ADDITION OF ALCOHOLS TO ISOBUTYLENE (Methyl- and Ethyl-Ter-Butyl Ether) |
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ADDITION OF ALCOHOLS TO ISOBUTYLENE (Methyl- and Ethyl-Ter-Butyl Ether)
The reaction between isobutylene and methyl and ethyl alcohols is an addition reaction catalyzed by a heterogeneous sulfonated polystyrene resin. When methanol is used a 98% yield of methyl-ter-butyl ether MTBE is obtained:
Ethyl-ter-butyl ether (ETBE) is also produced by the reaction of ethanol and isobutylene under similar conditions with a heterogeneous acidic ion-exchange resin catalyst (similar to that with MTBE):
MTBE and ETBE constitute a group of oxygenates that are currently in high demand for gasoline octane-number boosters. Both MTBE and ETBE have a similar research octane number of 118, but the latter ether has a motor octane number of 102 versus 100 for MTBE. However, the oxygen content of MTBE is 18.2% compared to 15.7% for ETBE. The lower oxygen content of ETBE is related to the air/fuel ratio, which may not require a change in the automobile carburetors. A comparison between the two ethers regarding phase separation, antiknock behavior, and fuel economy has been reviewed by Iborra et al.
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دراسة يابانية لتقليل مخاطر أمراض المواليد منخفضي الوزن
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اكتشاف أكبر مرجان في العالم قبالة سواحل جزر سليمان
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اتحاد كليات الطب الملكية البريطانية يشيد بالمستوى العلمي لطلبة جامعة العميد وبيئتها التعليمية
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