Patent ID: 7288691

Claim:
A process for heat treatment of a hydrocarbon feedstock in a furnace that comprises at least one parallelepipedic radiation chamber with two opposite radiant walls supporting catalytic burners comprising parallelepipedic panels each comprising one face along one radiant wall and an opposite face formed by a porous panel parallel to said one radiant wall and emitting heat toward at least one essentially vertical exchange tube bundle bundle, the process comprising: providing at least one essentially vertical exchange tube bundle inside of which circulates the hydrocarbon feedstock to be treated, equipping said radiant walls with catalytic radiant burners with porous panels that are typically used in the form of essentially horizontal or optionally vertical bands that are distributed over several levels in the vertical direction, or respectively in the horizontal direction, generating with the catalytic radiant burners a mean temperature Tm of the radiant walls of between 900° C. and 1300° C., having a ratio R of the cumulative surface of the porous panels to the cumulative surface of the radiant walls of at least 0.3 and selecting the ratio R high enough and mean temperature Tm low enough that the NOx level in the smoke at the outlet of the furnace is at most 100 mg/NM 3 .