National Technical University of Athens, School of Chemical Engineering, Unit of Environmental Science Technology, 9 Heroon Polytechniou Str., Zographou Campus, Athens, GR-15780, Greece.
National Technical University of Athens, School of Chemical Engineering, Unit of Environmental Science Technology, 9 Heroon Polytechniou Str., Zographou Campus, Athens, GR-15780, Greece.
Environ Pollut. 2021 Feb 1;270:116069. doi: 10.1016/j.envpol.2020.116069. Epub 2020 Dec 11.
In this work, valorisation pathways of brewers' spent grains (BSG) towards biofuels production under the biorefinery concept were studied utilizing experimental data that provide a common base for straightforward comparison. The dehydration and the recovery of used oil, bioethanol and biogas from BSG were studied. The process units involved were thoroughly investigated and optimized. The oil extraction efficiency reached up to 70% using solid-liquid extraction process with hexane as solvent. The optimal ethanol yield achieved was 45% after the application of acid pretreatment, enzymatic hydrolysis with CellicCTec2 and fermentation with S. Cerevisiae. As far as biogas potential is concerned, the raw BSG, defatted BSG and stillage presented values equal to 379 ± 19, 235 ± 21 and 168 ± 39 mL biogas/g for respectively. Through the combination of the proposed schemes, three biorefinery scenarios were set up able to produce biodiesel, bioethanol and/or biogas. Material flow diagrams were set up in order to assess these schemes. Given that BSG could ensure 'green' energy production in the range of 4.5-7.0 million MJ/y if the European BSG potential is fully valorised, BSG could substantially contribute to the biofuel energy strategy.
在这项工作中，利用提供共同基础的实验数据，研究了在生物炼制概念下将啤酒糟（BSG）转化为生物燃料的增值途径，以便进行直接比较。研究了从 BSG 中脱水和回收废油、生物乙醇和沼气。深入研究并优化了所涉及的工艺单元。使用正己烷作为溶剂的固液萃取工艺，可将油提取效率提高至 70%。经过酸预处理、纤维素酶水解和酿酒酵母发酵后，可获得最高 45%的乙醇收率。就沼气潜力而言，原 BSG、脱脂 BSG 和酒糟的沼气值分别为 379±19、235±21 和 168±39 mL/g。通过结合提出的方案，建立了三个生物炼制方案，能够生产生物柴油、生物乙醇和/或沼气。建立了物料流程图以评估这些方案。如果充分利用欧洲 BSG 的潜力，BSG 每年可产生 450-700 万 MJ 的“绿色”能源，因此，BSG 可以为生物燃料能源战略做出重大贡献。
