Sulaiman Al-Zuhair

Biofuels Production from UAE Indigenous Biomass

The desert climate of the UAE may suggest that the nation cannot move into large scale biofuels production, owing to the scarceness of biomass. This is, however, is far from true. The country enjoys good sunshine throughout the year, making it ideal for microalgae cultivation that do not require arable land or freshwater, as microalgae can grow in saline water. In addition, the UAE has a large date palm plantation, making the country one of the major date producers worldwide. Date-pits (DPs), which constitute approximately 10% of the total weight of dates, are the largest agricultural by-product in palm growing countries, including the UAE. Therefore, finding ways to use this agricultural by-product profitably will benefit date farmers substantially and offers a useful alternative for its disposal or current use as animal feed.

To respond to the increased demand for biofuels, advanced biochemical processes using enzymes are being developed and are gaining increased attention. Research in this field aims at improving efficiency, and reducing the negative environmental impact of the production processes, in addition to enhancing the quality of the produced biofuels. There are several obstacles however, facing the use of enzymes as catalysts for biofuels production, most importantly is their high costs. Therefore, repeated use of the enzymes is essential from the economic point of view, which can be achieved by using them in immobilized form. In a continuous process using immobilized enzyme, the operational stability, the exhaustion of enzyme activity and inhibition by reactants and/or products play vital roles. However, using enzymes in immobilized form may work well with soluble substrates, but not in the case of lignocellulosic biomass, which is a heterogeneous substrate.

In this talk, ways to enhance the stability and reusability of the enzyme used in microalgae-to-biodiesel process with Thermoresponsive Switchable Solvents (TSS) are presented. The use TSS allows simultaneous cell disruption, oil-extraction-reaction and product separation from wet, untreated microalgae biomass in a single reactor. For bioethanol production from DSs, the use of membrane bioreactor for simultaneous product separation is also presented.