The bioethanol-to-ethylene (B.E.T.E.) process

Ethanol present at low concentration in a fermentation broth which also contains some leftover glucose as well as other fermentation residues, is totally converted into ethylene over a solid superacidic catalyst. Trifluoromethanesulfonic acid bound to the silica rich surface of the acidic ZSM-5 zeolite is thermally stable up to 300°C and can catalyse the reaction with nearly complete conversion at a temperature as low as 170°C. Below 200°C, the catalyst is extremely stable even in the presence of the high amount of water found in the feed. A rapid economical evaluation shows that ethylene produced by the B.E.T.E. (bioethanol-to-ethylene) process has a production cost 10% to 40% higher than petroleum ethylene. However, a more promising figure can be envisaged with a better integrated process working with cheaper raw materials.