Molecular sieve layers and processes for their manufacture

Abstract

Layers comprising a molecular sieve layer on a porous or non-porous support, having uniform properties and allowing high flux are prepared from colloidal solutions of zeolite or other molecular sieve precursors (particle size less than 100 nm), by deposition, e.g., by spin or dip-coating, or by in situ crystallization.

1 . A process for the separation of a fluid mixture which comprises contacting the mixture with one face of a supported inorganic layer comprising contiguous particles of a crystalline molecular sieve, the particles having a mean particle size within the range of from 20 nm to 1 μm, and wherein the layer primarily contains nanopores having a size of between 1 and 10 nm, under such conditions that at least one component of the mixture has a different steady state permeability through the layer from that of another component and recovering a component or mixture of components from the other face of the layer.  
     
     
         2 . The process of  claim 1 , wherein the separation is of a feed for a reaction from a feedstock.  
     
     
         3 . The process of  claim 1 , wherein paraxylene is separated from a mixture of xylenes.  
     
     
         4 . The process of  claim 1 , wherein aromatics are separated from a hydrocarbon-containing stream from an aromatics generation process.  
     
     
         5 . The process of  claim 1 , wherein the aromatics are separated from a hydrocarbon-containing stream from a catalytic reforming process.  
     
     
         6 . The process of  claim 1 , wherein benzene is separated from a hydrocarbon-containing stream.  
     
     
         7 . The process of  claim 1 , wherein olefins are separated from a hydrocarbon-containing stream.  
     
     
         8 . The process of  claim 1 , wherein hydrogen is separated from a hydrocarbon-containing stream.  
     
     
         9 . The process of  claim 8 , wherein the hydrocarbon-containing stream is produced by a process selected from catalytic reforming, alkane dehydrogenation, catalytic cracking and thermal cracking.  
     
     
         10 . The process of  claim 1 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
     
     
         11 . The process of  claim 10 , wherein paraxylene is separated from a mixture of xylenes.  
     
     
         12 . A process for the separation of a fluid mixture which comprises contacting the mixture with one face of a supported inorganic layer comprising contiguous particles of a crystalline molecular sieve, the particles having a mean particle size within the range of from 20 nm to 1 μm, wherein the support is selected from the group consisting of glass, fused quartz, silica, silicon, clay, metal, porous glass, sintered porous metal, titania, and cordierite, and wherein the layer primarily contains nanopores having a size of between 1 and 10 nm, under such conditions that at least one component of the mixture has a different steady state permeability through the layer from that of another component and recovering a component or mixture of components from the other face of the layer.  
     
     
         13 . The process of  claim 12 , wherein paraxylene is separated from a mixture of xylenes.  
     
     
         14 . The process of  claim 12 , wherein aromatics are separated from a hydrocarbon-containing stream from an aromatics generation process.  
     
     
         15 . The process of  claim 12 , wherein olefins are separated from a hydrocarbon-containing stream.  
     
     
         16 . The process of  claim 12 , wherein hydrogen is separated from a hydrocarbon-containing stream.  
     
     
         17 . The process of  claim 12 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
     
     
         18 . The process of  claim 17 , wherein paraxylene is separated from a mixture of xylenes.  
     
     
         19 . The process of  claim 12 , wherein the particle size distribution of the supported inorganic layer is such that at least 95% of the particles have a size within ±33% of the mean.  
     
     
         20 . The process of  claim 19 , wherein paraxylene is separated from a mixture of xylenes.