Abstract: An improved technique is described for the recovery of aliphatic diol reaction solvent in a process wherein ethylene is oligomerized at elevated temperature and pressure by contact with a solution of a nickel complex catalyst in an aliphatic diol solvent to afford a reaction product made up of (a) a liquid solvent phase containing dissolved catalyst, (b) a liquid hydrocarbon phase comprising ethylene oligomers containing dissolved ethylene, catalyst and diol solvent and (c) gaseous ethylene, said reaction product being passed to a series of phase separation zones whereby gaseous ethylene and a substantial portion of the diol reaction solvent containing dissolved catalyst are separated and recycled to the oligomerization reaction zone with a minor portion of the separated reaction solvent being passed to a fractionation zone for removal of light ends and spent catalyst prior to reuse in the process. With this improved process, the formation of diol solvent degradation products, e.g.

Abstract: An aliphatic, cycloaliphatic or aromatic polyol is incorporated in a catalyst of an organoaluminum halide and a nickel compound. The catalyst is used for a dimerization or codimerization of a lower monoolefin to improve a reaction velocity and a stability in the reaction.

Abstract: Catalyst composition for oligomerizing olefins, obtained by contacting (a) a bivalent nickel compound with (b) a hydrocarbylaluminum compound of the formula AIRCl.sub.2 where R is a monovalent hydrocarbon radical, and (c) a Bronsted acid consisting preferably of a halogenocarboxylic acid of the formula R.sub.1 COOH in which R.sub.1 is a halogenoalkyl radical of the formula C.sub.m H.sub.p X.sub.q, X being halogen, m an integer from 1 to 3, p being zero or an integer and q being an integer, the condition p+q=2m+1 being fulfilled. A preferred Bronsted acid is of the formula R.sub.2 COOH in which R.sub.2 is a halogenomethyl group of the formula CX.sub.n H.sub.3-n, X being halogen and n an integer from 1 to 3.

Abstract: Ethylene is oligomerized to even numbered alpha-monoolefins principally in the C.sub.4 to C.sub.40 range with minimal concomittant production of high molecular weight polyethylene by reacting ethylene in a diol solvent in an oligomerization reaction zone at elevated pressure with a nickel complex catalyst composition produced by combining in the reaction zone, (a) a stable preformed complex of nickel, ethylene and hydride in a diol solvent, said complex being prepared by contacting in a diol solvent and in the presence of ethylene, a nickel salt, a base and a boron hydride transfer agent and (b) a suitable bidentate ligand; the stable nickel complex solution and the bidentate ligand being added in separate portions to the reaction zone. These stable complexes of nickel, ethylene and hydride in diol solution are considered to be novel oligomerization catalyst precursor compositions.

Abstract: Olefins are dimerized in a loop reactor with flashing of the reactor effluent in a flashing zone within the loop. A subsequent flash in a second flashing zone can also be used for the removal of product as flash vapor. In another embodiment, separated product dimers or product heavies are used as absorbents for unreacted ethylene. The use of a vapor-liquid contacting device incorporated in the loop reactor is especially helpful in the dimerization of an olefin when the olefin is available in low-concentration gas streams. A thermosiphon loop reactor can also be used for low-concentration olefin streams to minimize the power requirements as the energy of the feed gas is used to induce the reactor circulation.

Abstract: An improvement as described for the recovery of ethylene oligomers from the reaction product obtained when ethylene is oligomerized by contact in the liquid phase at elevated temperatures and pressures with a nickel complexed catalyst dissolved in an aliphatic diol solvent. In this improved process, the liquid oligomer product phase, after separation from gaseous and dissolved ethylene and liquid diol solvent, is subject to an aqueous acid wash followed optionally and preferably by a water wash to hydrolyze and extract diol solvent degradation products which carry through from the oligomerization reaction zone.

Abstract: Novel acid systems are disclosed which are characterized as being capable of stabilizing high concentrations of tertiary cations, e.g., t-butyl cation, and further characterized as capable of forming carbonium ion salts containing both dimeric and monomeric anions. The ions undergo hydride and halide exchange with other alkanes and halides. The hydride transfer reaction renders them useful in isomerization and alkylation reactions.

Abstract: A process for oligomerizing monoolefins using a catalyst system comprising at least one organoaluminum halide and at least one trans-halo(acyl)bis(triethylphosphine nickel(II) complex.