An H2-rich fuel gas production plant comprising a. syngas production unit can be advantageously integrated, with an olefins production plant comprising a. steam cracker in at least one of the following: (i) fuel gas supply and consumption; (ii) feed supply and consumption; and (iii) steam supply and consumption, to achieve considerable savings in capital and. operational costs, enhanced energy' efficiency, and reduced CO2, emissions, compared to operating the plants separately.