Mechanically stable, porous shaped activated carbon article and filtering system

What claimed is:




1. A mechanically stable, porous shaped activated carbon article comprising first three-dimensional framework structure comprised carbonized resin, second three-dimensional inorganic framework structure comprising ceramic material and/or baked refractory material also binding agent, activated carbon particles, which first second framework structures penetrate each other least partially activated carbon particles are fixed position.


2. A shaped activated carbon article defined claim 1, wherein first second framework structure penetrate each other substantially completely.


3. A shaped activated carbon article defined claim 1, wherein activated carbon particles are fixed substantially first framework structure.


4. A shaped activated carbon article defined claim 1, wherein first framework structure substantially comprised carbonized resin having aromatic nuclei.


5. A shaped activated carbon article defined claim 1, wherein first framework structure substantially comprised carbonized synthetic resin.


6. A shaped activated carbon article defined claim 5, wherein synthetic resin novolak resin.


7. A shaped activated carbon article defined claim 5, wherein said carbonized synthetic resin selected group consisting phenolic resin, furan resin, epoxy resin, unsaturated polyester resin, or mixture thereof.


8. A shaped activated carbon article defined claim 1, wherein ratio, by weight, resin activated carbon prior carbonization ranges approximately 1:1 approximately 6:1.


9. A shaped activated carbon article defined claim 8, wherein ratio, by weight, resin activated carbon prior carbonization ranges approximately 2:1 approximately 4:1.


10. A shaped activated carbon article defined claim 1, wherein binding agent second framework structure silicate binder.


11. A shaped activated carbon article defined claim 10, wherein said silicate binder colloidal silica sol and/or water glass.


12. A shaped activated carbon article defined claim 1, wherein ceramic material and/or refractory material chamotte.


13. A shaped activated carbon article defined claim 1, wherein second framework structure additionally contains fluxing agent for decreasing sintering temperature.


14. A shaped activated carbon article defined claim 13, wherein second framework structure contains fluxing agent Na2O concentration up approximately 1 wt % based total weight ceramic material and/or baked refractory material.


15. A shaped activated carbon article defined claim 14, wherein fluxing agent Na2O concentration approximately 0.3 approximately 1 wt % based total weight ceramic material and/or baked refractory material.


16. A shaped activated carbon article defined claim 1 wherein stabilizing fibers are present first and/or second framework structure.


17. A shaped activated carbon article defined claim 16, wherein said stabilizing fibers are glass fibers and/or carbon fibers.


18. A shaped activated carbon article defined claim 1, wherein shaped activated carbon article honeycomb structure.


19. A filtering system, containing mechanically stable, porous shaped activated carbon article said carbon article comprising: first three-dimensional framework structure comprised carbonized resin, second three-dimensional inorganic framework structure comprising ceramic material and/or baked refractory material also binding agent, activated carbon particles, which first second framework structures penetrate each other least partially activated carbon particles are fixed position.


20. A filtering system defined claim 19 wherein first second framework structures shaped activated carbon article penetrate each other substantially completely.


21. A filtering system defined claim 19, wherein shaped activated carbon particles shaped activated carbon article are fixed substantially first framework structure.


22. A filtering system defined claim 19, wherein first framework structure shaped activated carbon article substantially comprised carbonized resin having aromatic nuclei.


23. A filtering system defined claim 19, wherein first framework structure shaped activated carbon article substantially comprised carbonized synthetic resin.


24. A filtering system defined claim 23, wherein synthetic resin novolak resin.


25. A filtering system defined claim 23, wherein said carbonized synthetic resin selected group consisting phenolic resin, furan resin, epoxy resin, unsaturated polyester resin, or mixture thereof.


26. A filtering system defined claim 19, wherein ratio, by weight, resin activated carbon prior carbonization ranges approximately 1:1 approximately 6:1.


27. A filtering system defined claim 26, wherein ratio, by weight, resin activated carbon prior carbonization ranges approximately 2:1 approximately 4:1.


