Table 1.

Combinatorial pretreatment strategies to fractionate lignin from corn stover [38]

Case	Step 1			Step 2
	Chemicals	Conditions	Solid loading (%)	Chemicals	Conditions	Solid loading (%)
1	1% NaOH	120 °C, 60 min	10	–	–	–
2	Liquid hot water	120 °C, 30 min	10	1% NaOH	120 °C, 60 min	10
3	Liquid hot water	120 °C, 30 min	10	50% ethanol + 1% NaOH	120 °C, 60 min	10
4	1% H2SO4	120 °C, 30 min	10	1% NaOH	120 °C, 60 min	10
5	1% H2SO4	120 °C, 30 min	10	50% ethanol + 1% NaOH	120 °C, 60 min	10

% was calculated based on the weight percent, w/w