Catalytic process for the production of aromatic hydrocarbons from used cooking oil

A process for the preparation of aromatic hydrocarbons by aromatisation from used cooking oil using a polymetallic alumina-silicate zeolite catalyst comprising the steps of:

• a) synthesizing the Zn-X-MFI catalyst by adding nitrate/chloride salts or acids of elements selected from the group consisting of Zn, Co, Ga, Cr, Fe, Ce and B, to CTAB dissolved in water followed by heating at 70° C. to obtain a mixture, wherein the weight ratio of X to MFI is kept in a range of 3 to 6% and the weight ratio of Zn to MFI is kept in a range of 6 to 10%, wherein X is selected from Co, Ga, Cr, Fe, Ce, B, and combinations thereof;
• b) homogenizing the mixture obtained in step (a) followed by heating at a temperature in a range of 50 to 80° C. under stirring for 1 h to obtain a homogenized mixture;
• c) successively adding 1 to 10 wt % of a nano porous MFI zeolite to the homogenized mixture obtained in step [b] under stirring for 12-16 h at a temperature in a range of 50 to 80° C., to obtain a precipitate;
• d) cooling the precipitate obtained in step [c] to room temperature naturally, followed by collecting and washing with ethanol and water several times to obtain a material;
• e) calcining the material obtained in step [d] at 350 to 550° C. for 4-6 h in air to obtain the catalyst;
• f) aromatising a used cooking oil [UCO] in a fixed bed down-flow reactor with the Zn-X-MFI catalyst obtained in step [e] in the absence or presence of 1-5% nitrogen or steam while maintaining the reactor at atmospheric pressure at a temperature in a range of 250-550° C. with a gas hourly space velocity (GHSV) in a range of 600-1800 h−1 and liquid hour space velocity (LHSV) in a range of 1.5-2.5 h−1 to obtain reaction products comprising aromatics.