ALKALINE PRETREATMENT TO OPEN THE WOOD STRUCTURE FOR ENZYMATIC MODIFICATION
The LCC (lignin carbohydrate complex) structure of wood is so compact that the enzymes are too large to penetrate and thereby attacking the wood components for further modifications, which can be valuable for different purposes. Here we present a pretreatment method based on the traditional kraft pulping, which is a mature technology and can be used in large scale industrial production. To study this kind of chemical pretreatment, spruce wood samples were treated at different conditions for varying intensities (Hfactors). To verify if the structure was opened for enzymes, the pretreated wood samples were incubated with a cellulolytic culture filtrate which can degrade most of the cell wall to sugars, and the released reducing sugar concentration after the enzymatic treatment was measured. The results indicated that un-pretreated wood could not be attacked by the enzymes, but that only a relatively mild pretreatment was sufficient for letting the culture filtrate produce released reducing sugars which means it is enough with a relatively mild chemical treatment for allowing the enzymes to attack wood polysaccharides. This may be due to the lignin chains were cut down to shorter chains during this kind of pretreatment, which lowers the integrity of the wood structure by elimination of cross-links between polysaccharides, thereby compact wood structure can be opened to some degree. Or for the degradation of galactoglucomannan which has already suffered peeling reaction at 100℃ leads to opening of pores in the wood. Furthermore, kraft cooking liquor can easily be produced in large scale for a low price in processes integrated in chemical recovery system of kraft mills. Therefore the possibility to develop processes based on enzymatic treatment of wood biomass appears to be promising.
wood structure kraft pulping enzymatic modification LCC networks bio-refinery
Yan Wang Mikael E. Lindstr(o)m Gunnar Henriksson
Wallenberg Wood Science Centre (WWSC), School of Chemistry, Royal Institute of Technology, KTH, Stockholm 10044, Sweden
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
1041-1044
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）