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.sub.2 to produce a stream enriched in CO.sub.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.sub.2 or methane are then removed. Systems for removing the CO are also provided.

A process for producing a methane-containing gas mixture includes the steps of: (i) passing a first feed gas mixture including hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen, (ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and (iii) passing the second feed gas mixture through a bed of an oxidation catalyst to react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

A process for producing a methane-containing gas mixture includes the steps of: (i) passing a first feed gas mixture including hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen, (ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and (iii) passing the second feed gas mixture through a bed of an oxidation catalyst to react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

A process for producing a methane-containing gas mixture includes the steps of: (i) passing a first feed gas mixture including hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen, (ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and (iii) passing the second feed gas mixture through a bed of an oxidation catalyst to react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

A process for producing a methane-containing gas mixture includes the steps of: (i) passing a first feed gas mixture including hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen, (ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and (iii) passing the second feed gas mixture through a bed of an oxidation catalyst to react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

A method of safely mixing a hydrocarbon with an oxidant is provided. The hydrocarbon and oxidant are saturated with a non-flammable liquid in pre-mix zones that are flooded with the non-flammable liquid and fluidly connected to a common mixing zone that is partially flooded with the non-flammable liquid. The saturated hydrocarbon and oxidant combine within the common mixing zone forming bubbles of a homogeneous gas mixture of hydrocarbon and oxidant, preferably in a ratio of hydrocarbon to oxidant that is outside of the flammability limit, that can exit the non-flammable liquid into a headspace where it can be retrieved for use in an oxidative reaction process such as oxidative dehydrogenation.

A methane purification apparatus includes a flow path through which a gas containing methane flows, an ozone supply unit that supplies ozone to the gas, and a non-metallic heater that is provided downstream of the ozone supply unit in the flow path and heats the gas and the ozone. The heater supports a catalyst for purifying the methane by causing the ozone to react with the methane.