Wright Alexander, Marsh Adam, Ricciotti Federica, Shaw Alex, Iza Felipe, Holdich Richard, Bandulasena Hemaka
Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, United Kingdom.
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, 40136, Italy.
Biomass Bioenergy. 2018 Nov;118:46-54. doi: 10.1016/j.biombioe.2018.08.005.
Cellulose recalcitrance is one of the major barriers in converting renewable biomass to biofuels or useful chemicals. A pretreatment reactor that forms a dielectric barrier discharge plasma at the gas-liquid interface of the microbubbles has been developed and tested to pretreat α-cellulose. Modulation of the plasma discharge provided control over the mixture of species generated, and the reactive oxygen species (mainly ozone) were found to be more effective in breaking-up the cellulose structure compared to that of the reactive nitrogen species. The effectiveness of pretreatment under different conditions was determined by measuring both the solubility of treated samples in sodium hydroxide and conversion of cellulose to glucose via enzymatic hydrolysis. Solutions pretreated under pH 3 buffer solutions achieved the best result raising the solubility from 17% to 70% and improving the glucose conversion from 24% to 51%. Under the best conditions, plasma-microbubble treatment caused pronounced crevices on the cellulose surface enhancing access to the reactive species for further breakdown of the structure and to enzymes for saccharification.
纤维素的难降解性是将可再生生物质转化为生物燃料或有用化学品的主要障碍之一。一种在微气泡气液界面形成介质阻挡放电等离子体的预处理反应器已被开发并用于预处理α-纤维素。等离子体放电的调制可控制所产生的物种混合物，并且发现活性氧物种（主要是臭氧）在破坏纤维素结构方面比活性氮物种更有效。通过测量处理后样品在氢氧化钠中的溶解度以及纤维素通过酶水解转化为葡萄糖的情况，确定了不同条件下预处理的有效性。在pH 3缓冲溶液中预处理的溶液取得了最佳效果，溶解度从17%提高到70%，葡萄糖转化率从24%提高到51%。在最佳条件下，等离子体-微气泡处理在纤维素表面产生了明显的裂缝，增强了活性物种对结构进一步分解的接触以及对糖化酶的接触。
