Ethanol Production from Dates in Saudi Arabia on Industrial Scale

Abstract

Substandard dates were used as a cheep source for juice production. The seedless dates solution was mixed well, decanted, clarified and microfiltrated. The total sugar concentrations in the prepared date juice were adjusted to 13.5, 18.0 and 22.5%. Date juice with 18% sugars was the more suitable and economic concentration could be fermented to ethanol by using each of Saccharomyces cerevisiae or S. bayamus in submerged fermenters. Also S. bayamus was more active than S. cerevisiae in the fermentation of the date juice. The higher yield ethanol production was recorded by using S. bayamus grown on date juice with 18% sugars concentration at 30℃ and pH 3.5. The fermentation rate under these conditions was 2.0 Brix consumed per 12 hours and the fermentation was completed in 84 hours, with resulting in an ethanol concentration of 9.2%. This concentration of ethanol was nearly equal to the theoretical value. It was represented 50.9% of the total sugars in the date juice which was 18%. Addition, of different concentrations of Di-ammonium phosphate (1, 2 or 3 g/l of date juice) had no effect on the efficiency of fomentation. At the end of fermentation, the fermented date juice was distilled and alcohol with nearly 93% concentration was produced.