Evaluation of combined semi-humid chemo-mechanical pretreatment of lignocellulosic biomass in energy efficiency and waste generation.

A combination of chemo-mechanical pretreatment of lignocellulosic biomass was developed with objectives to evaluate and optimize the energy efficiency and waste generation occurred in the pretreatment process. Sugarcane bagasse (SCB) was chemically pretreated with alkaline and alkaline peroxide followed by mechanical size reduction and enzymatic hydrolysis. The high solid and low solid loading pretreatments were studied to compare the total energy consumption, energy efficiency as well as waste generation. SCBSHNa (1:5) namely semi-humid chemo-mechanical pretreatment was found as the most effective pretreatment by decreasing 65% of total energy consumption. Moreover, the SCBSHNa (1:5) achieved the highest energy efficiency resulting in 0.536 kg reducing sugars/kWh and generated 0.33 kg of waste/kg reducing sugars. The developed process represented the advantages on energy efficiency and less waste generation compared to the conventional chemical soaking pretreatment process.