Olefin Conversion Technology, also called the Phillips Triolefin Process, is the industrial process that interconverts propylene with ethylene and 2-butenes.
In ETP, ethylene is dimerized to 1-butene, which is isomerized to 2-butenes.
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:[2] The technology is founded on an olefin metathesis reaction discovered at Phillips Petroleum Company.
[3] The originally described process employed catalysts molybdenum hexacarbonyl, tungsten hexacarbonyl, and molybdenum oxide supported on alumina.