Table 2.

The accumulated methane yields obtained after 55 days of anaerobic digestion from untreated and pretreated lignocellulosic substrates together with the specific rate constants and the regression coefficients calculated from the first-order kinetic model fitting.

Sample	Pretreated conditions	CH4 (L·kg−1CH)	k (day−1)	r 2
Elmwood	Untreated	54.2 ± 3.5	0.054	0.975
	150°C, 0.5 h	55.4 ± 9.7	0.063	0.934
	150°C, 1 h	63.6 ± 12.3	0.066	0.914
	180°C, 0.5 h	78.7 ± 0.4	0.062	0.961
	180°C, 1 h	93.7 ± 0.9	0.097	0.937
Pinewood	Untreated	38.7 ± 4.1	0.066	0.973
	150°C, 0.5 h	71.4 ± 3.7	0.094	0.981
	150°C, 1 h	63.3 ± 9.3	0.073	0.933
	180°C, 0.5 h	61.1 ± 4.4	0.080	0.979
	180°C, 1 h	56.0 ± 8.5	0.065	0.962
Rice straw	Untreated	115.9 ± 12.8	0.081	0.943
	150°C, 0.5 h	143.3 ± 7.1	0.084	0.946
	150°C, 1 h	152.7 ± 20.2	0.088	0.918
	180°C, 0.5 h	93.8 ± 19.9	0.078	0.991
	180°C, 1 h	113.4 ± 1.6	0.068	0.984