Dehydration of ethylene glycol

Prepared commercially either by dehydration of ethylene glycol with H2SO4 and heating ethylene oxide or bis(B-chloroethyl)ether with NaOH. 

Abeles and associates showed that when dioldehydratase (Table 16-1) catalyzes the conversion of l,2-[l-3H]propanediol to propionaldehyde, tritium appears in the coenzyme as well as in the final product. When 3H-containing coenzyme is incubated with unlabeled propanediol, the product also contains 3H, which was shown by chemical degradation to be exclusively on C-5 . Synthetic 5 -deoxyadenosyl coenzyme containing 3H in the 5 position transferred 3H to product. Most important, using a mixture of propanediol and ethylene glycol, a small amount of inter-molecular transfer was demonstrated that is, 3H was transferred into acetaldehyde, the product of dehydration of ethylene glycol. Similar results were also obtained with ethanolamine ammonia-lyase 399... 

Dehydration of alcohols served as the starting point in some early Russian studies of catalytic conversions (40), such as in the preparation of pentamethylethanol and its dehydration to form triptene (2,3,3-tri-methyl-1-butene), which was reported by Butlerov (45), and in the preparation of dioxane by dehydration of ethylene glycol by Favorskil (102). 

Burshe MC, Sawant SB, and Pangarkar VG. Dehydration of ethylene glycol by pervaporation using hydrophilic ipns of PVA, PAA and PAAM membranes. Sep. Purific. Tech. 1998 13(l) 47-56. 

Dioxane, mp -12°C, bp 101 °C, is a colourless liquid of pleasant odour, hygroscopic, and miscible with water and most organic solvents. It is widely used as a solvent. It is prepared by a cyclizing dehydration of ethylene glycol or diglycol, and by dimerization of oxirane, under acid catalysis in each case ... 

Kuila SB, Ray SK, Das P, Singha NR. 2011. Synthesis of full interpenetrating network membranes of poly(acrylic acid-co-acrylamide) in the matrix of polyvinyl alcohol for dehydration of ethylene glycol by pervaporation. Chem. Eng. Proc. Intensif 50(4) 391 03. 

If process (1) occurs in parallel with process (2) in the dehydration of ethylene glycol, then the 8123 form of the enzyme, containing Co, which reacts rapidly with N2O, is formed. 

In liquid separation, hollow fiber membranes based on PBI have shown excellent performance for pervaporation dehydration of organic liquids. For example, a dual layer PEI-PBI hollow fiber membrane with an outer selective layer of PBI showed better performance than most other polymeric membranes in pervaporation dehydration of ethylene glycol. Sulfonation modifications of PBI membranes have demonstrated excellent separation efficacies in the dehydration of acetic acid. Studies have shown that PBI hollow fiber membranes were effective in separating chromates from solutions. Also, PBI nanofiltration hollow fiber membranes are promising candidates as forward osmosis membranes. In gas separation, recent studies sponsored by the Department of Energy at Los Alamos National Laboratories and SRI International demonstrated potential applications of PBI membranes in carbon capture and Hj purification from synthesis gas streams at elevated temperatures. H2/CO2 selectivity > 40 has been achieved at H2 permeability of 200 GPU at 250°C. ... 

Y. Wang, M. Gruender, T.S. Chung, Pervaporation dehydration of ethylene glycol through polybenzimidazole (PBI)-based membranes ,/ Membr. Sci.,363,149 (2010). 

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