You manage a chemical plant within a refinery complex that produces 60,000 tonne/y of methyl tertiary-butyl ether (MTBE). MTBE is a gasoline additive used to increase octane number that is produced from methanol and isobutylene. Methanol is purchased but the isobutylene is obtained from a refinery stream. The stream contains 23% isobutylene, 20% 1-butene and 57% 2-butenes and can be supplied at a maximum rate of 500 kmol/h. Only isobutylene reacts with methanol; 1- butene, cis-2-butene and trans-2-butene are inert for this reaction. MTBE is produced by a liquid-phase reaction over a catalyst.