28. A filtering system defined claim 19, wherein binding agent second framework structure silicate binder.


29. A filtering system defined claim 28, wherein silicate binder colloidal silica sol and/or water glass.


30. A filtering system defined claim 19, wherein ceramic material and/or refractory material chamotte.


31. A filtering system defined claim 19, wherein second framework structure shaped activated carbon article additionally contains fluxing agent for decreasing sintering temperature.


32. A filtering system defined claim 31, wherein second framework structure contains fluxing agent Na2O concentration up approximately 1 wt % based total weight ceramic material and/or baked refractory material.


33. A filtering system defined claim 32, wherein fluxing agent Na2O concentration approximately 0.3 approximately 1 wt % based total weight ceramic material and/or baked refractory material.


34. A filtering system defined claim 19 wherein stabilizing fibers are present first and/or second framework structure.


35. A filtering system defined claim 34, wherein stabilizing fibers are glass fibers and/or carbon fibers.


36. A filtering system defined claim 19 wherein shaped activated carbon article honeycomb structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit filing date German Patent Application No. 102 13 016.7 filed Mar. 22, 2002 pursuant 35 U.S.C. 119 Paris Convention.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates mechanically stable, porous shaped activated carbon article, process for production thereof, use thereof.

U.S. Pat. No. 4,518,704 discloses porous, baked, activated shaped carbon article having honeycomb structure activated carbon support material clay. To produce shaped article, mixture activated carbon granules mixed with clay, mixture extruded form shaped article having honeycomb structure, resulting shaped article dried finally baked non-oxidizing atmosphere.

U.S. Pat. No. 5,488,021 discloses shaped article having honeycomb structure comprising activated carbon particles, attapulgus clay, organic binding agent.

EP 0,645,346 A1 discloses shaped activated carbon article which activated carbon held together by phenolic resin binder. This achieved by first all forming aqueous mixture activated carbon phenolic resin then adding organic binding agent, extruding mixture form shaped article having honeycomb structure, followed by drying.

WO 00/69555 discloses honeycombed adsorbent monolith produced activated carbon, ceramic-forming material, fluxing agent, water.

U.S. Pat. No. 6,171,373 B1 likewise discloses adsorbent monolith consisting activated carbon ceramic-forming material.

A characteristic activated carbon that it tends become very brittle subject strong attrition. Furthermore, great drawback activated carbon that it binds only weakly ceramic skeletons. For this reason, content activated carbon prior shaped activated carbon articles comprising ceramics activated carbon limited with regard mechanical strength shaped activated carbon article. The honeycombed shaped activated carbon articles thus produced are subject strong attrition. The mechanical stability such shaped activated carbon articles depends entirely stability ceramic framework. The usefulness such shaped activated carbon articles very restricted, particularly filtering systems.

Since phenolic resin property sealing pores activated carbon particles, care must taken during production shaped activated carbon article activated carbon phenolic resin ensure that content phenolic resin relative amount activated carbon low, order that only small proportion pores activated carbon become sealed.

A disadvantage resulting herefrom that mechanical stability shaped activated carbon articles having low content phenolic resin very low. Raising content phenolic resin causes pores activated carbon particles sealed and, consequently, adsorptability such shaped activated carbon articles very weak.

Hitherto known honeycombed shaped activated carbon articles exhibit either low mechanical stability accompanied by increased sorptability, or increased mechanical stability accompanied by reduced sorptability.

Such honeycombed shaped activated carbon articles are used, inter alia, motor vehicles filtration systems for filtering air passenger compartment. Due fact that construction motor vehicles becoming more more complex, there decreasingly less room for such air filtration system motor vehicles. Therefore it necessary that such honeycombed shaped activated carbon articles exhibit, due confinement space, increased mechanical stability combined with high sorptability.

It object invention provide shaped activated carbon article exhibiting high mechanical stability high sorptability.

It another object invention increase sorptability shaped activated carbon articles relatively hitherto known activated carbon systems whilst maintaining or improving mechanical stability thereof, so make it possible reduce total volume filtering systems.

