| abstract |
In the process for the preparation of C2 to C4 olefins from methanol, dimethyl ether and, if appropriate, water vapor-containing gas mixtures in the presence of catalysts at temperatures from 250 to 500 ° C. and pressures from 0.1 to 6 bar with recycling of the unreacted starting materials, the mixture is evaporated Begins a methanol / water mixture in a volume ratio of 1: (0 to 2) and converts it into a reactor containing the catalyst, partially condenses the reaction gases by cooling, separates them into three phases in a separator, and draws those consisting of higher aliphatics and aromatics Oil phase, washes the remaining aqueous phase and the gas phase in a washing column at pressures from 1 to 40 bar with water, draws off a gaseous hydrocarbon mixture containing predominantly C2 to C4 olefins and separates it in a manner known per se, draws up the unconverted methanol and the dimethyl ether formed as an intermediate from the bubble of the washing column containing aqueous phase and distilled from it in a stripping column from methanol and dimethyl ether and leads them back into the reactor while the water is drawn off from the bubble of the stripping column. |