To enhance the energy security and promote energy diversity, biomass sources of energy are viable resources worldwide. Bioenergy is an organic source of power derived from various feedstock including fuel wood, energy crops, solid wastes, and residues of plants. This book chapter explores the use of biomass in Africa and the technical and economic potential of these resources for energy supply in the continent. Findings of literature revealed that the potential of biomass is high in Africa due to availability of land, its preference due to limited electricity supply and the exorbitant nature of fossil fuels, the assorted variety of energy crops suitable for growth in the continent and the green nature associated with the resource. The chapter also established that bioenergy is renewable and not carbon neutral. As such, accurate computation of its resultant greenhouse gas emissions based on their sequestration and emission rates is strongly advised to optimize biomass for energy utility and sustainability compared to conventional energy sources.

In this study, drying characteristics, kinetic modelling, energy and exergy analyses of a convective hot air dryer are presented for water yam. The drying experiments were carried out at temperature levels of 50, 60, and 70°C and slice thicknesses of 3, 6, and 9 mm. The effects of drying variables on the drying rate (DR), moisture diffusivity (Deff), activation energy (Ea), energy utilization (EU), energy utilization ratio (EUR), exergy loss (EXL), exergy efficiency (EXeff), improvement potential (IP), and exergetic sustainability index (ESI) were investigated. The results showed that increasing air temperature increased the DR, Deff, EU, EUR, EXL, EXeff, IP, and ESI, while increasing the slice thickness increased Deff and Ea, but decreased the DR. The highest Deff and Ea values were 4.2 × 10−8 m2/s, and 53 KJ/mol, respectively. EU and EUR varied from 10 to 150 J/s and 0.39 to 0.79, respectively. EXL and EXeff varied between 2 and 12.5 J/s and 58 to 75 %, respectively. Midilli’s model had the best performance in predicting the moisture ratio of water yam with coefficient of determination (R2 = 0.9998), root mean square error (RMSE = 0.0049), and sum of square error (SSE = 0.0023).

Farmers have not tested their soils for nutrient status and therefore are unaware of the fertility status of their soils. Therefore, a baseline fertility survey of 50 hectares of land of a gravelly Alfisol in the Teaching and Research Farm of Landmark University, Omu-Aran, Kwara State, Nigeria was carried out with a view to identifying soil health constraints and site-specific sustainable land management practices for optimizing crop production. Standard field protocols and laboratory analytical procedures were employed for all sample parameters measured. Results show that the soil textural classes vary from sand to loamy sand, exchangeable acidity, Ca, Mg, K, and Na and the effective cation exchange capacity has the surface and subsurface soil values of 0.0–0.92 and 0.00–0.89 cmol kg−1, 1.6–7.7 and 2.0–5.8 cmol kg−1, 1.2–11.5 and 0.7–8.0 cmol kg−1, 0.09–0.33 and 0.09–0.43 cmol kg−1, 0.0–0.16 and 0.04–0.16 cmol kg−1, 7.2–12.10 and 0.9–12.5 cmol kg−1, respectively. P values lie in the ranges of 2.5–68.9 mg kg−1 and 2.0–37.7 mg kg−1 in the surface and subsurface soils, respectively, organic C values were 0.86–2.81% and 0.68–3.49%, respectively, in the surface and subsurface soils while the values of N were 0.12–0.61% in the surface and 0.11–0.56% subsurface soils. Land evaluation shows that the soils of the project site are very fragile and poor in native fertility. Compound fertilizers low in nitrogen contents but high in phosphorus and potassium are recommended for gravelly Alfisol in a derived savannah ecological zone of the Kwara State, Nigeria to avoid a nutrient imbalance that may create artificial deficiencies of otherwise adequate nutrient elements.

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Field experiments were carried out in 2018 and 2019 cropping seasons at Landmark University Teaching and Research farm, Omu-Aran Kwara state, Nigeria, to determine the effect of soil applied Zn-fertilizer, Tithonia diversifolia (Ti), Chromolaena odorata (Ch) and poultry manure (PM) on the performance, yield, minerals and vitamins composition of okra fruits. Treatments were combined and tested as follows:—Control (T1), Control + 10 kg ha−1 Zn (T2), 5 t ha−1 Ti + 5 t ha−1 PM (T3), 5 t ha−1 Ch + 5 t ha−1 PM (T4), 5 t ha−1 Ch + 5 t ha−1 Ti (T5), 10 t ha−1 Ti + 0 kg ha−1 Zn (T6), 10 t ha−1 Ti + 10 kg ha−1 Zn (T7), 10 t ha−1 Ch + 0 kg ha−1 Zn (T8), 10 t ha−1 Ch + 10 kg ha−1 Zn (T9), 10 t ha−1 PM + 0 kg ha−1 Zn (T10), and 10 t ha−1 PM + 10 kg ha−1 Zn (T11). The experiment was laid out in a randomized complete block design with four repetitions. Vegetative, yield and quality parameters of okra were taken. Data were subjected to analysis of variance and means were compared using Duncan Multiple Range Test (DMRT) at p ≤ 0.05. Variations were observed on the vegetative parameters, yield, minerals and vitamin composition of okra among the applied amendments. The combined application of green biomass, poultry manure, and Zn-fertilizer improved all the variables tested as compared to when they were applied singly. Application of Zn-fertilizer to some selected plots significantly increased yield, Zn, Mg and vitamins concentration of okra. Application of 5 t ha−1 Ti + 5 t ha−1 PM + 10 kg ha−1 Zn (T3) and 5 t ha−1 Ch + 5 t ha−1 PM + 10 kg ha−1 Zn (T4) significantly improved all the parameters tested but the use of 5 t ha−1 Ti + 5 t ha−1 PM + 10 kg ha−1 Zn (T3) resulted in optimum yield and at the same time increase minerals and vitamin concentration of okra. The results of this study therefore showed that Tithonia diversifolia (Ti) as green biomass contained and released more and quality nutrients than Chromolaena odorata (Ch) when combined with equal rate of Zn fertilizer and poultry manure.

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Environmental hazards associated with release of emission from petroleum refineries have caused serious concerns for the host communities. The study focused on the assessment of the contribution of Nigerian refineries to the ambient air quality. Total emission of toluene, ethyl benzene and xylene (TEX) from Nigerian twenty-six (four existing and twenty-two proposed) refineries were estimated using emission factor approach, under no-control measure (worst case scenario) option. Results showed that the four existing refineries emit 2.90 × 10 13 tons of toluene, 1.93 × 10 13 tons ethyl benzene and 1.06 × 10 13 tons per year while the twenty-two proposed refineries have the capacity of releasing annually 9.17 × 10 13 tons of toluene, 6.69 × 10 13 tons of ethyl benzene and .95 x 10 13 tons of xylene. If operated at full capacity, the total estimated TEX emission from the existing refineries stood at 5.89 × 10 13 tons/year while the proposed refineries have the potential of adding additional 2.01 × 10 14 tons/year. These concentrations were considered as environmental menace that could have adverse health challenge of the residents of the host communities. Some technologically driven measures to control and subsequently reduce TEX emission from these refineries were suggested.