Economic evaluation of the methyl tertiary butyl ether (MTBE) complex was carried out staring from n-butane and by captive production of methanol from natural gas. The processing steps consist of isomerization of n-butane to isobutane, dehydrogenation of isobutane to make isobutene, and finally, the reaction of isobutene with methanol to produce MTBE. Two different plant sizes were considered, and the effect of 30% lower feedback prices on profitability was studied. It was found that the raw materials cost is a dominant component, composing about 55% of the total production cost. An internal rate of return of 19% could be realized for 500,000 tons per annum MTBE complex based on economic data in mid-1993. The payback period estimated at this capacity was 3.8 years, and the break-even capacity was 36.6%.