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Laboratory simulations of the spill behaviors of three different Nigerian crude oil samples over three media (fresh water, sea water and soil) were carried out with a view to determining the effect of crude oil spillage on emission of fine (PM2.5) and inhalable particulates fractions (PM10). The spillage experiments were carried out in an environmental test box fitted with equipment to regulate the micro climatic conditions (temperature and Relative humidity). The maximum concentrations of PM2.5 were 711, 689 and 680 µgm−3 while those of PM10 were 972, 946 and 940 µgm−3 for sample A, B and C respectively. These peak concentrations were obtained for spill conditions corresponding to fresh water at 45 °C and 49% relative humidity. The least concentrations of PM2.5 and PM10 emitted across all samples were 63 µgm−3 and 256 µgm−3 respectively and these corresponded to spillage over sea water at 15 °C and 80% relative humidity. These concentrations clearly exceeded the short time averaging period (24 h) standards set for PM2.5 and PM10 by the United States Environmental Protection Agency. Incessant crude oil spillages in the Nigerian oil fields are therefore predicted to cause degradation of air quality within a short duration from the spill.

Huge quantities of harvest wastes that are generated from agricultural practices at every farming season in Nigeria are not put into significant use. As an attempt towards adopting these abundant by-products as bioenergy resources for electricity generation, yearly quantities of both cocoa and kolanut harvest residues were estimated in this study. Hygroscopic natures and moisture contents of the two, and their blends, were also analyzed and compared. It was estimated that approximately 681,000 tons and 90,000 tons of cocoa and kolanut husks respectively, are produced in the country annually. While the proximate analyses showed that the sample made of 100% cocoa waste had the least volatile matter and moisture contents in addition to having highest fixed ash and fixed carbon contents, the reverse was the case with the sample made of 100% kolanut waste composition. From the ultimate analyses, however, the latter appears to possess the best characteristic (highest hydrogen and least oxygen contents), but its highest nitrogen content is a pointer to its exhibition of poor thermal property. The gross calorific contents of the samples were, therefore employed for definitive determination of their thermoelectric potentials and these gave higher heating values of 15.19 MJ/kg and 13.87 MJ/kg respectively, with the blends having their values within this range in proportionality to the mass percentage of kolanut husk in the blends. In addition to the two wastes exhibiting good energy characteristics, the study concludes that their blending offers benefit of reduction in ash content. At the optimal blend of equal composition of the two materials (50%CPH/50%KPH), it was estimated that 29,000 MW of electricity is accruable from the wastes., Highlights • Cocoa and kolanut harvest wastes of 681,000 and 90,000 tons respectively, are generated in Nigeria annually. • HHVs of the two agro-residues are 15.19 and 13.87 MJ/kg respectively, with their blends having values within this range. • The optimal blend composition of the two agro-residues has electric power generation potential estimated at 29,000 MW., Agro-wastes, biofuel materials, cocoa pod husk, kolanut pod husk, biomass blends, electrification.

A highly-active catalyst for biodiesel production was developed from calcite rock by calcination at different temperatures of 800°C (CCT800) and 900°C (CCT900). The calcination was to transform the...

This study presents a review of sources and atmospheric levels of anthropogenic air emissions in Nigeria with a view to reviewing the existence or otherwise of national coordination aimed at mitigating the continued increase. According to individual researcher's reports, the atmospheric loading of anthropogenic air pollutants is currently on an alarming increase in Nigeria. Greater concerns are premised on the inadequacy existing emission inventories, continuous assessment, political will and development of policy plans for effective mitigation of these pollutants. The identified key drivers of these emissions include gas flaring, petroleum product refining, thermal plants for electricity generation, transportation, manufacturing sector, land use changes, proliferation of small and medium enterprises, medical wastes incineration, municipal waste disposal, domestic cooking, bush burning and agricultural activities such as land cultivation and animal rearing. Having identified the key sources of anthropogenic air emissions and established the rise in their atmospheric levels through aggregation of literature reports, this study calls for a review of energy policy, adoption of best practices in the management air emissions and solid wastes as well as agriculture and land use pattern which appear to be the rallying points of all identified sources of emission. The study concluded that the adoption of cleaner energy policies and initiatives in energy generation and usage as against pursuit of thermal plants and heavy dependence on fossil fuels will assist to ameliorate the atmospheric loadings of these pollutants., Anthropogenic sources; Drivers of air pollutants; Emission inventory; Energy, Wastes; Nigeria