The basic object invention achieved by provision mechanically stable, porous shaped activated carbon article, wherein shaped activated carbon article exhibits first three-dimensional framework structure based carbonized resin, second three-dimensional inorganic framework structure comprising ceramic material and/or baked refractory material, binding agent, also activated carbon particles, which first second framework structures penetrate each other least partially activated carbon particles are fixed position.

Preferably, first second framework structures penetrate each other substantially completely. A further preference that activated carbon particles are substantially all fixed first framework structure.

Consequently, present invention provides monolithic structure, which activated carbon or activated carbon particles are enclosed arrangement two framework structures. The first framework formed by carbonization resinous material second framework ceramic framework comprising bonded ceramic material and/or refractory material.

The first three-dimensional framework structure resulting carbonization resin preferably binds activated carbon or activated carbon particles. The activated carbon or activated carbon particles are partially embedded porous carbon framework produced by carbonization resin or are fixed thereto, with result that abrasion-resistant, mechanically stable structure having very good sorption properties formed. A porous carbon produced by carbonization resin also known glass-like carbon.

The first three-dimensional framework structure produced by carbonization resin, i.e. porous carbon structure, reliably binds activated carbon particles extremely advantageous fashion. The second three-dimensional framework structure ceramic material and/or baked refractory material binding agent extremely stable excellent impact resistance properties.

The two framework structures are consequently present side-by-side penetrate each other, preferably completely. The high stability porous shaped activated carbon article invention result three-dimensional intermeshing two skeletons. Preferably, production shaped activated carbon article invention starts resin having aromatic nuclei. It been found that when pyrolysis carried out resins having aromatic nuclei porous carbon structure formed which particularly suitable for present purpose. This carbon structure reliably fixes activated carbon particles allows, by reason its porous structure, material adsorbed access activated carbon particles. Furthermore, carbon structure produced such manner seems itself possess certain sorptability.

Preferably, first framework structure substantially prepared carbonized synthetic resin, preferably phenolic resin, furan resin, epoxy resin, unsaturated polyester resin or mixture thereof.

Very particular preference given use phenolic resins, for example novolak.

It been found that excellent incorporation or fixation activated carbon particles first three-dimensional framework structure produced by carbonization resin, preferably synthetic resin, effected when ratio, by weight, resin activated carbon is, prior carbonization, approximately 1:1 approximately 6:1, preferably approximately 2:1 approximately 4:1, which case porous shaped activated carbon articles invention which result two framework structures possesses excellent overall mechanical stability combined with distinctly improved sorptability Very satisfactory results are obtained with ratio, by weight, resin activated carbon 3:1.

It been generally found that amount resin used production mechanically stable, porous shaped activated carbon article invention must so much larger than content activated carbon or activated carbon particles ensure that activated carbon particles are reliably embedded first three-dimensional carbon framework structure produced by carbonization resin, preferably synthetic resin.

Furthermore, it preferred that second framework structure contains not only ceramic material baked refractory material but also silicate binder.

The use ceramics and/or baked refractory material instead clay, conventionally employed prior art, during production shaped activated carbon article invention reduces water content total mixture thus leads reduction shrinkage drying. Preferably ceramic material and/or baked refractory material used chamotte.

Furthermore, it preferred that second framework structure contains, additional component, fluxing agent capable lowering sintering temperature refractory components inorganic framework structure.

Preferably, fluxing agent used Na2O amount up approximately 1 wt %, more preferably approximately 0.3 approximately 1 wt %, most preferably amount 0.5 approximately 1 wt %, based total weight ceramic material and/or baked refractory material.

The addition Na2O has, particularly when use made colloidal silica sol or water glass together with chamotte, effect reducing sintering temperature for silicate lattice also increasing stability ceramic framework. When portion Na2O raised more than approximately 1 wt %, stability ceramic framework may deteriorate.

Preferably, ratio, by weight, ceramic material and/or refractory material binding agent ranges approximately 2:1 1:2. When use made chamotte ceramic material silica sol binding agent, it been found that ratio, by weight, chamotte silica sol should least 2:1. Excellent results are obtained when ratio, by weight, chamotte silica sol 1:1. As regards stability sintered or baked second three-dimensional framework, SiO2 content silica sol should least 30%.

