A Study on Efficiency and Emissions From Improved Cook Stoves in Kenya

Abstract

This study investigated the thermal efficiency and emissions performance characteristics of various local and imported cook stoves. The low penetration and adoption of some of the efficient energy stoves has been attributed to lack of technical data to guide formulation and development of standards focusing on design and construction of the promising energy stoves, potential and current best-fit fuels and technology for testing and validating the energy stoves before adoption by institutions and households (Raman, 2014). It is on this basis that this project evaluated the efficiency and emissions from imported and local cook stoves used in Kenya by testing their thermal efficiencies and carbon monoxide and particulate matter emissions. Water boiling test (WBT) was conducted for firewood and charcoal cook stoves to determine their thermal efficiencies and Carbon Monoxide (CO) and Particulate Matter (PM2.5). Out of the 76 sample cook stoves tested, the imported stoves were found to have better thermal efficiencies compared to locally assembled cook stoves. On the other hand, the local stoves were found to have lower Carbon Monoxide (CO) and lower Particulate Matter (PM2.5) emissions compared to the imported cook stoves. The imported firewood cook stoves had thermal efficiencies ranging between 27-37% while the local cook stoves had thermal efficiencies ranging between 17-31%. Local cook stoves had Carbon Monoxide (CO) emissions ranging from 4-25ppm. This was lower than that of imported cook stoves that had emissions ranging from 13-47ppm. The imported firewood cook stoves had particulate matter (PM2.5) emissions ranging from 942-2985μg/m3 while the local cook stoves had emissions ranging from 221-1330μg/m3. For charcoal cook stoves the local stoves had thermal efficiencies ranging between 26-47% while the imported cook stoves had thermal efficiencies ranging from 30-46%. The local cook stoves had carbon monoxide (CO) emissions ranging from 35-96ppm while the imported cook stoves had the same emissions ranging from 49-67ppm. v The Three-Stone cook fires had low thermal efficiencies at 14% and high carbon monoxide emissions at 50ppm and particulate matter emissions was an average of 6265μg/m3. The thermal efficiencies for liquid fuels ranged between 33-49% while the carbon monoxide emissions ranged between 1-14ppm. The particulate matter emissions ranged between 39-95 μg/m3. From the results it was observed that the liquid fuels burned with less emissions compared to solid fuels. They had thermal efficiencies higher than solid fuels. Keywords: Thermal Efficiency, Biomass, Cook Stoves, Water Boiling Test, Carbon Monoxide, Particulate Matter and Emissions.