intensive bioethanol production using date stems by-products and natural sugars

Date stem by-products (dsb) have been used as agricultural feedstock to perform bioethanol production in a batch bioreactor. to study the effect of an optimal mixture of fruit hydrolysates (20%dates, 20% figs, and 20% sugar beet) on ethanol yield, different parameters have been followed up, including ph, total sugars, and ethanol yield. the optimal ethanol concentration was found for date stems by-products +20% dates, it was about 19.38 g/l after 72h fermentation process, in such case, the higher initial sugar concentration is close to 204.5 g/l, and the ph dropped from 4.5 to 4.21, while it was only about 18.48, 13.08 and 4.72 g/l for dsb+20% sugar beet, dsb+20% figs, and dsb, respectively. the maximum bioethanol production rate (rm) was about 2.633 (g/l/h) in the case of dsb+20% dates, which is higher compared to the other selected mixtures. the effect of some physical properties on the addition of ethanol/etbe (ethyl tertiary-butyl ether) to super-premium gasoline has been studied. it was found that the addition of 20% ethanol or etbe to super-premium gasoline increased the research octane number from 96 up to 99.3 and from 96 up to 99.8 in the case of dsb+20% dates and etbe, respectively.