Process for obtaining aromatics and aromatic stream
The present invention addresses to a process for the production of aromatic compounds from streams containing linear chains with 5 to 18 carbon atoms, of fossil or renewable origin, and application in the field of catalytic cracking aiming at a regenerator operation at much lower temperature, between 480° C. and 620° C., preferably the temperature should be between 500° C. and 600° C. The coked catalyst generated by the cracking of light streams with low potential for delta coke generation can have the combustion effected at a lower temperature. The regeneration temperature must be at least 40° C. and at most 100° C. higher than the reaction temperature, keeping the catalyst circulation high to maintain the energy balance in the reaction section. The minimum regeneration temperature can be ensured by installing an air preheating furnace before entering the regenerator and passing through the air distributor inside the regenerator. The used catalyst must contain zeolite with pores of intermediate size. Such conditions greatly favor the production of aromatics and the octane rating of the produced naphtha.
1 . A process for obtaining aromatics from streams with linear chains with 5 to 18 carbon atoms, the process comprising:
introducing a preheated feed stream into a fluid catalytic cracking reactor so that the preheated feed stream comes into contact with intermediate pore zeolite catalyst particles from a regenerator, to obtain a mixture between gaseous cracking products and coke-deactivated catalyst, wherein the cracking products comprise hydrocarbons comprising aromatics, wherein a catalyst-preheated feed stream ratio is in a range of 5 to 30;
separating, from the mixture, the cracking products and the coke-deactivated catalyst;
subjecting the coke-deactivated catalyst to a rectification step with water vapor for removing light hydrocarbons to produce a rectified catalyst;
subjecting the rectified catalyst to a regeneration step and combusting the coke deposited on the catalyst particles, in which a combustion temperature does not exceed 600° C., to obtain catalyst particles with activity higher than that of the rectified catalyst to produce a regenerated catalyst;
allocating the regenerated catalyst with restored activity back to the fluid catalytic cracking reactor to continue the catalytic cracking process; and
allocating the hydrocarbons to a fractionation section to separate the produced hydrocarbons according to their boiling points, wherein the combustion temperature is at least 40° C. and at most 100° C. higher than a reaction temperature in the fluid catalytic cracking reactor.
2 . The process according to claim 1 , wherein the preheated feed stream comprises triglycerides with carbonic chain fatty acids (C9-C18) from plant and/or animal biomass.
3 . The process according to claim 1 , wherein the preheated feed stream comprises free carbonic chain fatty acids (C9-C18).
4 . The process according to claim 1 , wherein the preheated feed stream comprises triglycerides with concentrations greater than 65% by mass of fatty acids.
5 . The process according to claim 2 , wherein the triglyceride is selected from soybean oil, castor oil, cottonseed oil, palm oil, pine oil, sunflower oil, jatropha oil, algae oil, or beef tallow.
6 . The process according to claim 1 , wherein the preheated feed stream comprises a single oil or a mixture of two or more oils.
7 . The process according to claim 1 , wherein the preheated feed stream comprises fossil hydrocarbons selected from oil refining streams that have boiling points in a range between 40° C. and 300° C.
8 . The process according to claim 1 , wherein the intermediate pore zeolitic catalyst is selected from types of structure consisting of: MFI, MEL, ZSM-8, ZSM-12, ZSM-21, ZSM-23, ZSM-35, ZSM-38, IMF, TUN, and any combination thereof.
9 . The process according to claim 1 , wherein the fluid catalytic cracking reactor operates at pressures in a range of 200 to 400 kPa and a contact time in a range between 1.0 and 3.0 seconds.
10 . The process according to claim 1 , wherein the hydrocarbon streams obtained in the fluid catalytic cracking reactor comprise fuel gas, liquefied gas, or naphtha.
11 . The process according to claim 1 , wherein the fluid catalytic cracking reactor is a riser type reactor.
12 . The process according to claim 1 , wherein air used in the combustion of the coke deposited on the catalyst is preheated through a furnace to complement a thermal balance, performing the regeneration step at temperatures from 400° C. to 550° C.
13 . An aromatic stream as obtained in the process defined in claim 1 , wherein the aromatic stream comprises a naphtha distillation range between 30° C. and 220° C.
14 . The aromatic stream according to claim 13 , wherein the aromatic stream is 100% renewable in origin.
15 . The aromatic stream according to claim 14 , wherein the aromatic stream comprises between 70% m/m and 90% m/m of aromatics with a benzene ring in mixture with paraffinic and olefinic compounds.
16 . The aromatic stream according to claim 14 , wherein the aromatic stream comprises at least 100 RON octane rating and 85 MON octane rating.
17 . The process according to claim 2 , wherein the triglyceride is selected from Glycine max, Ricinus communis, Gossypium hirsutum, G. barbadenseis, Elaies guinensis , Tall oil, Helianthus annuus, Jatropha curcas , or Tallow.