tert-Butyl ethyl ether

General description and preparation:

Ethyl tert-butyl ether (ETBE) [637-92-3] is a clear, colourless to pale yellow liquid with a distinctive ether-like odour and a boiling point of 72 °C.^[1] It is extremely flammable liquid and vapor and it may cause skin, eye and respiratory irritation. It may cause drowsiness or dizziness.^[2] Ethyl tert-butyl ether is manufactured industrially by the acidic etherification of isobutylene (IB) with ethanol. The reaction is carried out with an acidic ion-exchange resin as a catalyst (macroporous sulfonic acid resins) at a temperature below 80 1C under pressurized conditions of 0.6 MPa.^[3] However, the supply of IB is limited because it is obtained from refinery catalytic cracking and steam cracking fractions. In addition, IB is mostly derived from non-renewable crude oil. Therefore, an alternative routes were developed based on reaction of tert-butanol (TBA) with ethanol in the presence of acid catalyst (β-zeolite supported on monolith).^[4]

Application of Ethyl tert-butyl ether:

ETBE is commonly used as an oxygenate gasoline additive. It was firstly used in 1992 in France. ETBE’s unique properties of high octane, low boiling point and low vapour pressure make it a very versatile and environmentally friendly gasoline blending component. ETBE reduces the environmental air pollution when it is blended with fuel because it allows complete fuel combustion. Thus, it exhibits a lower emission level of nitrogen oxides and other airborne pollutant, such as formaldehyde and carbon monoxide, compared with MTBE.^[5]

Product categorization (Chemical groups):

Main category:

• Ethers / Alkoxy group containing compounds

Second level:

• Aliphatic compounds

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