USRE31093E - Process for making activated carbon with control of metal ion concentration in phosphoric acid - Google Patents
Process for making activated carbon with control of metal ion concentration in phosphoric acid Download PDFInfo
- Publication number
- USRE31093E USRE31093E US06/270,371 US27037181A USRE31093E US RE31093 E USRE31093 E US RE31093E US 27037181 A US27037181 A US 27037181A US RE31093 E USRE31093 E US RE31093E
- Authority
- US
- United States
- Prior art keywords
- phosphoric acid
- metal ion
- acid
- wood
- ion concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title claims abstract description 32
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims abstract description 24
- 230000008569 process Effects 0.000 title claims abstract description 21
- 229910000147 aluminium phosphate Inorganic materials 0.000 title claims abstract description 16
- 229910021645 metal ion Inorganic materials 0.000 title claims abstract description 15
- 239000002253 acid Substances 0.000 claims abstract description 20
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 13
- 150000003839 salts Chemical class 0.000 claims abstract description 9
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000011575 calcium Substances 0.000 claims abstract description 5
- 229910052700 potassium Inorganic materials 0.000 claims abstract description 5
- 239000011591 potassium Substances 0.000 claims abstract description 5
- 239000011734 sodium Substances 0.000 claims abstract description 5
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 3
- 239000011777 magnesium Substances 0.000 claims abstract description 3
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 3
- 239000002023 wood Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 8
- 230000003213 activating effect Effects 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- 159000000003 magnesium salts Chemical class 0.000 claims 1
- 238000004064 recycling Methods 0.000 claims 1
- 239000007858 starting material Substances 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 abstract description 13
- 239000002184 metal Substances 0.000 abstract description 13
- 230000000694 effects Effects 0.000 abstract description 3
- 239000000446 fuel Substances 0.000 abstract description 3
- 230000004913 activation Effects 0.000 description 8
- 238000001179 sorption measurement Methods 0.000 description 8
- 239000007789 gas Substances 0.000 description 6
- 150000002739 metals Chemical class 0.000 description 5
- 239000011148 porous material Substances 0.000 description 5
- 239000002585 base Substances 0.000 description 4
- 239000001273 butane Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 3
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 238000003763 carbonization Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 229910001414 potassium ion Inorganic materials 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910052936 alkali metal sulfate Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000004042 decolorization Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000007323 disproportionation reaction Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 235000013379 molasses Nutrition 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000011269 tar Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 239000003039 volatile agent Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/30—Active carbon
- C01B32/312—Preparation
- C01B32/342—Preparation characterised by non-gaseous activating agents
- C01B32/348—Metallic compounds
Definitions
- the present invention relates to a process for improving the properties of wood-base carbon activated in the presence of phosphoric acid. More particularly, this invention relates to controlling the amount of certain metal salts dissolved in the process acid.
- Activated carbon can also be made from wood by carbonizing it in the presence of phosphoric acid at temperatures around 800°-1,300° F. It has now been found that by controlling the amount of certain dissolved metals in this process acid during heat treatment, activated carbons having desirable decolorizing ability and desirable gas adsorbing ability, or both, may be obtained.
- the general object of this invention to provide a process for improving the decolorizing ability and the gas adsorbing ability of wood-base activated carbon produced in the presence of phosphoric acid.
- Another object of this invention is to provide an improved process for producing wood-base activated carbon by controlling the amount of dissolved metal salt in the process acid during activation.
- a suitable granulated cellulosic source material such as sawdust, ground wood, pulp or bark is saturated with phosphoric acid and simultaneously carbonized and activated at 800° F. to 1,300° F., preferably 1,000° F. to 1,050° F., for approximately 15 minutes to 1 hour in an activation furnace to drive off volatiles.
- the activated carbon containing residual phosphoric acid is washed with water to remove this acid and the carbon product is subsequently dried.
- the wash water is retained and evaporatively concentrated for acid recovery and recycle.
- This acid carries with it certain metal ions extracted from the wood; and with repeated use, metal concentrations gradually increase in this acid.
- the phosphoric acid probably serves to protect against cracking or disproportionation of cellulosic or other components of the wood which would produce small molecular groups tending to evaporate as vapors or tars. As carbonization proceeds under these conditions, the wood material undergoes structural changes ultimately resulting in a high-porous activated carbon.
- the adsorption properties of the activated product are highly dependent upon the concentration of dissolved Na + ,K + ,Mg ++ , and Ca ++ in the process acid.
