Patent ID: 7687050

Claim:
A process for producing a synthesis gas, SG, from overall feed F constituted by hydrocarbons and optionally from recycled compounds, F comprising a first feed F 1 and a second feed F 2 , in which: a stream comprising the first feed F 1 supplemented with steam undergoes steam reforming to produce a first synthesis gas SG 1 in at least one multi-tube reactor-exchanger R comprising a plurality of reaction tubes ( 38 ) containing a steam reforming catalyst, said first feed F 1 , steam and said first synthesis gas SG 1 , said reaction tubes being housed within a shell; said reaction tubes ( 38 ) are heated principally by convection by circulating in said shell a heating fluid HF external to said tubes, in which HF is a substantially free of nitrogen first partial oxidation stream of the second feed F 2 at a pressure in the range of 0.5 to 12 MPa, said first partial oxidation stream being formed within only the shell or immediately upstream of said reactor-exchanger R to produce a second synthesis gas SG 2 within said shell, said heating fluid HF transferring heat to said reaction tubes, thereby being cooled, said cooled heating fluid HF being then reheated in 1-8 complementary successive partial oxidation zones ( 32 , 34 , 42 , 44 ) fed by at least one second portion of said second feed F 2 and oxygen, to increase the temperature of successively heated and then cooled partial oxidation streams, the resultant mixture circulating in the shell of R serving to provide complementary heat to the reaction tubes before leaving said reactor-exchanger R, and wherein synthesis gas SG 1 and SG 2 produced by different processes are in indirect heat exchange relationship with each other in the same reactor-exchanger R; and synthesis gas SG is produced by mixing resultant SG 1 and SG 2 .