Techno-economic analysis of electricity and heat production by co-gasification of coal, biomass and waste tyre in South Africa

Abstract: South Africa has large deposit of coal that supports about 95 % of electric power generation in the country. The fuel is fast depleting, though the current reserve may serve for the next century. However, the emissions from the coal projects huge threat to the environment. Similarly, the country has abundant solid wastes that can be co-gasified with coal to H2 enriched syngas for clean energy production. A 5 MW combined heat and power plant was studied using different coal-to-solid waste ratios including 1:1, 3:2, and 4:1 with feedstocks costing, and without feedstock costing. The lower heating value of the fuels, determined from a model equation was applied to estimate the annual feedstocks requirement and the feed rate..

Analysis of clean coal technology in Nigeria for energy generation

Abstract: An analysis of clean coal technologies for the recovery of energy from Nigerian coals was carried out. The coal mines studied are Onyeama, Ogwashi, Ezimo, Inyi, Amasiodo, Okaba, Lafia-Obi, Owukpa Owukpa, Ogboyoga and Okpara. The estimated reserves of the ten coal deposit amount to 2.1 Gt, which is about 84 % of the total coal reserves of the country 2.5 Gt of coal Nigeria. The key clean coal technologies studied are Ultra-Supercritical Combustion (USC), Supercritical-Fluidised Bed Combustion (FBC), Integrated Gasification Combined Cycle (IGCC) and Coal bed Methane (CBM) and the results were compared with conventional subcritical pulverised fuel combustion (PF). The total potential energy recovery from these technologies are: PF 5800 TWh, FBC 7250 TWh, IGCC 7618 TWh, and USC 8519 TWh. This indicates an increase of about 31% in the total electricity generation if USC technology is used instead of the conventional sub-critical PF technology..

Prediction of emissions and profits from a biomass, tyre, and coal fired co-gasification CHP plant using artificial neural network: Nigerian and South African perspectives

Abstract : The local sourcing of feedstock for energy generation will reduce costs in the power plant, and promote energy sustainability. Most times, potential investors in this area show interest about understanding the profitability of the business because, the information boosts the confidence of the investors in the project, and gives them the opportunity of making a short and long term plans about the business. The emissions arising from the energy plant is an important aspect of the venture that requires proper attention, otherwise the costs of emission control may consume a greater part of the profit, hence rendering the business un-viable. Nigeria and South Africa (SA) have abundant biomass (e.g. corn cob, sugarcane bagasse, & pine saw dust) coal and tyre that can be used as fuel in an energy plant. A 10 MW CHP plant was fired with coal and biomass, and tyre obtained from Nigeria and South Africa (SA) respectively, at ratios of 1:1, 3:2, and 4:1 to study the emissions and profits in the plant. An empirical model was employed to estimate the annual amount of feedstock and feed rate required for the plant, after which, an artificial neural network (ANN); LevenbergMarquardt algorithm was used to predict the emissions and profits in the plant for 20-year- investment period with feedstock costing (WFC) and without feedstock costing (WOFC). The profit obtained from the South African feedstock, WFC and WOFC; produced about 45.18 % and 36.83 % ($3,900,000.07 and$3,179,184.49) higher profits than the Nigerian feedstock, but the CO, NOX, & SO2 emissions from Nigerian feedstock were lower than that of SA. The findings from this study could be used as a platform for decision making by potential investors and stake-holders, and further research and development in the area

Energy research in Nigeria : a bibliometric analysis

Abstract: The scant supply of energy in Nigeria in relation to its energy demand has triggered interest in the scientific investigation of various energy research. This study reports on the bibliometric analysis of energy publications from Nigerian researchers from 1974 to 2019 (45 years) from the Elsevier Scopus database. The analysis includes publication types, languages of publication, institutions of authors and collaborators. Based on the analysis, the number of publications has increased in the 45 years period. With significant changes being from the period 2006–2015 by an average of 113 publications per year, to an average of 326 publications per year from 2016 to 2019. The contributions of institutional energy publications by region showed that the South-Western States region had the highest number of publications. A global map showing energy collaboration at international level Nigerian-authors mainly co-author energy publications with South Africa, Malaysia, the United States and the United Kingdom institutions. The publications are mainly in solar energy, wind energy and biomass energy and surprisely less in gas and hydro energy which are the main sources of electricity generation in Nigeria

Effect of different pre-treatment methods on gasification properties of grass biomass

The effect of different pre-treatments method on the gasification efficiency of grass biomass have not previously been evaluated. In this study, the effect of three different pre-treatment methods on gasification properties of grass biomass was investigated under CO2 conditions. The pre-treatment methods were dry torrefaction, wet torrefaction, and leaching (chemical). The results obtained showed that the heating values increased by 2,77% in the leached grass, 8,3% in the dry torrefied grass and 13,5% in the wet torrefied grass. However, the wet torrefaction had the highest reactivity index of 0,25 followed by dry torrefaction 0,182, then leaching 0,156. The effect of the different pre-treatment on activation energy showed that the activation energy of raw grass biomass was reduced from 161,7 kJ/mol to 141.5 kJ/mol for leached grass, 124.3 kJ/mol for dry torrefied and 86.97 kJ/mol for wet torrefied grass. These results show that wet torrefaction can improve gasification properties significantly when compared to dry torrefaction and leaching. The pore structure and pore volume effect of treated biomass was likely the predominant reason for the better char reactivity and conversion during gasification of wet torrefied sample. The research supplied an insight into the effect of different pre-treatment methods on grass biomass gasification