Gasoline, MTBE

MTBE and related ethers are used to add octane to gasoline. MTBE also adds oxygen to the gasoline, which allows for more efficient combustion, and therefore less carbon monoxide and unbumed hydrocarbon in the exhaust emissions A relined grade of MTBE is used in the solvents and pharmaceutical industries. Its higher autoignition temperature and narrower flammability range also make it relatively safer to use compared to other ethers. 

Thus despite the occurrence as a subordinated component of gasolines, MTBE can appear in groundwater in higher concentrations than the CAH PCE and TCE exhibiting solubilities of 160 and 1200 mg/1. 

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. 

MTBE - Methyl Tertiary Butyl Ether (MTBE) is an ether compound used as a gasoline blending component to raise the oxygen content of gasoline. MTBE is made by combining isobutylene (from various refining and chemical processes) and methanol (usually made from natural gas). 

Contact and Inhalation Contact may irritate or bum skin and eyes. High eoneentrations of vapor are irritating to the eyes and respiratory traet. May eause dizziness and headaches. Inhalation of high concentrations eauses sleepiness and finally narcosis. Contact of the liquid with the eye eauses irritation. The foul odor of MTBE serves as a warning for water contamination by gasoline. MTBE is eonsidered to be of relatively low toxicity. 

Respiratory Respiratory depression may be noted. Labored and irregular breathing were associated with anesthetic effects in rats. Aspiration pneumonitis is possible following ingestion of gasoline-MTBE mixtures. 

MTBE Methyltert-butyl ether. Used as a gasoline additive. 

Acid catalyzed addition of alcohols to alkenes is sometimes used Indeed before Its use as a gasoline additive was curtailed billions of pounds of tert butyl methyl ether (MTBE) was prepared by the reaction... 

Small amounts of tert butyl methyl ether increase the octane rating of gasoline Before environmental concerns placed limits on its use the demand for MTBE exceeded the supply... 

Isobutyl alcohol [78-83-1] forms a substantial fraction of the butanols produced by higher alcohol synthesis over modified copper—zinc oxide-based catalysts. Conceivably, separation of this alcohol and dehydration affords an alternative route to isobutjiene [115-11 -7] for methyl /-butyl ether [1624-04-4] (MTBE) production. MTBE is a rapidly growing constituent of reformulated gasoline, but its growth is likely to be limited by available suppHes of isobutylene. Thus higher alcohol synthesis provides a process capable of supplying all of the raw materials required for manufacture of this key fuel oxygenate (24) (see Ethers). 

Isomeri2ation of straight-chain hydrocarbons is of particular importance for lead-free gasoline. Addition of high octane aromatic hydrocarbons or olefins is questionable based on environmental considerations (77). An efficient octane enhancing additive is methyl tert-huty ether (MTBE). 

More than 95% of MTBE produced worldwide is used to blend with gasoline. In 1987 U.S. production of MTBE exceeded 3.8 X 10 m /yr (1 X 10 gal/yr) (82). The worldwide capacity for MTBE is increasing, especially in the United States and Europe, and has been projected to exceed production for years to come. 

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. 

Methyl -Butyl Ether. MTBE is used as an oxygen additive foi gasoline. Production of MTBE in tiie United States has increased due to the... 

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