Abstract: A process for converting oxygenates to olefms comprising: a) contacting an oxygenate containing stream with a molecular sieve catalyst under oxygenate to olefms conversion conditions in a reactor to form an effluent comprising olefms; b) separating C3-hydrocarbons from C4+ hydrocarbons in the effluent; c) separating C1 hydrocarbons and other light gases from C2+ hydrocarbons; d) separating C2 hydrocarbons from the C3 hydrocarbons; e) sending the C3 hydrocarbons to a C3 splitter to separate pro pylene from propane; f) removing propylene from the C3 splitter; and g) removing propane from the C3 splitter.

Abstract: A process for converting oxygenates to olefins comprising: a) contacting an oxygenate containing stream with a molecular sieve catalyst in an oxygenate to olefins conversion reactor under oxygenate to olefins conversion conditions to form an effluent comprising olefins; b) quenching the effluent by contacting with water; and c) contacting the quenched olefin stream with a molecular sieve to remove at least a portion of the water from the quenched olefin stream wherein the molecular sieve has a dimethyl ether adsorption capacity of less than 0.1 wt %.

Abstract: A process for preventing contaminants from forming in a compressor in a methanol to olefin separation system comprising: compressing an effluent in the compressor, the compressor having an inlet in fluid communication with a suction line, an outlet, and an inner compressor surface; and injecting a contaminant prevention medium into the suction line of the compressor wherein any contaminants are removed from the compressor with the effluent and optionally separated or otherwise removed from the effluent stream in downstream equipment.

Abstract: A method of converting an oxygenate comprising feedstock to olefins comprising: feeding an oxygenate comprising feedstock into a reactor containing an oxygenate to olefins conversion catalyst; contacting the feedstock with the catalyst at oxygenate conversion conditions to produce olefins; removing an effluent comprising the olefins from the reactor; passing the effluent through a compression section to form a compressed effluent; and adding methane to the compression section.