Patent ID: 7329787

Claim:
A process for transforming an initial hydrocarbon feed comprising linear and branched olefins containing 4 to 15 carbon atoms, said process comprising the following steps: (y) a preliminary step of at least partially eliminating the nitrogen-containing or basic impurities contained in the initial hydrocarbon feed, a) selectively etherifying the majority of the branched olefins present in said initial hydrocarbon feed with an alcohol to obtain an effluent; b) treating all the effluent from step (a) including the linear olefins contained in said initial hydrocarbon feed under moderate oligomerization conditions to obtain an effluent; c) separating the effluent from step b) into at least two cuts: a β cut having a maximum boiling point that is below a temperature in the range 150° C. to 200° C. and comprising the ethers formed during step (a); a y cut with an initial boiling point higher than a temperature in the range 150° C. to 200° C. and at least partially comprising hydrocarbons; d) treating a hydrocarbon fraction containing the ethers formed during step a) under conditions for cracking ethers at least partially, said treatment being followed by separation into a gasoline fraction with an improved octane number and into a fraction containing the initial alcohol; e) hydrogenating the y cut under conditions for producing a gas oil with a high cetane index.