It also preferred that porous shaped activated carbon articles invention contain, first and/or second framework structure, stabilizing fiber, preferably glass fibers and/or carbon fibers.

Particular preference given embodiment which shaped activated carbon article honeycomb structure. Such honeycomb structures, for example, form classical honeycomb, proven extremely advantageous when shaped activated carbon article invention used filtering systems.

The object invention also achieved by filtering system which contains shaped activated carbon article that exhibits first three-dimensional framework structure based carbonized resin, second three-dimensional inorganic framework structure comprising ceramic material and/or baked refractory material also binding agent activated carbon particles which first second framework structures penetrate each other least partially activated carbon particles are fixed position.

The object invention also achieved by process for production mechanically stable, porous shaped activated carbon article, which following process steps:

(a) mixing activated carbon particles, resin, binding agent with ceramic material and/or baked refractory material with addition liquid phase prepare extrudable composition, (b) extruding composition formed step (a) monolithic shaped article, (c) drying shaped article extruded step (b), (d) heating shaped article dried step (c) temperature above melting temperature resin keeping it this temperature for period time, (e) pyrolyzing product resulting conclusion step (d), (f) sintering pyrolyzate resulting conclusion step (e).

The liquid phase added step (a) preferably water. The amount added water determines viscosity mixture. The viscosity suitably adjusted so that mixture or composition extruded form monolithic shaped article.

It is, course, possible add other auxiliaries step (a). For example, wax added mixture order provide good slip between individual particles, ie, improve so-called internal slip. Such improved internal slip facilitates homogeneous distribution individual components during extrusion composition through die extruder. Furthermore, increase internal slip extremely advantageous effect avoiding local damming individual channels die during extrusion.

In addition, surfactant or soap added composition step (a), order improve sliding composition extruder or mold. A comparable effect obtained when 10–50 wt % content surfactant or soap replaced by graphite powder.

In order improve strength green molding obtained conclusion extrusion it preferable add liquid starch step (a). Following drying extruded monolithic shaped article starch that added produces stable framework which increases stability green molding.

According preferred embodiment process invention, green molding binder added mixture step (a). Preferably, green molding binder added cellulose ether or cellulose ether derivative, preferably methylhydroxypropyl cellulose. In mixture provided step (a), cellulose ether binds water surrounding activated carbon contributes stabilization green molding. Furthermore, green molding binder promotes homogenization mixture comprising activated carbon ceramic material or refractory material preferably synthetic resin by counteracting separation mixture could occur by reason different component densities.

The cellulose ether used be, for example, methyl cellulose, ethylhydroxyethyl cellulose, hydroxybutyl cellulose, hydroxybutylmethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, methylhydroxypropyl cellulose, hydroxyethylmethyl cellulose, sodium carboxymethyl cellulose, or mixture thereof.

Preferably, amount green molding binder added, for example, cellulose ether, not more than approx. 5 wt %, based total composition. Otherwise there risk big defects occurring form macro pores extruded monolithic shaped article when article sintered, result green molding binder being burnt out.

Preferably, when water added for purpose adjusting viscosity extruded composition obtained step (a), up 20% water mixed with portion cellulose ether. In this manner excessive adsorption water or activated carbon advantageously avoided.

Following extrusion composition obtained step (a) form monolithic shaped article, latter preferably cut length then dried. Drying preferably carried out forced air oven approximately 50° C. approximately 80° C. Of course, other drying process, such microwave techniques, may used, if desired.

It been found that it advantageous when moisture permanently quickly removed order avoid tearing extruded shaped article during drying process. The monolithic shaped article preferably dried until water content 2.5 wt % or less.

In step (d), shaped article dried step (c) heated temperature above melting temperature preferably synthetic resin, provide precured green molding. During this heating stage, preferably synthetic resin added step (a) melts so cause activated carbon particles embedded resulting melt. The resins used are preferably aforementioned resins having aromatic nuclei synthetic resins. Phenolic resins, furan resins, epoxy resins, unsaturated polyester resins, mixtures thereof been found very suitable. Particular preference given use novolak resins.

