Ethyl ETBE process

Application The Uhde (Edeleanu) ETBE process combines ethanol and isobutene to produce the high-octane oxygenate ethyl tertiary butyl ether (ETBE). 

Ethers, such as MTBE and methyl / fZ-amyl ether (TAME) are made by a catalytic process from methanol (qv) and the corresponding isomeric olefin. These ethers have excellent octane values and compete on an economic basis with alkylation for inclusion in gasoline. Another ether, ethyl tert-huty ether (ETBE) is made from ethanol (qv) and isobutylene (see Butylenes). The cost and economic driving forces to use ETBE vs MTBE or TAME ate a function of the raw material costs and any tax incentives that may be provided because of the ethanol that is used to produce it. 

Some isopentane is dehydrogenated to isoamylene and converted, by processes analogous to those which produce methyl /-butyl ether [1634-04-4] (MTBE) to /-amyl methyl ether [994-05-8] (TAME), which is used as a fuel octane enhancer like MTBE. The amount of TAME which the market can absorb depends mostly on its price relative to MTBE, ethyl /-butyl ether [637-92-3] (ETBE), and ethanol, the other important oxygenated fuel additives. 

Ethyl er -Butyl Ether. Ethanol can react with isobutylene to form ETBE much the same way as methanol is now processed into MTBE, methyl tert-huty ether (see Ethers). 

The most important application of RD today seems to be the production of ethers such as methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), and tertiary amyl methyl ether (TAME), which are widely used as modem gasoline components. Figure 7, upper part, shows a traditional process for MTBE production, which is a strongly exothermic reaction. The disadvantages of that process can be avoided if the reaction and separation take place within the same zone of the reactor (Figure 7, lower part). 

The ether process combines an alcohol with an iso-olefin. In the United States, a weight percentage of oxygenate (2 wt.%) content is mandated for reformulated gasoline (RFG). The most common oxygenate currently used is methyl tertiary butyl ether (MTBE). Methanol and the iso-olefin form of isobutylene are reacted to form MTBE. Other alcohols, such as ethanol, may be reacted with iso-butylene to form ethyl tertiary butyl ether (ETBE). Methanol can be reacted with iso-amylene, another iso-olefin, to form tertiary amyl-methyl ether (TAME). Of all the mentioned ethers, MTBE is the one most widely used as a gasoline-blending component.16... 

Ethyl Tertiary Butyl Ether (ETBE) - A chemical compound produced in a reaction between ethanoi and isobutyiene (a petroleum-derived by-product of the refining process). ETBE has characteristics superior to other ethers iow voiatiiity, iow water soiubiiity, high octane value, and a large reduction in carbon monoxide and hydrocarbon emissions. 

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. 

Blending and Additives. In the end, all gasoline components are blended together. At a modern refinery, this is done in a computer-controlled process. Additives are used primarily to boost octane rating. Lead was widely used once but was banned in 1996 in the United States, as well as in many other nations. With the increasing prohibition of methyl-tert-butyl-ether (MTBE) in many U.S. states, use of alternatives such as tertiary amyl methyl ether (TAME) or ethyl tert-butyl ether (ETBE) increased. There are many... 

Hydroalkoxylation reactions refer to the addition of an alcohol over an insaturation. This highly atom economical process is potentially a straightforward and clean access to ethers, and the reaction is successfully applied at the industrial level for the production of MTBE (methyl terf-butyl ether) and ETBE (ethyl tert-butyl ether) from isobutylene and methanol or ethanol. If this transformation is well known with activated olefins (reaction referred to a Michael addition), a real challenge is the synthesis of ethers from unactivated olefins. Veiy few reactions involving carbohydrates or polyols have been reported to date and most of them involve isobutylene as this substituted olefin is prompt to generate stabilized carbenium ion under acidic conditions. Dimerization reactions of the alcohol or isobutylene are the main side reactions that have to be avoided in order to reach high selectivities into the desired ethers. ... 

Other desirable ether compounds for gasoline blending can be made in a similar process. For example, ethyl tertiary butyl ether (ETBE) is made from ethanol and isobutylene. Tertiary amyl methyl ether (TAME) is made from methanol and isoamylene. 

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