Zabihi Samyar, Sharafi Amir, Motamedi Hossein, Esmaeilzadeh Feridun, Doherty William O S
Department of Process Engineering, Research and Development Department, Shazand-Arak Oil Refinery Company, Arak, Iran.
Department of Biology Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Environ Sci Pollut Res Int. 2021 Jul;28(28):37867-37881. doi: 10.1007/s11356-021-13410-x. Epub 2021 Mar 15.
It is well established that pretreatment of lignocellulosic biomass is required to achieve an effective enzymatic saccharification process. At the present time, most of the touted pre-treatment technologies would cause environmental pollution and unsustainable water use for the pretreated material prior to enzymatic saccharification. To address these shortcomings, the pretreatment technology which combines the supercritical CO, SC-CO (a green solvent), acetic acid, and steam explosion was used to assess the pretreatment of wheat straw for enzymatic saccharification. The effects of solvent concentration, impregnation temperature and time, pre-treatment time, and temperature, as well as SC-CO pressure, contact time, and temperature, were evaluated. The results identified that at the optimum SC-CO pressure of 18 MPa, the highest amount of reducing sugars (RS) was produced from the cellulosic pulp using Acetic acid/Steam/SC-CO at 200 °C for 30 min, a value 20% more than the pulp produced with the Water/Steam/SC-CO. The effectiveness of the pretreatment process was attributed not only to delignification and defibrillation but also to the exposure of the cellulose structure evidenced from the proportion of the β-glycosidic linkages as shown by FTIR. Passing SC-CO after the pretreatment reduces the amounts of fermentation inhibitors and eliminates the use of wash water.
众所周知，为了实现有效的酶促糖化过程，需要对木质纤维素生物质进行预处理。目前，大多数备受吹捧的预处理技术会在酶促糖化之前对预处理材料造成环境污染和不可持续的用水。为了解决这些缺点，采用了将超临界CO₂（一种绿色溶剂）、乙酸和蒸汽爆破相结合的预处理技术来评估小麦秸秆用于酶促糖化的预处理效果。评估了溶剂浓度、浸渍温度和时间、预处理时间和温度，以及超临界CO₂压力、接触时间和温度的影响。结果表明，在18 MPa的最佳超临界CO₂压力下，使用乙酸/蒸汽/超临界CO₂在200°C下处理30分钟，纤维素纸浆产生的还原糖（RS）量最高，比用水/蒸汽/超临界CO₂产生的纸浆高出20%。预处理过程的有效性不仅归因于脱木质素和纤维分离，还归因于从FTIR显示的β-糖苷键比例所证明的纤维素结构的暴露。预处理后通过超临界CO₂可以减少发酵抑制剂的量并消除洗涤水的使用。
