Table 2.
Element composition of HTC lignin (S/L ratio of 2/50) with different heating time

Temp. (℃) / Time (h)	Elemental content (wt%)				O/C	H/C
	C	O	H	N
Control	61.96	30.34	5.69	0.25	0.37	1.10
200 ℃/1h	63.92	28.93	5.47	0.27	0.34	1.03
200 ℃/2h	64.10	28.81	5.36	0.27	0.34	1.00
200 ℃/3h	64.38	28.50	5.43	0.26	0.33	1.01
200 ℃/5h	64.34	28.38	5.45	0.30	0.33	1.02
200 ℃/10h	64.96	28.05	5.40	0.26	0.32	1.00