Abstract:
Effect ion-exchange of an alpha-alumina supported zeolite (e.g. a MFI zeolite, an LTA zeolite or a FAU zeolite) membrane, which process comprises: a) placing the membrane, which has a first surface and a spaced apart second surface, the first and second surfaces defining therebetween the membrane, in an ion exchange apparatus such that the first surface is in contact with an ion exchange solution and the second surface is in contact with a vapor space that is connected to a source of reduced pressure; b) actuating the source of reduced pressure to create a pressure differential between the first and second membrane surfaces of at least 0.4 atmosphere (0.405×105 pascals); and c) maintaining the pressure differential under ion exchange conditions for a period of time sufficient to effect exchange of an ion contained in the ion exchange solution with an ion in the zeolite membrane in an amount that is greater than an amount of ion exchange attained using an apparatus that places the second surface in contact with a liquid solvent that is at a pressure of at least one atmosphere (1.013×105 pascals) and the first surface in contact with the ion exchange solution at a pressure of at least two atmospheres (2.026×105 pascals) so as to establish a pressure differential between the two surfaces of at least one atmosphere (1.013×105 pascals), maintaining the pressure differential for the same period of time, and using the same ion exchange membrane, ion exchange solution and ion exchange temperature, the greater amount of ion exchange yielding an improved ion exchange membrane that a ratio of the ion that entered the membrane from the solution to the ion that left the membrane that is greater than that of the ion exchanged membrane prepared with the second surface in contact with the liquid solvent.
Abstract:
The present invention relates to a method for preparing MWW type zeolite; said method comprising i) intimately mixing together, in the absence of any organic structure directing agent or crystalline MWW type zeolite seeds, a predetermined quantity of a source of silicon dioxide, a source of metal oxide, water and a pH modifier to obtain an aqueous amorphous metallosilicate gel; and ii) hydrothermally treating said gel in the presence of an organic templating agent to provide a crystalline MWW type zeolite.
Abstract:
The present invention relates to selectively isolating gases using a natrolite-based zeolite, and more particularly, to a novel natrolite-based zeolite and to selectively isolating hydrogen and/or helium gas using a natrolite-based zeolite. The present invention is characterized in that gas containing hydrogen is brought into contact with a natrolite-based zeolite to selectively isolate the hydrogen. The present invention provides a sorbent which can selectively isolate hydrogen and/or helium, and provides a method for isolating the hydrogen and/or helium at room temperature or at a high temperature.
Abstract:
The present invention relates to a method for preparing MWW type zeolite; said method comprising i) intimately mixing together, in the absence of any organic structure directing agent or crystalline MWW type zeolite seeds, a predetermined quantity of a compound containing silicon dioxide, a compound containing metal oxide, water and a pH modifier to obtain an aqueous amorphous metallosilicate gel; and ii) hydrotherinally treating said gel in the presence of an organic tempiating agent to provide a crystalline M W w type zeonte.
Abstract translation:本发明涉及一种制备MWW型沸石的方法; 所述方法包括i)在不存在任何有机结构导向剂或结晶MWW型沸石种子的情况下,将预定量的含有二氧化硅的化合物,含金属氧化物的化合物,水和pH调节剂紧密混合在一起,以获得含水 无定形金属硅酸盐凝胶; 和ii)在有机温和剂存在下水解处理所述凝胶以提供结晶的M W w型沸腾。
Abstract:
This invention relates to novel compositions of zeolites or microporous metallosilicates characterized by a continuous spatial distribution of the metal and silicon in the crystals and characterized by a crystal surface enriched in silicon relative to the internal part of the same crystals. This invention also relates to a synthesis method of producing these metallosilicates with spatial distribution of the constituting elements. These novel zeolitic compositions can be used in various hydrocarbon conversion reactions. The crystalline metallosilicates can be selected from the group consisting of aluminosilicates, gallosilicates, ferrosilicates, titanosilicates and borosilicates.
Abstract:
A process is described for converting synthesis gas containing carbon monoxide and hydrogen to hydrocarbons via methanol as an intermediate, by contacting the synthesis gas with a catalyst system containing a mixture of gallium silicate zeolite catalyst and a methanol catalyst. The process results in reduced amounts of undesirable low carbon number hydrocarbons, e.g., C4 and lower, undesirable high carbon number hydrocarbons, e.g., C10 and higher, and aromatic hydrocarbons. The process provides higher yields of useful, high octane hydrocarbons boiling in the gasoline range.
Abstract:
This invention relates to novel compositions of zeolites or microporous metallosilicates characterised by a continuous spatial distribution of the metal and silicon in the crystals and characterised by a crystal surface enriched in silicon relative to the internal part of the same crystals. This invention also relates to a synthesis method of producing these metallosilicates with spatial distribution of the constituting elements. These novel zeolitic compositions can be used in various hydrocarbon conversion reactions. The crystalline metallosilicates can be selected from the group consisting of aluminosilicates, gallosilicates, ferrosilicates, titanosilicates and borosilicates.
Abstract:
The invention relates to a crystalline zeolite-like gallosilicate having an atomic ratio of Si/Ga in the outer crystalline surface that is not larger than the average Si/Ga ratio for the whole of the crystal. The invention also relates to a method of making such a gallosilicate comprising the hydrothermal crystallization of a strictly inorganic reaction mixture having the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05-1.0; and H.sub.2 O/SiO.sub.2 =10-1,000. The invention further relates to the above-described method wherein said reaction mixture is prepared by adding an aged gel to a first mixture, the first mixture preferably having a composition with the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05 to 1.0; and H.sub.2 O/SiO.sub.2 =20 to 100.
Abstract translation:本发明涉及外晶面中Si / Ga原子比不大于整个晶体的平均Si / Ga比的结晶沸石状半硅酸盐。 本发明还涉及一种制备这种硅酸盐硅酸盐的方法,其包括具有以下摩尔比的严格无机反应混合物的水热结晶:SiO 2 / Ga 2 O 3> = 5; OH- / SiO 2 = 0.05-1.0; 和H2O / SiO2 = 10-1,000。 本发明还涉及上述方法,其中所述反应混合物通过将老化凝胶加入到第一混合物中制备,第一混合物优选具有以下摩尔比的组成:SiO 2 / Ga 2 O 3> = 5; OH- / SiO 2 = 0.05〜1.0; 和H 2 O / SiO 2 = 20〜100。
Abstract:
There is provided a gallium-containing MCM-22 zeolite. There are also provided methods for making this zeolite and processes for using this zeolite as a catalyst for the conversion of organic molecules. Particular conversions are reforming and the dehydrogenation of methylcyclohexane to form toluene.