In heating stage (c) crosslinking curing resinous material occurs during melting or melt. The final temperature used during this heating stage preferably range approximately 80° 180° C. depending resin or resin formulation used. The residence time this final temperature preferably range approximately 60 minutes approximately 180 minutes.

Preferably, preferably synthetic resin added step (a) powdered form. This extremely advantageously result that pores activated carbon particle are not occupied or sealed by resin long resin not molten. In order cause incorporation activated carbon particles thus adequate fixation activated carbon particles carbon framework structure later produced by carbonization preferably synthetic resin, amount resin used must sufficiently large relation quantity activated carbon used.

It been found that very satisfactory results are obtained when using ratio, by weight, resin activated carbon step (a) ranging approximately 1:1 approximately 6:1, preferably approximately 2:1 approximately 4:1. Very good results are obtained using ratio, by weight, resin activated carbon step (a) approximately 3:1.

For preferred use novolak resin synthetic resin ratio, by weight, novolak resin activated carbon approximately 3:1 proven very suitable.

During step (d), which preferably synthetic resin melts crosslinks activated carbon particles become embedded molten resin, inorganic framework ceramic material and/or baked refractory material binding agent stabilizes structure extruded monolithic shaped article. Without any stabilization monolithic shaped article by inorganic framework structure, monolithic shaped articles would become instable step (d) become deformed.

In pyrolysis step (e), temperature further increased until carbonization crosslinked cured resinous material occurs. During carbonization crosslinked resinous material, porous solid carbon structure forms, which also referred glass-like carbon. The activated carbon particles are then fixed position this porous carbon framework. The pores activated carbon occupied by resinous material are again made available for adsorption purposes by carbonization formation porous carbon framework. The pyrolysis or carbonization crosslinked cured resin preferably carried out final temperature which ranges approximately 350° C. approximately 550° C. more preferably approximately 450° C. The final temperature preferably maintained for period approximately 60 minutes approximately 180 minutes.

The end pyrolysis resinous material monitored by watching smoking pyrolyzate. When substantially no more new degradation products are formed, pyrolysis or carbonization complete.

In sintering step (f) following pyrolysis step (e), temperature raised further until sintering ceramic materials or refractory materials occurs. The sintering operation preferably carried out final temperature ranging approximately 600° C. approximately 1000° C., preferably approximately 650° 800° C. The final temperature preferably maintained for period approximately 60 minutes approximately 180 minutes. During this sintering step, silicate lattice already formed during drying process additionally reinforced by eliquation refractory components.

On completion sintering operation monolithic shaped article cooled.

During pyrolysis or sintering, any added auxiliaries, such wax, surfactant or soap, cellulose ether, starch are naturally likewise carbonized or decomposed.

The carbon shaped carbon article activated by conventional methods. For example, activation carbon carried out temperature 700° 950° C. activating atmosphere containing 25 35 vol % steam.

The sorption properties shaped activated carbon article obtained process invention can, course, additionally influenced by properties activated carbon. The important parameters this case are pore size, pore-size distribution active surface area activated carbon used also particle size particle-size distribution activated carbon. All types activated carbon used present invention. Both microporous coconut carbon having content micro pores more than 95% surface area (BET) 1200 m2/g mesoporous charcoal having content mesopores more than 50% surface area (BET) 2000 m2/g been used. The former preferably used for cabin air filtration for deodorization purposes, latter preferably used for tank ventilation solvent recovery. It essential both cases that pore structure retained finished shaped article.

Preferably, synthetic resinous material used powdered novolak material which partially crosslinked phenolformaldehyde resin melting point between approximately 80° approximately 160° C., particularly between approximately 100° 140° C.

For further stabilization strength properties shaped article stabilizing fibers incorporated mixture produced step (a). Glass fibers and/or carbon fibers are preferably added.

