olefin conversion technology
Olefin Conversion Technology, also called the Phillips Triolefin Process, is the industrial process that interconverts propylene with ethylene and 2-butenes.{{cite journal|journal=Catalysis Reviews Science and Engineering|title=Converting Olefins to Propene: Ethene to Propene and Olefin Cracking|first1=Vincent |last1=Blay|first2=Eva |last2=Epelde|first3=Rubén|last3=Miravalles|first4=Leo Alvarado|last4= Perea|volume=60|year=2018|issue=2 |page=278|doi=10.1080/01614940.2018.1432017}} The process is also called the ethylene to propylene (ETP) process. In ETP, ethylene is dimerized to 1-butene, which is isomerized to 2-butenes. The 2-butenes are then subjected to metathesis with ethylene.
Rhenium- and molybdenum-containing heterogeneous catalysis are used. Nowadays, only the "reverse" reaction is practiced, i.e., the conversion of ethylene and 2-butene to propylene:{{cite journal|last1=Ghashghaee|first1=Mohammad|title=Heterogeneous catalysts for gas-phase conversion of ethylene to higher olefins|journal=Rev. Chem. Eng.|year=2018|volume=34|issue=5 |page=595-655|doi=10.1515/revce-2017-0003}}
:CH2=CH2 + CH3CH=CHCH3 → 2 CH2=CHCH3
The technology is founded on an olefin metathesis reaction discovered at Phillips Petroleum Company.{{cite journal | last1 = Banks | first1 = R. L. | last2 = Bailey | first2 = G. C. | title = Olefin Disproportionation. A New Catalytic Process | journal = Industrial & Engineering Chemistry Product Research and Development | volume = 3 |issue=3| pages = 170–173 | year = 1964 | doi = 10.1021/i360011a002}} The originally described process employed catalysts molybdenum hexacarbonyl, tungsten hexacarbonyl, and molybdenum oxide supported on alumina.