Thermal efficiency of charcoal fired cookstoves in Ghana

Gloria Boafo-Mensah*, Kofi Ampomah-Benefo,  Maame Adwoa Bentumah Animpong, William Owusu Oduro, Ebenezer Neequaye Kotey, Kisiedu Akufo-Kumi and Gabriel Nii Laryea

Council for Scientific and Industrial Research, Institute of Industrial Research (CSIR-IIR), P. O. Box LG 576, Legon, Ghana

*Corresponding Author’s E-mail: gloriasante80@yahoo.com

Accepted 12 March 2013

Abstract

Biomass is a predominant feedstock for household cooking and heating in developing countries. Charcoal fired cookstoves can be considered an important intermediary for sustainable energy consumption as well as promoting healthy kitchen environments due to the significant reduction in the emission of indoor pollutants associated with smoke in wood fires. The performance indicators (Boiling time, Burning rate, Thermal efficiency and specific fuel consumption) of three popular charcoal fired cookstoves in Ghana (Gyapa, Ahinbenso and the Traditional coalpot) were assessed using the water boiling test (WBT) version 4.1.2 method with Kopie von WBT data calculation sheet 4.1.2 software to generate the performance indicators for five (5) replicate measurements. Charcoal from neem was used as fuel. The specific fuel consumption (MJmin^-1L^-1) at low power was determined to be 0.018±0.004 MJmin^-1L^-1 for Ahinbenso, 0.022±0.004 MJmin^-1L^-1 for Gyapa and 0.023±0.010 MJmin^-1L^-1 for the Traditional cookstove. These compared favorably with the Global Alliance for Clean Cookstoves’ benchmark value of 0.017 MJmin^-1L^-1. The targeted 45% for thermal efficiency was however, not met by any of the stoves at both high and low power operations. Ahinbenso (31.3±1.7% and 28.3±1.7%) had the highest efficiency at high power (cold start and hot start respectively) whilst Gyapa (35.3± 6.11%) had the highest efficiency at low power operations. From the assessment of the performance indicators Gyapa (1.5) was most efficient, followed by Ahinbenso (1.75) and the Traditional Stove (2.75). The burning rate of bamboo charcoal was also determined to be twice that of neem charcoal for similar dimensions of the charcoal.

Keywords: Charcoal fired cookstoves, Thermal efficiency, Water boiling test