Honeywell and its subsidiary UOP LLC have filed a series of patent applications revealing nano adsorbents, catalysts and zeolites to improve refinery processes for hydrocracking and separating heavy hydrocarbons into lighter fuels and products.
In U.S Patent Application 20090326310, Honeywell/UOP inventors Santi Kulprathipanja, Stanley J. Frey, Richard R. Willis and Lisa M. Knight disclose processes for separating meta-xylene from a relatively impure mixture of one or more C8 alkylaromatic hydrocarbons containing the desired meta-xylene. The mixture is contacted under adsorption conditions with an adsorbent comprising nano sodium-exchanged zeolite Y.
The inventors found that "nano sodium zeolite Y" (i.e., nano-size zeolite Y crystallites in sodium form with an average crystallite size below one micron) provides highly favorable performance characteristics when incorporated into adsorbents used in the adsorptive separation of meta-xylene. In particular, the mass transfer rate of meta-xylene into the zeolite pores is significantly greater, relative to sodium zeolite Y synthesized according to conventional methods which typically having an average crystallite size on the order of 1-3 microns.
U.S. Patent Application 20090326310, FIG. 1 shows a Scanning Electron Microscopy (SEM) micrograph of nano sodium-exchanged zeolite Y crystallites
In U.S. Patent Application 20090326309 Honeywell/UOP inventors Jim Priegnitz, Darryl Johnson, Linda Cheng, Scott Commissaris, Jack Hurst, Mike Quick and Santi Kulprathipanja detail binderless adsorbents and their use in the adsorptive separation of para-xylene.
Suitable adsorbents comprise nano-size zeolite X with an average crystallite size ranging from 20 to about 500 nanometers. The adsorbents provide both improved capacity and mass transfer, which is especially advantageous for improving productivity in low temperature, low cycle time adsorptive separation operations in a simulated moving bed mode.
U.S. Patent Application 20090326309, FIG. 5 shows the performance of a para-xylene adsorptive separation process using nano-size zeolite X operating in a simulated moving bed mode at temperatures of 150.degree. C. (302.degree. F.) and 177.degree. C. (350.degree. F.).
This barrier to obtaining even higher productivity, observed in practice, is due to mass transfer limitations. The bottom curve in FIG. 5 (open diamonds) illustrates the impact of mass transfer limitations on productivity, in terms of the possible feed stream volumetric rate increase (Y-axis, right side) that is obtained by reducing operating temperature from 177.degree. C. (350.degree. F.) to 150.degree. C. (302.degree. F.) at each cycle time. For a cycle time of 34 minutes, for example, the benefit of lower operating temperature translates into an approximately 14% increase in the volumetric rate at which the C8 alkylaromatic feed stream that can be processed. The productivity advantage, however, decreases to only about 7% for a cycle time of 24 minutes, as a result of mass transfer limitations. The dashed lines in FIG. 5, in contrast, illustrate the para-xylene adsorptive separation performance parameters and feed productivity advantages that are theoretically possible in the absence of mass transfer limitations.
In U.S. Patent Application 20090326308 UOP and Honeywell inventors Santi Kulprathipanja, Richard Willis, Dorothy Kuechl, Jim Priegnitz, Jack Hurst, Scott Commissaris and Linda Chengdivulge binderless adsorbents comprised of nano-size zeolite X and their use in the adsorptive separation of para-xylene. Adsorbents and methods for the adsorptive separation of para-xylene from a mixture containing other C8 aromatic hydrocarbons (e.g., a mixture of ortho-xylene, meta-xylene, para-xylene, and ethylbenzene) are described. Suitable adsorbents comprise nano-size zeolite X with an average crystallite size of less than about 500 nanometers. The adsorbents provide both improved capacity and mass transfer, which is especially advantageous for improving productivity in low temperature, low cycle time adsorptive separation operations in a simulated moving bed mode.
U.S. Patent Application 20090326308, FIG. 5 shows the effect of cycle time on para-xylene recovery, in a para-xylene adsorptive separation process operating in a simulated moving bed mode, for an adsorbent comprising conventional zeolite X crystallites and another adsorbent comprising zeolite X having a reduced crystallite size.
