Complete utilization of date seeds for biofuel production

Abstract

The utilization of agricultural waste to produce energy is considered a promising solution that combines waste minimization with energy diversification. This study investigated the full utilization of date seeds (DSs) for the combined production of biodiesel, bioethanol, and bio-oil. To optimize this process, the efficacy of oil extraction as a pretreatment method to enhance enzymatic hydrolysis was explored. Oil extraction was not only proved to be a good pretreatment method, it was also shown that it is superior to the conventional alkaline-pretreated under optimum operating conditions. Using post oil extraction samples, with 7% oil yield, the total sugars production by enzymatic hydrolysis increased by an impressive 75%, as compared to alkaline pretreatment, with 30% lignin removal. Subjecting the leftover DSs, after oil extraction and enzymatic hydrolysis, to pyrolysis at a temperature, heating rate, and residence time of 500 °C, 10 °C/min, and 10 min, respectively, resulted in bio-oil yield of 33.3%. This work demonstrated the potential of fully utilizing DSs for producing various biofuels, by providing a promising alternative for managing agricultural waste.