School of Engineering, University of Borås, Borås, Sweden,
Appl Biochem Biotechnol. 2014 Mar;172(6):2998-3008. doi: 10.1007/s12010-014-0747-z. Epub 2014 Jan 29.
Lignocellulosic biomass represents a great potential for biogas production. However, a suitable pretreatment is needed to improve their digestibility. This study investigates the effects of an organic solvent, N-Methylmorpholine-N-oxide (NMMO) at temperatures of 120 and 90 °C, NMMO concentrations of 75 and 85% and treatment times of 3 and 15 h on the methane yield. The long-term effects of the treatment were determined by a semicontinuous experiment. The best results were obtained using 75% NMMO at 120 °C for 15 h, resulting in 141% increase in the methane production. These conditions led to a decrease by 9% and an increase by 8% in the lignin and in the carbohydrate content, respectively. During the continuous digestion experiments, a specific biogas production rate of 92 NmL/gVS/day was achieved while the corresponding rate from the untreated sample was 53 NmL/gVS/day. The operation conditions were set at 4.4 gVS/L/day organic loading rate (OLR) and hydraulic retention time (HRT) of 20 days in both cases. NMMO pretreatment has substantially improved the digestibility of forest residues. The present study shows the possibilities of this pretreatment method; however, an economic and technical assessment of its industrial use needs to be performed in the future.
木质纤维素生物质具有很大的沼气生产潜力。然而，需要进行适当的预处理才能提高其可消化性。本研究考察了有机溶剂 N-甲基吗啉-N-氧化物（NMMO）在 120 和 90°C 的温度下、75%和 85%的 NMMO 浓度和 3 和 15 小时的处理时间对甲烷产量的影响。通过半连续实验确定了处理的长期效果。使用 75%的 NMMO 在 120°C 下处理 15 小时的效果最佳，甲烷产量增加了 141%。这些条件分别导致木质素和碳水化合物含量下降 9%和增加 8%。在连续消化实验中，未处理样品的特定沼气产率为 92 NmL/gVS/天，而处理后的样品达到了 141 NmL/gVS/天。在这两种情况下，操作条件均设定为 4.4 gVS/L/天的有机负荷率（OLR）和 20 天的水力停留时间（HRT）。NMMO 预处理大大提高了森林残余物的可消化性。本研究展示了这种预处理方法的可能性；然而，需要对其工业应用进行经济和技术评估。
