摘要:
Disclosed herein is a method of making xylene isomers. More specifically, the method includes contacting a C9 aromatics-comprising feed with a catalyst under conditions suitable for converting the feed to an intermediate product stream comprising xylene isomers, separating at least a portion of the xylene isomers from the intermediate product stream, and recycling to the feed the xylene isomers-lean intermediate product stream. Alternatively, the method of making xylene isomers includes contacting a feed comprising C9 aromatics and less than about 30 wt. % benzene, based on the total weight of the feed, with a non-sulfided, large-pore zeolite impregnated with a Group VIB metal oxide, under conditions suitable for converting the feed to a product stream comprising xylene isomers. The disclosed method is characterized by unexpectedly high ratios of xylene isomers to ethylbenzene, xylene isomers to C9 aromatics (e.g., methylethylbenzene), xylene isomers to C10 aromatics, trimethylbenzene to methylethylbenzene, benzene to ethylbenzene, in the product of the conversion, and the high conversion of C9 aromatics and methylethylbenzene.
摘要:
Disclosed herein are methods of making xylene isomers. The methods generally include contacting an aromatics-comprising feed with a non-sulfided catalyst under conditions suitable for converting the feed to a product comprising xylene isomers. The catalyst includes a support impregnated with a hydrogenation component. The support includes a macroporous binder and a sieve selected from the group consisting of a medium pore sieve, a large pore sieve, and mixtures thereof. The selection of the sieve will depend upon the size of the molecules in the feed, intermediate, and product that can be expected from the catalytic reactions. When the molecules are expected to be large, a large pore sieve should be used. In contrast, when the molecules are expected to be smaller, either a large pore sieve, a medium pore sieve, or a mixture thereof may be used. The macropores within the support have been found to be especially beneficial because they help to overcome diffusional limitations observed when utilizing highly-active catalysts lacking such macropores.
摘要:
Processes and apparatus are disclosed for recovery of purified products from a fluid mixture by means of integrated perm-selective separations with purified product recovery operations. More particularly, integrated processes of the invention comprise separations by means of one or more devices using polymeric membranes coupled with recovery of purified products by means of fractional crystallization and/or selective sorption. Processes of the invention are particularly useful for recovery of a very pure aromatic isomer when processing aromatic starting materials, for example, a pure para-xylene product from liquid mixtures even containing ethylbenzene as well as the three xylene isomers.
摘要:
Processes are disclosed for production of purified products from a fluid mixtures of C8 aromatics by means of integration of perm-selective separations with purified product recovery operations. The perm-selective separations of the invention comprise of one or more devices using polymeric perm-selective membrane devices to separate a meta-xylene enriched stream from fluid mixtures of C8 aromatics thereby producing a fluid comprising the remaining aromatic compounds which advantageously includes para-xylene. Processes of the invention are particularly useful for recovery of very pure meta-xylene and para-xylene co-products from liquid mixtures even containing ethylbenzene as well as the three xylene isomers.
摘要:
Compositions and processes are disclosed for economical separation of fluid mixtures. Broadly, the present invention discloses ionic polymer compositions that are useful for perm-selective membrane separations. More particularly, ionic polymers of the invention comprise a plurality of repeating structural units having as a constituent part thereof organic ionic moieties consisting of nitrogen containing anions and/or cations. In the form of non-porous membranes, ionic polymers of the invention facilitate recovery of purified organic and inorganic products from fluid mixtures by means of perm-selective membrane separations. The present invention also provides methods for forming the ionic polymers, for example by treating selected nitrogen-containing organic polymers with acids, or treating a polymeric material comprising a plurality of carboxylate groups with an amine. Ionic polymer compositions of the invention are particularly useful for simultaneous recovery of a permeate product of an increased concentration, and a desired non-permeate stream, from a fluid mixture containing at least two compounds of different boiling point temperatures.
摘要:
Tissue augmentation devices, as well as methods of manufacturing and using the same, are disclosed. In certain embodiments, a tissue augmentation device comprises an elongate tissue penetrating member and an amount of remodelable material, wherein at least a portion of the elongate member is cannulated, and at least a portion of the amount of material is received within at least a portion of the cannulated portion of the elongate member. The elongate tissue penetrating member may provide at least one deformation that is configured to constrict portions of the amount of remodelable material received within the elongate member. In alternate embodiments, a flexible covering over an implantable biomaterial provides protection and allows an easier delivery of the biomaterial to a tissue tract.
摘要:
The present invention relates to methods of forming substrate elements, including semiconductor elements such as nanowires, transistors and other structures, as well as the elements formed by such methods.
摘要:
Described, in certain inventive embodiments, are unique devices and methods for introducing implants into soft tissue of a patient. One of these devices includes a tissue-penetrating member that is configured to pass in its entirety through a volume of patient tissue. The tissue-penetrating member has a leading end and a trailing end, and provides a receiving space for receipt of an implant body portion for carrying the implant body portion into the volume of patient tissue. The device also includes an implant that has an implant body portion removably received in the receiving space of the tissue-penetrating member. The implant body portion is configured for deployment from the receiving space in the volume of patient tissue so as to remain deployed there along a passageway traversed by the tissue-penetrating member.
摘要:
A system for use in presenting media content includes a media server configured to provide media content and a media client configured to obtain the media content from the media server and to present the media content on a device. The media client is configured to generate a first code and to transmit information to the media server. The information identifies the media client and the information indicates that the media client is available for pairing. The media server is configured to reply to the information with a second code that corresponds to the first code in order to enable pairing between the media server and the media client.
摘要:
Graded artificial dielectrics using nanostructures, such as nanowires, are disclosed. The graded artificial dielectric includes a material (typically a dielectric) with a plurality of nanostructures, such as nanowires, embedded within the dielectric material. One or more characteristics of the nanostructures are spatially varied from a first region within the dielectric to a second region within the dielectric to produce permittivity of the graded artificial dielectric that is spatially varied. The characteristics that can be varied include, but are not limited to, nanostructure density, nanostructure length, nanostructure aspect ratio, nanostructure oxide ratio, and nanostructure alignment. Methods of producing graded artificial dielectrics are also provided. A wide range of electronic devices such as antennas can use graded artificial dielectrics with nanostructures to improve performance.