Biogas is competitive, viable, and generally a sustainable energy resource due to abundant supply of cheap feedstocks and availability of a wide range of biogas applications in heating, power generation, fuel, and raw materials for further processing and production of sustainable chemicals including hydrogen, and carbon dioxide and biofuels. The capacity of biogas based power has been growing rapidly for the past decade with global biogas based electricity generation capacity increasing from 65 GW in 2010 to 120 GW in 2019 representing a 90% growth. This study presents the pathways for use of biogas in the energy transition by application in power generation and production of fuels. Diesel engines, petrol or gasoline engines, turbines, microturbines, and Stirling engines offer feasible options for biogas to electricity production as prme movers. Biogas fuel can be used in both spark ignition (petrol) and compression ignition engines (diesel) with varying degrees of modifications on conventional internal combustion engines. In internal combustion engines, the dual-fuel mode can be used with little or no modification compared to full engine conversion to gas engines which may require major modifications. Biogas can also be used in fuel cells for direct conversion to electricity and raw material for hydrogen and transport fuel production which is a significant pathway to sustainable energy development. Enriched biogas or biomethane can be containerized or injected to gas supply mains for use as renewable natural gas. Biogas can be used directly for cooking and lighting as well as for power generation and for production of Fischer-Tropsch (FT) fuels. Upgraded biogas/biomethane which can also be used to process methanol fuel. Compressed biogas (CBG) and liquid biogas (LBG) can be reversibly made from biomethane for various direct and indirect applications as fuels for transport and power generation. Biogas can be used in processes like combined heat and power generation from biogas (CHP), trigeneration, and compression to Bio-CNG and bio-LPG for cleaned biogas/biomethane. Fuels are manufactured from biogas by cleaning, and purification before reforming to syngas, and partial oxidation to produce methanol which can be used to make gasoline. Syngas is used in production of alcohols, jet fuels, diesel, and gasoline through the Fischer-Tropsch process.

Plastics are cheap, lightweight, and durable and can be easily molded into many different products, shapes, and sizes, hence their wide applications globally, leading to increased production and use. Plastic consumption and production have been growing since its first production in the 1950s. About 4% of global oil and gas production is being used as feedstock for plastics, and 3–4% is used to provide energy for their manufacture. Plastics have a wide range of applications because they are versatile and relatively cheap. This study presents an in-depth analysis of plastic solid waste (PSW). Plastic wastes can be technically used for oil production because the calorific value of the plastics is quite comparable to that of oil, making this option an attractive alternative. Oil can be produced from plastic wastes via thermal degradation and catalytic degradation, while gasification can be used to produce syngas. Plastic pyrolysis can be used to address the twin problem of plastic waste disposal and depletion of fossil fuel reserves. The demand for plastics has continued to rise since their first production in the 1950s due to their multipurpose, lightness, inexpensiveness, and durable nature. There are four main avenues available for plastic solid waste treatment, namely, reextrusion as a primary treatment, mechanical treatment as secondary measures, chemical treatment as a tertiary measure, and energy recovery as a quaternary measure. The pyrolysis oil has properties that are close to clean fuel and is, therefore, a substitute to fresh fossil fuel for power generation, transport, and other applications. The study showed that plastic wastes pyrolysis offers an alternative avenue for plastic waste disposal and an alternative source of fossil fuel to reduce the total demand of virgin oil. Through plastic pyrolysis, plastic wastes are thermally converted to fuel by degrading long-chain polymers into small complex molecules in the absence of oxygen, making it a technically and economically feasible process for waste plastic recycling. The process is advantageous because presorting is not required, and the plastic waste can be directly fed without pretreatment prior to the process. Products of plastic pyrolysis are pyrolysis oil, a hydrocarbon-rich gas, with a heating value of 25–45 MJ/kg, which makes it ideal for process energy recovery. Hence, the pyrolysis gas can be fed back to the process to extract the energy for the process-heating purpose, which substantially reduces the reliance on external heating sources.

Floods lead to tremendous losses of property, infrastructure, business and increased risk of diseases. Floods are also the most frequent natural disasters, affecting over 2.8 billion people in the world and causing over 200 000 deaths over the past three decades. The World Health Organization categorised the 2012 flood disaster in Nigeria as the worst flood to have hit the country in the past 50 years. This study reviews flood disasters in Nigeria and how they have been managed over the past two decades. The extensive review of the literature is complemented by data obtained from Ajegunle, a community in Ajeromi–Ifelodun Local Government Area. Because of its proximity to water bodies, its large population and its small land mass, the Ajegunle community is highly susceptible to floods and outbreaks of waterborne diseases. The study also discusses the institutionalisation and development of disaster management in Nigeria. Further, it critically evaluates the disaster management framework and other current disaster management policies as well as the effectiveness and functions of the disaster management focus areas and government response. The study takes a historic approach to flood disasters, linking disaster management to human health with a special focus on flood-related infectious diseases, isolating waterborne diseases as being predominant. Quantitative and qualitative data were collected to develop an understanding of how the people of Ajegunle are affected by flood disasters. This study reveals poorly managed health reforms and argues that in spite of government’s disaster management policies, there is an absence of organised and coordinated institutional structures to plan and respond to flood emergencies. It also revealed that diarrhoea outbreak was the predominant waterborne disease associated with flood disasters. Although Lagos State has been said to have the best flood preparedness plan in Nigeria, it has failed to reduce the yearly flood disasters and their impact on the health of the people. The article suggests a holistic approach by the government to get stakeholders, especially the health sector, more actively involved in disaster management planning.

Sustainable energy development (SED) is a crucial component of the Sustainable Development Goals (SDG), aiming to maintain economic and social progress while protecting the environment and mitigating climate change’s effects. SED serves as a transition paradigm for sustainable development, providing a blueprint for energy peace and prosperity for people and all uses. This article presents the history of SED and then uses a critical discourse approach to summarize existing review studies in SED. Ten interlinked themes of SED are identified, with two of them considered to be among the least studied in existing SED reviews and in the current global discussion around climate change. This study explores these two themes, which include energy financing and the need for 100% renewable energy (RE), a sub-theme of decarbonization strategy working towards the 1.5–2.0 °C scenario. The study suggests that the current G20 countries’ contributions, if maintained continuously per annum, in addition to 80% more funding from private investment compared to the amount in the 1.5 °C scenario financial requirements for clean energy, are sufficient to limit global warming. In addition to the present drive for 100% RE, the article also discusses emerging issues, such as energy storage options with an indication of hydrogen as the most promising, other energy-related development agendas, and the need for regional security stability to prevent energy wars. Selected SED decarbonization strategies are presented across the power, transport, building, and industrial sectors. The study concludes with progress and directions for future research, mainly the need for re-defining nationally determined contribution (NDC) through an emissions budgeting and centralized global or regional emissions stock-taking strategy working towards the 1.5 °C scenario.