Abstract
In order to dissolve xylan with high yield, but also to
preserve the average molar mass of the dissolved xylan as
high as possible, stepwise pressurized hot water
extraction (HWE) followed by alkali extraction was
applied to industrial birch sawdust in a semi-pilot scale
apparatus. This process revealed that the hot water
extraction at 160°C for 2 h was the most effective step
to dissolve xylan. The total extraction process dissolved
99% of the native xylan. HWE at 160°C for 30 min released
material with the highest weight average molar mass (Mw
12-14 kDa), and consisting mainly of xylan. The
extraction residue, containing mainly cellulose (76%) and
lignin (21%), was delignified and bleached to remove the
residual lignin and to produce hemicellulose-and
lignin-free cellulose. After soda pulping and oxygen and
chlorine dioxide bleaching, the pulp had kappa number
0.85 and ISO-brightness 79.8%. The cooking and bleaching
process should be further optimized. (10 refs.)
| Original language | English |
|---|---|
| Title of host publication | Proceedings |
| Subtitle of host publication | 16th International Symposium on Wood, Fiber and Pulping Chemistry, 16th ISWFPC |
| Pages | 666-671 |
| Volume | 1 |
| Publication status | Published - 2011 |
| MoE publication type | A4 Article in a conference publication |
| Event | 16th International Symposium on Wood, Fiber and Pulping Chemistry, ISWFPC 2011 - Tianjin, China Duration: 8 Jun 2011 → 10 Jun 2011 |
Conference
| Conference | 16th International Symposium on Wood, Fiber and Pulping Chemistry, ISWFPC 2011 |
|---|---|
| Country/Territory | China |
| City | Tianjin |
| Period | 8/06/11 → 10/06/11 |
Keywords
- alkali extraction
- betula verrucosa
- bleaching
- birch sawdust
- cellulose
- hot water extraction
- lignin
- molar mass
- pressurized extraction
- pulping
- xylan