SHOP olefin oligomerization catalysts

The chelate effect is important in the oxidative additions of P—C bonds which, in the case of nickel, give P—O and P—N chelate complexes of the type used as ethylene oligomerization catalysts in the Shell higher olefin process (SHOP),91 for example,... 

Homogeneous nickel catalysts are formed when well-known oligomerization catalysts (29) of the Shell Higher Olefin Process (SHOP cf. Section 2.3.1.3)... 

The reaction of the stabilized ylide benzoylmethylene-triphenylphosphorane with Ni(0) in the presence of triphenylphosphane leads to the oligomerization catalyst 2, which catalyzes the reaction of 6000 moles of ethylene per mole of complex at 50 bar and 50°C. The catalyst 2 is a model system for the Shell Higher Olefin Process (SHOP) for the production of liquid a-olefms of high linearity, which has been studied in detail by Keim and coworkers at the RWTH Aachen [9 c and literature, reviewed in 8]. 

Another area of investigation was based on nickel complexes anchored to cyclodextrins as an alternative to ethylene oligomerization catalysts for the Shell Higher Olefins Process (SHOP). The idea was that the cydodextrin cavity could lead to... 

Shell Higher Olefins Process (SHOP). In the Shell ethylene oligomerization process (7), a nickel ligand catalyst is dissolved in a solvent such as 1,4-butanediol (Eig. 4). Ethylene is oligomerized on the catalyst to form a-olefins. Because a-olefins have low solubiUty in the solvent, they form a second Hquid phase. Once formed, olefins can have Htfle further reaction because most of them are no longer in contact with the catalyst. Three continuously stirred reactors operate at ca 120°C and ca 14 MPa (140 atm). Reactor conditions and catalyst addition rates allow Shell to vary the carbon distribution. 

In addition to the neutral nickel/phosphine complexes used in the Shell Higher Olefins Process (SHOP), cationic Ni-complexes such as [(mall)Ni(dppmo)][SbF6] (see Figure 5.2-7) have attracted some attention as highly selective and highly active catalysts for ethylene oligomerization to HAOs [106]. 

Catalysts based on nickel that dimerize or oligomerize a-olefins have been known for many years and are commercially valuable. The Shell higher olefin process (SHOP), for example, uses Ni(II) catalysts developed by Keim and coworkers such as 1.1 and 1.2 bearing P-O chelating ligands to oligomerize ethylene into higher olefins in the manufacture of surfactants, lubricants, and fine chemicals (Fig. 1) [9-11]. Late transition metals are more suited for the polymerization of... 

SHOP [Shell Higher Olefins Process] A process for producing a-olefins by oligomerizing ethylene, using a proprietary rhodium/phosphine catalyst. The a-olefins can then be iso-merized to internal olefins as required. Invented by W. Keim in the Institut fur Technische Chemie und Petrolchemie, Aachen, in the 1970s. The first plant was built in Geismar, LA, in 1979 the second in Stanlow, Cheshire, in 1982. Licensed worldwide by a consortium of Union Carbide, Davy-McKee, and Johnson Matthey. 

Probably the first example of a process employing the biphasic concept is the Shell process for ethylene oligomerization in which the nickel catalyst and the ethylene reactant are dissolved in 1,4-butanediol, while the product, a mixture of linear alpha olefins, is insoluble and separates as a second (upper) liquid phase (see Fig. 7.1). This is the first step in the Shell Higher Olefins Process (SHOP), the largest single feed application of homogeneous catalysis [7]. 

Shell manufactures a-olefins from ethylene by oligomerization with a nickel catalyst in a polar solvent such as ethylene glycol, under the conditions specified in Equation 27. This corresponds to the first part of the SHOP process (Shell Higher Olefin Process) described in Section 6.2.2. The world production is estimated to be over 1 Mt/a. 

---