Environmental and socio-economic benefits of a circular economy for bioethanol production in the northern part of Ghana

Abstract

Sweet sorghum grains (SSG) cultivation are the primary source of income and subsistence for approximately 80% of poor smallholder farmers in the northern part of Ghana. Regrettably, sorghum prices in rural markets are constantly falling, resulting in a small income for smallholder farmers and a negative impact on their socioeconomic lives. This study presents a shift towards a circular sweet sorghum supply chain in the northern part of Ghana through bioethanol production from excess sweet sorghum. The study looks at using excess red and white sweet sorghum grains (RSG and WSG) grown in northern Ghana to produce bioethanol. The SSG was pre-treated and fermented with Saccharomyces cerevisiae yeast to produce 87.6 g/L and 84.24 g/L of WSG and RSG bioethanol, respectively. This was equivalent to an estimated yield of 91.57% (WSG) and 89.24% (RSG). Likewise, the bioethanol volumetric production of SSG was between 3.50 g/h·L and 3.70 g/h·L, indicating that its production was efficient after 24 h of fermentation. The fuel properties of the bioethanol were also found to be acceptable for commercial use in bioethanol cookstoves, reducing the reliance on firewood in the northern part of Ghana. A sweet sorghum supply chain based on two different models was developed and could be implemented in the northern sector to benefit smallholder farmers and to save the environment.