Agricultural and industrial wastes like sawdust and corncobs are definitely pollutants as they are disposed in dump sites and burnt in open air in most developing countries, like Nigeria. Proper utilization of these wastes could help reduce the environmental pollution arising from wastes disposal and combustion of fuels. Emissions generated from running an internal combustion (IC) engine with blends of gasoline and bio-ethanol produced from these wastes, as well as those of pure gasoline were compared in this work. A gas emission analyzer was placed at the exhaust of the IC engine and the readings were taken for each blend and for each round of testing period. The read out emissions were then compared with each other. The range of emissions for carbon monoxide (CO) were 1.45-2.75; 2.10-2.90; 2.00-2.62 and 3.0 % vol., for corncobs bio-ethanol/gasoline, softwood sawdust bio-ethanol/gasoline, hardwood sawdust bio-ethanol/gasoline and pure gasoline samples respectively while the emission ranges for hydrocarbon (HC) were 260-435; 328-360; 313-350 and 480 ppm for the same samples respectively. In the case of carbon dioxide (CO2), the samples gave 2.6-4.0; 2.2-3.9; 3.2-4.2 and 3.0 % vol. emissions. Thus all stakeholders considering the adoption of fuel blends in the country’s quest for increased energy mix can be properly guided on the pollutants associated with the investigated waste materials. This may help in the choice of appropriate waste to energy.

This study identified one hundred samples of woody biomasses in the southwest, Nigerian. The woody biomass samples identified were collected from different saw mills, farms and kitchens in Osun State, Nigeria. The identification of the woody biomass samples was done using literature materials and at a herbarium in the Botany Department, Obafemi Awolowo University, Nigeria, using the vegetative parts of their trees. The identification was carried out to know the numerical availability, the family or English names, the common names and the botanical names of the southwest Nigeria woody biomasses. From the findings, 100 samples of the woody biomasses were identified of 39 families and classes of hard woody biomasses and soft woody biomasses out of which only two are soft and rest are hard. It was discovered that Southwest, Nigeria has the capacity to embark on the massive production of these woody biomasses identified due to her land mass of 77,818 km2 comprising 85 forests. In conclusion, serious investment in the propagation of these energy crops would lead to the production of woody masses to serve as feedstocks in thermal power plants for sustainability in power supply, air pollution control and employment opportunities.

As a way of waste-to-voltage conversion, a laboratory-based test trial of electricity generation from a blend of cocoa and kola nut harvest by-products is presented in this study. Bioethanol obtained from the blend through a process of fermentation is mixed with gasoline at specific proportions and employed to fire a spark-ignition engine that serves as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine as the fuel-mix proportion and its speed of rotation varies is studied. Likewise, the electric power output characteristic of the driven machine operated at its rated synchronous speed is examined. It is found that the driving machine performs better on mixed fuel than on pure gasoline as the machine develops a gradual increase in mechanical torque and power as the proportion of ethanol in the fuel-mix and the rotational speed increases. While the highest values of torque and power developed on using pure gasoline are 12.4Nm and 2574W respectively at 1900rpm, 13.1Nm torque and 2953W power are obtained from the machine when powered with 10%-bioethanol fuel-mix at the same speed. Also, with 90V excitation voltage and rotation at 1500rpm synchronous speed, the driven machine continuously generates electricity at 207.6Vrms (line-to-line), 1.169A, 0.698pf, 48.17Hz, 0.294kW output. Therefore, this investigation shows that the availability of cocoa and kola nut harvest wastes could be explored as a steady source of biofuel for off-grid microgrid electrification at locations with such agricultural wastes advantages.

