Abstract: The invention concerns an improved process for the conversion of ethylene into butene-1, wherein the ethylene is brought into contact with a catalyst obtained by the reaction of an alkyl titanate, possibly mixed with an ether, with a compound of aluminium of the formula AlR.sub.3 or AlR.sub.2 H, and in the presence of an additive formed by at least one quaternary ammonium salt.

Abstract: The invention concerns a process for the separation of a mixture comprising ethylene, 1-butene, alpha-olefins containing at least 6 carbon atoms per molecule and possibly heavier hydrocarbon products, the ethylene content of the mixture being in the range 30% to 70% by weight, in which separation is effected in a distillation zone to obtain an overhead fraction comprising the major portion of the ethylene present in the mixture and between 0% and 100% by weight of the 1-butene present in the mixture, the process being characterized in that the zone is also supplied with supplemental 1-butene in an amount in the range 1 to 40 times the quantity (by weight) of 1-butene present in the mixture. In a preferred implementation of the process of the invention, the mixture originates form a homogenous liquid phase ethylene oligomerisation zone.

Abstract: The invention concerns an improved process for the conversion of ethylene into light alpha olefins wherein the ethylene is brought into contact with a catalyst obtained by mixing a compound of zirconium with an organic compound selected from the class of acetals and ketals, esters, ketones, ethers, amines, nitrites, anhydrides, chlorides of acids, amides, aldehydes, thioethers, sulphides and disulphides, thiophenes, thioureas and phosphines, and with a chloro or bromo compound of aluminium hydrocarbyl, in the presence of an additive formed by at least one quaternary ammonium salt.

Abstract: For obtaining of improved purity of light alpha olefines produced by oligomerization of ethylene, the ethylene is placed in contact with a catalyst obtained by mixture of a zirconium compound with an organic compound selected from the class of acetals and ketals and with a chlorinated or brominated aluminium hydrocarbyl compound, and that the raw oligomerization effluent is firstly treated with an amine, then subjected to vaporization so as to collect the alpha olefines in the vaporized fraction.

Abstract: The invention concerns an improved process for the conversion of ethylene into but-1-ene, wherein the ethylene is brought into contact with a catalyst obtained by the interaction of an alkyl titanate, possibly mixed with an ether, with a compound of aluminium of the formula AlR.sub.3 or AlR.sub.2 H, and in the presence of an additive formed by at least one polyethylene glycol and/or one of its derivatives such as a monoether or a monoester of polyethylene glycol.

Abstract: Process for producing a hydrocarbon cut of high octane number by etherification of an olefin-containing hydrocarbon cut.The olefinic cut, to which methanol is added, passes into an etherification reactor (1) wherefrom are separated (3) a bottom product (15) containing ethers, and a top product (14) containing residual methanol and unreacted light olefins. This top product passes into an etherification reactor (2) and then is washed with water (8).The top product is finally admixed with the bottom product.The so-obtained motor-fuel has a higher octane number than that of the initial hydrocarbon cut.