Table 4.
Production of methane from different microalgae
| Biomass | Source | Pretreatment | Operation conditions | System | Methane yield | Methane yielda, m3 ha−1 year−1 | COD removal efficiency | References |
|---|---|---|---|---|---|---|---|---|
| 35% Scenedesmus, 30% Dictyosphaerium, 15% Keratococcus, 10% Oscillatoria, 8% Monoraphidium and 2% Nitzchia | Phoreactors, illumination of 54 W daylight neon lamp at intensity of 5000 lumens. 28 °C, pH 8 for 8 days | Ozonation 382 mg O3 g−1 VS | 35 °C and 150 rpm | Batch assays | 432.7 mL CH4g−1 VS | 15,572 | – | Cardeña et al. (2017) |
| Chlorella vulgaris | Race-ways at 25 °C | Enzymatic | Semi-continuous | Anaerobic reactors (CSTRs) | 137 mL CH4 g−1 COD | – | 52% | Mahdy et al. (2016) |
| Chlorella sorokiniana | – | Sonication (200 Watts at 80% amplitude for 10 min) | 30 °C, 42 days | Bench-scale batch | 388 mL CH4 g−1 VS | 13,968 | – | Ayala-Parra et al. (2017) |
| Chlorella sorokiniana | – | – | 30 °C, 42 days | Bench-scale batch | 298 mL CH4 g−1 VS | 10,728 | – | Ayala-Parra et al. (2017) |
| Scenedesmus residues | – | Enzymatic at 50 °C | 37 °C | Batch | 272.8 mL CH4 g−1 VS | 9820.8 | 61.8% | Ramos-Suárez and Carreras (2014) |
| Scenedesmus spp. | – | Rumen microorganisms as inoculum | SRT 100 days | CSTR and anaerobic membrane bioreactor | 214 mL CH4 g−1 COD | – | 70% | Giménez et al. (2017) |
| Chlamydomonas reinhardtii | Batch with white light, nitrogen-limited biomass | 38 °C, 100 rpm, HRT of 20 days | Reactor in semi-continuous mode | 462 mL CH4 g−1 VS days−1 | 16,632 | – | Klassen et al. (2017) | |
| Hydrodictyon reticulatum | – | Enzyme/acid-saccharified | 35 °C | Batch assays | 537.5 mL CH4 g−1 VS | 19,350 | – | Lee et al. (2017) |
COD chemical oxygen demand, HRT hydraulic retention time, SRT sludge retention time
aAssuming a biomass yield of 36 t ha−1 year−1 (Tredici et al. 2015). Calculated value assumes 90% volatile solid content