Table 3.

Different chemical pretreatment applied to the biogas production and yield

S/N	Biomass	Pretreatment	Degradation of hemicellulose (%)	Degradation of lignin (%)	Anaerobic digestion condition	YBP	YAP	Refs
1	Agave tequilana bagasse	2% (w/w) HCl			Batch at 32 °C, pH 5		0.26 L CH4/g COD	[177]
2	Pinewood	Organosolv (150 °C, 1 h)	21.3	26.5	250 mL conical flask at 39 ± 1 °C	38.7 ± 4.1 CH4 (L/kg CH)	63.3 ± 9.3 CH4 (L/kg CH)	[178]
3	Sugarcane bagasse	Alkaline autoclaving			Batch at 35 °C for 30 days	222 mL CH4/g VS	420 mL CH4/g VS	[179]
4	Wheat straw	Urea (1% w/w)			Batch at 35 °C, 120 rpm	210.4 mL CH4/g VS	305.5 mL CH4/g VS	[180]
5	Corn Straw	Hydrochloric acid 2% v/v			1 L Erlenmeyer flask at 37 ± 1 °C	100.6 mL/g VS	216.7 mL/g VS	[176]
6	Corn Straw	Sodium hydroxide 8% v/v			1 L Erlenmeyer flask at 37 ± 1 °C	100.6 mL/g VS	163.5 mL/g VS	[176]
7	Corn Straw	Ammonia 10% v/v			1 L Erlenmeyer flask at 37 ± 1 °C	100.6 mL/g VS	168.3 mL/g VS	[176]
8	Cotton gin waste	Ethanol 0.5 mmol/g VS substrate			250 mL conical flasks at 35 °C	172.5 mL/g VS	241.5 mL/g VS	[181]
9	Sorghum bicolor stalk	H2SO4	10.5	41.8	250 mL batch reactors at 37 °C	55% CH4	54.5% CH4	[129]
10	Sorghum bicolor stalk	H2O2	17.5	9.2	250 mL batch reactors at 37 °C	55% CH4	61.5 CH4	[129]