- concentration of these ions increases from 0% to at least 4% of the acid weight
- the adsorptivity for fuel vapors as measured by the "Butane Working Capacity” (BWC) test monotonically decreases.
- the metal ion content increases from 0% to about 2-3%, (relative to the acid) the decolorizing ability increases as measured by the "Decolorizing Index” (DI) or Molasses Value (MV) test.
- DI Decolorizing Index
- MV Molasses Value
- the presence of these metal ions in the process acid can be the result of accumulative extraction from the wood itself or can be due to intentional addition of acid soluble metal salts.
- a product showing satisfactory performance by both BWC and DI tests may be obtained by controlling the metal ion content in the process acid at concentrations between 0.5% and 2% relative to the acid. This is equivalent to about 0.35-1.4% relative to sawdust.
- the decolorizing ability of the carbon increases because of this pore enlargement.
- the optimum pore size for liquid decolorization is larger than that for vapor phase BWC. This size is thought to be promoted under the process conditions by metal ion concentration of about 2-3%. At higher concentrations, the optimum is exceeded; and DI or MV is observed to decrease.
- pore size development and associated adsorption properties are sensitive to the presence of critical amounts of the metal ions during carbonization/activation of wood by the action of phosphoric acid at temperatures between 800° F. and 1,300° F. Therefore, the adsorption properties related to BWC and DI can be controlled by controlling the amount of these metals present during activation.
Abstract
A process for improvement of wood-base active carbon made in the presence of phosphoric acid is disclosed herein. The improvement comprises controlling the amount of dissolved salts of the group sodium, potassium, calcium and magnesium in the process acid to provide a metal ion concentration from 0.5% to 2.0% by weight. The controlled addition of these metal salts improves the adsorptivity for fuel vapors and the decolorizing activity of the carbon.
Description
(1) Field of the Invention
The present invention relates to a process for improving the properties of wood-base carbon activated in the presence of phosphoric acid. More particularly, this invention relates to controlling the amount of certain metal salts dissolved in the process acid.
(2) Description of the Prior Art
In the production of activated carbon from wood, sawdust is mixed with various chemical agents, carbonized and often subsequently activated by gas reactions. Wood-base carbons have been used for decolorizing by contacting solutions with the activated carbon. One such example appears in U.S. Pat. No. 1,383,755 wherein alkali metal sulfates were added to sawdust and other materials to assist in activation. Another use for carbons is in the gas phase for adsorption of hydrocarbon vapor. An example of this type of carbon is described in U.S. Pat. No. 3,764,561.
These and other patents have sought to improve one adsorbing property or another using varied techniques including the application of metal salts. The use of such metals is generally characterized by large proportions of salt relative to the wood, high temperatures (around 1,800° F.), and frequently contact with oxidizing gases at 1,500°-1,800° F.
Activated carbon can also be made from wood by carbonizing it in the presence of phosphoric acid at temperatures around 800°-1,300° F. It has now been found that by controlling the amount of certain dissolved metals in this process acid during heat treatment, activated carbons having desirable decolorizing ability and desirable gas adsorbing ability, or both, may be obtained.
It is, therefore, the general object of this invention to provide a process for improving the decolorizing ability and the gas adsorbing ability of wood-base activated carbon produced in the presence of phosphoric acid.
Another object of this invention is to provide an improved process for producing wood-base activated carbon by controlling the amount of dissolved metal salt in the process acid during activation.
Other objects, features, and advantages will be evident from the following detailed description of the invention.
It has been found that controlling the amount of dissolved metal salts from the group consisting of sodium, potassium, magnesium, calcium and mixtures thereof in the process acid to provide a metal ion concentration between 0.5% and 2.0%, preferably 0.6% to 1.0%, by weight of acid improved the adsorbing activity for both decolorizing and gas phase adsorption.
In the production of activating carbon, a suitable granulated cellulosic source material such as sawdust, ground wood, pulp or bark is saturated with phosphoric acid and simultaneously carbonized and activated at 800° F. to 1,300° F., preferably 1,000° F. to 1,050° F., for approximately 15 minutes to 1 hour in an activation furnace to drive off volatiles.
Following furnace activation, the activated carbon containing residual phosphoric acid is washed with water to remove this acid and the carbon product is subsequently dried.
