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Table 3 Chemical composition of liquid and solid fractions after steam pretreatment, and enzymatic hydrolysis conversion

From: Novel ethanol production using biomass preprocessing to increase ethanol yield and reduce overall costs

  Liquid fraction Solid fraction
     Chemical composition Elemental composition3 Enzymatic hydrolysis
  pH Total sugars1 Glucan Xylan Lignin Ash Ca S Glucose conversion4
   kg/tonne mono %2 % % % % µg/g µg/g  %
Whole-tree chips (WTC)
 Untreated  1.8 239 ± 7 79.0% 60.7 ± 0.5 2.4 ± 0.0 36.6 ± 0.3 1.0 ± 0.3 3000 ± 171 1062 ± 13 67.7 ± 1.4
 Acidic 1.4 258 ± 2 91.1% 62.7 ± 0.1 1.3 ± 0.0 38.4 ± 0.9 0.2 ± 0.0 1349 ± 55 811 ± 22 75.7 ± 1.2
 Alkaline 1.6 245 ± 5 78.7% 63.1 ± 0.7 2.6 ± 0.0 35.2 ± 0.1 0.5 ± 0.2 2315 ± 10 1084 ± 16 72.7 ± 1.2
 Neutral 1.6 257 ± 9 78.9% 61.9 ± 0.5 1.6 ± 0.1 37.6 ± 0.3 1.0 ± 0.1 2766 ± 81 1144 ± 19 72.8 ± 0.6
Clean pulp chips (CPC)
 Untreated 1.4 168 ± 5 96.2% 68.0 ± 1.1 1.2 ± 0.1 34.4 ± 0.4 <0.1% 126 ± 16 486 ± 20 78.2 ± 2.3
 Acidic 1.4 213 ± 4 101.2% 66.8 ± 1.1 0.0 ± 0.0 33.6 ± 0.2 <0.1% 97 ± 19 408 ± 12 76.7 ± 1.2
 Alkaline 1.6 176 ± 1 93.4% 72.9 ± 0.6 2.4 ± 0.0 28.3 ± 0.2 <0.1% 99 ± 10 562 ± 21 69.8 ± 1.4
 Neutral 1.5 201 ± 5 93.5% 70.6 ± 0.3 1.4 ± 0.1 31.5 ± 0.5 <0.1% 57 ± 6 431 ± 11 73.2 ± 0.1
  1. Data represented as the mean values of triplicate analysis (except elemental composition that was done in duplicate), which in turn comes from two steam pretreatments replicates
  2. 1 Total sugars (kg/tonne of original biomass) include glucan, xylan, arabinan, galactan, and mannan
  3. 2 Monomeric sugar percentage of the total sugars
  4. 3 Magnesium, potassium, phosphorus, and sodium were completely removed (0 µg/g) during steam pretreatment from both WTC and CPC. Other elements were analyzed (including barium, iron, manganese, and silica), but they were either not detected or they were present at trace amounts (lower than 50 µg/g)
  5. 4 Maximum glucose conversion: WTC samples after 96 h of hydrolysis, and CPC samples after 48 h