Patent ID: 8552240

Claim:
Process for the production of propylene from a propanol feedstock A 2 comprising the following steps: 1. reacting the propanol feedstock A 2 in a vapour phase dehydration reactor wherein the propanol is converted at a temperature comprised between 160 and 270° C. and at a pressure of above 0.1 MPa but less than 4.5 MPa, into a product stream B 2 comprising propylene, propyl ethers, water and unconverted and/or isomerised propanols, 2. cooling said product stream B 2 , 3. disengaging said cooled product stream B 2 in a separation unit to give a first stream C 2 comprising propylene and propyl ethers, and a second product stream D 2 comprising water, propyl ethers and unconverted and/or isomerised propanols, 4. feeding said product stream D 2 to a dewatering unit wherein a water stream F 2 is separated from a propyl ethers and unconverted and/or isomerised propanols stream E 2 , 5. recycling said stream E 2 into the dehydration reactor of step 1, 6. cooling said product stream C 2 , 7. feeding said cooled product stream C 2 to a purification unit wherein a propyl ethers stream G 2 is separated from a propylene stream H 2 , and 8. optionally, recycling the propyl ethers stream G 2 to either the dewatering unit of step 4 or directly to dehydration reactor of step 1, wherein the propanol feedstock A 2 comprises at least 10 wt % but less than or equal to 85 wt % ethers; said ethers being selected from the group consisting of di n-propyl ether, n-propyl isopropyl ether and di iso-propyl ether.