The wash water is retained and evaporatively concentrated for acid recovery and recycle. This acid carries with it certain metal ions extracted from the wood; and with repeated use, metal concentrations gradually increase in this acid.
In the activation of sawdust at an optimum temperature of about 1,000° F., the phosphoric acid probably serves to protect against cracking or disproportionation of cellulosic or other components of the wood which would produce small molecular groups tending to evaporate as vapors or tars. As carbonization proceeds under these conditions, the wood material undergoes structural changes ultimately resulting in a high-porous activated carbon.
It was found that the adsorption properties of the activated product are highly dependent upon the concentration of dissolved Na+,K+,Mg++, and Ca++ in the process acid. For example, as the concentration of these ions increases from 0% to at least 4% of the acid weight, the adsorptivity for fuel vapors as measured by the "Butane Working Capacity" (BWC) test monotonically decreases. Also, as the metal ion content increases from 0% to about 2-3%, (relative to the acid) the decolorizing ability increases as measured by the "Decolorizing Index" (DI) or Molasses Value (MV) test. As the concentration increases above this level, the decolorizing ability then decreases. The presence of these metal ions in the process acid can be the result of accumulative extraction from the wood itself or can be due to intentional addition of acid soluble metal salts.
Thus, a product showing satisfactory performance by both BWC and DI tests may be obtained by controlling the metal ion content in the process acid at concentrations between 0.5% and 2% relative to the acid. This is equivalent to about 0.35-1.4% relative to sawdust.
Experiments have shown that the carbon product using pure phosphoric acid has a very high "BWC." This is determined by a test which measures the amount of butane which can be purged from carbon with air under certain flow conditions after the carbon is presaturated with this vapor. This property is related to performance in fuel evaporation control. It is likely that good performance in this test results from the development of pores which are of optimum size for adsorption and desorption of butane under the test conditions. When even small amounts of such metal ions as Na+,K+,Ca+, and Mg++ are present, the resultant carbon shows poorer BWC. It is suspected that the metal ions catalyzed oxidation of the carbon material under the process conditions and enlarge the pores beyond the optimum size.
It is also believed that the decolorizing ability of the carbon increases because of this pore enlargement. According to this concept, the optimum pore size for liquid decolorization is larger than that for vapor phase BWC. This size is thought to be promoted under the process conditions by metal ion concentration of about 2-3%. At higher concentrations, the optimum is exceeded; and DI or MV is observed to decrease.
The presence or absence of residual metals in the carbon product is not believed to affect adsorption significantly. For the most part, these metals are retained in the acid which is washed off. The importance of the metal is thought to lie in the effect of its ions on the activation mechanism.
In summary, it is believed that pore size development and associated adsorption properties are sensitive to the presence of critical amounts of the metal ions during carbonization/activation of wood by the action of phosphoric acid at temperatures between 800° F. and 1,300° F. Therefore, the adsorption properties related to BWC and DI can be controlled by controlling the amount of these metals present during activation.
In order to more clearly illustrate the present invention, the following example is set forth:
Sawdust at 42% moisture content was mixed with phosphoric acid at an acid to sawdust ratio of 1.4:1. The amount of potassium ions in the phosphoric acid was measured by a Model 330 Perkin-Elmer Atomic Adsorption Spectrophotometer. The activating temperature was 1,050° F. at a residence time of 45 minutes. The purpose of this run was to see if the DI could be increased while still maintaining BWC above 9.0. It was found that when the concentration of potassium ion was maintained between 0.5% and 2.0% that the BWC remained above 9 and the DI was between 14 and 32.5.
While the invention has been described and illustrated herein by references to various specific materials, procedures and examples, it is understood that the invention is not restricted to the particular materials, combinations of materials, and procedures selected for that purpose. Numerous variations of such details can be employed, as will be appreciated by those skilled in the art.
Claims (6)
1. In a process for producing wood-base active carbon by the steps of treating a wood material with phosphoric acid at a temperature between 800° F. and 1,300° F. and recovering and recycling the phosphoric acid wherein the wood material contains one or more salts selected from the group consisting of sodium, potassium, calcium and magnesium salts and mixtures thereof, the improvement comprising maintaining the concentration in the phosphoric acid of metal ions from the group consisting of sodium, potassium, calcium and magnesium between 0.5% and 2.0% by weight of the acid.
