Evaluation of a Bioethanol Based on Sweet Sorghum Stalk Juice in Kenya Throughout Its Life Cycle

Abstract

A lot of nations have been pushing for biofuels as a way to cut down on fossil fuel use and
emissions of greenhouse gases (GHG). The rapid growth and drought resilience of sweet
sorghum have made it a promising feedstock for bioethanol production. This research looks
at the energy and greenhouse gas (GHG) outputs of making bioethanol in Kenya from sweet
sorghum stalk juice. Growing the crop, grinding the grain, converting it to bioethanol, and
then co-generating are the steps involved in making bioethanol. According to the research,
for every liter of bioethanol generated, the greenhouse gas emissions amount to 424.19
gCO2eq. The overall energy required to create one liter of bioethanol was determined to be
10.08 MJ. Net energy value (NEV) = 11.12 MJ, net renewable energy value (NREV) = 19.68
MJ, and net energy ratio (NER) = 13.6 were the results achieved for energy balances per liter
of bioethanol in the research. A positive result for NEV suggests that the amount of energy
needed to create one liter of bioethanol is lower than the energy content of the fuel itself. A
small quantity of fossil fuels is needed to make one liter of bioethanol, as seen by the strong
positive values of NREV and NER. Using mass allocation, the research separated the energy
inputs and greenhouse gas emissions for each phase of the sweet sorghum lifecycle. We ran
a sensitivity analysis to see how different amounts of stalk, juice, and bioethanol affected our
greenhouse gas emissions and our NEV. Results showed that greenhouse gas emissions were
stalk yield sensitive and NER was bioethanol yield sensitive.