This paper assessed the chromium and cadmium emissions from consumption of premium motor spirit (PMS) and automotive gas oil (AGO) across the states, regions and the nation, Nigeria as a whole. This was with a view to determining the levels of per capita and land exposures to the emissions and the associated risks to humans, plants and animals. Annual fuel consumption and toxic transition metals contents were combined to estimate the annual emission rates of chromium and cadmium emissions from combustion of the PMS and AGO for a period of ten years (2009–2018). Per capita and land distributions of emissions were then calculated by using population and land areas, respectively. The results showed that total emission rates from both PMS and AGO were lowest in 2012, with 1,102 million mg/yr of chromium and 3,253 million mg/yr of cadmium, and highest in 2018, with 14,454 million mg/yr of chromium and 39,580 million mg/yr of cadmium. Emission rates per capita were also lowest in 2012, with 7 mg/yr.person of chromium and 20 mg/yr.person of cadmium, and highest in 2018 with 74 mg/yr.person of chromium and 201 mg/yr.person of cadmium. Land distribution was lowest in 2012, with 1.19 mg/yr.km2 of chromium and 3.52 mg/yr.km2 of cadmium, and highest in 2018, with 15.63 mg/yr.km2 of chromium and 42.81 mg/yr.km2 of cadmium. Comparing to regulatory limits, the risks of humans, animals and plants be poisoned are very high. It is recommended that stiff regulations concerning the heavy metal contents of fuels imported and distributed in Nigeria should be created and implemented to mitigate the risks of poisoning to humans, animals and crops., Engineering; Chemical engineering; Energy Engineering; Petroleum Engineering; Environmental Science; cadmium; chromium; emissions; premium motor spirit; automotive gas oil; Nigeria.

The annual emission rates of three key greenhouse gases and their total carbon dioxide equivalents were determined for the operation of several thousands of diesel fueled electric power generators deployed across the base transceiver stations (BTS) of telecommunication industries in Nigeria. Emission inventory technique was adopted for the determination of annual emission rates of individual greenhouse gas while and global warming potentials were used to convert these emissions to carbon dioxide equivalents (CO2e). Results showed that the annual levels of N20, CH4 and CO2 which were 242.88 ton/year, 80.76 ton/year and 1617 kton/year, respectively in 2012 rose to 317.42 ton/year, 105.54 ton/year and 2113 kton/year in 2014. By the end of 2020, these had risen to 561.97 ton/year, 186.86 ton/year, and 3741 kton/year, respectively. The total GHG emission rose from 1.7 × 106 tCO2e in 2012 to 2.2 × 106 tCO2e in 2014 and by 2020 it had reached 3.9 × 106 tCO2e. Going by the projected 80,000 diesel fueled electric power generators, the total emission rate of the three GHGs (tCO2 eq) is expected to hit 5.8 × 106 tCO2e in the nearest future. Considering the implications of these on the global climate, the deployment of hybrid renewable energy sources is considered necessary as against burning of diesel.

Woody biomass is being employed as energy resource in some countries of the world; coincidentally, huge amount of sawdust is generated annually in southwestern Nigeria. This study assessed the comp...

Nigeria’s energy supply in the form of electricity has been erratic and unreliable in recent time that people now depend on their own power generation in order to meet demands. Thus majority of the populace have to depend on traditional fuelwood for cooking without knowing the impacts of air emissions from it. This study estimated the ground-level concentrations of the air pollutants emitted from the fuelwoods using the American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD). The maximum 24 h averaging ground-level concentrations were 6.378–87.319, 1.546–75.164, 0.079–2.759, and 0–0.164 µg/m3, respectively for CO, HC, NO, and SO2. With this all stakeholders will be properly guided on the usage of fuelwood with minimal negative impact.

This study is to determine in-vehicle and pedestrian exposure to carbon monoxide (CO) and volatile organic compounds (VOCs) in six roadways in Lagos mega city. Measurements were made twice a day for two weeks for four major modes of transportation in the city using the MultiRae ambient gas monitor. The levels of CO measured were 4.40–39.78 ppm while that of VOCs were 0.00–0.39 ppm. Highest average CO and VOCs concentrations were obtained inside car during morning commuting periods. These average concentrations were found to be statistically significant when compared with other three transportation modes studied. The average concentrations of the pollutants in the morning were statistically similar to average concentration in the afternoon as Student's t-test indicated no statistical significant difference (p > 0.05). This study revealed that car commuters are exposed to higher concentrations of CO and VOCs than bus and BRT commuters with pedestrians having the lowest exposure to the pollutants.

