Fiber wastes of date palm for bioethanol production in Saudi Arabia

Abstract

A huge rise in energy consumption has been observed in the past few decades because of population and economic growth. One of the renewable energy fuels that can be made from biomass is bioethanol. In Saudi Arabia, date palm provides tons of biomass waste each year, leading to serious problems. The current study aimed to use the date palm fibers (DPF) for bioethanol production via a saccharization step (by hydrochloric acid or by Trichoderma harzianum) for cellulose. This was followed by fermentation (by Saccharomyces cerevisiae). The maximum amount of total carbohydrates (95.55 ± 2.6 mg/dL) and reducing sugar (11.35 ± 0.35 mg/dL) were obtained on the 7th day using T. harzianum. The optimum period of bioethanol production was at day 6 (12.52 ± 1.3 g/L), while at day 5 it became (12.76 ± 0.75 g/L) when the DPF were fortified with yeast extract. The bioethanol maximum yield (12.03 ± 1.10 g/L) was obtained at 30 °C. Moreover, 2 mL of S. cerevisiae inoculum gave maximum yield of bioethanol. Gas chromatographic analysis showed that bioethanol in the fermented broth represented the major constituent with a peak area of 75.01%. The findings indicate that the fortified DPF with yeast extract gave a promising bioethanol yield.