Table 1 Recent studies of bioenergy conversion using different methods
From: Waste to bioenergy: a review on the recent conversion technologies
Method | Type of bioenergy | Type of feedstock | Composition/Yield/ Efficiency/Energy recovery | Operating condition | Reference |
|---|---|---|---|---|---|
Gasification | Fuel gas | Pine woodchips | Syngas composition: H2 gas: 26–42% CO gas: 25–37% CO2 gas: 16–19% CH4 gas: 8–11% | Dual circulating fluidized-bed gasifier Temperature: 700–900 °C Steam to fuel ratio: 0.3 kg·kg− 1 | [23] |
Bioelectricity | MSW and hazardous waste | Plant efficiency: 41.1% Power: 81 MW | Co-gasification using plasma gasifier. Composition of MSW: 90%wt Oxygen volume: 95% | [24] | |
Fuel gas | Eucalyptus chips and coffee husk | Higher heating value (MJ·N− 1 m− 3): Eucalyptus chips: 6.81 Coffee husk: 7.76 | Eucalyptus chip Temperature: 22.1 °C Air input flow: 182.7 Nm3·s− 1 Air consumption: 38.2 Nm− 3 Coffee husk Temperature: 26.3 °C Air input flow: 124 Nm3·s− 1 Air consumption: 13.4 Nm− 3 | [25] | |
Fuel gas | Rice straw | Efficiency: 33.78% CO gas: 2.01% H2 gas: 5.48% CH4 gas: 0.51% | Temperature: 600–800 °C Oxygen ratio: 33% Air flow: 0.6 Nm3·h− 1 Feed rate: 1.12 kg·h− 1 Equivalence ratio: 0.2 | [26] | |
Fuel gas | Acid hydrolysis residues and sewage sludge | Cold gas efficiency: 70.68% | Co-gasification using downdraft fixed gasifier at atmosphere pressure. Temperature: 800 °C Catalyst: CaO Sewage sludge composition: 50 wt% CaO/C (molar ratio):1.0 Equivalence ratio: 0.22 | [27] | |
Liquefaction | Bio-crude oil | Microalgae | Yield: 60.0% | Temperature: 350 °C Reaction time: 15 min | [28] |
Bio-crude oil | Jatropha curcas cake | Energy recovery: 41.48–54.78% | Temperature: 250 °C Catalyst: ChCl–KOH DESs Reaction time: 40 min | [29] | |
Bio-crude oil | Human faeces | Yield: 34.44% | Temperature: 300 °C Reaction time: 30 min Total solid content: 25% | [30] | |
Bio oil | Domestic sewage in high-rate ponds | Yield: 44.4% | Temperature: 300 °C Operation time: 15 min Biomass/water ratio: 1/10 (kg·kg− 1) | [31] | |
Crude biodiesel | Wet & dry microalgae (Nannochloropsis sp) | Biodiesel yield Wet microalgae: 14.18% Dry microalgae: 12.48% | Fermentation and Ethanol assisted liquefaction Temperature: 265 °C Ethanol: 15% (v/v) Ethanol to algae ratio: 2:1 | [32] | |
Methane and Energy | Microalgae Chlorella 1067 | Methane: 32–117% Energy recovery: 70.5% | Integrating HTL and anaerobic digestion with zeolite adsorption process. HTL process: Temperature: 300 °C Reaction time: 30 min Air pressure: 20 bar | [33] | |
Pyrolysis | Bio-oil | Sugarcane residues sugarcane leaves and tops | Yield: Sugarcane leaves: 52.5 wt% Sugarcane tops: 59.0 wt% | Fast pyrolysis Temperature: Sugarcane leaves: 429 °C and sugarcane tops: 403 °C Nitrogen gas flow rate: 7 L·min− 1 Biomass feed rate: 300 g·h− 1 | [34] |
Biochar, Bio-oil and gas | Greenhouse vegetable wastes and coal | Biochar yield: 40.22, 54.65, 45.93% | Fast pyrolysis Temperature: 500 °C Catalyst: calcite, dolomite, and zeolite Nitrogen gas flow: 1450 mL·min− 1 | [35] | |
Syngas (H2 and CO) | Spent coffee grounds loaded with cobalt | Yield concentration H2: 1.6 mol% CO: 4.7 mol% | Catalyst: Co-biochar Generation of H2: CO2 as atmospheric pressure Reaction time: 110 min Generation of CO: Temperature 700 °C | [36] | |
Bio-oil | Pinyon-juniper wood chips | Yield: 47.8 wt% | Temperature: 400 °C Catalyst: Red mud Feeding rate: 0.9 kg·h− 1 HDO of oil produced: Temperature: 350 °C Catalyst Ni/red mud | [37] | |
Bio-oil | beech wood | Yield: 86.1% | Hydrotreatment Temperature: 250 °C Catalyst: NiCu/Al2O3 | [38] | |
Anaerobic digestion | Methane | Sewage sludge | 181 mL CH4/g volatile solids | Thermal pretreatment Temperature: 95 °C Reaction time: 10 h Anaerobic incubation temperature: 35 °C | [39] |
Methane | Biomass from co-culture of microalgae and bacteria | 325 mL CH4/g volatile solids | CaO pretreatment Temperature: 72 °C Reaction time: 24 h Anaerobic incubation temperature: 35 °C | [40] | |
