Process for producing synthesis gas

Process for the production of synthesis gas by catalytic steam reforming of hydrocarbon feedstock by parallel arrangement of heat exchange reforming (HER) and autothermal reforming (ATR) comprising:

• passing a first hydrocarbon feedstock through an autothermal reforming stage and withdrawing an effluent gas of raw synthesis gas;
• dividing the raw synthesis gas into at least a first and second portion of raw synthesis gas, wherein the ratio of the volumetric flow rate of the second portion of the raw synthesis gas to the volumetric flow rate of the effluent gas of raw synthesis gas is 50-95%;
• passing a second hydrocarbon feedstock through the catalyst side of a heat exchange reforming stage and withdrawing a primary reformed synthesis gas;
• combining a portion or all of the primary reformed gas with the first portion of raw synthesis gas to form a synthesis gas,
• passing the synthesis gas through the non-catalyst side of the heat exchange reforming stage to provide heat for the steam reforming reactions in said catalyst side by indirect heat exchange with said synthesis gas;
• and
• withdrawing, from the heat exchange reforming stage, a cooled synthesis gas.