“…For process intensification, the approaches such as pure culture, continuous operation, consolidated saccharification and fermentation, chemical additions, are optimization avenues. In this work, for convenience of discussions, the comparisons were divided into the following five categories, namely pure culture (PC) [73,[84][85][86][87][88][89][90][91][92][93][94], chemical additions (CA) [2,39,76,[95][96][97], continuous operation with mixed culture (COMC) [98][99][100][101][102], batch operation with mixed culture (BOMC) [103][104][105][106][107][108] and consolidated saccharification and fermentation (CSF) [18,31,61,[109][110][111], respectively. For quantitative comparison of hydrogen yield across different literatures, the necessary Carbon-molar-based mass balance for DF is pivotal and necessary.…”