Abstract
Hemicelluloses are potential raw materials for different
types of biobased materials. Alkaline extraction of
bleached birch kraft pulp yields pure, high molecular
weight hemicellulose (xylan) and hemicellulose-poor pulp.
In this work, the concentration of alkali and the
extraction temperature were studied as parameters for
xylan yield and mass balance in the extraction.
Extraction at room temperature using 1 molar aqueous
sodium hydroxide (NaOH) showed the highest value for the
mass balance with 98.5 wt.% on dry matter of pulp - 16.1
wt.% xylan in the extract and 82.4 wt.% extracted pulp.
Recycling of 90% of the NaOH used for the extraction was
demonstrated by ultrafiltration. The ultrafiltration
process is thus a highly potential tool offering an
economical way to simultaneously recycle chemicals and
separate products from process liquids in xylan
extraction and other biorefinery processes. The concept
of alkaline extraction was also demonstrated for brewer's
spent grain (BSG). Arabinoxylan comprised 80% of the
carbohydrates in the alkaline extract of BSG. However,
the selectivity of the extraction was poor as proteins,
lipids and some lignin were also efficiently extracted
from BSG in alkaline conditions.
Original language | English |
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Pages (from-to) | 231-237 |
Journal | Industrial Crops and Products |
Volume | 70 |
DOIs | |
Publication status | Published - 2015 |
MoE publication type | A1 Journal article-refereed |
Keywords
- xylan
- birch kraft pulp
- brewer's spent grain
- alkaline extraction
- sodium hydroxide
- mass balance