Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion

• DOI: 10.1016/j.cjche.2015.11.005
• Publication Date: 2015-11-11T08:01:44Z
• Authors: Muhammad Jaffar; Yunzhi Pang; Hairong Yuan; Dexun Zou; Yanping Liu; Baoning Zhu; Rashid Mustafa Korai; Xiujin Li
• Keywords: Biogas; Digestate; Hemicellulose

Abstract Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide (KOH) to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations of 1% (K1), 3% (K2), 6% (K3) and 9% (K4) were tested for wheat straw pretreatment at ambient temperature with a C:N ratio of 25:1. 86% of total solids (TS), 89% of volatile solids (VS) and 22% of lignocellulose, cellulose and hemicellulose (LCH) (22%) were decomposed effectively with the wheat straw pretreated by 6% KOH. Enhanced biogas production and cumulative biomethane yield of 258 ml·(g VS) − 1 were obtained increased by 45% and 41% respectively, compared with untreated wheat straw. Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium (138%), calcium (22%) and magnesium (16%). These results show that TS, VS and LCH can be effectively removed from wheat straw pretreated with KOH, improving biodegradability biomethane production and fertilizer value.