Process and device for the steam cracking of a hydrocarbon charge comprising a heating stage in a heat exchanger/reactor

摘要

The invention relates to a process and to a device for the steam cracking of a hydrocarbon charge. The heating stage of the charge is carried out by passing an amount of air and an amount of fuel into at least one gas generator (1), known as "Jet Engine", which delivers heating gases at a suitable pressure and a suitable temperature and which contains from 10 to 21% by volume of oxygen. These hot gases are conveyed into the shell (14) of a heat exchanger/reactor (11) which operates under pressure so as to crack the hydrocarbons which move in reaction tubes (12) of the exchanger/reactor. Controlled combustion in the exchanger/reactor of an amount of fuel, and optionally of an inert gas, by at least part of the heating gases containing oxygen is moreover carried out by appropriate means (16) so as to maintain the temperature substantially constant throughout the length of the tubes (12). The hot heating gases are then conveyed into a second heat exchanger (18) and then to a power recovery turbine (22). The steam cracking effluent is subjected to a quench (27) and recovered. <IMAGE>