Patent ID: 7279610

Claim:
A method for the preparation of ethene, propene and butene by steam cracking comprising: subjecting a feed comprising heavy hydrocarbons obtained by Fischer-Tropsch synthesis, which Fischer-Tropsch hydrocarbons have an initial boiling point of above 150° C. and a final boiling point of below 400° C., to steam cracking in a naphtha designed steam cracking furnace, wherein the furnace comprises a convection zone provided with a first preheating zone in which the Fischer-Tropsch feed is heated, a second preheating zone in which the heated Fischer-Tropsch hydrocarbons are heated in the presence of steam to form a mixture of liquid and gaseous Fischer-Tropsch hydrocarbons; and a super heating zone in which the liquid and gaseous Fischer-Tropsch hydrocarbons are super heated; and a cracking zone in which the gaseous super heated Fischer-Tropsch hydrocarbons are steam cracked into ethene, propene and butene.