Chemistry of hydrocarbon compounds – Adding hydrogen to unsaturated bond of hydrocarbon – i.e.,... – Hydrocarbon is contaminant in desired hydrocarbon
Reexamination Certificate
1999-09-29
2001-05-22
Yildirim, Bekir L. (Department: 1764)
Chemistry of hydrocarbon compounds
Adding hydrogen to unsaturated bond of hydrocarbon, i.e.,...
Hydrocarbon is contaminant in desired hydrocarbon
C585S259000, C208S144000
Reexamination Certificate
active
06235954
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a catalyst composition, the preparation of a catalyst composition, and to a process of using a catalyst composition for hydrogenating a highly unsaturated hydrocarbon.
It is well known to one skilled in the art that an unsaturated hydrocarbon can be produced by a thermal cracking process. For example, a fluid stream containing a saturated hydrocarbon such as, for example, ethane, propane, butane, pentane, naphtha, or combinations thereof can be fed into a thermal (or pyrolytic) cracking furnace. Within the furnace, the saturated hydrocarbon is converted to a less unsaturated hydrocarbon such as, for example, ethylene and propylene. Less unsaturated hydrocarbons are an important class of chemicals that find a variety of industrial uses. For example, ethylene and propylene can be used as a monomer or comonomer for producing polyolefins. Other uses of less unsaturated hydrocarbons are well known to one skilled in the art.
However, a less unsaturated hydrocarbon produced by a thermal cracking process generally contains an appreciable amount of highly unsaturated hydrocarbons such as less desirable alkyne(s), diolefin(s), polyene(s), or combinations thereof. For example, ethylene produced by thermal cracking of ethane is generally contaminated with some acetylene which must be selectively hydrogenated to ethylene, but not to ethane, in a hydrogenation reaction. Similarly, in a thermal cracking process for producing a butene, butynes and butadienes are generally co-produced which must be selectively hydrogenated to a butene, but not further hydrogenated to a butane.
These highly unsaturated hydrocarbons described above are undesirable for several reasons. Generally, these highly unsaturated hydrocarbons are highly reactive and tend to polymerize by forming gums if they are left in the product stream. Also, these undesirable products can have an effect on further processes, such as alkylation. Thus, these highly unsaturated hydrocarbons are preferably removed. A preferred process for removing such undesirable highly unsaturated hydrocarbons is a selective hydrogenation process. This process not only minimizes the loss of desired less unsaturated hydrocarbons, but can also help to avoid a “runaway” reaction which is difficult to control in front-end and total-cracked-gas processes thereby increasing the selectivity by which desired products, as opposed to undesired products, are produced.
Catalysts comprising palladium and an inorganic support are known catalysts for the hydrogenation of highly unsaturated hydrocarbons such as alkynes and/or diolefins. Sulfided catalysts comprising a metal selected from the group consisting of molybdenum, cobalt, and nickel and combinations thereof have also been used as hydrogenation catalysts. However, these catalysts can be expensive to prepare and can have the potential to introduce sulfur contaminants which can poison and deactivate catalysts used in hydrogenation processes.
As such, development of a catalyst which is cost-efficient and easier to prepare than known catalysts and processes therewith in the selective hydrogenation of a highly unsaturated hydrocarbon such as a diolefin to a less unsaturated hydrocarbon such as a monoolefin in which selectivity is improved and unnecessary introduction of contaminants is avoided would be a significant contribution to the art and to the economy.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a catalyst composition which can be useful as a catalyst in the selective hydrogenation of a highly unsaturated hydrocarbon such as a diolefin to a less unsaturated hydrocarbon such as a monoolefin.
It is another object of this invention to provide a process for producing such catalyst composition which can be useful as a catalyst in the selective hydrogenation of a highly unsaturated hydrocarbon such as a diolefin to a less unsaturated hydrocarbon such as a monoolefin.
