Application of different pre-treatment techniques for enhanced biogas production from lawn grass: A review

Biogas is considered as the best possible alternative source of energy. Biogas is clean, cheap, sustainable, and environmentally friendly. The biogas production potential from energy crops, grass, in particular, has been investigated widely. Although grass produces quality methane in comparison to other feedstock, low biogas yield has been a common challenge. This is because the grass is part of lignocellulosic biomass, consisting of cellulose and hemicelluloses, which are linked together by strong chemical bonds. These characteristics make it resistant to anaerobic digestion. Pre-treatment including chemical, mechanical, thermal, biological and/or a combination of them may be used to break the ether bonds, resulting in an easy accessibility of sugars present in a substrate for the enzyme. For these reasons, this chapter evaluates the various pre-treatment techniques to optimize the biodegradability of grass. All the pre-treatment techniques have been reported to increase biogas production rate. Among the pre-treatments options, chemical pre-treatment has been considered as the most preferred though its operational cost is still under investigation.