Process for recovering power in a process for producing ethylene

A process for power recovery in a process for producing ethylene, comprising the steps of:

• a) steam cracking a hydrocarbon feed in a cracking furnace at temperatures above 1000° C. to produce a cracked gas product having a temperature in the range of from 700 to 1000° C.;
• b) cooling the cracked gas product by indirect heat exchange with high pressure liquid water having an initial temperature above 270° C., an initial pressure above 65 bar (gauge) and a boiling point to obtain cooled cracked gas product while evaporating the high pressure liquid water to high pressure steam having a pressure above 65 bar (gauge) wherein the high pressure steam is at a temperature of the boiling point of the high pressure liquid water;
• c) expanding at least part of the high pressure steam in a first steam expansion turbine to produce power and to obtain medium pressure steam having a reduced temperature and reduced pressure compared to the high pressure steam wherein the high pressure steam is not superheated before it is expanded in the first steam expansion turbine;
• d) heating at least part of the medium pressure steam to increase the temperature of the medium pressure steam by in the range of from 40 to 100° C. by passing the medium pressure steam through a convection zone of the cracking furnace and retrieving reheated medium pressure steam from the convection zone;
• e) expanding at least part of the reheated medium pressure steam in a second steam expansion turbine to produce power and to obtain low pressure steam having a reduced pressure compared to the reheated medium pressure steam.