Screening of steam explosion conditions for glucose production from non-impregnated wheat straw
Screening of steam explosion conditions for glucose production from non-impregnated wheat straw
复制标题
DOI：
10.1016/j.biombioe.2011.10.013
复制
发表时间：
2011-12-01
影响因子：
6
通讯作者：
Eijsink, Vincent G. H.
中科院分区：
文献类型：
--
作者：
Horn, Svein J.;Nguyen, Quang D.;Eijsink, Vincent G. H.
小麦秸秆转化为可发酵糖用于生物乙醇生产通常涉及一个热预处理步骤，其次是酶水解。采用新设计的蒸汽爆炸装置和无酸浸渍工艺，研究了蒸汽爆炸参数对麦秸消化率的影响。在170-220摄氏度的温度范围内使用18种不同的条件对麦秸进行蒸汽预处理，所得材料直接（即不洗涤）在单独水解和发酵（SHF）型或同时糖化和发酵（SSF）型装置中进行酶解和发酵。在210℃预处理10 min后，酶解获得最大葡萄糖产率，在更苛刻的条件下产率相似。木糖产量随着温度和停留时间的增加而增加，达到190℃，但在较苛刻的预处理条件下，木糖产量下降，因为这些条件会导致木聚糖降解并伴随产生糠醛。在一个shf型设置乙醇形成不跟随酶促葡萄糖释放，并与糠醛水平负相关。sff类型的设置显示了预期葡萄糖释放量与乙醇产量之间的直接相关性。最高的糖化率相当于底物中约90%的纤维素。综上所述，无酸催化剂的蒸汽爆破法是麦秸糖化的一种较好的预处理方法。最佳的蒸汽爆炸条件需要在糖的可及性和糖的降解之间折衷。(C) 2011 Elsevier Ltd.版权所有。
The conversion of wheat straw to fermentable sugar for bioethanol production typically involves a thermal pretreatment step, followed by enzymatic hydrolysis. In this study we have investigated the effect of steam explosion parameters on wheat straw digestibility using a newly designed steam explosion unit and a process without acid impregnation. The wheat straw was steam pretreated using 18 different conditions in the temperature range of 170-220 degrees C and the resulting material was used directly (i.e. without washing) for enzymatic hydrolysis and fermentation in either a separate hydrolysis and fermentation (SHF)-type or a simultaneous saccharification and fermentation (SSF)-type set-up. Maximum glucose yields upon enzymatic hydrolysis were obtained after pretreatment at 210 degrees C for 10 min and yields were similar at harsher conditions. Xylose yields increased with temperature and residence time up to 190 degrees C, but decreased at harsher pretreatment conditions since these led to xylan degradation and concomitant production of furfural. In an SHF-type set-up ethanol formation did not follow enzymatic glucose release and was inversely correlated with furfural levels. An SFF-type set-up displayed a straightforward correlation between the expected amount of released glucose and the ethanol yields. The highest saccharification yields corresponded to about 90% of the cellulose in the substrate. Overall, this study shows that steam explosion without an acid catalyst is a good pretreatment method for saccharification of wheat straw. Optimal steam explosion conditions need to be a compromise between sugar accessibility and sugar degradation. (C) 2011 Elsevier Ltd. All rights reserved.