It is another object of this invention to employ such catalyst composition in a process for selectively hydrogenating a highly unsaturated hydrocarbon such as a diolefin to a less unsaturated hydrocarbon such as a monoolefin.
Advantages of this invention include a catalyst composition which avoids unnecessary introduction of contaminants which can poison and deactivate catalysts used in hydrogenation processes. Another advantage of this invention is that the process of making such catalyst is cost-efficient and easier to prepare than known catalysts. Yet another advantage of this invention is an increased or enhanced selectivity to a desired product such as a less unsaturated hydrocarbon.
The present invention is directed to a catalyst composition which comprises a carburized, calcined, modified zeolite having incorporated therein a metal of Group VIB of the Periodic Table of the Elements (i.e., a Group VIB metal) such as chromium, molybdenum, tungsten and combinations thereof. The composition also comprises an inorganic support. The inorganic support can be selected from the group consisting of silica, alumina, titanium dioxide, zirconia, a spinel such as zinc aluminate, zinc titanate, magnesium aluminate, calcium aluminate, and the like and combinations thereof.
The present invention is also directed to a process for producing a catalyst composition which can be useful as a catalyst in the selective hydrogenation of a highly unsaturated hydrocarbon such as a diolefin to a lower unsaturated hydrocarbon such as a monoolefin. The process can comprise: (1) combining a zeolite, a metal of Group VIB of the Periodic Table of the Elements (i.e., a Group VIB metal), and an inorganic support to form a modified zeolite; (2) calcining such modified zeolite under a calcining condition to produce a calcined, modified zeolite; and (3) contacting such calcined, modified zeolite with a carburizing agent under a carburizing condition to provide a carburized, calcined, modified zeolite.
The present invention is also directed to a process which can be used to employ a catalyst composition of this invention in the selective hydrogenation of a highly unsaturated hydrocarbon such as a diolefin to a less unsaturated hydrocarbon such as a monoolefin. The process can comprise contacting a hydrocarbon-containing fluid, which comprises a highly unsaturated hydrocarbon, in the presence of hydrogen with a catalyst composition in a hydrogenation zone under a hydrogenation condition effective to selectively hydrogenate a highly unsaturated hydrocarbon to a less unsaturated hydrocarbon. The catalyst composition can be a catalyst composition of the present invention.
Other objects and advantages of the invention will be apparent from the detailed description of the invention and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
As used in the present invention, the term “hydrocarbon” generally refers to, unless otherwise indicated, one or more hydrocarbons, saturated or unsaturated, having in the range of from about 1 carbon atom per molecule to about 50 carbon atoms per molecule, preferably in the range of from about 2 carbon atoms per molecule to about 40 carbon atoms per molecule, more preferably in the range of from about 2 carbon atoms per molecule to about 30 carbon atoms per molecule and, most preferably, in the range of from about 2 carbon atoms per molecule to about 20 carbon atoms per molecule. Preferably, a hydrocarbon is a saturated hydrocarbon, a mixture of saturated hydrocarbons, or a mixture of saturated hydrocarbons and less unsaturated hydrocarbons. Also, as used in the present invention, the term “fluid” denotes gas, liquid, vapor, or combinations thereof.
The term “saturated hydrocarbon” refers to any hydrocarbon which does not contain any carbon-to-carbon double bonds or carbon-to-carbon triple bonds. Examples of saturated hydrocarbons include, but are not limited to, ethane, propane, butanes, hexanes, octanes, decanes, naphtha, and the like and combinations thereof.
The term “highly unsaturated hydrocarbon” refers to a hydrocarbon having a carbon-to-carbon triple bond or two
Drake Charles A.
Wu An-hsiang
Phillips Petroleum Company
Scott Reece A.
Yildirim Bekir L.
LandOfFree
Hydrocarbon hydrogenation catalyst and process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrocarbon hydrogenation catalyst and process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrocarbon hydrogenation catalyst and process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2451097