Comparative study of acid- and alkali-catalyzed 1,4-butanediol pretreatment for co-production of fermentable sugars and value-added lignin compounds

Table 3 Effect of acid and alkali BDO pretreatment on substrate characteristics

Pretreatment	Water retention value (WRV)	XRD results			XPS results
Pretreatment	Water retention value (WRV)	CrI	CrI/cellulose	Crystallite size (nm)	Surface lignin coverage	C1 (%)	C2 (%)	C3 (%)
HCl-BDO 10 mM	2.06	0.58	1.02	3.15	0.99	75.55	20.33	4.12
HCl-BDO 20 mM	2.27	0.66	0.99	3.22	0.86	71.42	23.70	4.88
HCl-BDO 30 mM	2.43	0.68	0.93	3.33	0.81	61.04	34.24	4.72
HCl-BDO 40 mM	2.50	0.69	0.88	3.34	0.70	51.20	44.49	4.30
HCl-BDO 50 mM	2.68	0.71	0.80	3.38	0.56	47.91	48.23	3.86
NaOH-BDO 250 mM	2.32	0.59	0.95	3.18	0.75	57.88	40.66	1.45
NaOH-BDO 300 mM	2.36	0.57	0.88	3.22	0.72	54.90	42.95	2.16
NaOH-BDO 350 mM	2.44	0.55	0.81	3.22	0.68	49.86	47.40	2.75
NaOH-BDO 400 mM	2.46	0.55	0.78	3.30	0.64	47.94	48.46	3.59
NaOH-BDO 450 mM	2.51	0.55	0.76	3.30	0.63	45.37	48.34	6.29

ISSN: 2731-3654