Purpose: Recent developments in the electricity generation sector of Nigeria necessitated the re-assessment of its contribution to air emission level in the country as information provided by previous inventory is nearly out-of-date. The purpose of this paper is to quantify the carbon dioxide (CO₂) emissions generated from existing thermal power plants in the country.Design/methodology/approach: Thermal power plants in Nigeria and their installed capacities were identified, and estimation of CO₂emission from each of the plants was carried out using the emission factor method. In addition to the direct emissions generated through the combustion operation of the power plants, indirect emissions resulting from upstream activities such as extraction, production, and transportation of fuels consumed by the thermal power plant was determined using the same method.Findings: In total, 40 thermal power plants are currently operational in Nigeria. Additional 18 thermal plants are at different stages of completion. The operational thermal plants have average generation output of 40 percent of their installed capacity and produce 87.3 million metric tonne (mmt)/annum CO₂emissions. In total, 66.9 percent of the estimated emissions are direct emissions, i.e. fuel combustion emissions; the rest are indirect emissions. Additional 67.9 mmt was estimated as expected overall emissions from the thermal power plants under construction. Considering the global warming potential of CO₂, proactive measures must be taken to regulate its emissions from the country’s thermal power plants.Originality/value: This paper bridged the information gap existing in the emission inventory from the Nigeria electricity sector by providing up-to-date data on the contribution of the sector to greenhouse gas emission level in the country.

In order to examine the gaseous pollutants generated by artisanal refined gasoline and the contribution to air pollution associated with such combustion in the Niger-Delta region of Nigeria, this study collected a sample of indigenously refined gasoline product each from thirty (30) different randomly selected artisanal camps in the Niger-Delta region and subjected all the collected samples to combustion. Fifty (50) ml of each gasoline sample was combusted at controlled conditions, and the concentrations of gaseous emissions from the process were measured using a combustion emission analyser. Pollutants characterised by the Department of Petroleum Resources which include sulphur dioxide (SO₂), carbon monoxide (CO), oxides of nitrogen (NO_x), hydrocarbons (HC) and carbon dioxide (CO₂) were characterised. The average concentrations of the emissions were 211.50 mg/m³, 7.18 mg/m³, 17.51 mg/m³, 3011.33 mg/m³, and 500.39 mg/m³ for CO, NO_x, SO₂, CO₂, and HC respectively. The concentrations of SO₂ and NO_x measured were within the Federal Environmental Protection Agency (FEPA) set limits for combustion emissions from stationary sources but breached World Health Organization (WHO), World Bank and Environmental Guidelines and Standard for Petroleum Industry in Nigeria (EGASPIN) set limits. The concentrations of CO and HC exceeded FEPA, WHO, World Bank and EGASPIN set limits and hazardous on Air Quality Index (AQI) classification. Elevated concentrations of CO and HC in the atmosphere pose a major threat to ambient air quality and human health, especially in locations where artisanal-refined fuel is predominantly utilised. Associated risks include poor visibility, occurrence of acid rain, blood poisoning and cancer-related diseases. In addition to these effects are the worsening global warming crises associated with CO₂ emission, a major product of fossil fuel combustion.

The profitability of a cement plant depends largely on the efficient operation of the blending stage, therefore, there is a need to control the process at the blending stage in order to maintain the chemical composition of the raw mix near or at the desired value with minimum variance despite...

Fuel produced by artisanal refiners using indigenous technology continues to find its way into the Nigerian oil market despite the proscription of such refining activities in the Niger Delta, owing largely to the illegal means by which the artisans procure crude oil and also related to doubt about the quality of products coming from their covertly operated facilities. Therefore, in this study, gasoline samples were collected across 30 artisanal refiner camps, and their properties were examined to ascertain their conformity with the minimum requirements of the Standard Organisation of Nigeria (SON) and the American Society for Testing and Materials (ASTM) on fuel quality. Standard test protocols on fuel characterisation published by ASTM were utilised for the analysis. The specific gravity of the samples determined at 15℃ ranged from 0.796 – 0.807 g/cm3. The Antiknock Index ranged between 78.75% and 82.45% for the fuel, and the initial and final boiling points of the samples were about 32 – 39.1℃ and 226.3 – 238.7℃, respectively. The distillation profiles of most of the fuel samples were satisfactory. Experimental data gathered from this study indicate that notwithstanding the artisanal refiners’ shortcomings, they are still able to produce fuels that meet some minimum local and international requirements

Co‐pyrolysis of plastics is a simultaneous thermochemical conversion of a mixture of plastics to value‐added products. This study quantified air emissions from co‐pyrolysis of low‐density polyethylene (LDPE), polystyrene (PS), and polyethylene terephthalate (PET) at varying mixture compositions. The emissions were modelled using simplex lattice design (SLD) and artificial neural network (ANN). A mixture containing 100% LDPE, 0% PS, and 0% PET emits the highest quantities of hydrocarbons (HCs), carbon monoxide (CO), and nitrogen oxide (NO) with values of 7980.46, 1793.67, and 41.41 mg/m ³ , respectively, with no indication of NO ₂ , SO ₂ , H ₂ S, or CO ₂ emissions. Meanwhile, mixture containing 0% LDPE, 0% PS, and 100% PET emits the lowest quantities of HCs and CO, with values of 200.47 and 44.69 mg/m ³ , respectively. Mixtures containing 17% LDPE, 17% PS, and 66% PET; 17% LDPE, 66% PS, and 17% PET; and 0% LDPE, 50% PS, and 50% PET showed no emissions of NO. The study generated predictive models for the emissions of HC, CO, and NO and statistically established that using SLD, a special quartic model best describes HC and CO emissions, while a quadratic model best describes NO emissions. Although ANN shows good modelling of the emissions, the coefficients of estimate were lower than that of simplex lattice design.