Catalytic distillation hydration

The first commercial and most well-known application of CD was in the production of MTBE. Besides etherification for the production of MTBE, CD could be applied in a number of processes such as alkylation, hydrogenation, isomerization, esterification, desulfurization, aldol condensation, oligomerization, hydration, hydrolysis, amination, and halogenation. Catalytic Distillation Technology (CDTECH), a partnership between ABB Lummus Global and Chemical Research and Licensing, is the leader in the development and commercialization of CD processes particularly related to the refining, petrochemical, and chemical industries. However, there are many more potential applications of CD that could be developed. 

Xu, Y. Chuang, K.T. Sanger, A.R. Design of a process for production of isopropyl alcohol by hydration of propylene in a catalytic distillation column. Inst. Chem. Eng. Trans. IChem. E 2002, 80, Part A, 686-694. 

Other industrial processes that have taken advantage of the process intensification deriving from the introduction of reactive (catalytic) distillation are (i) production of high purity isobutene, for aromatic alkylation (ii) production of isopropyl alcohol by hydration of propylene (iii) selective production of ethylene glycol, which involves a great number of competitive reactions and (iv) selective desulfurization of fluid catalytic cracker gasoline fractions as well as various selective hydrogenations. Extraction distillation is also used for the production of anhydrous ethanol. 

In the second part, the possible products of kinetically controlled catalytic distillation processes are analyzed using residue curve maps. Ideal, as well as non-ideal, ternary mixtures are considered. Current research activities are presented that are focussed on reaction systems exhibiting liquid-phase splitting phenomena such as the hydration of cyclohexene to cyclohexanol at strongly acidic catalyst partides. 

Laurone has been prepared by hydrating and decarboxylating decylketene dimer.3 It has also been prepared by distilling calcium laurate 4 by heating lauric acid with phosphorus pent-oxide 5 by heating barium laurate under reduced pressure 6 by the ester condensation of ethyl laurate with sodium ethoxide 7 or of methyl laurate with sodium hydride 8 followed by ketonic hydrolysis by catalytic ketonization of lauric acid over a chromate catalyst 9 or by passing lauric acid over thorium dioxide at 400°.10... 

The dehydrogenation process feed can be refinery streams from the catalytic cracking processes. This mixed C4 stream typically contains less than 20 percent n-butenes. For use in dehydrogenation, however, it should be concentrated to 80-95 percent. The isobutylene generally is removed first by a selective extraction-hydration process. The n-butenes in the raffinate are then separated from the butanes by an extractive distillation. The catalytic dehydrogenation of n-butenes to 1,3-butadiene is carried out in the presence of steam at high temperature (>600°C) and... 

Many hydroxypyrazine A oxides have been A(-deoxygenated to pyrazines with a variety of reducing agents which include heating with hydrazine hydrate in alcohols hydriodic acid and red phosphorus in acetic or phosphoric acid iodine and red phosphorus in refluxing acetic acid phosphorus tribromide in ethyl acetate sodium dithionite catalytic reduction with hydrogen over Raney nickel dry distillation with copper-chromite catalyst and titanium trichloride in tetrahydrofuran at room temperature. 

Reusch, D. Beckmann, A. Nierlich, F. Tuchlenski, A. Catalytic Hydration Procedure for the Production of Tert-Butanol from Isobutylene and Water and using Reactive Distillation German Patent DE10260991(A1), Jul 8, 2004. 

The difficulties attending the catalytic vapor phase hydration of olefins, while not apparent from the claims made in the patents which have been obtained for such processes, are serious and numerous. Aside from those already mentioned, the difficulties of separating the alcohol from the dilute liquid condensate by distillation and of purifying the alcohols from hydrocarbon polymers by a process of chlorination or selective absorption must be overcome. In view of the success that has attended the hydration of olefins, particularly those higher than ethylene, by means of absorption in sulfuric acid followed by dilution and distillation, it is probable that direct hydration processes at the present stage of the art will be unable to compete as long as cheap sulfuric acid is available. 

To a benzene solution of 10.7 g (60 mmol) of dimethyl (2/ ,32 )-tartrate and 10.6 g (60 mmol) of acetophenone dimethyl acetal is added a catalytic amount of 4-tohienesulfonic acid hydrate, and the mixture is heated to reflux to remove the liberated CH3OH azeotropically with occasional addition of henzene until the boiling point reaches 80.5 "C. The mixture is washed with sat. aq NulICO, and then with brine and is dried over Na2S04. The solvent is removed under reduced pressure and the residual oil is purified by silica gel column chromatography to afford the product, whieh is further purified by bulb-to-buib distillation yield 10.7 g (63%) bp 140 rC/0.15 Torr [a]D +11 (c = 2.6. CH,Cl2). 

The acetylene process was developed in Germany in the early 1940s to supply the synthetic rubber industry [19]. Acetylene is reacted with hydrogen cyanide in an aqueous medium in the presence of catalytic amounts of cuprous chloride. The reaction is maintained at 80 90°C at a pressure of 1-2 atm. The reaction is highly exothermic forming a gaseous reactor effluent. This crude product is water-scrubbed and the pure acrylonitrile product is recovered from the resultant 1-3% aqueous solution by fractional distillation. The major drawbacks of this process are the large number of by-products formed by hydration, the loss of catalyst activity from hydrolysis reactions, and the buildup of ammonium chloride and tars. 

Acetaldehyde is obtained by the catalytic hydration of acetylene or by the catalytic dehydrogenation of ethanol. Formic acid and formaldehyde are by-products of acetic acid synthesis. They are removed by distillation. Chemically pure acetic acid is diluted with water to 60-80% by volume to obtain the vinegar essence. The essence is a strongly corrosive liquid and is sold with special precautions. It is diluted further with water for production of food grade vinegar. 

In 1984,150 million gallons of ethanol were produced synthetically in the United States, and around 500 million gallons of ethanol were produced by fermentation. Close to 1.1 billion gallons of fermentation alcohol will be produced in 1992. Synthetic ethanol is produced from ethylene via catalytic hydration. Its major U.S. producers include Shell Chemical, Union Carbide, National Distillers and... 

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