Sustainable valorisation of date waste for bioethanol production in Algeria: combustion, engine performance and emissions analyses in a CI diesel engine

Abstract

The appalling environmental problems caused by harmful emissions from the transportation sector besides the anticipated depletion of fossil fuels has prompted the scientific community to search for renewable, clean and sustainable fuels. The aim of this study is to evaluate the lower quality common dates for bioethanol production using the yeast Saccharomyces cerevisiae. During the fermentation reaction, the evolution of the sugar level, pH and density was monitored. The produced bioethanol was then used as an additive and blended with the conventional diesel fuel at different volumes 5, 10 and 15% with the use of Span 80 as a surfactant. The tests were performed under stationary conditions in a four-stroke single-cylinder CI diesel engine at different loads 25, 50, 75 and 100% respectively. The main findings of this study indicated that using bioethanol as an additive in the CI diesel engine has led to changes in the combustion characteristics, as well as in the performance and pollutant emissions. Ethanol-blended fuels revealed higher engine efficiencies than pure diesel fuel along with low exhaust gas temperatures. However, high specific fuel consumption was recorded due to the lower calorific value of bioethanol. In regards to the pollutant emissions, bioethanol reduced the NOx, PM and CO emissions, but slightly influenced CO₂ emissions and favored the formation of UHCs emissions.