The conversion of methanol or synthesis gas is an attractive route for producing ethylene and propylene from coal. Utilizing a chabazite ion exchanged with ammonium and rare earth chlorides, methanol is converted to ethylene and propylene with carbon yields of 70 to 90% at reaction temperatures of 375 to 425/sup 0/C and pressures to 100 psi. Carbon disulfide in the feed at concentrations less than 200 ppM increases the operating time between regenerations from four hours to twenty hours. At carbon disulfide concentrations of 300 ppM or greater, the catalyst goes through the stages of dehydrogenation catalysts, a producer of ethylene and propylene, and then a dehydration catalyst. Water has no detrimental effect on the catalyst, and appears to enhance its activity. When synthesis gas (a one-to-one mixture of hydrogen and carbon monoxide) is passed over the catalyst at 365/sup 0/C and atmospheric pressure, methane, carbon and carbon dioxide are produced.