Browsing by Author "Awafo, Edward A."

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    Assessment of the potential of charred briquettes of sawdust, rice and coconut husks: Using water boiling and user acceptability tests
    (Scientific African, 2021-05-21) Akolgo, Gilbert Ayine; Awafo, Edward A.; Essandoh, Eric Osei
    Charred briquettes production is a sustainable way of producing cooking fuel from waste. Unsustainable harvesting of wood for fuel production has contributed immensely to the rapid deforestation in Ghana. This study determined the potential of charred briquettes of sawdust, rice and coconut husks in meeting cooking energy needs of households. In a further step, the acceptability of biomass users in the study to replace their current fuels with charred briquettes was established. The calorific value of the charred briquettes was found to be 24.69 MJ/kg. The highest combustion efficiency of briquettes was determined as 34.7% when a multi-feed gasifier stove (MFGS) was used. There were 14% and 80% reduction in particulate matter and carbon monoxide emissions, respectively when briquettes was used instead of charcoal in the MFGS. The analysis of the production cost of briquettes revealed that 1 kg of briquettes should be sold at Gh¢ 2.48 in order to make a 10% profit. The user acceptability survey indicated that about 40% of respondents are ready to patronize briquettes should it be sold at Gh¢ 2.48. This study established that briquette is a suitable replacement for wood and charcoal, if its full potential is harnessed and the energy utilization efficiency of biomass (sawdust, rice and coconut husts) briquettes is confirmed
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    Techno-economic studies of an industrial biogas plant to be implemented at Kumasi Abattoir in Ghana
    (Scientific African, 2021-01-20) Awafo, Edward A.; Amenorfe, Joshua
    Kumasi Abattoir is one of Ghana’s largest slaughterhouses. The Abattoir is a state-owned facility and its main activity is the slaughtering of cattle, goats, sheep and pigs. Production takes place 7 days per week, 8 hours per day. The Government of Ghana has planned to construct a pilot industrial biogas plant at the Abattoir to support them manage the waste generated, but to a large extent, support green industrial development and business promotion in Ghana. This study assesses the technical and financial aspects of the pilot biogas project with a focus on the technical solutions for biogas production from the waste, scenarios analyses for the gas usage and financial analysis of selected scenarios. Desk studies, studies of the abattoir slaughter operations, waste fractions, energy consumption patterns and projected energy demand as well as energy efficiency measures were all studied. Analysis of the financial data, namely; electricity bills of the abattoir, liquefied petroleum gas (LPG) and diesel consumption costs and abattoir staff wages were also done. The main wastes generated at the abattoir are solid waste and wastewater. The solid waste concerns mainly solid rumen content and dung, with a total quantity of about 8 tons per day. This waste is currently disposed off at a nearby landfill. The wastewater mainly consists of flushing water, blood and liquid rumen content, with a total quantity of some 170 tons per day. Wastewater is currently disposed in a stream that runs at the border of the abattoir premises, and this causes the most problems for the neighbouring communities. Total biogas potential of the combined waste components is estimated at 846 m3 per day. Energy demand at the abattoir concerns mainly electricity, LPG and diesel. Potential energy efficiency measures include repair of an existing power factor correction system, replacement of chillers, replacement of insulation of the cooling system, and replacement of the diesel backup generator. Full replacement of the abattoir energy and fuel consumption would require approximately 1448 m3 of biogas, which is 70% more than the total biogas potential of the abattoir. Even with energy efficiency measures, biogas demand would be in the order of 1250 m3/d. The abattoir uses LPG for singeing. Financial analyses show that singeing (substituting LPG) is financially the most attractive application for the biogas; the resulting gas value is 0.46 USD/m3. Using the gas for electricity production yields some 0.10–0.18 USD/kWh (depending on the scale); using it for diesel substitution yields some