From: Fermentative hydrogen production using pretreated microalgal biomass as feedstock
Treatment methods | Substrate | Substrate concentration (g/L TS) | Inoculum | Operational conditions | Hydrogen yield (mL H2/g VS) | Comments | References |
---|---|---|---|---|---|---|---|
Acid: HCl 2.0%, 12 h; Heat: 121 °C, 20 min | Chlorella sorokiniana | 10 | Enterobacter cloacae IIT-BT 08 | pH = 7.0, 37 °C; batch | 201.6c | Algal biomass of C. sorokiniana was produced by CO2 sequestration in continuous mode, and then used as substrate for anaerobic hydrogen production. Substrate concentration was optimized to enhance the hydrogen yield from C. sorokiniana | [32] |
Acid-heat: HCl 5%, 121 °C, 20 min | Chlorella sorokiniana | 14 | Anaerobic sludge | pH = 6.5, 60 °C; batch | 760 | Better hydrogen production was achieved from microalgae biomass treated by combined treatment than single treatment method including autoclave, sonication and H2O2 treatment | [25] |
Acid-heat: HCl 20%, 121 °C, 20 min | Chlorella sorokiniana | 14 | Anaerobic sludge | pH = 6.5, 60 °C; batch | 958 | Hydrogen yield was increased from 760 to 958 mL/g VS when HCl concentration was increased from 5 to 20% | [25] |
Acid-heat: H2SO4 0.1 mM, 108 °C, 30 min | Chlorella vulgaris | 20 | Clostridium acetobutylicum B-1787 | pH = 6.8, 37 °C; batch | 2.24d | Immobilized Clostridium acetobutylicum cells were used for hydrogen production from various microalgae species | [33] |
Acid-heat: H2SO4 0.1 mM, 108 °C, 30 min | Nannochloropsis sp. rsemsu-N-1 | 20 | Clostridium acetobutylicum B-1787 | pH = 6.8, 37 °C; batch | 0.90–9.52d | Different microalgae species were used as substrate, and highest hydrogen yield was obtained from wet Nannochloropsis sp. biomass | [33] |
Acid-heat: H2SO4 0.1 mM, 108 °C, 30 min | Arthrospira platensis | 20 | Clostridium acetobutylicum B-1787 | pH = 6.8, 37 °C; batch | 2.24–8.06d | Heating temperature range of 100–121 °C, with and without acid addition were applied in treating microalgae biomass, most efficient treatment condition was determined to be 108 °C, 30 min with 0.1 mmol/L H2SO4 | [33] |
Acid-heat: H2SO4 0.1 mM, 108 °C, 30 min | Dunaliella tertiolecta | 20 | Clostridium acetobutylicum B-1787 | pH = 6.8, 37 °C; batch | 0.22–1.46d | Immobilized Clostridium acetobutylicum cells were used for hydrogen production from various microalgae species | [33] |
Acid-heat: H2SO4 0.5 mol/L, 100 °C, 30 min | Scenedesmus obliquus | – | Clostridium butyricum | pH = 7.0, 37 °C; batch | 2.9e | Potential of H2 production from microalgae biomass and the respective energy consumption and CO2 emissions in the bioconversion process were evaluated. Energy consumption of 7270 MJ/MJH2 and 670 kg CO2/MJH2 were achieved, 98% of which owed to microalgae culture process due to the use of artificial lighting | [34] |
Acid-heat: H2SO4 0.5%, 121 °C, 60 min | Spirulina platensis | 10 | Bacillus firmus NMBL-03 | pH = 6.5, 38 °C; batch | 0.38e | A wide variety of substrates (glucose, xylose, arabinose, lactose, sucrose, and starch) and carbohydrate rich waste products (bagasse hydrolysate, molasses, potato peel and cyanobacterial mass) were used for dark fermentative hydrogen production. Abundant VFA were present in spent medium of hydrogen production from cyanobacterial mass, which can be further used as substrate for photo fermentative hydrogen production | [35] |
Acid-heat: H2SO4 1%, 135 °C, 15 min | Chlorella pyrenoidosa | 20 | Clostridium butyricum | pH = 6.0, 35 °C; batch | 81.2 | Heat and acid treated Chlorella pyrenoidosa biomass was used as substrate for hydrogen production. Energy was further removed through following photo hydrogen production and methane fermentation | [36] |
Acid-heat: H2SO4 1%, 135 °C, 15 min | Chlorella pyrenoidosa | 10 (additional cassava starch 10 g/L) | Clostridium butyricum | pH = 6.0, 35 °C; batch | 276.2 | Hydrogen production from microalgae biomass was significantly increased from 81.2 to 276.2 mL/g VS by the addition of cassava starch to get an optimum C/N ratio | [36] |
Acid-heat: H2SO4 3%, 121 °C, 60 min | Lipid extracted algae cake (collected from a lake) | 5b | Anaerobic sludge | pH = 6.0, 29 °C; batch | 122d | Comparison of hydrogen production from algae untreated, liquid fraction of treated algae, solid fraction of treated algae and treated algae mixture was examined. Best hydrogen and VFA generation was achieved from liquid fraction of treated algae | [37] |
Acid-microwave: H2SO4 0–2.0%, 80–180 °C, 5–25 min | Nannochloropsis oceanica | 50 | Anaerobic sludge | pH = 6.0, 35 °C; batch | 39 | Hydrogen production from microalgae biomass was significantly increased by combined acid and microwave treatment | [21] |
Base-heat: NaOH, 8 g/L, 100 °C, 8 h | Scenedesmus (lipid extracted) | 18a | Anaerobic sludge | pH = 6.3, 37 °C; batch | 45.54 | For the combined treatment, lower temperature and longer treating time was preferred than higher temperature and shorter time | [15] |
Base-heat: NaOH, 8 g/L, 121 °C, 4 h | Scenedesmus (lipid extracted) | 18a | Anaerobic sludge | pH = 6.3, 37 °C; batch | 37.42 | Better hydrogen production was achieved from microalgae biomass treated by combined treatment than single treatment method | [16] |
Acid-heat: pH 1.4, 140 °C, 15 min; biological: cellulase 0.05 g/g TVS, 48 h; glucoamylase 0.05 g/g VS, 24 h | Mixed algae (collected from algae bloom in Taihu Lake) | 25 | Anaerobic sludge | pH = 6.0, 35 °C; batch | 33.56–43.84 | Steam with acid treatment showed better reducing sugar release than steam with alkaline treatment. The energy conversion efficiency was significantly increased through 3-stage process: dark-fermentation, photo-fermentation, and methanogenesis | [30] |
Acid-microwave: pH 1.4, 140 °C, 15 min; biological: cellulase 0.05 g/g TVS, 48 h; glucoamylase 0.05 g/g TVS, 24 h | Mixed algae (collected from algae bloom in Taihu Lake) | 25 | Anaerobic sludge | pH = 6.0, 35 °C; batch | 42.4–47.07 | Microwave with diluted acid treatment degraded algal cells into smaller fragments (< 5 mm), and resulted in higher saccharification efficiency of microalgae | [30] |
Acid-microwave: H2SO4 0.2 mL, 140 °C, 15 min; biological: glucoamylase 0.2% | Arthrospira platensis | 10–40 | Anaerobic sludge | pH = 6.5, 35 °C; batch | 86.5–96.6d | Hydrogen yield was significantly enhanced from 96.6 to 337.0 mL H2/g DW using a combination of dark- and photo-fermentation. Removal of harmful byproducts from hydrolysis pretreatment and dark fermentation can further enhance the overall hydrogen yield | [38] |