Table 2.

Effect of additives on pretreatment efficacy and characteristics of pretreated substrates (EOS-20 mM ethanol organosolv pretreatment with 20 mM sulfuric acid, 2N 2-naphthol, NS 2-naphthol-7-sulfonate, MT mannitol, SA syringic acid)

	Cellulose recovery (%)	Hemicellulose recovery (%)	Lignin removal (%)	Delignification selectivity	Fiber swelling (WRV)	BET surface area (m2 g−1)	Cellulosic surface area (m2 g−1)a
EOS-20 mM	93.57 ± 0.80	38.40 ± 0.59	59.87 ± 0.01	1.02 ± 0.03	1.82 ± 0.14	3.86	184.83 ± 2.45
20 mM + 2N	94.68 ± 1.79	37.37 ± 0.30	55.68 ± 1.36	0.95 ± 0.11	1.70 ± 0.22	9.01	210.15 ± 4.67
20 mM + NS	93.08 ± 1.26	35.30 ± 0.45	76.13 ± 0.07	1.20 ± 0.01	2.48 ± 0.22	7.80	234.56 ± 7.37
20 mM + MT	94.42 ± 0.39	42.94 ± 0.28	59.49 ± 1.08	1.09 ± 0.02	2.03 ± 0.08	6.99	214.33 ± 2.81
20 mM + SA	93.60 ± 0.21	38.96 ± 0.64	59.53 ± 2.71	1.02 ± 0.10	2.04 ± 0.14	6.94	200.97 ± 2.71

^aCellulosic surface area was indicated by the maximum adsorption of DR28 to the pretreated solid, and 1 g of adsorbed dye corresponds to 1055 m² surface