Reactive distillation ether

Methyl acetate-methanol Minimum-hoiling azeotrope Ethylene glycol monomethyl ether Element of recovery system for alternative to production of methyl acetate hy reactive distillation alternative to azeotropic, pressure, swing distillation... 

Reactive distillation is used in the production of MTBE (methyl tertiary butyl ether)... 

Figure 1 Examples of industrial processes employing reactive distillation (a) methyl ferf-butyl ether (MTBE) from isobutene and methanol (b) cumene via alkylation of benzene with propylene (c) ethylene glycol via hydration of ethylene oxide.

Preston KL. Use of reactive distillation in the manufacture of methyl tertiary-butyl ether. U.S. Patent 5741953, Huntsman Specialty Chemicals Corp., 1998. 

Sundmacher K, Hoffmann U. Multicomponent mass and energy transport on different length scales in a packed reactive distillation column for heterogeneously catalyzed fuel ether production. Chem Eng Sci 1994 49 4443 4464. 

Reactive stripping has its own importance, in addition to reactive distillation. Several situations exist in which reactive stripping becomes more interesting for example, in the production of high-boiling esters and ethers, especially, when reactants or products are temperature-sensitive, and also in gas-liquid-solid processes, where product inhibition may play a role. 

Methyl tert-butyl ether (MTBE) has been produced by reactive distillation of isobutylene and methanol. The reaction is conducted in a distillation column loaded with socks containing a solid acid catalyst. 

Thiel, C Sundmacher, K., Hoffmann, U Residue curve maps for heterogeneously reactive distillation of fuel ethers MTBE and TAME, Chem. Eng. Sci., 52, no. 6, 993-1005, 1997... 

Fig. 18.26. Ethers—Axens. Includes alcohol purification (1), hydrocarbon purification (2), main reactor (3), reactive distillation system (4), wastewater system to remove water from the raffinate (5), and product fractionation column (6). (Source Hydrocarbon Processing, 2004 Refining Process Handbook. CD-ROM. September 2004 copyright 2004 by Gulf Publishing Co., all rights reserved.)...

FTocesses for the production of tertiary amyl methyl ether (TAME) Brockwell et ah, Hyd. Proc., 70(9), 133 (1991)]. Highly endothermic reactions may require intermediate reboilers. None of these heat management issues preclude the use of reactive distillation, but must be taken into account during the design phase. Comparison of heat of reaction and average heat of vaporization data for a system, as in Fig. 13-97, gives some indication of potential heat imbalances [Sundmacher, Rihko, and Hoffmann, Chem. Eng. Comm., 127, 151 (1994)]. The heat-neutral systems [-AH (avg)]... 

Quitain, A.T. Itoh, H Goto, S. Reactive distillation for synthesizing ethyl tert-butyl ether from bioethanol. In Reaction Engineering for Pollution Prevention, Abraham, M.A., Hesketh, R.P., Eds. Elsevier Science B.V. Amsterdam, Netherlands, 2000 237-246. 

Chemical Co. s methyl acetate reactive distillation process and processes for the synthesis of fuel ethers are classic success stories in reactive distillation. Improvements for the Eastman process are very high five-times lower investment and five-times lower energy use than the traditional process. However, combining reaction and distillation is not always advantageous and in some cases it may not even be feasible. The methyl acetate process based on reactive distillation has fewer vessels, pumps, flanges, valves, piping and instruments. This is an advantage also in terms of safety and maintenance. However, a reactive distillation column itself is more complex (multiple unit operations occur within one vessel) and thus more difficult to control and operate. It is thus not possible to make unique conclusions. 

The benefits of using reactive distillation are clearly proven in the production of fuel components (ethers) such as ferf-amyl methyl ether (TAME), methyl tert-butyl ether (MTBE) and methyl acetate. The latter is synthesized from acetic acid and methanol with a reversible liquid-phase reaction ... 

The reactive distillation operation is obviously not limited to zeolite catalysts. It can also be carried out with homogeneous acids such as sulfuric acid or p-toluene-sulfonic acid. Since they lack shape selectivity, these catalysts first convert phenyl-ethanol to the corresponding ether and only then to styrene. Hence, the reaction proceeds in a solution of heavy products that have accumulated over time. Additives have been developed to control the oligomerization reactions and keep the liquid viscosity at a workable level [35]. The heavy liquid medium needs to be bled. Its contamination with strong acid makes its disposal costly, however. 

A further process for which reactive distillation is commonly used in industrial practice is the synthesis of methyl-tert-butyl ether (MTBE) which is an additive for gasoline. MTBE is produced by etherification ofisobutene with methanol. The process based on reactive distillation leads to conversions of 99%. Isobutene and methanol are fed into the pre-reactor where the equilibrium conversion is obtained. The stream leaving the pre-reactor is fed into the reactive distillation column where MTBE is obtained as the bottom product. 

Over the last decade reactive distillation (RD) has become a key technology for meeting increased productivity demands. The best-known example in C4 chemistry is given by MTBE (methyl tert butyl ether) synthesis. Both the CD Tech process and the Ethermax process by UOP consist of fixed-bed reactors followed by an RD col-... 

The introduction of lead-free gasoline brought about a new technical process on a large scale reactive distillation (RD). Although the principle of this process had been known for many years [1], the need to produce huge quantities of ethers as antiknock enhancers caused rapid development of this technique more than 14 X 10 tonnes/year of ethers are produced. The catalysts for the production of methyl-t-butylether (MTBE), t-amylmethylether (TAME), or ethyl- butylether (ETBE), which are the main products for the fuel market, are acidic ion-exchange resins. The most important type is based on cross-linked polystyrene that is sulfo-nated to create the active acid sites. These resins are produced as beads of less than 3 mm in a suspension polymerization process. 

K. Sundmacher, U. Hoffmann, Multicomponent Mass and Energy Transport on Different Length Scales in a Packed Reactive Distillation Column for Heterogeneously Catalysed Fuel Ether Production, Chem. Eng. Sci., 1994, 49, 3077-3089. 

The tert-amyl methyl ether (TAME) reactive distillation system considered in Section 9.3 has similar chemistry (two reactants and only one product), and an internal composition controller is required to balance the reaction stoichiometry. There is a recycle stream of one... 

At this moment, fractionating reactors are mostly studied and applied outside the fine-chemical field. Examples are the large-scale production of the fuel ethers MTBE and TAME via reactive distillation. Also, biocatalytic studies have been performed. Malcata and co-workers investigated the integration of ester formation by Upases and distillative separation of the final products ester and water [44]. A number of synthesis reactions have been studied such as the esterification of ethanol and acetic acid to form ethyl acetate and water [45] in an SMB reactor with chemocatalysts (acidic ion exchange resins). Another, fairly similar appUcation was presented by Kawase et al. [46] to manufacture an ester from 2-phenylethanol. Mensah and Carta [47] used a chromatography column with lipases immobilised on resin to produce esters as well. 

Bisowarno B.H. and Tade M.O. (2000). Dynamic simulation of startup in ethyl tert-butyl ether reactive distillation with input multiplicity. Process Design and Control 39, 1950-1954. 2.9.1.2, 2.9.1.2, 2.9.2... 

Jacobs R. and Krishna R. (1993). Multiple solutions in reactive distillation for methyl tert-butyl ether synthesis. Industrial and Engineering Chemistry Research 32 (8), 1706-1709. 2.1, 2.9, 2.9.1.1,... 

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