Table 1.

Conditions of aqueous ammonia extraction, mass yield of solids and soluble lignin, and composition of the resulting solid fractions before enzymatic saccharification.

Entry	Pre-treatment		Mass yield		Composition of solids, % dry weight basis
	NH3 (wt-%)	T (°C)	Solids (%)	Soluble lignin (% of HT-straw)	Glca	Xyla	Araa	Ligninb
1	0	0	100.0	0	39.8 ± 0.2	23.5 ± 0.4	2.7 ± 0.0	23.6 ± 0.2
2	0	140	80.2	n.a.	41.5 ± 0.3	21.2 ± 0.3	1.8 ± 0.1	23.9 ± 0.0
3	0	100	92.7	1.3	43.6 ± 0.5	21.1 ± 1.2	0.8 ± 0.1	22.9 ± 0.2
4	4	100	84.9	6.5	47.0 ± 0.6	20.9 ± 1.2	0.8 ± 0.2	22.0 ± 0.0
5	4	130	80.8	9.4	51.1 ± 0.3	20.0 ± 0.5	1.9 ± 1.0	19.7 ± 0.5
6	4	160	77.1	11.6	54.5 ± 0.7	18.3 ± 0.5	0.7 ± 0.2	19.5 ± 0.3
7	12	100	83.8	6.6	48.7 ± 0.5	20.5 ± 0.3	0.5 ± 0.5	20.6 ± 0.5
8	12	130	75.4	12.0	53.5 ± 1.3	18.6 ± 1.2	0.5 ± 0.5	17.3 ± 0.4
9	12	130	76.3	10.7	52.4 ± 0.4	19.2 ± 1.0	0.4 ± 0.4	18.0 ± 0.5
10	12	160	72.7	14.2	54.8 ± 0.8	18.1 ± 1.0	0.5 ± 0.2	16.2 ± 0.8
11	20	100	80.2	8.3	51.7 ± 0.6	20.9 ± 0.1	0.7 ± 0.2	20.1 ± 0.7
12	20	130	73.2	11.5	54.8 ± 0.7	17.5 ± 0.8	0.4 ± 0.4	16.2 ± 0.7
13	20	160	68.6	15.8	59.2 ± 0.5	18.2 ± 0.5	0.7 ± 0.2	13.2 ± 0.2

^aCalculated as anhydrous sugars;

^bIncludes acid-insoluble and acid-soluble lignin. n.a., not analyzed. Entries: 1 = original wheat straw, 2 = wheat straw subjected to 5 h hydrothermal (HT) treatment at 140°C; 3 = 100°C water-extracted HT-straw (entry 2), 4–13 = aqueous ammonia pre-treated HT-straw (entry 2).