Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland.
Faraday Discuss. 2017 Sep 21;202:269-280. doi: 10.1039/c7fd00066a.
For the production of second generation biofuels from lignocellulosic biomass, pretreatment of the biomass feedstock is necessary to overcome its recalcitrance in order to gain fermentable sugars. Due to many reasons, steam-explosion pretreatment is currently the most commonly used pretreatment method for lignocellulosic biomass on a commercial scale [S. Brethauer and M. H. Studer, CHIMIA, 2015, 69, 572-581]. In contrast to others, we showed that the explosive decompression at the end of this pretreatment step can have a positive influence on the enzymatic digestibility of softwood, especially in combination with high enzyme dosages [T. Pielhop, et al., Biotechnology for Biofuels, 2016, 9, 152]. In this study, the influence of the explosive decompression on the enzymatic digestibility of hardwood and herbaceous plants was systematically studied. Beech and corn stover were pretreated under different pretreatment conditions and enzymatically hydrolysed with different enzyme dosages. The maximum enhancement of the digestibility of corn stover was 16.53% after a 2.5 min pretreatment step at 15 barg steam pressure. For beech, a maximum relative enhancement of 58.29% after a 10 min pretreatment step at 15 barg steam pressure could be reached. With this, we show that the explosive decompression can also enhance the enzymatic cellulose digestibility of hardwood and herbaceous plants.
为了从木质纤维素生物质生产第二代生物燃料，需要对生物质原料进行预处理，以克服其抗降解性，从而获得可发酵糖。由于诸多原因，蒸汽爆破预处理目前是木质纤维素生物质在商业规模上最常用的预处理方法[ S. Brethauer 和 M. H. Studer，CHIMIA，2015，69，572-581]。与其他预处理方法不同，我们表明，该预处理步骤结束时的爆炸减压可以对软木的酶解性产生积极影响，特别是与高酶剂量结合使用时[ T. Pielhop 等人，Biotechnology for Biofuels，2016，9，152]。在这项研究中，系统研究了爆炸减压对硬木和草本植物的酶解性的影响。山毛榉和玉米秸秆在不同的预处理条件下进行预处理，并使用不同的酶剂量进行酶水解。在 15 巴蒸汽压力下进行 2.5 分钟预处理后，玉米秸秆的消化率最大提高了 16.53%。对于山毛榉，在 15 巴蒸汽压力下进行 10 分钟预处理后，相对消化率最大可提高 58.29%。由此可见，爆炸减压也可以提高硬木和草本植物的酶解纤维素消化率。
