Process for the removal of carbon monoxide from non-catalytic oxidative dehydrogenation product streams
A method of removing CO from a mixture of CO and saturated or unsaturated hydrocarbons is provided. In one embodiment, the method is to contact a feed stream with an oxygen transfer agent; and then oxidize at least a portion of the CO to CO 2 to produce a stream enriched in CO 2 . The saturated and unsaturated hydrocarbons in the feed are not further oxidized during the oxidation. The oxygen transfer agent includes at least one of: i) water; ii) at least one reducible metal oxide; iii) at least one reducible chalcogen; or mixtures thereof. In another embodiment, the CO is converted to methane. The unsaturated hydrocarbons in the feed are not hydrogenated. In both of these alternatives, the CO 2 or methane are then removed. Systems for removing the CO are also provided.
1. A method of converting CO to CO 2 comprising,
a1) oxidative coupling of methane or oxidative dehydrogenation of hydrocarbons at hydrocarbon oxidation reaction conditions to produce a first process stream comprising the CO and at least one of C1 to C12 saturated or unsaturated hydrocarbons;
a) contacting the first process stream comprising the CO and the at least one of C1 to C12 saturated or unsaturated hydrocarbons with an oxygen transfer agent; and
b) oxidizing at least a portion of the CO to CO 2 and reducing at least a portion of the oxygen transfer agent to a reduced oxygen transfer agent, at reaction conditions, to provide a second process stream comprising the CO 2 , the reduced oxygen transfer agent, and the at least one of C1 to C12 saturated or unsaturated hydrocarbons;
wherein:
the C1 to C12 saturated or unsaturated hydrocarbons are not further oxidized in step b);
the hydrocarbon oxidation reaction conditions include the presence of less than 5 wt % of O 2 with respect to the total amount of CO in the first process stream; and
the oxygen transfer agent in step b) comprises water.
2. The method of claim 1 wherein the step a1) produces at least a portion of the water that is used as the oxygen transfer agent in step a).
3. The method of claim 2 , wherein step a1) and step a) are performed in the same reactor.
4. The method of claim 1 , wherein at least a portion of the water that is used as an oxygen transfer agent is added to step a).
5. The method of claim 1 , wherein the first process stream is contacted with a catalyst comprising at least one of iron, zinc, nickel, rhodium, iridium, platinum, palladium, gold, ruthenium, or a combination thereof.
6. The method of claim 1 , wherein the method further comprises
step e) removing at least a portion of the CO 2 from the second process stream.
7. The method of claim 1 , wherein the reduced oxygen transfer agent comprises H 2 .
8. A system for oxidatively converting CO to CO 2 comprising:
at least one reactor configured for:
a1) oxidative coupling of methane or oxidative dehydrogenation of hydrocarbons at hydrocarbon oxidation reaction conditions to produce a first process stream comprising the CO and at least one of C1 to C12 saturated or unsaturated hydrocarbons;
a) contacting a first process stream comprising the CO and the at least one of C1 to C12 saturated or unsaturated hydrocarbons with an oxygen transfer agent; and
b) oxidizing at least a portion of the CO to CO 2 , at reaction conditions, and reducing at least a portion of the oxygen transfer agent to provide a second process stream comprising the CO 2 , the reduced oxygen transfer agent, and the at least one of C1 to C12 saturated or unsaturated hydrocarbons; wherein:
the at least one of C1 to C12 saturated or unsaturated hydrocarbons are not further oxidized in step b);
the hydrocarbon oxidation reaction conditions include the presence of less than 5 wt % of O 2 with respect to the total amount of CO in the first process stream; and
the oxygen transfer agent in step b) comprises water.
9. The system of claim 8 , wherein the step a1) produces at least a portion of the water that is used as the oxygen transfer agent in step a).
10. The system of claim 9 , wherein step a1) and step a) are performed sequentially in the same reactor.
11. The system of claim 8 , wherein at least a portion of the water that is used as an oxygen transfer agent is added to step a).
12. The system of claim 8 , wherein the first process stream is contacted with a catalyst comprising at least one of iron, zinc, nickel, rhodium, iridium, platinum, palladium, gold, ruthenium, or a combination thereof.
13. The system of claim 8 , wherein the system further comprises a purification unit in communication with the at least one reactor, wherein the purification unit is constructed and arranged to remove at least a portion of the CO 2 from the second process stream.
14. The system of claim 8 , wherein the reduced oxygen transfer agent comprises H 2 .