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

Patent metadata

Field	Value
Publication number	US-2018125886-A1
Application number	US-201815862007-A
Country	US
Kind code	A1
Filing date	Jan 4, 2018
Priority date	Mar 14, 2007
Publication date	May 10, 2018
Grant date	—

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, wherein:
at 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, and the high-performance adsorbents have a BET surface area of at least 1250 m 2 /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.

First claim

We claim:

1 . A process for producing the high-performance adsorbents based on activated carbon,
which high-performance adsorbents are in the form of discrete grains of activated carbon and which high-performance adsorbents are characterized by the following properties:
at least 70% of the total pore volume of the high-performance adsorbents is formed by pores having pore diameters of more than 20 Å,
the mean pore diameter of the high-performance adsorbents is more than 25 Å,
the BET surface area of the high-performance adsorbents is at least 1,250 m 2 /g, and
the iodine number of the high-performance adsorbents have at least 1,250 mg/g;
which process comprises the following steps: a carbonaceous starting material is initially carbonized and subsequently activated, wherein the activation is carried out in two stages, wherein, in a first activating step, the carbonized starting material is initially subjected to an activation in an atmosphere comprising water vapor, followed by a second activating step of activation in an atmosphere comprising CO 2 .

2 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor, wherein the throughput of water vapor is 25 to 350 m 3 /h, calculated as pure water vapor.

3 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor, wherein the throughput of water vapor is 50 to 300 m 3 /h, calculated as pure water vapor.

4 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor, wherein the mass-based throughput of water vapor is 0.01 to 50 l/(h·kg), calculated as pure water and based on the amount of starting material to be activated with water vapor.

5 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor, wherein the mass-based throughput of water vapor is 0.02 to 25 l/(h·kg), calculated as pure water and based on the amount of starting material to be activated with water vapor.

6 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor in the form of a mixture of water vapor and an inert gas.

7 . The process as claimed in claim 1 ,
wherein the first activating step is carried until a predetermined iodine number of at least 1,000 mg/g is attained.

8 . The process as claimed in claim 1 ,
wherein the first activating step is carried out at temperatures of from 700 to 1,300° C. and for a duration of 5 to 24 hours.

9 . The process as claimed in claim 1 ,
wherein the first activating step is carried out at temperatures of from 800 to 1,200° C. and for a duration of 6 to 15 hours.

10 . The process as claimed in claim 1 ,
wherein the atmosphere of the second activating step comprises CO 2 , wherein the throughput of CO 2 is 10 to 250 m 3 /h, calculated as pure gaseous CO 2 .

11 . The process as claimed in claim 1 ,
wherein the atmosphere of the second activating step comprises CO 2 , wherein the throughput of CO 2 is 20 to 200 m 3 /h, calculated as pure gaseous CO 2 .

12 . The process as claimed in claim 1 ,
wherein the atmosphere of the second activating step comprises CO 2 , wherein the mass-based throughput of CO 2 is 0.001 to 100 m 3 /(h·kg), calculated as pure gaseous CO 2 under activating conditions and based on the amount of starting material to be activated with CO 2 .

13 . The process as claimed in claim 1 ,
wherein the atmosphere of the second activating step comprises CO 2 , wherein the mass-based throughput of CO 2 is 0.01 to 50 m 3 /(h·kg), calculated as pure gaseous CO 2 under activating conditions and based on the amount of starting material to be activated with CO 2 .

14 . The process as claimed in claim 1 ,
wherein the atmosphere of the first activating step comprises water vapor in the form of a mixture of CO 2 and an inert gas.

15 . The process as claimed in claim 1 ,
wherein the second activating step is carried out at temperatures of from 700 to 1,300° C. and for a duration of 1 to 10 hours.

16 . The process as claimed in claim 1 ,
wherein the second activating step is carried out at temperatures of from 800 to 1,200° C. and for a duration of 3 to 8 hours.

17 . The process as claimed in claim 1 ,
wherein carbonization is carried out at temperatures in the range of from 100 to 950° C. and for a duration of 0.5 to 6 hours.

18 . The process as claimed in claim 1 ,
wherein carbonization is carried out under an inert or at most slightly oxidizing atmosphere.

19 . The process as claimed in claim 1 ,
wherein the carbonaceous starting material comprises sulfonated styrene-divinylbenzene polystyrenes.

20 . The process as claimed in claim 1 ,
wherein the high-performance adsorbents are further characterized by at least one of the further following properties:
a Gurvich total pore volume of the high-performance adsorbents of at least 0.8 cm 3 /g and up to 3.5 cm 3 /g,
a carbon black method pore volume of the high-performance adsorbents which is formed by pores having pore diameters of more than 20 Å in the range of from 0.4 to 3.3 cm 3 /g,
a butane adsorption of the high-performance adsorbents in the range from 30 to 80%,
a methylene blue value of the high-performance adsorbents in the range from 15 to 60 ml,
a molasses number of the high-performance adsorbents in the range from 300 to 1,400.
an iodine number of the high-performance adsorbents in the range from 1,250 to 2,100 mg/g.

Assignees

• Bluecher Gmbh

Inventors

• Böhringer Bertram
• Fichtner Sven
• Giebelhausen Jann-Michael

Classifications

• B01J20/28083

  being in the range 2-50 nm, i.e. mesopores · CPC title

• B01J20/28076

  being more than 1.0 ml/g · CPC title

• B01D2253/102

  Carbon · CPC title

• A61K33/44 Primary

  Elemental carbon, e.g. charcoal, carbon black · CPC title

• B01D53/02

  by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} · CPC title