The current electricity shortage from Nigeria’s national grid and the scarcity of refined petroleum products including kerosene which is used for domestic purposes make the use of fuelwoods more dominant in the country; especially in the rural areas. Air emissions from open burning of pre-determined quantity of some common fuelwoods identified in regions were characterized for gaseous air pollutants using the E8500 combustion analyzer. The measured concentrations were used to calculate emission factors of the air pollutants. The emission factors for the gaseous emission from the fuelwoods were 181.84–6547.57 g/kg for CO, 44.07–2986.40 g/kg for HC, 2.24–267.36 g/kg for NOx while SO2 had 0.0–9.87 g/kg. This study establishes that Gliricidia sepium had the minimum emission factor for all the considered gaseous pollutants except for SO2, thus all stakeholders considering the adoption of fuelwood in the country’s quest for increased energy mix can be properly guided on the pollutants associated with th...

The review looked at Nigeria's energy status, energy mix, and renewable energy potentials in order to provide information on the opportunities in the country's energy sector that could be taken advantage of, by people, researchers, investors, businesses, and governments. This is critical in light of the existing energy supply gaps hence the need for sustainable energy production.

This study investigated the toxicity potential of carbon monoxide along a major highway in Sango-Ota, an emerging city, in Nigeria. Ambient air carbon monoxide was monitored and measured at ten different locations using the GM8805 benetech carbon monoxide monitor. Coca-Cola junction was selected as the control location for this study. The 1-hr averaging period measured for carbon monoxide concentrations within the selected locations ranged between 25.2 ppm and 29.3 ppm while at the control point, it was measured to be 8 ppm. The extrapolated 8-hr averaging period for carbon monoxide concentration ranged between 14.076 ppm and 16.366 ppm with the concentration at the control point being at 4.4688 ppm. The extrapolated 24-hr averaging period for carbon monoxide concentration ranged between 10.357 ppm and 12.042 ppm with the concentration at the control point being 3.288 ppm. An assessment of toxicity potential of these locations based on Federal Environmental Protection Agency (FEPA), United States Environmental Protection Agency (USEPA) and World Health Organization (WHO) statutory limits were all above unity (one) except at the control location and this poses as a threat to human lives. These values showed unhealthy air conditions at these regions of the emerging city. This study establishes that traffic congestions contribute significantly to the ambient air thereby reducing its quality thus calls for the attention of regulatory bodies to rise to protection of commuters and businessmen along the major highways in emerging cities in Nigeria.

This study examined the infiltration of oxides of nitrogen (NOx) from outdoor into the indoor environments in the commercial areas of Osogbo, Nigeria. Outdoor NOx concentrations were monitored at four different locations with a high volume of commercial and vehicular activities using Toxirae II NOx monitor. A control sampling point was also set at another location with no commercial and vehicular activities. The indoor concentrations at each location were simulated using IAQX 1.0f simulation tool of the US EPA. The mean measured outdoor NOx concentration over the entire commercial area ranged between 0.14 and 0.58 ppm with an average of 0.351 ppm but at the control point it ranged between 0.0 and 0.2 ppm with an average of 0.027 ppm. A simulation of the indoor concentration revealed an unhealthy indoor air quality. The stabilized indoor concentrations at commercial areas ranged between 0.054 and 0.169 ppm but it was 0.00917 ppm at the control point. The study establishes that emissions associated commercial activities may contribute significantly to indoor air quality degradation in an unplanned area thus calls for appropriate regulatory measures to protect public health.

Data from literature and a stoichiometric material balance model were employed to estimate associated emissions with flaring of sweet gas in Nigerian oil and gas companies. Emission factors were obtained using AP 42 formula. Results showed that thousands of tonnes, ranging from 6500 to 22,000 tonnes of natural gas were flared from 1997 to 2016. At flaring stack efficiencies of 97% and 98%, the associated emissions are: CH4, C2H6, C3H8, iC4H10, nC4H10, iC5H12, nC5H12, C6H14, C7H16, C8H18, C9H20, CO2, and N2 from unburnt natural gas and in addition to CO2, CO, N2, NO, NO2, H2O and H2 from incomplete combustion. At both flaring stack efficiencies, the amount of emissions from unburnt condition ranged from1,608 tonnes N2 to 9,146 tonnes CO2 all higher than any emission standards in the world, while the amounts of emissions from incomplete combustion ranged from 467,964 tonnes for CO2 the lowest to 2,476,011 tonnes for N2 the highest all higher than any emission standards in the globe. Emission factors of emissions from unburnt natural gas ranged from 0.000090 tonne/tonne for C10H22 to 0.026235 tonne/tonne for CH4 while those of the emissions from incomplete combustion ranged from 0.10285 tonne/tonne for H2 to 1.13137 for CO2 tonne/tonne. It was observed that thousands of tonnes of emissions are released into the atmosphere during flaring of sweet natural gas either at complete or incomplete combustion. It is recommended that flaring of natural gas should be reduced to a minimal level to safeguard the environment.

