Table 3 Hydrogen production from microalgae without pretreatment
From: Fermentative hydrogen production using pretreated microalgal biomass as feedstock
Substrate | Substrate concentration (g/L TS) | Inoculum | Operational conditions | Hydrogen yield (mL H2/g VS) | Comments | References |
|---|---|---|---|---|---|---|
Chlorella vulgaris | 5 | Anaerobic sludge | pH = 7.0, 37 °C; batch | 10.8 | Due to the activities of satellite bacteria associated with algal cultures, hydrogen can be produced with and without inocula. Addition of BESA inhibited both hydrogen production and methane production | [17] |
Chlorella vulgaris | 5–30 | Anaerobic sludge | pH = 7.5, 60 °C; batch | 1.75–19 | Combination of hydrogen production from microalgae and methane production from hydrogen fermentation residues was investigated. Effects of different enzymatic pretreatment on hydrogen and methane yield were examined | [15] |
Chlorella vulgaris | 3–117 | Anaerobic sludge | pH = 4.2–9.8, 35 °C; batch | 14.6–31.2b | Hydrogen production from microalgae biomass via dark fermentation was optimized by response surface methodology (CCD). The optimal condition was found at 76 g TS/L and initial pH of 7.4 | [18] |
Chlorella sp. | 4–40 | Anaerobic sludge | pH = 6.5, 35 °C; batch | 0.37–7.13 | Influences of inoculum–substrate ratio, VFAs and NADH on anaerobic hydrogen production from Chlorella sp. were examined. Results showed that inoculum–substrate ratio and NADH had a negative correlation with hydrogen production and increase of VFA formation was accompanied with increased hydrogen production. 3D EEM fluorescence spectrometry was used to determine NADH | [19] |
Nannochloropsis sp. NANNO-2 | 2.5–10 | Enterobacter aerogenes ATCC 13048 | 30 °C; batch | 26.4–60.6b | Hydrogen was produced from Nannochloropsis sp. biomass before or after lipid extraction. Higher hydrogen yield was obtained from lipid extracted microalgae biomass | [20] |
Nannochloropsis oceanica | 50 | Anaerobic sludge | pH = 6.0, 35 °C; batch | 2 | The flue gas-cultivated microalgae biomass (N. oceanica) is efficiently used as feedstock to cogenerate hydrogen and methane through a novel three-stage method comprising dark fermentation, photo-fermentation and methanogenesis | [21] |
Scenedesmus sp. (lipid extracted) | 18a | Anaerobic sludge | pH = 6.3, 37 °C; batch | 16.99 | Different treatment methods on hydrogen production from microalgae biomass were examined. Include base, heat and combination of base and heat treatment. Treatment methods except base treatment all led to a significant increase in hydrogen production from microalgae biomass | [16] |
Scenedesmus sp. (lipid extracted) | 4.5–45a | Anaerobic sludge | pH = 5.0–7.0, 37 °C; batch | 0.42–40.27 | Effects of inoculum treatment, inoculum concentration, initial pH and substrate concentration on hydrogen production were investigated. Optimum condition was determined to be initial pH 6.0–6.5, heat treated inoculum concentration of 2.35 g VSS/L and the microalgae biomass concentration of 36 g VS/L | [22] |
Chlamydomonas reinhardtii | 50 | Clostridium butyricum NCBI 9576 | pH = 6.0, 37 °C; batch | 16.6b | Anaerobic hydrogen production from Chlamydomonas reinhardtii biomass was followed by photo fermentation, increased hydrogen yield from 2.58 mol H2/mol starch–glucose to 8.30 mol H2/mol starch–glucose equivalent algal biomass | [23] |
Dunaliella tertiolecta | 5 | Anaerobic sludge | pH = 7.0, 37 °C; batch | 12.6 | The high salinity of the D. tertiolecta slurry was prohibitive to methanogens, result in low methane production and high hydrogen yield | [17] |