Benzene Reduction by Alkylation in a Solid Phosphoric Acid Catalyzed Olefin Oligomerization Process

Abstract

A refinery with a solid phosphoric acid olefin oligomerization unit can reduce the benzene content of its motor-gasoline by co-feeding the benzene-containing material to that unit. It has been shown that benzene co-feeding has little disruptive impact on olefin oligomerization, and >80% benzene conversion to alkylated benzenes has been demonstrated during a commercial test run on an industrial unit. Benzene conversion is insensitive to reactor inlet temperature in the range of 160-180 °C and remains better than 80% at liquid hourly space velocities of up to 1.5 h -1 . A high propene content in the olefinic feed promotes benzene alkylation, and although butene-rich feeds can be employed, benzene conversion is lower.

Catalysis in the Refining of Fischer–Tropsch Syncrude

“…It has been reported that 480% conversion of benzene to alkylated benzenes was obtained over SPA during industrial testing (Table 8.3). 34 It has also been reported that combined propene OLI and aromatic alkylation is able to produces a synthetic Jet A-1 jet fuel. 35 Propene is the preferred alkene feed for alkylation over SPA, although butene-rich feeds can also be employed.…”

Sasol 2 and 3 Facilities

“…Technology to reduce the refinery benzene level was evaluated on a commercial scale [61] but not implemented. Whatever the ultimate technology decision, in future further refinery changes will have to be made when legislation calls for a reduction in benzene.…”

Patent Literature

“…50 This invention has been demonstrated on an industrial scale with FT feed. 59 The benzene-containing refinery material is cofed with light FT alkenes at a high alkene-to-aromatics ratio. By doing so, the benzene is alkylated without disrupting the OLI process.…”