The amount stabilizing fibers added range 1 15 wt %, based total weight mixture produced step (a). The melting point fibers that are added should this case above maximum sintering temperature used avoid fusion fibers during sintering. If glass powder or glass frit material additionally added mixture step (a), this provides additional cross-linkage between glass fibers end product. Preferably glass fibers sintered-glass material are added mixture produced step (a) amount approximately 10 wt %, based weight activated carbon, improve mechanical stability end product.

When use made carbon fibers, such cross-linkage achieved via carbon framework obtained following carbonization.

Preferably, fluxing agent added mixture produced step (a) for lowering sintering temperature ceramic material and/or refractory material. Preferably, Na2O added amount up approximately 1 wt %, preferably approximately 0.3 wt % approximately 1 wt %, based total weight ceramic material and/or refractory material. Very preferably, amount Na2O added ranges approximately 0.5–1 wt %, based total weight ceramic material and/or refractory material.

Preferably, pyrolysis step (e) sintering step (f) are carried out inert gas atmosphere, preferably nitrogen atmosphere.

In preferred embodiment process invention, approximately 0.5 approximately 1.5 vol % oxygen added inert gas atmosphere sintering step while holding final temperature. It been found that this measure enlarges surface area that consequently adsorptability shaped article produced raised.

In this case adsorptability shaped article raised when amount added oxygen increased 0.5 vol % 1.5 vol %. Further raising amount oxygen inert gas atmosphere lead partial or complete destruction porous carbon lattice, i.e. first framework structure.

Preferably extrudable composition provided step (a) exhibits following composition (in percentages by weight):

resin:	10–50%	preferably	11–15%
activated carbon:	10–50%	preferably	11–15%
chamotte:	10–50%	preferably	11–15%
glass fibers:	 1–15%	preferably	1.5–5%  
silica sol:	 5–50%	preferably	10–15%
cellulose ether:	 1–50%	preferably	  3–4.5%
water:	 5–45%	preferably	18–35%
plasticizer:	0.25–2%  	preferably	  1–1.5 %
soap:	0.1–1%  	preferably	0.5–1.0%

The present invention illustrated detail below with reference examples accompanying drawings. The examples serve exclusively provide further explanation are not regarded limitation invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For more complete understanding present invention, reference now made following descriptions taken conjunction with accompanying drawing, which:

FIG. 1 large-scale diagrammatic representation section mechanically stable, porous shaped activated carbon article invention illustrating mutual penetration first second three-dimensional framework structures;

FIG. 2 shows adsorptability shaped activated carbon article invention compared with filter medium prior art comprising ceramics framework containing activated carbon;

FIG. 3 shows seven adsorption/desorption cycles mechanically stable, porous shaped activated carbon article invention;

FIG. 4 shows adsorptability two different mechanically stable, porous shaped activated carbon articles invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 diagrammatic illustration structure shaped activated carbon article invention shown. The activated carbon particles 1 are embedded first three-dimensional framework structure based carbonized resin 2 , surface activated carbon particle 1 being not wholly but only partially enclosed by three-dimensional framework structure carbonized resin 2 . Thus substantially entire surface activated carbon particles available for sorption purposes.

The second three-dimensional inorganic framework structure consists ceramic material and/or refractory material 3 SiO2 matrix 4 . The SiO2 matrix 4 formed by addition silicate binder bind ceramic material and/or refractory material 3 during production shaped activated carbon article invention. In diagrammatic representation enlarged section shaped activated carbon article invention it clearly visible that first three-dimensional framework structure comprising activated carbon 1 carbonized resin 2 second three-dimensional inorganic framework structure ceramic material bonded by SiO2 matrix 4 and/or baked refractory material 3 penetrate each other, i.e. are interlocked.

By reason three-dimensional interlocking two framework structures fixation activated carbon particles position porous carbon structure produced by carbonization resinous material, there results mechanically extremely stable porous shaped activated carbon article.

FIG. 2 shows adsorption curve for n-butane mechanically stable, porous shaped activated carbon article invention, described detail below, compared with adsorption filter identical geometry prior art, which activated carbon present ceramic lattice. Recording curves was carried out for both shaped activated carbon article invention comparative filter employing stream having in-flow concentration 80 ppm n-butanol air volumetric flow rate 40 L/min 23° C. relative humidity 10%.

