NOVELTY - Natural gas processing system comprises (a) an oxidative coupling of methane (OCM) reactor system comprising at least a first reactor vessel having at least a first OCM catalyst; (b) an extraction system for separating at least one hydrocarbon compound from at least one non-hydrocarbon compound, (c) a fractionation system for separating at least two different hydrocarbon compounds, and (d) an interconnected pipeline fluidly connecting an inlet or an outlet of the reactor system to an inlet or an outlet of the extraction system and the fractionation system.    USE - The system is useful for processing natural gas to produce integrated hydrocarbon compounds and carbon dioxide (all claimed), where the hydrocarbon compounds include olefins, ethane, ethylene, propane, propylene, butanes, pentanes, iso-butane and natural gasoline used for oil refineries or petrochemical plants.    ADVANTAGE - The system processes the natural gas to produce integrated hydrocarbon compounds and carbon dioxide with reduced energy consumption in a flexible, cost and time effective and efficiency manner.    DETAILED DESCRIPTION - Natural gas processing system comprises either (a) an oxidative coupling of methane (OCM) reactor system comprising at least a first reactor vessel having at least a first OCM catalyst; (b) one or more of an extraction system for separating at least one hydrocarbon compound from at least one non-hydrocarbon compound, (c) a fractionation system for separating at least two different hydrocarbon compounds, and (d) an interconnected pipeline fluidly connecting one or more of an inlet or an outlet of the OCM reactor system to one or more of an inlet or an outlet of the one or more of the extraction system and the fractionation system, or (A) the component (a) as above per se for processing natural gas to produce an OCM product, where the OCM reactor system comprises a thermal energy extraction system thermally coupled to the OCM reactor system for removing thermal energy from the OCM reactor system, (B) a natural gas fractionation unit for separating one or more hydrocarbon components in one or more of natural gas or the OCM product from at least one other hydrocarbon product in the natural gas or OCM product, and (C) one or more heat exchangers thermally coupled to each of the thermal energy extraction system and the fractionation unit to convey thermal energy from the thermal energy extraction system to the fractionation unit to heat the natural gas or OCM product in the fractionation unit to separate the one or more hydrocarbon components in the natural gas or OCM product from at least one other hydrocarbon product in the natural gas or OCM product, or the component (a) as above per se, the component (b) as above per se for separating methane from natural gas liquids (NGLs) in natural gas, a thermal energy removal system for removing thermal energy from the OCM reactor system, and (C) as above per se for heating a methane rich effluent from the extraction system to greater than 400 degrees C, or the component (a) as above per se, a steam generator thermally coupled to the OCM reactor to generate steam from thermal energy produced by the OCM reactor, and an electrical generator coupled to the steam generator for generating electricity from steam produced by the steam generator. INDEPENDENT CLAIMS are included for:    (1) an integrated hydrocarbon processing system comprising a steam cracker to convert one or more saturated hydrocarbons into one or more unsaturated hydrocarbons, an OCM reactor system to convert methane to ethylene, and a hydrocarbon fractionation system, where the outlets of each of the steam cracker and OCM reactor system are fluidly connected to an inlet of the hydrocarbon fractionation system such that C2+ containing streams from each of the steam cracker and OCM reactor system are passed into the fractionation system;    (2) producing hydrocarbon compounds comprising either (a1) contacting methane and air/oxygen with an OCM catalyst under OCM reaction conditions in a first reactor system to produce an OCM product comprising two or more different hydrocarbon compounds, (b1) transferring the OCM product to an integrated fractionation system fluidly coupled to the first reactor system, and (c1) separating at least one hydrocarbon compound in the OCM product from at least one other hydrocarbon compound in the OCM product, or the step (a1) as above per se, the step (b1) as above per se to produce one or more higher hydrocarbon compounds from the one or more hydrocarbon compounds in the OCM product, (c2) transferring the one or more higher hydrocarbons produced in the oligomerization system to a fractionation system fluidly coupled to the oligomerization system, and the component (d) as above per se, or directing a first hydrocarbon feedstock comprising saturated hydrocarbons to a steam cracker to produce an unsaturated hydrocarbon containing stream, directing a second hydrocarbon feedstock comprising methane to an OCM reactor system to produce an ethylene containing stream, and directing the unsaturated hydrocarbon containing stream and the ethylene containing stream to an integrated fractionation system; and    (3) collecting carbon dioxide, comprising in the OCM reactor system, contacting methane and air/oxygen with the OCM catalyst under OCM reaction conditions to produce a product stream comprising one or more NGLs and carbon dioxide, separating carbon dioxide from the NGLs in the product stream in a NGL extraction system integrated with the OCM reactor system, and collecting carbon dioxide separated from the product stream.