured using a Velometer model ALNOR – 6000 –P. Questionnaires were administered to establish the fuel types used in different parts of Dar-es-Salaam City and the amount of fuel used per household. The Dar-es-Salaam City annual fuel consumption in kilotons (kt) has been estimated to be 139.68, 90.03, and 0.65 for charcoal, fuel wood, and sawdust correspondingly. The specific Emission factors (Ef) for CO₂, CO, and NO_x from charcoal, sawdust and fuel wood combustion were estimated in terms of both mass ratios and the amount of energy produced by the fuels. The Global Warming Commitment (GWC) of emissions from charcoal making activities and the use of the three fuel types in cooking have been estimated. The annual emissions of these gases in kilotons for the three fuels have been established. The emission factor based on energy released Efl in g-pollutants per KJ delivered by charcoal, saw dust, and fuel wood have been evaluated. The annual non-renewable global warming commitment (GWC) in equivalent kilotons of CO₂ were 1231.7 kt for charcoal, 1.4 kt for sawdust, 947.8 kt for fuel wood and 924.3 kt for charcoal making process. The annual non- renewable GWC in g-C as CO₂ per KJ delivered were 0.33, 0.79 and 0.11 for charcoal, fuel wood and sawdust in that order. Since charcoal had the highest GWC and the highest emissions of CO, it is considered the most contributor to global warming. This study recommends that the community should practice renewable harvesting of biomass so as to reduce the GWC from domestic fuels production and usage. Furthermore, the study recommends the use of properly designed stoves that will allow good air-fuel mixing and hence reduce emissions of products of incomplete combustions such as CO.