The adsorptability was determined each case by taking n-butane breakthrough reading. This was done by determining n-butane concentration emergent volumetric stream provided by shaped activated carbon article invention comparative filter respectively.

The diameter circular monolithic shaped activated carbon article comparative filter 32 mm their length 100 mm, whilst their cell content 200 cpsi (cells per square inch).

As may seen FIG. 2, adsorptability mechanically stable, porous shaped activated carbon article invention (continuous line) distinctly greater than that adsorption filter consisting ceramics framework provided with activated carbon (dashed line).

FIG. 3 shows seven adsorption/desorption cycles mechanically stable, porous shaped activated carbon article invention which plot shown FIG. 2. For each cycle shaped activated carbon article invention was loaded with n-butane degree saturation 95% followed by stream pure air passed through same direction until concentration downstream shaped activated carbon article was 16 ppm (desorption). After only two adsorption/desorption cycles state equilibrium established, which amount n-butane adsorbed during one cycle totally desorbed subsequent desorption cycle. These findings show that properties mesoporous activated carbon used filter this example are fully retained. Mesoporous activated carbon property providing good desorption previously adsorbed n-butane when flushed with pure air. For this reason it used for tank ventilation automotive industry or, alternatively, for solvent recovery. The filter illustrated this example conceived for use tank ventilation residual emission filter must possess properties mesoporous activated carbon.

FIG. 4 shows that adsorptability shaped activated carbon article used for readings shown FIGS. 2 3 distinctly improved if 0.5% oxygen present protective nitrogen gas during residence time final temperature sintering step. The improvement breakthrough curve particularly evident beginning recording, where distinctly better adsorptive dynamics hold.

The dashed line FIG. 4 shows breakthrough behavior shaped activated carbon article invention with respect n-butane, said article being produced described below. The continuous line shows breakthrough curve shaped activated carbon article invention, during production which 0.5% oxygen was added protective nitrogen atmosphere during sintering.

The measurement conditions are identical measurement conditions used when plotting curve shown FIG. 2.

The readings show that mechanically stable, porous shaped activated carbon articles invention exhibit excellent sorptability are very suitable for use filtering systems or adsorption filter systems, particularly for gas purification, preferably purification air.

To produce shaped activated carbon article invention, following components are used process step (a) they are mixed until homogeneous mixture obtained:

Constituent	Amount, g
activated carbon	1540
novolak powder	4620
chamotte	1540
glass fibers	160
cellulose ether	506
silica sol, 30% solid SiO2	1400
deionized water	2550
oleic acid	250
soap	120

Activated carbon: mesoporous wood charcoal, content mesopores >50%, surface area (BET) 1800 m2/g.

The above mixture was extruded give shaped activated carbon article (step (b)), which was then cut size:

length:	100 mm
diameter:	 32 mm
cell content:	200 epsi

The extruded shaped activated carbon article was dried for one hour forced air oven 70° C. (step (c)), heated for one hour 150° C. (step (d)), then pyrolyzed over period two hours 450° C. (step (e)), sintered over period two hours 650° C. (step (f)).

On shaped activated carbon article thus produced readings were taken give plots shown FIGS. 2 4.

For comparative measurements plotted FIG. 4, 0.5% oxygen was added blanket nitrogen during final temperature period sintering step.

Although present invention its advantages been described detail, it should understood that various changes, substitutions alterations made herein without departing spirit scope invention defined by appended claims. Moreover, scope present application not intended limited particular embodiments process, machine, manufacture, composition matter, means, methods steps described specification. As one ordinary skill art readily appreciate disclosure present invention, processes, machines, manufacture, compositions matter, means, methods, or steps, presently existing or later developed that perform substantially same function or achieve substantially same result corresponding embodiments described herein may utilized according present invention. Accordingly, appended claims are intended include within their scope such processes, machines, manufacture, compositions matter, means, methods, or steps.