Steam exploded wheat straw
Sun Fangfang, Xu Lu of A and C, Sun of B Bureau, Ms. B, C, * pages fowlerc and bairdd.
College of Forestry, Northwest University, Yangling 7 12 100.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 5 1064 1.
Ll57 2uw Biology Center, Bangor University, UK
Department of Chemistry, Bangor University, England, ll57 2uw
Received on 27 April 2004; 2004127 October accepted +65438.
On February 2, 2004, 65438 was provided online.
The cellulose in wheat straw was treated by steam explosion in two steps.
Followed by alkaline hydrogen peroxide post-treatment. Straw at 200°c, 10 and 33 15, and 220°c, 3,5 and 22 bar.
After 8 minutes, the solid-liquid ratio was 2: 1 (width/width) and 220°c, 22bar, 5 minutes, and the solid-liquid ratio was 10: 1 respectively. should
Washing the cooked straw with hot water to produce a solution rich in hemicellulose derivatives and oligosaccharides.
The residues of 6 1.3%, 60.2%, 66.2%, 63. 1%, 60.3% and 6 1.3% are respectively. Detergent fibers are refined and bleached.
2%, hydrogen peroxide, ph 1 1.5 at 50℃ for 5 hours, 34.9%, 32.6%, 40.0%, 36.9%, 36. 1% (accounting for dry wheat straw) were obtained.
Preparation of cellulose. The best cellulose yield (40.0%) can be obtained by steam explosion before treatment.
The performance was carried out at 220℃ and 22 bar for 3 minutes, and the solid-liquid ratio was 2∶ 1, in which the cellulose fraction obtained an average viscosity.
The polymerization degree is 587, and it contains 65438 04.6% hemicellulose and 65438 0.2% klassen lignin. Steam explosion pretreatment
The post-treatment of hemicellulose and alkaline hydrogen peroxide caused great losses, resulting in a large number of dissolved lignin and a kind of
Increase the crystallization of cellulose. The further characteristics of the six separated cellulose samples include infrared spectrum and 13c-cp/mas.
Nuclear magnetic resonance spectroscopy and thermal analysis.
Elsevier Limited, 2004 All rights reserved.
Key words: wheat straw; Steam explosion; Cellulose; Hydrogen peroxide solution
1 。 Introduction mason 1 granted a patent, which is a process in 1928. After wood chips or shavings are briefly treated with steam, the pressure is released quickly, and the steam explodes through the valve. This has become a well-known separation method of wood fiber materials and has been incorporated into its main components: cellulose, lignin and hemicellulose. 2-4. During steam explosion, a large number of chemical substances are partially hydrolyzed and part of lignin is degraded, resulting in the dissolution of sugars and phenolic compounds in water. Hydrolyzed glucoside and wave-4 methyl ether bond linked to lignin in hemicellulose catalyze the generation of acetic acid at high temperature, and acetic acid exists in hemicellulose by acetyl groups. On the other hand, in
Lignin fragments that are hydrolyzed and degraded automatically remain in the adjacent condensation zone in the biomass energy matrix. five