| Parameters | Dilute Acid | Hot Water | Dilute Alkali | Steam Explosion | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
 |  | Present Study | Laser et al. [30] | Aden et al. [19] | Kazi et al. [29] | Eggeman and Elander[31] | Present Study | Kazi et al. [29] | Eggeman and Elander[31] | Present Study | Present Study |
Biomass | Biomass | Tall Fescue | Switchgrass | Corn Stover | Corn Stover | Corn Stover | Tall Fescue | Corn Stover | Corn Stover | Tall Fescue | Tall Fescue |
Biomass Processing | Feedstock Rate (dry Mg/day) | 704.5 | 4535 | 2000 | 2000 | 2000 | 704.5 | 2000 | 2000 | 704.5 | 704.5 |
Pretreatment | Temperature (°C) | 180 | 190 | 190 | 190 | 140 | 180 | 190 | 180 | 180 | 180 |
 | Pressure (bar) | 11 | 12.3 | 12.3 | 11.8 | - | 11 | 12.5 |  | 11 | 11 |
 | Residence Time (min) | 15 | 2 | 2 | 2 | - | 15 | 5 | 5 | 15 | 15 |
 | Solid Loading (%) | 20 | 30 | 30 | 29.6 | - | 20 | 12.9 | 13.9 | 20 | 30 |
 | Acid/Alkali Concentration (%) | 1 | 1.1 | 1.1 | 1.9 | 1 | 0 | 0 |  | 1 | - |
 | Cellulose + 0.111 H2O→ 1.111 Glucose (%) | 13.04 | 6.5 | 7 | 6.3 | 8c | 0.43 | 0.32 | 4.5c | 0.29 | 5 |
 | Xylans + 0.136 H2O → 1.136 Xylose (%) | 60.26 | 85 | 90 | 82.5 | 90.2c | 70 | 2.39 | 50.8c | 0.72 | 70 |
 | Lignin → Soluble Lignin (%) | 5 | 5 | 5 | 10 | - | 5 | 5 |  | 25 | 5 |
 | Xylose → 0.64 Furfural + 0.36 H2O (%) | 5 | 5a | 5a | 10a | - | 2.5 | 0a | - | 0.01 | 15 |
 | Glucose → 0.7 HMF + 0.3 H2O (%) | 5 | - | - | 3b | - | 2.5 | 0b |  | 0.01 | 15 |
Hydrolysis and Fermentation | Bioconversion Method | SSCoFd | SSFe | SSCoF | SSCoF | - | SSCoF | SSCoF | Â | SSCoF | SSCoF |
 | Temperature (°C) | 35 | 37 | 65 (Sacchaarification) 41 (Co-fermentation) | 32 | - | 35 | 32 |  | 35 | 35 |
 | Enzyme Loading (FPU/g cellulose) | 15 | 15 | 12 | 18f | 15 | 15 | 18f | 15 | 15 | 15 |
 | Time (Saccharification + Fermentation) (days) | 5 | 7 | 3 (1.5 + 1.5) | 7 (5+2) | - | 5 | 7 (5+2) |  | 5 | 5 |
 | Cellulose + 0.111 H2O→ 1.111 Glucose | 79 | 80 | 90 | 91.09 | 83.8c | 78.5 | 89.97 | 90c | 84.75 | 70 |
 | Xylans + 0.136 H2O → 1.136 Xylose (%) | 80 | 80 | - | 57.13 | 55.1c | 80 | 56.6 | 64.63c | 80 | 80 |
 | Glucose → 0.489 CO2 + 0.511 Ethanol (%) | 95 | 90 | 95 | 95 |  | 95 | 95 |  | 95 | 95 |
 | Xylose → 0.489 CO2 + 0.511 Ethanol (%) | 70 | 90 | 85 | 75.6 |  | 70 | 75.6 |  | 70 | 70 |
 | Cellulase → 0.1 Protein Soluble + 0.9 water (%) | 99 | - | - | - | - | 99 | - | - | 99 | 99 |
Ethanol Recovery | Ethanol Recovery (%) | 98.76 | 98.8 | 98.9 | - | - | 98.76 | - | - | 98.76 | 98.76 |