In U.S. Patent Application 20090326304 Honeywell/UOP inventors Alakananda Bhattacharyya and Beckay J. Mezza reveal a process for using catalyst with nanometer iron sulfide crystallites in slurry hydrocracking.
The Honeywell/UOP process for converting heavy hydrocarbon feed into lighter hydrocarbon products includes: mixing the heavy hydrocarbon liquid feed with catalyst particles and hydrogen to form a heavy hydrocarbon slurry; hydrocracking hydrocarbons in said heavy hydrocarbon slurry in the presence of hydrogen and catalyst particles in a hydrocracking reactor to produce a hydrocracked slurry product comprising lighter hydrocarbon products, said catalyst particles comprising iron sulfide crystallites with a mean diameter of about 1 to about 150 nanometers; and withdrawing said hydrocracked slurry product from said hydrocracking reactor.
U.S. Patent Application 20090326304, FIG. 7 is a SEM micrograph of iron sulfide monohydrate catalyst. A micrograph of the iron sulfide crystallites formed from iron sulfate monohydrate precursor crystallites from run 523-4 in FIG. 7 by SEM at 10,000 times indicates a variety of crystallite sizes ranging typically from 150 to 800 nm. The iron sulfide crystallites are the black particles in FIG. 7.
In U.S. Patent Application 20090326303, Honeywell/UOP inventors Alakananda Bhattacharyya and Beckay J. Mezza reveal a Process for Using Iron Oxide and Alumina Catalyst for Slurry Hydrocracking. A process for converting heavy hydrocarbon feed into lighter hydrocarbon products comprising: mixing said heavy hydrocarbon liquid feed with catalyst particles and hydrogen to form a heavy hydrocarbon slurry comprising hydrocarbon liquid and catalyst particles, said catalyst particles comprising about 2 to about 45 wt-% iron oxide and about 20 to about 98 wt-% alumina; hydrocracking hydrocarbons in said heavy hydrocarbon slurry in the presence of hydrogen and catalyst particles in a hydrocracking reactor to produce a hydrocracked slurry product comprising lighter hydrocarbon products, said reactor comprising no less than about 0.1 and no more than about 4 wt-% iron content based on the total weight of non-gas materials in the reactor; and withdrawing said hydrocracked slurry product from said hydrocracking reactor.
U.S. Patent Application 20090326303, FIG. 9 is a SEM micrograph of limonite catalyst. The micrograph of the iron sulfide crystallites were formed from limonite precursor crystallites from run 522-73. FIG. 9 by SEM at 50,000 times magnificadtion indicates a variety of crystallite sizes ranging typically from 50 to 800 nm. The iron sulfide crystallites are the black particles in FIG. 9.
The crystallites of iron sulfide generated by bauxite in the reactor at reaction conditions have diameters across the crystallite in the in the nanometer range. An iron sulfide crystal is a solid in which the constituent iron sulfide molecules are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. An iron sulfide crystallite is a domain of solid-state matter that has the same structure as a single iron sulfide crystal. Nanometer-sized iron sulfide crystallites disperse well over the catalyst and disperse well in the reaction liquid. The iron sulfide crystallites are typically about the same size as the iron sulfide precursor crystallites from which they are produced. In bauxite, the iron sulfide precursor crystallite is iron oxide.
By not thermally treating the bauxite, iron oxide crystals do not sinter together and become larger. Consequently, the catalytically active iron sulfide crystallites produced from the iron oxide remain in the nanometer range. The iron sulfide crystallites may have an average largest diameter between about 1 and about 150 nm, typically no more than about 100 nm, suitably no more than about 75 nm, preferably no more than about 50 nm, more preferably no more than about 40 nm as determined by electron microscopy. The iron sulfide crystallites suitably have a mean crystallite diameter of no less than about 5 nm, preferably no less than about 10 nm and most preferably no less than about 15 nm as determined by electron microscopy. Electron microscopy reveals that the iron sulfide crystallites are fairly uniform in diameter, well dispersed and predominantly present as single crystals.
