The current feedstocks, reaction products and manufacturing processes are summarized in the following table:

Olefin oligomerization processes can be divided into three main groups according to the type of catalyst employed:
1. Acidic catalysis with mineral acids such as H₃PO₄ or H₂SO₄, and with acidic ion-exchangers
2. Organometallic catalysis with Al-alkyls and possibly co-catalysts
3. Organometallic catalysis with alkali metals

To 1:

The UOP process employing H₃PO₄/SiO₂ in a fixed bed is widely used industrially. In this process, propene-rich fractions are oligomerized at 170-220°C and 40-60 bar with 90% propene conversion to yield a liquid reaction mixture consisting mainly of 'tri-' and 'tetrapropene'. Both products were once used mainly for the alkylation of benzene and phenol. However, sulfonates manufactured from alkyl derivatives have greatly diminished in importance as detergent bases due to their poor biodegradability. Increasing amounts of tetrapropene are undergoing hydroformylation, analogous to diisobutene (described below), and then hydrogenation to produce plasticizer alcohols.

Isobutene oligomerization with H₂SO₄ or acid ion-exchangers (Bayer Process) has been mentioned previously. After hydrogenation, 'diisobutene' is used as an additive in motor gasoline. It is also a precursor in the manufacture of isononanol by hydroformylation and hydrogenation. The alcohol is employed in plasticizer manufacture.

Exxon Chemical is the world's largest producer of branched higher olefins using this technology.

To 2:

There are two basic parameters affected by the choice of catalyst in the dimerizations and co-dimerizations of lower olefins. When a trialkylaluminum alone is used, high selectivity can be attained. When it is used in combination with a transition metal cocatalyst such as a nickel salt, the activity of the system increases at the expense of the selectivity.

Industrial applications have been developed for both types of processes.

In the Goodyear Scientific Design process, propene is dimerized to 2-methyl-l-pentene, an isoprene precursor, using tripropylaluminum at at 200 °C and 200 bar:

The other process was developed by IFP (Dimersol process). In this liquid-phase process, propene or butene can be homo-dimerized, or propene and butene can be codimerized. The Dimersol process is operated continuously with a trialkyl-ahminiurnhickel salt catalyst at 60°C and 18 bar with 50% selectivity, producing relatively few branched isoheptenes. The low selectivity is not due solely to the addition of cocatalyst, but also to the homodimerization of the two reaction partners, which takes place simultaneously with statistical probability. If only propene or n-butene is introduced into the dimerization, then isohexenes or isooctenes are formed with high selectivity (85-92 % at 90% conversion), and are distinguished by their low degree of branching.

This dimerization process to C₆, C₇, and C₈ isoolefins is therefore a good source of intermediates for the production of highoctane gasoline as well as feedstocks for hydroformylation, where branching on both sides of the olefinic double bond would sharply reduce the rate of the 'oxo' reaction.

Since the first commercial operation of the Dimersol process in 1977, worldwide production capacity has grown to ca. 3×10⁶ tonnes per year in 26 plants.

To 3:

The third possibility, dimerization of propene with an alkali metal catalyst, is of only limited industrial significance. The reaction is conducted in the liquid phase at ca. 150 °C and 40 bar using Na/K₂CO₃ catalyst. Selectivity to 4-methyl-1-pentene (4MPI) can reach 80%:

4MPI is produced by BP in a 25000 tonne-per-year plant and is polymerized by ICl to high melting (240 °C) transparent polymer known as TPX. In 1975 Mitsui Petrochemical began operation of a plant using the BP technology (current capacity, 15000 tonnes per year) to produce monomer to be used in the manufacture of poly-4-methyl-1-pentene. Phillips began smaller-scale production in 1986. 4MPI is also used as a comonomer in polyethylene (LLDPE).