Table 2 The comparison of extrusion methods
From: Alkaline twin-screw extrusion pretreatment for fermentable sugar production
References | Feedstock/size | Pretreatment methods | Optimum conditions | Sugar yields (%) | ||
|---|---|---|---|---|---|---|
Glucose | Xylose | Total | ||||
Kadam KL, Chin CY and Brown LW[16] | Corn stover/through 1/2” screen | A pilot-scale twin-screw extruder; autohydrolysis followed by NaOH treatment | Autohydrolysis at 210°C followed by NaOH (0.06 g/g biomass) at 220°C, 6 liquid/1 biomass, extruder speed of 28 rpm | 80a | 60 | - |
Karunanithy C and Muthukumarappan K[15] | Corn stover/4 mm | Single screw extruder; no chemical applied | 125°C, extruder speed of 75 rpm, 21% moisture content | 75 | 49 | 61 |
Karunanithy C and Muthukumarappan K[29] | Prairie cord grass/8 mm | Alkali soaking followed by single screw extrusion | 114°C, extruder speed of 122 rpm, 1.7% NaOH concentration, 7 liquid/1 biomass | 86.8 | 84.5 | 82.0 |
Karunanithy C and Muthukumarappan K[30] | Switchgrass/6 mm | Alkali soaking followed by single screw extrusion | 180°C, extruder speed of 118 rpm,2% NaOH concentration, 7 liquid/1 biomass | 90.5 | 81.5 | 88.0 |
Karunanithy C and Muthukumarappan K[26] | Swithgrass/8 mm | Single screw extrusion; no chemical applied | 176°C, extruder speed of 155 rpm, moisture content 20% | 41.4 | 62.2 | 47.4 |
Zhang S, Keshwani DR, Xu Y and Hanna MA[22] | Corn stover/2 mm | Alkali soakage followed by twin screw extrusion | 140°C, screw speed of 80 rpm, NaOH loading of 0.04 g/g biomass, 3.67 g/min biomass | 86.8 | 50.5 | - |
Zhang S, Xu Y and Hanna MA[27] | Corn stover/2 mm | Twin-screw extruder; no chemical applied | 140°C, screw speed of 80 rpm, 27.5% moisture content, 3.67 g/min biomass | 49 | 25 | 40 |
Karunanithy C, Muthukumarappan K and Gibbons WR[28] | Pine wood/8 mm | Single screw extruder; no chemical applied | 180°C, screw speed of 150 rpm, 25% moisture content | 65.8 | 65.6 | 66.1 |
Choi CH and Oh KK[31] | Rape straw/1.40-2.36 mm | Twin screw extrusion with sulfuric acid | 165°C, screw speed of 19.7 rpm, 3.5% sulfuric acid concentration, 6.9 mL/min liquid,0.5 g/min biomass | 70.9b | - | - |
ATSE method (present work) | Corn stover/2-5 cm | Twin screw extrusion with NaOH solution | 99°C, screw speed of 325 rpm, NaOH loading of 0.06 g/g biomass, 2 liquid/1 biomass, 200 kg/h biomass | 82 | 69 | 78 |