Pretreatment of Sweet Sorghum Bagasse Using EFB-Based Black Liquor for Ethanol Production

Lignocellulose-based bioethanol provides one potential alternative energy. Pretreatment is one of the steps in the bioconversion of lignocellulose material. Pretreatment also contributes the largest cost in the bioethanol production and produces black liquor as a wastewater which provides environmental impacts. In order to improve the cost-effectiveness of bioethanol production, the black liquor from empty fruit bunch (EFB) pretreatment was collected and used for pretreatment of sweet sorghum bagasse (SSB). The pretreatment process was conducted in a 5-liter reactor at 150 °C. The result by using black liquor was compared with pretreatment by using NaOH solution. The delignification of SSB by using black liquor in 30 and 60 min pretreatment time was 61.57% and 55.87%, respectively. The ethanol production after the SSF process reached 45.06 gl−1 and 46.49 gl−1.