Continuous dark fermentation experiments for hydrogen production from synthetic cheese whey were conducted at different HRTs and OLRs. The study mainly aimed at developing a novel criterion to quantitatively assess stability and relating it to the evolution of microbial pathways and associated metabolic products. For HRTs = 6-8 h and OLRs = 65-97.5 g TOC/(L.d), the best hydrogen generation performance was attained, yielding 42-50 L H-2/kg TOC. Instead of using a stability index for the entire test length, accounting for the fluctuations of hydrogen production over 1HRT periods (dynamic stability index) provided a more accurate assessment of process stability showing a clear correlation with the hydrogen yield. The analysis of the metabolic reactions provided evidence of a competition among acidogenic, hydrogen consuming and hydrogen-neutral microbial species. This explained the lower process performance in comparison to the theoretical yield expected, pointing out at the need for further investigation on suitable strategies to effectively inhibit undesired metabolic pathways. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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机译:在不同的HRTs和OLRs下进行合成干酪乳清制氢的连续暗发酵实验。该研究主要旨在开发一种新的标准来定量评估稳定性,并将其与微生物途径和相关代谢产物的进化联系起来。当HRTs = 6-8 h和OLRs = 65-97.5 g TOC/(L.d)时,氢气生成性能最佳,产生42-50 L H-2/kg TOC。考虑到 1HRT 周期内制氢量的波动(动态稳定性指数),而不是使用整个测试长度的稳定性指数(动态稳定性指数)可以更准确地评估过程稳定性,显示出与氢气产量的明显相关性。对代谢反应的分析提供了产酸、耗氢和氢中性微生物物种之间竞争的证据。这解释了与预期的理论产量相比较低的工艺性能,指出需要进一步研究合适的策略来有效抑制不需要的代谢途径。(c) 2022 Hydrogen Energy Publications LLC.,由爱思唯尔有限公司出版。保留所有权利。
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