Ethylene → Ethylene

Participants

Reaction Steps

According to the present invention, the reactor effluent from the oxygenate conversion process of Example I, Run A, at 435° C. is passed to a separation zone consisting of COx removal zone and a H2O separation zone to remove water and provide a hydrocarbon effluent. The hydrocarbon effluent is passed to a demethanizer to remove methane as an overhead stream and provide a demethanizer bottoms stream. The demethanizer bottoms consist of 50.3 equivalents of ethylene, 33.5 equivalents of propylene and 9.0 equivalents of butenes. The demethanizer bottoms stream is combined with a recycle stream from the propylene metathesis reactor consisting of 2.4 equivalents of ethylene, 27.1 equivalents of propylene and 4.0 equivalents of butenes to provide a combined stream to an ethane-ethylene column with 52.7 equivalents of ethylene, 60.6 equivalents propylene and 13.0 equivalents butenes. In the ethane-ethylene column the 52.7 equivalents of ethylene and 0.6 equivalents of ethane are separated overhead and C3+ fraction is recovered. The C3+ stream is passed to a propane-propylene (P-P) column wherein 13.0 equivalents of butenes and 2.0 equivalents of C5+ products are recovered as P-P bottoms. The overhead of the propane-propylene column, consisting of 60.6 equivalents of propylene is divided into two portions; 33.5 equivalents of propylene are passed to a propylene metathesis reactor while 27.1 equivalents of propylene are recovered as a propylene product. The propylene metathesis reactor is operated as described in Example 3 of U.S. Pat. No. 3,723,562 wherein the propylene conversion was 19% with a 37.6% selectivity to ethylene and a 62.4% selectivity to butenes. The entire effluent of this reactor is combined with the demethanizer bottoms as the recycle stream described above.

Provenance & Evidence