Production of cellulosic ethanol from steam-exploded Eucalyptus urograndis and sugarcane bagasse at high total solids and low enzyme loadings

Sustainable Chemical Processes

Table 1 Chemical compositions of native and pretreated sugarcane bagasse and E. urograndis

Components	Sugarcane bagasse		E. urograndis
Components	Native	Pretreated	Native	Pretreated
Anhydroglucose	36.32 ± 0.77	46.50 ± 3.12	44.72 ± 0.78	56.34 ± 1.36
Anhydroxylose	15.62 ± 1.51	2.74 ± 0.44	12.25 ± 0.21	1.07 ± 0.03
Anhydroarabinose	1.40 ± 0.59	bdl	bdl	bdl
Acetyl group	2.58 ± 0.29	bdl	2.94 ± 0.22	bdl
Unidentified anhydrohexose^a	1.91 ± 0.03	2.24 ± 0.01	2.13 ± 0.03	2.10 ± 0.02
Unidentified anhydropentose^b	6.40 ± 1.35	0.95 ± 0.09	3.11 ± 0.77	0.92 ± 0.44
Acid soluble lignin	0.06 ± 0.01	0.04 ± 0.01	0.06 ± 0.01	0.04 ± 0.09
Acid insoluble lignin	22.13 ± 1.63	36.66 ± 1.18	25.16 ± 1.40	39.06 ± 1.86
Total extractives	5.34 ± 0.49	nd	1.72 ± 0.11	nd
Ashes	7.79 ± 0.53	10.43 ± 0.65	0.36 ± 0.06	0.32 ± 0.03
Total	99.55	99.56	99.83	99.85
Total glucan content^c	38.23	48.74	46.85	58.44
Total hemicellulose content^d	26.00	3.69	18.30	1.99
Total lignin content^e	22.19	36.70	25.22	39.10

nd not detected; bld below the detection level of the method
^aDehydration by-products from hexoses, quantified as hydroxymethylfurfural
^bDehydration by-products from pentoses, quantified as furfural
^cTotal anhydroglucose content plus its corresponding value in HMF
^dSummation of anhydroxylose, anhydroarabinose, acetyl groups and the pentose equivalents that were detected as furfural
^eAcid soluble lignin plus acid insoluble lignin