Metathesis olefins conversion technology

Olefin metathesis (Olefin Conversion Technology, OCT) of ethylene and 2-butene (manufaaured by isomerization of 1 -butene) yielding propylene. ... 

As mentioned above, the first metathesis reaction studied was the equilibrium between propylene and an ethylene 2-butene mixture. In the initial Phillips process this was used to convert excess propylene into ethylene and 2-butene (Scheme 5.55). When propylene demands surged, the process was reversed and is now known as olefins conversion technology (OCT). The OCT process is operated with a fixed-bed reactor, W03 on silica serves as a catalyst. In order to allow... 

This process, called OCT (olefin conversion technology), formerly the Phillips Triolefin Process, which utilizes a heterogeneous catalyst system, was originally developed by Phillips Petroleum Co. for the conversion of propene into ethene and butene. The reaction takes place in a fixed-bed reactor over a mixture of the metathesis catalyst W03/S102 and the isomerization catalyst MgO at temperatures above 540 K and an overall pressure of approximately 30 bar [3]. 1-Butene present in the feedstock is isomerized to 2-butene as the original 2-butene is consumed in the metathesis reaction. 

Because olefin metathesis is an equilibrium reaction, the Triolefin Process can be mn in the reverse direction to produce propylene from 2-butene and ethylene. Lyondell licensed the Phillips Triolefin process and opened the first propylene plant based on this technology in 1984, eventually expanding capacity to 450 000 metric tons per year. In 1997, Lummus Technology, who engineered the first two applications under license from Phillips, purchased the technology from Phillips. The metathesis of ethylene and butenes to propylene is now commercialized as Olefins Conversion Technology (OCT )... 

Olefins Conversion Technology [OCT] A process for converting mixtures of ethylene and butenes to propylene by metathesis (disproportionation). Based on technology developed by Phillips Petroleum in the... 

The Phillips triolefin process [56] developed at Phillips Petroleum, used a heterogeneous WOj/SiOj catalyst in metathesis reaction to convert propene 127 into mixture of ethene 125 and 2-butene 126. As it is a reversible reaetion (Scheme 9.32) and the price of propene rose high, the reverse reaction of Philips process offered is now by using Lummus teehnology to produce propene known as Olefin Conversion Technology (OCT). 

Disproportionation of Olefins. Disproportionation or the metathesis reaction offers an opportunity to convert surplus olefins to other desirable olefins. Phillips Petroleum and Institut Fransais du Petrc le have pioneered this technology for the dimerization of light olefins. The original metathesis reaction of Phillips Petroleum was intended to convert propylene to 2-butene and ethylene (58). The reverse reaction that converts 2-butene in the presence of excess ethylene to propylene has also been demonstrated (59). A commercial unit with a capacity of about 136,000 t/yr of propylene from ethylene via 2-butene has been in operation in the Gulf Coast since 1985 (60,61). In this process, ethylene is first dimerized to 2-butene foUowed by metathesis to yield propylene. Since this is a two-stage process, 2-butene can be produced from the first stage, if needed. In the dimerization step, about 95% purity of 2-butene is achieved at 90% ethylene conversion. 

The procedure reported above represents a facile and reproducible method for the execution of various olefin metathesis reactions using a highly active and recoverable catalyst. Table 9.2 gives a list of representative substrates compatible with the technology and the time taken for quantitative conversion of the substrate using the ring-closing metathesis procedure. 

---