Upon conversion of the iron oxide to iron sulfide in the reactor, a composition of matter comprising about 2 to about 45 wt-% iron sulfide and about 20 to about 98 wt-% alumina is generated and dispersed in the heavy hydrocarbon medium to provide a slurry. The composition of matter has iron sulfide crystallites in the nanometer range as just described. We have found that the iron oxide precursor crystallites in bauxite have about the same particle diameter as the iron sulfide crystallites formed from reaction with sulfur. We have further found that the alumina and iron oxide catalyst can be recycled to the SHC reactor at least twice without iron sulfide crystallites becoming larger.
In U.S. Patent Application 20090326302 Honeywell/UOP inventors Alakananda Bhattacharyya and Beckay J. Mezza reveal a process for using nano alumina catalyst in slurry hydrocracking. The catalyst are used for converting heavy hydrocarbon feed into lighter hydrocarbon products in a process comprised of: mixing the heavy hydrocarbon liquid feed with catalyst particles and hydrogen to form a heavy hydrocarbon slurry to produce a hydrocracked slurry product comprising lighter hydrocarbon products; and withdrawing the hydrocracked slurry product from the hydrocracking reactor having a yield fraction of mesophase which is no more than about 0.5 as a weight percentage of feed.
U.S. Patent Application 20090326302, FIG. 11 is a STEM micrograph of bauxite catalyst. The micrograph in FIG. 11 was made by scanning transmission electron microscopy (STEM) compositional x-ray mapping. The micrograph indicates that the boehmite particles range in size from 70 to 300 nm while the iron sulfide crystallites range uniformly at about 25 um between about 15 nm to about 40 nm. The alumina particles are the larger, lighter gray materials in FIG. 11. The dark black material in the top center of FIG. 11 is believed to be an impurity
The crystallites of iron sulfide generated by bauxite in the reactor at reaction conditions have diameters across the crystallite in the in the nanometer range. An iron sulfide crystal is a solid in which the constituent iron sulfide molecules are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. An iron sulfide crystallite is a domain of solid-state matter that has the same structure as a single iron sulfide crystal. Nanometer-sized iron sulfide crystallites disperse well over the catalyst and disperse well in the reaction liquid. The iron sulfide crystallites are typically about the same size as the iron sulfide precursor crystallites from which they are produced. In bauxite, the iron sulfide precursor crystallite is iron oxide. By not thermally treating the bauxite, iron oxide crystals do not sinter together and become larger. Consequently, the catalytically active iron sulfide crystallites produced from the iron oxide remain in the nanometer range.
The iron sulfide crystallites may have an average largest diameter between about 1 and about 150 nm, typically no more than about 100 nm, suitably no more than about 75 nm, preferably no more than about 50 nm, more preferably no more than about 40 nm as determined by electron microscopy. The iron sulfide crystallites suitably have a mean crystallite diameter of no less than about 5 nm, preferably no less than about 10 nm and most preferably no less than about 15 nm as determined by electron microscopy. Electron microscopy reveals that the iron sulfide crystallites are fairly uniform in diameter, well dispersed and predominantly present as single crystals.
In U.S Patent Application, 20090326311, Honeywell/UOP inventors Linda Shi Cheng and James A. Johnson detail adsorbents and methods for the adsorptive separation of para-xylene from a mixture containing at least one other C8 aromatic hydrocarbon (e.g., a mixture of ortho-xylene, meta-xylene, para-xylene, and ethylbenzene) are described. Suitable adsorbents comprise zeolite X having an average crystallite size of less than 1.8 microns (typically from about 500 nanometers to about 1.5 microns). The adsorbents provide improved mass transfer, which is especially advantageous for improving productivity in low temperature, low cycle time adsorptive separation operations in a simulated moving bed mode.
Honeywell/UOP Nano Adsorbents and Catalysts Patent Applications for Cracking Hydrocarbons
1. 20090326311 Adsorbents With Improved Mass Transfer Properties And Their Use In The Adsorptive Separation Of Para-Xylene
4 20090326308 Binderless Adsorbents Comprising Nano-Size Zeolite X And Their Use In The Adsorptive Separation Of Para-Xylene
5 20090326304 Process for Using Catalyst with Nanometer Crystallites in Slurry Hydrocracking 6 20090326303 Process for Using Iron Oxide and Alumina Catalyst for Slurry Hydrocracking
