Filterable composite adsorbents

Abstract

This invention relates to filterable composite adsorbents comprising one or more adsorbent components and one or more filtration components, and methods for preparing and using same. More particularly, this invention pertains to filterable composite adsorbents and filterable composite adsorbent products which are suitable for use in filtration applications, and which comprise one or more microparticulate or colloidal adsorbent components selected from the group consisting of silica gel, fumed silica, neutral clay, alkaline clay, zeolite, solid catalyst, alumina, adsorbent polymer, alkaline earth silicate hydrate, and combinations thereof, which bear the property of adsorption, which are intimately bound to one or more functional filtration components selected from the group consisting of biogenic silica (e.g., diatomite, rice hull ash, sponge spicules), natural glass (e.g., expanded perlite, pumice, expanded pumice, pumicite, expanded obsidian, expanded volcanic ash), buoyant glass, buoyant polymer, cellulose, and combinations thereof, which bear a distinguishing porous and intricate structure and buoyancy suitable for filtration.

Description

[0001] This application is a continuation-in-part of U.S. Ser. No. 09 / 001,965 filed Dec. 31, 1997, which is a continuation-in-part of U.S. Ser. No. 08 / 781,325 filed Jan. 10, 1997. The prior applications are incorporated herein by reference in their entirety.[0002] This invention relates to composites comprising one or more adsorbent components and one or more filtration components, and methods for preparing and using same. More particularly, this invention pertains to filterable composite adsorbents and filterable composite adsorbent products which are suitable for use in filtration applications, and which comprise one or more microparticulate or colloidal adsorbent components selected from the group consisting of silica gel, fumed silica, neutral clay, alkaline clay, zeolite, solid catalyst, alumina, adsorbent polymer, alkaline earth silicate hydrate, and combinations thereof, which bear the property of adsorption, which are intimately bound to one or more functional filtration com...

AI Technical Summary

Benefits of technology

[0043] The filterable composite adsorbents of the present invention retain both the adsorptive properties of the adsorbent component and the intricate and porous structure of a functional filtration component, thus greatly enhancing the utility of the filterable composite adsorbents in practical applications. The filterable composite adsorbents of the present invention offer a spectrum of permeabilities comparable to the range offered by their functional filtration components.

[0106] The silanized hydrophobic or hydrophilic filterable composite adsorbent products are desirable when these properties further improve the filtration performance, owing to their greater compatibility with other materials or ingredients in a specific application.

Problems solved by technology

Although not usually as effective for the selective adsorption as commercial adsorbents, these products do have intricate and porous structures of greater size that are uniquely suited to the effective physical entrapment of particles, for example in filtration processes.

Since the requirement for high specific surface area is inextricably coupled with extremely fine pore size in order to create an effective, practical adsorbent, many adsorbents are not readily separated (e.g., filtered) from the fluids in which they have been suspended, because the individual particles of adsorbents cannot be made larger than the colloidal or fine microparticulate size range in their pure form and still retain both buoyancy and the desired adsorbent properties.

The filtration of microparticulate or colloidal adsorbents is usually difficult, since the adsorbent particles are not readily and / or effectively filterable.

For example, merely blending microparticulate or colloidal adsorbents into porous filtration media products reduces the efficiency and permeability of the porous filtration media, as the adsorbents are typically of such a size as to behave as particles that detrimentally occupy the valuable void spaces that result from the intricate structure of the porous filtration media.

This method appears to be highly limited with regard to the quantity of acidic montmorillonite clay that can be effectively bound to the perlite after expansion, as perlite particles greatly increase in volume, up to twenty times, during expansion.

Beer contains certain high molecular weight proteins (e.g., anthocyanodins) that precipitate when finished beer is chilled, creating a haze in beer that is deemed undesirable by brewers.

Removing the silica gel-protein complexes from the beer significantly adds to the filtration burden such that the efficiency of the porous filtration media is reduced.

However, bleaching clay is a very fine powder, and must be separated from the oil after adsorption has taken place; this separation is a slow and tedious process.

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