Table 1 Comparison of final ethanol concentrations, total ethanol space–time yields, and ethanol-to-acetate ratio in autotrophic processes with C. ragsdalei
From: Continuous sulfide supply enhanced autotrophic production of alcohols with Clostridium ragsdalei
Reactor mode Gas composition CO/H2/CO2/N2, % (v/v) | Process time, h Temperature, °C pH Medium additive | Ethanol concentration, g L−1 Ethanol space–time yield, mg L−1 h−1 Ethanol to acetate, g g−1 | References |
|---|---|---|---|
Fed-batch CSTR, uncontrolled pH 20/5/15/60 | 360 h; 37 °C; pH 6.1 1 g L−1 YEa | 6.10 g L−1; 16.94 mg L−1 h−1; 4.07 g g−1 | Maddipati et al. (2011) |
360 h; 37 °C; pH 6.1 10 g L−1 CSLb | 8.60 g L−1; 23.89 mg L−1 h−1; 3.58 g g−1 | ||
360 h; 37 °C; pH 6.1 20 g L−1 CSL | 9.60 g L−1; 26.67 mg L−1 h−1; 2.82 g g−1 | ||
1416 h; 37 °C; pH 6.0 10 g L−1 CSL | 25.26 g L−1; 17.84 mg L−1 h−1; 5.24 g g−1 | Kundiyana et al. (2010) | |
Semi-continuous trickle bed reactor, uncontrolled pH 38/28.5/28.5/5 | 171 h; 37 °C; pH 5.6 0.5 g L−1 YE | 5.70 g L−1; 30.41 mg L−1 h−1 (estimated); 0.46 g g−1 | Devarapalli et al. (2016) |
Fed-batch CSTR, controlled pH *Sulfide feed 0.05 mmol S L−1 h−1 60/20/20/0 | 144 h; 37 °C; pH 6.0 1 g L−1 YE | 2.33 g L−1; 16.18 mg L−1 h−1; 0.31 g g−1 | This study |
*144 h; 37 °C; pH 6.0 1 g L−1 YE | 5.18 g L−1; 35.94 mg L−1 h−1; 1.48 g g−1 | ||
*140 h; 32 °C; pH 6.0 1 g L−1 YE | 7.67 g L−1; 54.82 mg L−1 h−1; 1.36 g g−1 | ||
*144 h; 32 °C; pH 5.5 1 g L−1 YE | 6.00 g L−1; 41.65 mg L−1 h−1; 14.82 g g−1 |