High-performance adsorbents based on activated carbon having high meso- and macropososity

Abstract

The invention concerns high-performance adsorbents based on activated carbon of high meso- and macroporosity which are present in the form of discrete grains of activated carbon, whereinat least 55% of the total pore volume of the high-performance adsorbents are formed by pores (i.e. meso- and macropores) having pore diameters of more than 20 Å,the high-performance adsorbents have a measure of central tendency pore diameter of more than 25 Å, andthe high-performance adsorbents have a BET surface area of at least 1250 m2 / g.These high-performance adsorbents are obtainable by a novel process comprising specific two-stage activation, and have, in addition to the aforementioned properties, an excellent abrasion and bursting resistance, so that they are useful for a multiplicity of different applications.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a National Stage filing of International Application PCT / EP2008 / 000606, filed Jan. 25, 2008, claiming priority to German Application Nos. DE 10 2007 012 963.9 filed Mar. 14, 2007 and DE 10 2007 050 971.7, filed Oct. 25, 2007. The subject application claims priority to PCT / EP2008 / 000606, to German Application Nos. DE 10 2007 012 963.9 and DE 10 2007 050 971.7 and incorporates all by reference herein, in their entirety.BACKGROUND OF THE INVENTION[0002]The present invention concerns the adsorption arts. More particularly, the present invention concerns high-performance adsorbents based on activated carbon of high meso- and macroporosity and a process for production thereof and also the use of these high-performance adsorbents, particularly for adsorptive filtering materials, for the food industry (for example for preparing and / or decolorizing food products, for the adsorption of toxins, noxiants and odors, particularly f...

AI Technical Summary

Benefits of technology

[0013]This invention relates to high-performance adsorbents based on activated carbon in the form of discrete grains of activated carbon having: (a) at least 70% of the total pore volume formed by pores having pore diameters of more than 20 Å; (b) a measure of central tendency pore diameter (mean pore diameter) of more than 25 Å; (c) a BET surface area of at least 1,250 m2 / g; and (d) an iodine number of at least 1,250 mg / g. Such adsorbents typically have a high meso- and macroporosity, (i.e. a high meso- and macroporous fraction relative to the total pore volume), a large total pore volume and yet retain high stability to abrasion and bursting.

Problems solved by technology

Spherocarbon is mostly still being produced today by multistage and very costly and inconvenient processes.

These multistage processes are very cost intensive and the associated high cost of this spherocarbon prevents many applications wherein spherocarbon ought to be preferable by virtue of its properties.

True, the activated carbon known for this purpose from the prior art does have a certain degree of meso- and macroporosity, but that degree is not sufficient in all cases.

In addition, increasing porosity is often observed to be accompanied by an unwelcome, occasionally unacceptable decrease in mechanical stability or to be more precise abrasion resistance.

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