CPC C07C 5/2708 (2013.01) [C07C 4/06 (2013.01); C07C 2529/40 (2013.01)] | 5 Claims |
1. A method of producing olefins, the method comprising:
isomerizing hydrocarbons of a naphtha stream by converting straight chain Cn hydrocarbons to branched Cn hydrocarbons and thereby form an isomerized naphtha stream;
catalytically cracking hydrocarbons of the isomerized naphtha stream to form olefins;
separating the isomerized naphtha stream to remove light gases including H2, methane, and ethane;
adding hydrogen to the naphtha stream prior to the isomerizing step;
heating hydrocarbons of the isomerized naphtha stream prior to the catalytic cracking step;
wherein the naphtha stream comprises straight run light naphtha and/or heavy naphtha;
wherein the catalyst for the isomerizing step is a chlorinated alumina-based catalyst;
wherein the isomerizing comprises contacting the naphtha stream with a catalyst at a temperature of 220 to 300° C. and pressure of 10 to 40 bars;
wherein the catalytic cracking is performed in a fixed catalyst bed reactor at a weight hourly space velocity in a range of 1 to 20 hr−1;
wherein the catalytic cracking is performed over a catalyst including Zeolite Y, and a metal including germanium, gallium, iron or combinations thereof;
wherein the naphtha stream is pre-heated to a temperature of 80 to 250° C. prior to isomerizing;
wherein the isomerizing is conducted in a fixed bed isomerization reactor; and
further comprising heating hydrocarbons of the isomerized naphtha stream to a temperature in a range of 500 to 680° C. prior to the catalytic cracking step.
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