A process comprising: supplying a hydrocarbon feed and a steam feed into a syngas producing unit comprising a reforming reactor under syngas producing conditions to produce a reformed stream exiting the reforming reactor, wherein the syngas producing conditions include the presence of a reforming catalyst, and the reformed stream comprises H 2, CO, and steam; cooling the reformed stream by using a waste heat recovery unit ("WHRU") to produce a cooled reformed stream and to generate a high-pressure steam ("HPS") stream; contacting the cooled reformed stream with a first shifting catalyst in a first shift reactor under a first set of shifting conditions to produce a first shifted stream exiting the first shift reactor, wherein the first shifted stream has a lower CO concentration and a higher CO 2 concentration than the cooled reformed stream; cooling the first shifted stream to obtain a cooled first shifted stream; contacting the cooled first shifted stream with a second shifting catalyst in a second shift reactor under a second set of shifting conditions to produce a second shifted stream exiting the second shift reactor, wherein the second shifted stream has a lower CO concentration and a higher CO 2 concentration than the cooled first shifted stream; abating steam present in the second shifted stream to produce a crude gas mixture stream comprising CO 2 and H 2; recovering at least a portion of the CO 2 present in the crude gas mixture stream to produce a CO 2 stream and a H 2 -rich stream, wherein the H 2 -rich stream comprises H 2 at a concentration of at least 80 mol%, based on the total moles of molecules in the H 2 -rich stream; (VIII) combusting a portion of the H 2 -rich stream in the presence of an oxidant to generate thermal energy and to produce a flue gas stream; operating a steam cracker located in an olefins production plant under steam cracking conditions to convert a steam cracker feed into a steam cracker effluent comprising olefins; producing a CH 4 -rich stream from the steam cracker effluent; and providing the CH 4 -rich stream as at least a portion of the hydrocarbon feed in step; wherein the H 2 -rich stream is supplied to at least one combustion device used in the process for producing the H 2 -rich stream. supplying a hydrocarbon feed and a steam feed into a syngas producing unit comprising a reforming reactor under syngas producing conditions to produce a reformed stream exiting the reforming reactor, wherein the syngas producing conditions include the presence of a reforming catalyst, and the reformed stream comprises H 2, CO, and steam; cooling the reformed stream by using a waste heat recovery unit ("WHRU") to produce a cooled reformed stream and to generate a high-pressure steam ("HPS") stream; contacting the cooled reformed stream with a first shifting catalyst in a first shift reactor under a first set of shifting conditions to produce a first shifted stream exiting the first shift reactor, wherein the first shifted stream has a lower CO concentration and a higher CO 2 concentration than the cooled reformed stream; cooling the first shifted stream to obtain a cooled first shifted stream; contacting the cooled first shifted stream with a second shifting catalyst in a second shift reactor under a second set of shifting conditions to produce a second shifted stream exiting the second shift reactor, wherein the second shifted stream has a lower CO concentration and a higher CO 2 concentration than the cooled first shifted stream; abating steam present in the second shifted stream to produce a crude gas mixture stream comprising CO 2 and H 2; recovering at least a portion of the CO 2 present in the crude gas mixture stream to produce a CO 2 stream and a H 2 -rich stream, wherein the H 2 -rich stream comprises H 2 at a concentration of at least 80 mol%, based on the total moles of molecules in the H 2 -rich stream; (VIII) combusting a portion of the H 2 -rich stream in the presence of an oxidant to generate thermal energy and to produce a flue gas stream; operating a steam cracker located in an olefins production plant under steam cracking conditions to convert a steam cracker feed into a steam cracker effluent comprising olefins; producing a CH 4 -rich stream from the steam cracker effluent; and providing the CH 4 -rich stream as at least a portion of the hydrocarbon feed in step;