Chemistry of hydrocarbon compounds – Unsaturated compound synthesis – By c content reduction – e.g. – cracking – etc.
Reexamination Certificate
2000-07-27
2002-05-28
Griffin, Steven P. (Department: 1754)
Chemistry of hydrocarbon compounds
Unsaturated compound synthesis
By c content reduction, e.g., cracking, etc.
C585S653000
Reexamination Certificate
active
06395949
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the field of hydrocarbon upgrading processes. In another aspect, the invention relates to the conversion of cracked gasoline and a lower-alkane diluent in the presence of an improved zeolite material and/or a second diluent to aromatics and ethylene and propylene preferably with an increased conversion of the lower-alkane diluent in the presence of such improved zeolite material and/or the second diluent.
It is known to those skilled in the art that aromatic hydrocarbons and olefins are each a class of very important industrial chemicals which find a variety of uses in petrochemical industry. It can be desirable to co-feed a lower-alkane diluent with gasoline-range hydrocarbons to a process which uses a zeolite conversion catalyst to enhance the conversion of the gasoline-range hydrocarbons. One problem with the co-feeding of lower-alkane diluents is the generally low conversion of the diluent. It is desirable to improve processes for converting gasoline-range hydrocarbons and lower-alkane diluents to aromatics and lower olefins by increasing the conversion of the gasoline-range hydrocarbons and the co-fed lower-alkane diluent.
SUMMARY OF THE INVENTION
It is an object of this invention to at least partially convert hydrocarbons, in particular, a hydrocarbon feed mixture comprising cracked gasoline and a lower-alkane diluent, to ethylene, propylene and BTX aromatics.
A further object of this invention is to provide an aromatization process for the conversion of at least a portion of a hydrocarbon feed mixture comprising cracked gasoline and a lower-alkane diluent to aromatics and lower olefins in which the conversion of the lower-alkane diluent is enhanced by co-feeding a second hydrocarbon diluent.
A still further object of this invention is to provide an improved zeolite material that gives improved conversion of a lower-alkane diluent in a process for the conversion of a hydrocarbon feed mixture comprising cracked gasoline and a lower-alkane diluent to aromatics and lower olefins.
Another further object of this invention is to provide a method for making an improved zeolite material having such desirable properties as providing for increased conversion of a lower-alkane diluent in a process for the conversion of a hydrocarbon feed mixture comprising cracked gasoline and a lower-alkane diluent to aromatics and lower olefins.
The invention includes a novel catalyst composition for use in converting hydrocarbons. This novel catalyst composition comprises phosphorus and a calcined, acid-leached zeolite and is prepared by incorporating phosphorus into a calcined, acid-leached zeolite material.
One of the inventive processes provides for the conversion of hydrocarbons to aromatics and lower olefins by contacting under conversion conditions a hydrocarbon feed mixture comprising cracked gasoline and a lower-alkane diluent with a catalyst composition comprising phosphorus and a calcined, acid-leached zeolite.
Another of the inventive processes provides for the conversion of hydrocarbons to aromatics and lower olefins by:
a) introducing a hydrocarbon feed mixture comprising cracked gasoline and a first diluent comprising isopentane to a reaction zone, the reaction zone contains a catalyst comprising a zeolite and a phosphorus component and is operated under reaction conditions for converting hydrocarbons to light olefins;
b) withdrawing from the reaction zone a reactor effluent comprising light olefins; and
c) controllably introducing a second diluent comprising propane into the reaction zone in an amount such that the mole ratio of the second diluent to the first diluent is in the range of from about 1:0.1 to about 1:10, whereby the percent conversion of the first diluent is enhanced over the percent conversion of the first diluent when there is no step c.
Yet another of the inventive processes provides for the conversion of hydrocarbons to aromatics and lower olefins by:
a) introducing a hydrocarbon feed mixture comprising cracked gasoline and a first diluent comprising isopentane to a reaction zone, the reaction zone contains a catalyst comprising a zeolite and a phosphorus component and is operated under reaction conditions for converting hydrocarbons to light olefins;
b) withdrawing from the reaction zone a reactor effluent comprising light olefins; and
c) controllably introducing a second diluent comprising 1-hexene into the reaction zone in an amount such that the mole ratio of the second diluent to the first diluent is in the range of from about 1:0.1 to about 1:10, whereby the percent conversion of the first diluent is enhanced over the percent conversion of the first diluent when there is no step c.
Other objects and advantages of the invention will become apparent from the detailed description and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The inventive composition includes a zeolite starting material that has been treated with an acid followed by calcining to thereby provide a calcined, acid-leached zeolite. The inventive composition further contains a phosphorus component.
An important aspect of the invention is for the starting zeolite material, which is being modified to provide the inventive composition having the desirable properties as earlier described herein, to be treated with an acid to give an acid leached zeolite. A further important aspect of the invention is for the acid-leached zeolite to be calcined to give a calcined, acid-leached zeolite. The calcined, acid-leached zeolite is further modified by the incorporation of a phosphorus component.
Any suitable means or method can be used to treat the zeolite starting material with acid. It is preferred for the zeolite to be soaked with an acid solution by any suitable means known in the art for contacting the zeolite with such acid solution. The acid solution used to treat the zeolite can be a solution of any acid that suitably provides for the leaching of aluminum atoms from the zeolite particles. Preferably, the acid concentration in this solution is about 1-10 equivalents per liter. Examples of such suitable acids include sulfuric, phosphoric, nitric and hydrochloric. The preferred acid solution is aqueous hydrochloric acid solution. The zeolite is soaked in the acid solution (preferably at a temperature of about 50-100° C.) for a period upwardly to about 15 hours, but, preferably from 0.1 hour to 12 hours. After soaking, the resultant acid-leached zeolite is washed free of the acid and then can be dried.
The zeolite starting material used in the composition of the invention can be any zeolite which is effective in the conversion of non-aromatic to aromatics when contacted under suitable reaction conditions with non-aromatic hydrocarbons. Preferably, the zeolite has a constraint index (as defined in U.S. Pat. No. 4,097,367, which is incorporated herein by reference) in the range of from about 0.4 to about 12, preferably from about 2 to about 9. Generally, the molar ratio of SiO
2
to Al
2
O
3
in the crystalline framework of the zeolite is at least about 5:1 and can range up to infinity. Preferably the molar ratio of SiO
2
to Al
2
O
3
in the zeolite framework is about 8:1 to about 200:1, more preferably about 12:1 to about 100:1. Preferred zeolites include ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-35, ZSM-38, and mixtures thereof. Some of these zeolites are also known as “MFI” or “Pentasil” zeolites. The presently more preferred zeolite is ZSM-5.
Any suitable means or method can be used to calcine the acid-leached zeolite. The means or method to calcine generally can include heating the acid-leached zeolite to a temperature in the range of from about 250° C. to about 1,000° C., preferably about 350° C. to about 750° C., and most preferably from 400° C. to 650° C. at a pressure in the range of from below atmospheric upwardly to about 1000 psia (pounds per square inch absolute), preferably from about atmospheric to about 100 psia, and for a time period in the range of from about 0.1 hour to about 30 hours, preferably from about 0.5 hour to a
Drake Charles A.
Yao Jianhua
Griffin Steven P.
Nguyen Cam N.
Phillips Petroleum Company
Stewart Charles W.
LandOfFree
Acid treated zeolite containing phosphorus used as a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Acid treated zeolite containing phosphorus used as a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acid treated zeolite containing phosphorus used as a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2818580