Integrated dimerization process

In a process for manufacturing vinyl olefins containing from 4 to 30 carbon atoms, comprising:

• (1) reacting ethylene in a chain growth reaction in the presence of an alkyl aluminum chain growth catalyst in at least one chain growth step;
• (2) displacing the alkyl moieties of the resulting aluminum alkyl chain growth product in at least one displacement step to form a displacement product mixture comprising the corresponding vinyl olefins formed from the alkyl moieties;
• (3) fractionating the displacement product mixture from at least one aforesaid displacement step to separate a liquid fraction comprising vinyl olefins containing from 4 to 30 carbon atoms;
• and
• (4) fractionating the resulting liquid fraction to separate therefrom a lower molecular weight fraction comprising vinyl olefins;
• the improvement which comprises:
• (5) dimerizing vinyl olefins to form vinylidenes and deep internal olefins in the presence of an alkyl aluminum dimerization catalyst comprising alkyl aluminum at an initial molar ratio of alkyl aluminum to vinyl olefins of from about 0.01 to about 1.5:1 and at a temperature in the range of from 200° C. to about 288° C. for a period of time in the range of from about 30 minutes to about 120 minutes to thereby convert vinyl olefins at a selectivity for the formation of vinylidenes and deep internal olefins combined of at least 50 mole percent;
• and
• (6) treating the resulting dimerization product mixture by
• (a) combining it in its entirety with the feed to at least one aforesaid chain growth step (1) or to at least one aforesaid displacement step (2);
• or
• (b) combining it in its entirety with the product mixture from the least one aforesaid chain growth step (1) or with the product mixture from at least one aforesaid displacement step (2);
• or
• (c) fractionating it to separate a light olefin fraction and a heavier fraction comprising vinylidenes and deep internal olefins which heavier fraction is then treated as in step (a) or (b);
• such that the resulting displacement product mixture comprises vinylidenes and deep internal olefins from the dimerization product mixture or chain growth products of such vinylidenes and deep internal olefins which are separated with the aforesaid vinyl olefins in the liquid fraction separated in step (3) and are subsequently separated as the higher molecular weight fraction from the vinyl olefins in step (4).