Ethylene coupling

W, Keim/SHELL (1977) SHOP W, S, Knowles / MONSANTO (1971) L-DOPA R, L, Pruett (1970) Rh/PRs-oat, for 0x0 synth. F. E. Paulik, J. F. Roth / MONSANTO (1968) carbonylation of CH3OH T. Alderson / DuPONT (1961) RhCi3-catalyzed butadiene/ethylene coupling G. Wilke (1959) Ni-catalyzed trimerization of butadiene... 

Coupling between ethene and CO2 can also be induced by Fe(0) complexes [26]. Remarkably, these systems can promote ethylene coupling with two CO2 molecules, affording a dicarboxylate which was esterified by means of acid hydrolysis in methanol. The nature of the ancillary ligands had a marked influence on the product distribution. In the presence of PMeg, methyl malonate was obtained... 

Wang, L.P., MiUman, W.S., and Tysoe, W.T. The hydrogenation of CO over molybdenum/alumina in the presence of ethylene coupling of olefin metathesis and CO hydrogenation. Catal. Lett. 1988, 7, 159-167. 

Jin D, Williard PG, Hazari N, Bemskoetter WH. Effect ofsodium cation on metallacycle y3-hydride elimination in C02-ethylene coupling to acrylates. Chem Em J. 2014 20 3205-3211. 

The direct methane conversion technology, which has received the most research attention, involves the oxidative coupling of methane to produce higher hydrocarbons (qv) such as ethylene (qv). These olefinic products may be upgraded to Hquid fuels via catalytic oligomerization processes. 

Generally, the most developed processes involve oxidative coupling of methane to higher hydrocarbons. Oxidative coupling converts methane to ethane and ethylene by... 

Ethylene glycol can be produced by an electrohydrodimerization of formaldehyde (16). The process has a number of variables necessary for optimum current efficiency including pH, electrolyte, temperature, methanol concentration, electrode materials, and cell design. Other methods include production of valuable oxidized materials at the electrochemical cell s anode simultaneous with formation of glycol at the cathode (17). The compound formed at the anode maybe used for commercial value direcdy, or coupled as an oxidant in a separate process. 

Nitric acid oxidation is used where carbohydrates, ethylene glycol, and propylene are the starting materials. The diaLkyl oxalate process is the newest, where diaLkyl oxalate is synthesized from carbon monoxide and alcohol, then hydrolyzed to oxahc acid. This process has been developed by UBE Industries in Japan as a CO coupling technology in the course of exploring C-1 chemistry. 

Allyl Glycidyl Ether. This ether is used mainly as a raw material for silane coupling agents and epichlorohydrin mbber. Epichlorohydrin mbber is synthesized by polymerizing the epoxy group of epichlorohydrin, ethylene oxide, propylene oxide, and aHyl glycidyl ether, AGE, with an aluminum alkyl catalyst (36). This mbber has high cold-resistance. 

A different approach, taken by both Monsanto (58) and Gulf Research and Development Company (59), involved the oxidative coupling of two molecules of toluene to yield stilbene. The stilbene is then subjected to a metathesis reaction with ethylene to yield two molecules of styrene. 

When heated to very high temperatures, methyl chloride couples giving ethylene according to the reaction ... 

Catalytic reactions at somewhat lower temperatures also produce ethylene and other olefins. When coupled with a methane process to methyl chloride, this reaction results ia a new route to the light hydrocarbons that is of considerable interest. 

Benzyl chloride readily forms a Grignard compound by reaction with magnesium in ether with the concomitant formation of substantial coupling product, 1,2-diphenylethane [103-29-7]. Benzyl chloride is oxidized first to benzaldehyde [100-52-7] and then to benzoic acid. Nitric acid oxidizes directly to benzoic acid [65-85-0]. Reaction with ethylene oxide produces the benzyl chlorohydrin ether, CgH CH20CH2CH2Cl (18). Benzylphosphonic acid [10542-07-1] is formed from the reaction of benzyl chloride and triethyl phosphite followed by hydrolysis (19). 

The palladium chloride process for oxidizing olefins to aldehydes in aqueous solution (Wacker process) apparendy involves an intermediate anionic complex such as dichloro(ethylene)hydroxopalladate(II) or else a neutral aqua complex PdCl2 (CH2=CH2)(H2 0). The coordinated PdCl2 is reduced to Pd during the olefin oxidation and is reoxidized by the cupric—cuprous chloride couple, which in turn is reoxidized by oxygen, and the net reaction for any olefin (RCH=CH2) is then... 

Although ethylene is produced by various methods as follows, only a few are commercially proven thermal cracking of hydrocarbons, catalytic pyrolysis, membrane dehydrogenation of ethane, oxydehydrogenation of ethane, oxidative coupling of methane, methanol to ethylene, dehydration of ethanol, ethylene from coal, disproportionation of propylene, and ethylene as a by-product. 

Most ethylene plants operate continuously with the expanders operating at or near design conditions. If necessary, due to their unique design characteristics, radial inflow turboexpanders can accommodate a wide range of process conditions without significant losses in thermal or mechanical efficiency. Expanders may be loaded with booster compressors, gear-coupled generators, dynamometers, or other in-plant mechanical equipment such as pumps. In ethylene plants, turboexpanders are typically used in eitlier post-boost or pre-boost applications. 

---