This paper estimated the annual levels of sulphur dioxide (SO2) from consumption of premium motor spirit (PMS) and automotive gas oil (AGO) across the States and Regions of Nigeria. This was with a view to estimating the per capita and land distributions of emissions. Annual fuel consumption, average fuel sulphur contents and emission factors were combined to estimate the annual levels of SO2. Per capita and land distributions of emissions were then established using population and land area, respectively. Results showed that Lagos and Ogun States had the maximum SO2 emissions from consumption of PMS and AGO, respectively, in 2012. Between 2001 and 2014; most of the SO2 emissions from consumption of PMS and AGO came from the South-western and South-southern regions of the country, respectively. Based on projected future fuel consumption, annual SO2 emissions from utilization of PMS and AGO are projected to further increase over their 2014 estimates. Interim measure suggested for mitigation of SO2 emission is the importation of refined products with highly reduced sulphur contents. Medium to long-term measures include building of more refineries locally to make use of Nigeria’s crude oil which is generally low in sulphur content and a massive improvement in the country’s energy generation so as to lower the demand pressure on refined petroleum products.

PurposeThe aim of this paper is to provide basic information on the types of particulate cyclones separators used in the chemical and process industries, their principles of operation and factors affecting their performance.Design/methodology/approachA general review of the types of particle cleaning cyclones used in the chemical and process industries was carried out and the principles guiding their operation and performance discussed. Information which could aid the choice of cyclone for new applications is also discussed.FindingsIt was concluded that the choice of cyclone for any application is associated with a trade‐off between two contrasting performance indicators (collection efficiency and pressure drop). Adequate and accurate data gathering is essential right from the design stage for smooth operation of cyclone.Originality/valueThe paper highlights the general principle of operation of cyclone separators and the factors that affect their performance.

This paper reported the results of the investigation of motorcycle emissions in selected roads in Abeokuta, Nigeria. Five roads: Ijaye, Kuto, M.K.O. Abiola way, Olabisi Onabanjo, and Olorunsogo roads were considered with five different motorcycle types (Bajaj, Day Long, Frajend, Hajue Suzuki and Honda) on each road. Motorcycles were parked 8.0m away from the main road in downwind direction. The motorcycle exhaust emissions monitored were CO2, O2, CO, and HC emissions. The total mean concentration of measured CO2emission from motorcycle exhaust on all the roads, ranged between 18800ppm for Frajend and 37400ppm for Bajaj, while O2ranged between 139200ppm for Honda and 171800ppm for Frajend, also CO ranged between 14500ppm for Hajue Suzuki and 30700ppm for Bajaj, and HC ranged between 674ppm for Honda and 3289ppm for Day Long. It could be noted that the air pollutants are high for almost every type of the motorcycles, and significantly higher than the National standards. This implies that these motorcycles, which are mostly used for commercial purposes are poorly maintained. This study therefore concluded that motorcycle pollution in Abeokuta is significant with possible serious environmental and health consequences.

The study investigated the compositions of air emissions from a steel recycling factory with a view to assessing the impact of emissions from the factory on elemental deposition in the immediate environment of the factory. Wet atmospheric depositions samples were collected in four geographic directions and at varying distances from the factory. The collected samples were filtered; oven dried and subjected to elemental determination using energy dispersive x-ray fluorescence (ED-XRF) technique. Results showed that maximum elemental depositions occurred between 0.4 – 0.6 km away from the factory in the north-east direction, with potassium being the most dominant element. Generally, the concentrations of elements decreased with increasing distance from the factory except for potassium whose trend suggested that other sources such as bush burning might also be contributing to its concentration. The possibilities of bio- accumulation and uptake of heavy metals by crops planted in the neighbourhood of the factory most especially in the north-eastern direction exist. The study concluded that emissions from the factory be treated before their release into the environment. Keywords : Atmospheric deposition; Bio-accumulation; Elemental ratio; Steel recycling; Energy dispersive xray fluorescence