DISSOLUTION AND STRUCTURAL CHANGES OF LIGNIN FROM PRETREATED STEAM EXPLODED WHEAT STRAW BY ETHANOL PRETREATMENT
Pretreatment of steam exploded wheat straw by ethanol has been tried to achieve dissolution of lignin.Different reaction conditions were explored for pretreatment by varying reaction temperature(150,160 and 170 oC),time(10,20 and 30 min),the ratio of solid to liquid(1:4,1:5 and 1:6),ethanol concentration(55%(v/v)),and experiment to find out that temperature was the main factor leading to degree of dissolution of lignin,the rate of which could achieve almost 51.63%which was measured by NREL procedure.Based on the FT-IR,UV,TGA,1H NMR studies,the further research of structural changes of LP(lignin was extracted with 60%(v/v)alkaline-ethanol(5%(w/w)NaOH)concent rations at 80 oC for 3h from ethanol pretreatment pulp and obtained by weak acid precipitation)and LL(lignin was obtained from black liquor by weak acid precipitation)were investigated.From the FT-IR spectra of the lignin,it can be known that the conjugated carbonyl/carboxyl of lignin were destroyed,and LP has experienced demethoxyl reaction during ethanol pretreatment process,which is contrary to LL,which could be further confirmed by UV and 1H spectra.Thermostability of LP was relatively good due to the reason of the condensation reaction during ethanol pretreatment process,relative to LL.The lignin of steam exploded wheat straw mutual change between the three kinds of aromatic structure,and methoxyl protons indicate the happening of demethoxyl reaction during ethanol pretreatment process.
Cheng Pan Zhong Liu Lanfeng Hui Yimei Hong
Tianjin Key Laboratory of Pulp and Paper,Tianjin University of Science and Technology,Tianjin,300457 Tianjin Key Laboratory of Pulp and Paper,Tianjin University of Science and Technology,Tianjin,300457
国际会议
第五届制浆造纸新技术国际研讨会(ISETPP)暨第三届国际造纸与环境学术大会(IPEC)
广州
英文
1-9
2016-11-07（万方平台首次上网日期，不代表论文的发表时间）