A process to make propylene can include providing a reaction zone containing a catalyst and introducing a feedstock into the reaction zone. The catalyst can be an acid. The feedstock can include ethylene, dimethyl ether or methanol and dimethyl ether with at least 1000 wppm of dimethyl ether, and optionally steam. The feedstock can be contacted with the catalyst at temperature and pressure conditions to produce an effluent, including propylene, hydrocarbons, steam, optionally unconverted methanol and/or unconverted dimethyl ether and optionally unconverted ethylene. The temperature at the inlet of the reaction zone can be under 280° C., such as from 50 to 280° C. The effluent can be sent to a fractionation zone to recover propylene, optionally methanol, dimethyl ether and optionally ethylene. At least a part of methanol, dimethyl ether, and ethylene can be recycled to the reaction zone at step b).