Environmental life cycle assessment of cowpea production, storage and disposal in Ilorin, Kwara State, Nigeria

Abstract

Life cycle assessment (LCA) was developed to estimate the environmental impacts of industrial production processes and systems. This paper assessed the environmental impacts associated with the production, storage and disposal of cowpea grains in Ilorin, Kwara state, Nigeria, and proffer ways of improving and reducing some of the environmental impacts associated with the system. Three scenarios were created in the cowpea study; production and storage in an inert atmosphere silo, hermetic storage, and cold shock (freezer) storage respectively. The inventory data obtained from the scenario was analysed using Gabi 8.7 think step 2018 version. From the cradle-to-grave research study and Centre of Environmental Science (CML) methodology used, it was obtained that the Global Warming Potential (GWP) for the three scenarios were 6.7, 6.46, and 8.82 kg CO2-equivalent for inert, hermetic and cold shock respectively. Acidification Potential (AP) values for the three scenarios were: 0.0105, 0.01 and 0.0121kgSO2 equivalent respectively, Eutrophication Potentials (EP), were 1.68, 1.56, and 2.012e-3kg phosphate equivalent respectively. Ozone layer depletion potential (ODP) gave same values each in the scenarios with 9.99e-13kgR11 equivalent, and human toxicology potential (HTP) values for each were 0.181, 0.151 and 0.24kg DCB equivalent respectively. Diesel and petrol fuel used for tillage and post farm operations respectively were major hotspots in the scenarios. Based on the emissions value and characterization factor from each scenario, inert storage and hermetic storage are recommended for environmentally friendly storage over cold shock storage in the cowpea scenario.