Energy Use, Exergy Assessment, and Environmental Impacts of Agricultural Production and Agro Processing Systems in Nigeria: A Comprehensive Review
Abstract
Agriculture remains central to Nigeria’s socio-economic development, providing livelihoods, food security, and raw materials for agro-based industries. However, the sector is characterised by high dependence on fossil energy, low thermodynamic efficiency, and increasing environmental pressures. Over the past two decades, a substantial body of Nigerian-based research has examined energy use patterns, exergy performance, life cycle environmental impacts, and biomass energy potential across agricultural production and agro-processing systems. This paper presents a comprehensive and integrative review of these studies, synthesising evidence from crop production, irrigation, agro-processing industries, and biomass resource assessments. The review shows that indirect energy inputs, particularly mineral fertilisers, agrochemicals, machinery manufacture, and diesel fuel, dominate total energy consumption in most farming systems. Exergy analyses consistently reveal high irreversibilities associated with combustion processes, fertiliser use, and inefficient thermal operations, especially in steam boilers and dryers used in agro-processing. Life cycle assessment studies identify fossil fuel use and agrochemical application as the main environmental hotspots, contributing significantly to greenhouse gas emissions, acidification, and eutrophication. In contrast, Nigeria possesses substantial biomass energy resources that could partially displace fossil fuels and improve system sustainability. The review concludes that meaningful sustainability gains will require integrated energy, exergy, and environmental optimisation across entire value chains, supported by coherent policy frameworks and targeted technological interventions.
