纤维素直接催化转化制乙二醇及其他化学品_从基础研究发现到潜在工业应用

1、Direct catalytic conversion of cellulose to ethylene glycolcatSource of this paper：1. Introduction 介绍2. Catalyst development for CEG 纤维素直接转化为乙二醇的催化及的发展2.1 tungsten carbide catalysts 碳化钨催化剂2.1.1first application of tungsten carbide for CEG 碳化钨对CEG的首次应用2.1.2high performance tungsten carbide catalyst 高

2、绩效的碳化钨催化剂2.2 M(8,9,10)-W bimetallic catalysts M（8,9,10）钨双金属催化剂2.3 tungsten acid based composite catalysts 钨基复合催化剂2.4 other metal based catalysts 其他金属基催化剂3. reaction mechanism 反应机理4. lignocellulosic feedstock conversion 木质纤维素原料转化5. strategy to develop the CEG process for commercialization发展CEG工艺商业化策略

3、6. incorporating the CEG process into a bio-refinery process 将CEG的过程变成一个生物炼制过程7. conclusions and prospects 结论与展望Ethylene glycol（EG) is the largest bulk polyol with a global consumption of up to 21 million ton/year . It is widely used in synthesis of polyester, antifreeze,ect .And is estimated to hav

4、e increasing demand in the coming decades , currently , EG is mainly produced from petroleum ethylene byselectively catalytic oxidation and hydration Process . some recent endea-vors have also been made for the catalytic preparation of EG from coal,which is also a fossil carbon resource . Using Cell

5、ulose to synthesize EGwould notably contribute to alleviating the dependence on fossil energyresources and cut down on co2 emission . Meanwhile , this process could keep All the atoms from cellulose in the products , and thus it would havea very high atom economy , which is required for green chemis

6、try. The one-pot catalytic conversion of cellulose to ethylene glycol is a highly attractive way for biomass utilization to lessen the consumption of fossil energy resources.Reaction mechanism:For one thing :1.The cellulose hydrolysis to form oligosaccharides and glucose.2.The catalytic breakage of

7、the C-C bond selectively takes places At the position between the carbon . in the degradation ofGlucose-based oligosaccharides , glycol aldehyde group.For another : Glucose isomerizes into fructose , C3 molecules will be formed , leading to the 1,2-PG and glycerol formation after a series of subsequ

8、ent reaction .Catalysts for the one-pot catalytic conversion of cellulose to EG and chemicals can beClassified two categories : (1) tungstenic catalysts . (2) other transition metal based binaryCatalysts(其他过渡金属二元催化剂）.Tungstenic catalyst : tungsten carbides , tungsten phosphides , tungstenic bimetall

9、ic catalysts , tungsten acid based binary catalystsOther transition metal based binarycatalysts: Group 8,9,10 metals in combination with basic or amphoteric metal oxidesCurrent level: Since the first disclosure in 2008 , the one-pot catalytic conversion of cellulose to EG has gained remarkable advan

10、ces in scientific understanding and industrial application.The EG yield has been improved from 61% to 71% by more efficient tungstenicCatalysts .the active components of the catalysts have been vastly broadened from tunsten carbides to binary components , which comprise tungsten and a hydrogenation

11、metal. Catalyst stability has been significantly improved ,as shown by the performance of tungsten acid-based binary catalysts. Current research hotspot:(1). The Raney NI-tungsten acid catalyst is the most promising candidated for CEG process industrialization due to low cost ,good reusability,and e

12、asy recycling properties .(2) Some non-tungstenic catalysts , including Ni/ZnO and Cu-Cr-Ca catalysts, have been explored and shown to give reasonably good performance . Some questioned should be answered in the future:(1): How do the tungsten species interact with sugar and oligosaccharide molecules?(2):What is the kinetics of the cascade reaction involved i