Effect of Extruder Screw Speed, Temperature, and Enzyme Levels on Sugar Recovery from Different Biomasses

Table 6

Various methods used for pretreatment of switchgrass along with enzyme dose and reported results.

Pretreatment	Pretreatment condition	Cellulase, FPU/g DM	β-glucosidase CBU/g DM	Glucose %	Xylose %	Total %	Reference
Lime		5	28.4	60	72	64
	0.1 Ca(OH)2 g^−1, 120^°C, 2 h, 9 mL; water/g	10	28.4	68	80	70
		25	28.4	76	90	80	[21]
		50, 75, 100	28.4	80	>90	84
Lime	0.1 Ca(OH)2 g^−1, 121^°C, 15 min	38	66.5			75.8	[44]
AFEX	1 : 1 ammonia to switchgrass with 80% moisture, 100^°C, 5 min (hydrolysis 7 days)	15^*	40^*	93	70		[31]
Alkali-microwave	0.1 g NaOH/g, 190^°C, 2 h, solid loading 50 gL^−1	12	21	87.3	95.4	90.2	[34]
Alkali-RF	0.2–0.25 g NaOH/g, 90^°C, 20% solid loading	12	21	67.8	96.8	78.5	[35]
Aqueous ammonia soaking		26	NR			44
	5 mL aqueous ammonium hydroxide g^−1, 5 days (hydrolysis 4 days)	38.5	NR			68
		77	NR			60
		26	NR			60
	10 mL aqueous ammonium hydroxide g^−1, 10 days (hydrolysis 4 days)	38.5	NR			72	[36]
		77	NR			65
Alkali-microwave		2.5	70	31		44.7
		5	70	53.5		55.5
		10	70	67.6		75.0
	2% NaOH, 250 W, 10 min	15	70	81.7		80.5	[37]
		20, 40	70	82.0		80.0
		15	10	67.6
		15	20	82.0	63	80
		15	40, 70	80.0

DM—dry matter, ^*per gram of cellulose, NR—not reported.