摘要:
The present invention involves the use of a multi-stage membrane system for gas, vapor, and liquid separations. In this multi-stage membrane system, high selectivity and high permeance or at least high selectivity polybenzoxazole membranes or cross-linked polybenzoxazole membranes are applied for a pre-membrane or both the pre-membrane and the secondary membrane. A primary membrane can be from conventional glassy polymers. This multi-stage membrane system can reduce inter-stage compression cost, increase product recovery and product purity for gas, vapor, and liquid separations. It can also save the cost compared to the system using all the high cost polybenzoxazole membranes or cross-linked polybenzoxazole membranes.
摘要:
Using a high pressure rotary adsorbent wheel, a high value compressed gas feed can be purified by concentrating the impurity such as water, condensing it out, before final purification. Instead of exhausting gas from the system, the effluent can be put back into the feed at a point prior to condensation of the high value gas feed, and therefore the entire feed is purified without any high value gas feed going into a waste stream.
摘要:
This invention relates to multi-compositional, multiphase composite compositions comprising as phases thereof (i) an electronically conducting or semi-conducting substrate, (ii) an inorganic oxide composition layer in proximity to at least a portion of the surface of said electrically conducting or semi-conducting substrate and (iii) an inorganic crystalline molecular sieve composition layer upon at least a portion of the surface of said inorganic oxide composition layer. The inorganic crystalline molecular sieve composition layer is grown by crystal growth upon at least a portion of the inorganic oxide composition layer surface. The different phases of the composite compositions are substantially contiguous and exhibit a distinct compositional and/or structural heterogeneity of one phase to another. The multi-compositional, multiphase composite compositions have beneficial utility as a moisture sensing element in an electric hydrometer which measures the moisture content of moisture-containing systems by change in electrical impedance. This invention also relates to processes for preparing the multi-compositional, multiphase composite compositions.
摘要:
The present invention discloses a new type of high performance polymer membranes prepared from aromatic polyimide membranes by thermal treating and crosslinking and methods for making and using these membranes. The polymer membranes were prepared from aromatic polyimide membranes by thermal treating under inert atmosphere followed by crosslinking preferably by using a UV radiation source. The aromatic polyimide membranes were made from aromatic polyimide polymers comprising both pendent hydroxy functional groups ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone. The membranes showed significantly improved selectivity and permeability for gas separations compared to the aromatic polyimide membranes without any treatment. The membranes can be fabricated into any convenient geometry and are not only suitable for a variety of liquid, gas, and vapor separations, but also can be used for other applications such as for catalysis and fuel cell applications.
摘要:
The present invention discloses a new type of high performance polymer membranes derived from aromatic polyimide membranes and methods for making and using these membranes. The polymer membranes described in the present invention were derived from aromatic polyimide membranes by crosslinking followed by thermal treating. The aromatic polyimide membranes were made from aromatic polyimide polymers comprising both pendent hydroxy functional groups ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone. The high performance polymer membranes showed significantly improved permeability for gas separations compared to the aromatic polyimide membranes without any treatment. The high performance polymer membranes also showed significantly improved selectivity for gas separations compared to the thermal-treated but non-UV-crosslinked aromatic polyimide membranes. The high performance polymer membranes of the present invention are suitable for liquid, gas, and vapor separations, as well as for catalysis and fuel cell applications.
摘要:
The present invention discloses a new type of high performance polymer membranes prepared from aromatic polyimide membranes by thermal treating and crosslinking and methods for making and using these membranes. The polymer membranes were prepared from aromatic polyimide membranes by thermal treating under inert atmosphere followed by crosslinking preferably by using a UV radiation source. The aromatic polyimide membranes were made from aromatic polyimide polymers comprising both pendent hydroxy functional groups ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone. The membranes showed significantly improved selectivity and permeability for gas separations compared to the aromatic polyimide membranes without any treatment. The membranes can be fabricated into any convenient geometry and are not only suitable for a variety of liquid, gas, and vapor separations, but also can be used for other applications such as for catalysis and fuel cell applications.
摘要:
A moisture sensing element is disclosed which comprises an electrically continuous article comprising a multi-compositional, multi-phase composite composition comprising as phases thereof (i) an electrically conducting or semiconducting substrate, (ii) an inorganic oxide composition layer in proximity to at least a portion of the surface of the electrically conducting or semiconducting substrate and (iii) an inorganic crystalline molecular sleeve composition layer upon at least a portion of the surface of the inorganic oxide composition layer, wherein the different phases of the composite composition are substantially contiguous and exhibit at least one of a distinct compositional heterogeneity and a distinct structural heterogeneity of one phase to the other; and at least one electrode affixed to the article in current carrying relationship so that the current carried by the electrode passes through at least a portion of the inorganic crystalline molecular sieve composition layer.
摘要:
Linear and/or branched claim C.sub.2 to C.sub.12 olefins are converted to hydrocarbon mixtures suitable for use as liquid motor fuels by contact with a catalyst capable of ensuring the production of desirable products with only a relatively minor amount of heavy products boiling beyond the diesel oil range. The catalyst having desirable stability during continuous production operations, comprises a steam stabilized zeolite Y catalyst of hydrophobic character, desirably in aluminum-extracted form. The olefins such as propylene, may be diluted with inerts, such as paraffins or with water, the latter serving to moderate the acidity of the catalyst, or to further moderate the activity of the aluminum-extracted catalyst, so as to increase the effective life of the catalyst.
摘要:
The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.
摘要:
The present invention provides a process for treating a natural gas stream comprising sending a natural gas stream to at least one membrane unit to produce a permeate stream containing a higher concentration of carbon dioxide and a retentate stream containing a lower concentration of carbon dioxide. Then the retentate stream is sent to an adsorbent bed to remove carbon dioxide and other impurities to produce a natural gas product stream. The regeneration gas stream is sent through the molecular sieve adsorbent bed to desorb the carbon dioxide. In one process flow scheme, the regeneration stream is combined with the permeate stream from the membrane unit. Then the combined stream is sent to an absorbent column to remove carbon dioxide from the permeate stream to produce a second natural gas product stream. In the alternative flow scheme, a second membrane unit is used to improve efficiency.