Methane | Biomass from mixed culture of 3 microalgae strains | 146 mL CH4/g COD | Batch culture of biomass Ammonia concentration: 250 mg NH4+·L− 1 Temperature: 23 °C Reaction time: 14 h Illumination 10 days Anaerobic incubation with sludge from wastewater plant Temperature: 35 °C | [41] | |
171 mL CH4/g COD | Semi-continuous culture of biomass Ammonia concentration: 300 mg NH4+·L− 1 Temperature: 23 °C Reaction time: 14 h Illumination 25 days Anaerobic incubation Temperature: 35 °C | ||||
Alcoholic fermentation | Bioethanol | Microalgae biomass (Chlamydomonas mexicana) | 0.22 g ethanol·L− 1 h− 1 | Simultaneous enzyme hydrolysis of biomass and fermentation with immobilized yeast Anaerobic incubation Temperature: 30 °C RPM: 120 | [42] |
Bioethanol | Biomass of 2 microalgae strains | 0.18 kg·kg− 1 biomass | Combined sonication, heat, and enzyme pretreatment of biomass Anaerobic incubation Temperature: 37 °C pH 5.5 Hydraulic retention time: 2.5 days | [43] | |
Mixture of acetone, butanol, and ethanol | Microalgae biomass (Chlorella vulgaris) | 0.32 g·L− 1 h− 1 | Lipid extraction of biomass: ionic liquid, acid hydrolysis (2% H2SO4) and detoxification (resin L-493) of biomass residue, then fed to yeast under anaerobic condition | [44] | |
0.35 g·L− 1 h− 1 | Lipid extraction of biomass: hexane/2-propanol, acid hydrolysis (2% H2SO4) and detoxification (resin L-493) of biomass residue, then fed to yeast under anaerobic condition | ||||
Photobiological hydrogen production | Hydrogen | Microalgae biomass (Chlorella sp.) | 11.65 mL·L− 1 | Medium: modified TAP Glycerol concentration: 16 g·L− 1 Anaerobic condition pH: 6.8 Light intensity: 48 μmol·m− 2 s− 1 Temperature: 30 °C Reaction time: 24 h | [45] |
Hydrogen | Microalgae biomass (Chlamydomonas reinhardtii CC124) | 1.05 mL·L− 1 h− 1 | Medium: sulfur-free TAP Light intensity: 50 μE·m− 2 s− 1 Anaerobic condition Reaction time: 120 h | [46] | |
1.3 mL·L− 1 h− 1 | Medium: sulfur-free TAP Light intensity: 50 μE·m− 2 s− 1 Anaerobic condition Reaction time: 120 h | ||||
Hydrogen | Microalgae biomass (Chlamydomonas reinhardtii CC124) | 0.60 mL·L− 1 h− 1 | Medium: sulfur-free TAP 40 mg·L− 1 nanoparticle Anaerobic condition Reaction time:72 h | [47] | |
Transesterification (Acid/Base Enzyme Catalyst) | Biodiesel | Triacylglycerols | – | Catalysed by acid or base | [48] |
Biodiesel | Crude oil of Pongamia pinnata, Jatropha curcas, Calophyllum innophylum | 90% | Esterification: Temperature: 60 °C Reaction time: 3 h Transesterification: mixture of oil with methanol Temperature: 60 °C Reaction time: 2 h | [49] | |
94% | Mixture of methanol and sodium methoxide (base catalyst) Temperature: 50 °C Reaction time: 2 h Stirring: 700 rpm | ||||
Biodiesel | Recycled cooking oil | MgO + CaO: 98.95% | Mixture heated to 55 °C for 20 min, added with methanol and warmed to 75 °C, moved to decanter after 4–6 h | [50] | |
Biodiesel | Mangifera indica oil | MgO: 79.26% ZnO: 77.14% SiO2: 94.9% | Optimized conditions: Methanol-to-oil molar ratio: 15:1 Catalyst: 0.5 wt% Temperature: 64 °C Reaction time: 1.5 h | [51] | |
Biodiesel | Refined sunflower oil | Yield: 94% | Optimized conditions: Methanol-to-oil molar ratio: 9:1 Catalyst: 0.3 wt% Temperature: 67 °C Reaction time: 3 h | [52] | |
Supercritical fluid | Lipid | Spent coffee grounds | Yield: 98.14% | Optimized conditions: Temperature: 40 °C Ethanol (18 ml/100 g) as modifier Pressure: 250 bar | [53] |
Biodiesel | FAME | 100% | Optimized conditions: Methanol-to-oil molar ratio: 40:1 Pressure: 200 bar Temperature: 350 °C Reaction time: 10 min | [54] | |
Lipid | Corn | 99% | Optimized conditions: Temperature: 60 °C Pressure: 300 bar CO2 flow: 3 ml/min 10 min static extraction 150 min dynamic extraction | [55] | |
MFC | Bioelectricity | Wastewater | Power density: 642 mW·m− 2 | MFC equipped with Pt electrode | [56] |
Bioelectricity | MSW | Power density: 1817.88 mW·m− 2 | Two chamber MSW MFCs with alkali hydrolysis pre-treatment | [57] | |
Bioelectricity | Fermentable household waste | Power density: 29.6 mW·m− 2 | Dual-chamber MFCs | [58] |