2. The process according to claim 1 wherein the activating temperature is between 1,000° F. and 1,050° F.
3. The process according to claim 1 wherein sawdust is the starting material for said wood-base carbon.
4. The process according to claim 1 wherein the metal ion concentration in the phosphoric acid is maintained between .[.1.0% and 1.5%.]. .Iadd.0.6% and 1.0% .Iaddend..
5. The process according to claim 1 wherein said metal ion is sodium.
6. The process according to claim 1 wherein said metal ion is potassium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/270,371 USRE31093E (en) | 1978-05-10 | 1981-06-04 | Process for making activated carbon with control of metal ion concentration in phosphoric acid |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/904,696 US4155878A (en) | 1978-05-10 | 1978-05-10 | Process for making activated carbon with control of metal ion concentration in phosphoric acid |
| US06/270,371 USRE31093E (en) | 1978-05-10 | 1981-06-04 | Process for making activated carbon with control of metal ion concentration in phosphoric acid |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US05/904,696 Reissue US4155878A (en) | 1978-05-10 | 1978-05-10 | Process for making activated carbon with control of metal ion concentration in phosphoric acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| USRE31093E true USRE31093E (en) | 1982-11-30 |
Family
ID=26954242
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US06/270,371 Expired - Lifetime USRE31093E (en) | 1978-05-10 | 1981-06-04 | Process for making activated carbon with control of metal ion concentration in phosphoric acid |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | USRE31093E (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5637339A (en) * | 1995-04-27 | 1997-06-10 | Hickory Specialties, Inc. | Method of making a tar-depleted liquid smoke |
| US20050035062A1 (en) * | 1999-11-23 | 2005-02-17 | Hiltzik Laurence H. | Coated activated carbon for contaminant removal from a fluid stream |
| US20050123763A1 (en) * | 1999-11-23 | 2005-06-09 | Hiltzik Laurence H. | Colored activated carbon and method of preparation |
| US20070012185A1 (en) * | 2005-07-14 | 2007-01-18 | Access Business Group International Llc | Air treatment filter and related method |
| US20080236389A1 (en) * | 2006-04-24 | 2008-10-02 | Mead Westvaco Corporation | Impregnated Monoliths |
| US20090056827A1 (en) * | 2006-04-10 | 2009-03-05 | Meadwestvaco Corporation | Control of vapor emissions from gasoline stations |
| EP2574618A1 (en) | 2011-08-19 | 2013-04-03 | EMD Millipore Corporation | Methods of reducing level of one or more impurities in a sample during protein purification |
| WO2014133741A1 (en) | 2013-02-26 | 2014-09-04 | Emd Millipore Corporation | Selective removal of a protein from a mixture of proteins using activated carbon by adjusting solution conditions |
| CN108793558B (en) * | 2018-06-22 | 2021-04-27 | 浙江奇彩环境科技股份有限公司 | Method for treating wastewater generated in activated carbon production by phosphoric acid activation method |
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|---|---|---|---|---|
| US29560A (en) * | 1860-08-14 | Improvement in compounds used as decolorizers | ||
| US1250228A (en) * | 1916-07-11 | 1917-12-18 | Alfred Henry Bonnard | Preparation of vegetable charcoal. |
| US1286187A (en) * | 1917-05-11 | 1918-11-26 | Refining Products Corp | Decolorizing and purifying agent and method of making the same. |
| US1383755A (en) * | 1919-05-12 | 1921-07-05 | Eastman Kodak Co | Process of producing decolorizing-carbon |
| US1438113A (en) * | 1919-02-15 | 1922-12-05 | Claude S Hudson | Method of making decolorizing carbons |
| US1502592A (en) * | 1923-03-26 | 1924-07-22 | Sauer Johan Nicolaas Adolf | Process for preparing decolorizing carbon |
| US1505496A (en) * | 1921-04-12 | 1924-08-19 | Chem Fab Auf Actien | Process of manufacturing active carbon |
| US1520437A (en) * | 1921-09-29 | 1924-12-23 | Pipkin Marvin | Process of catalyzing gaseous reactions |
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| US3923689A (en) * | 1972-11-29 | 1975-12-02 | Ici America Inc | Removal of iron contaminants from porous materials |
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| US4075282A (en) * | 1975-02-22 | 1978-02-21 | Laboratorium Fur Adsorptionstechnik Gmbh | Process for impregnating active carbon with iodine compounds |
-
1981
- 1981-06-04 US US06/270,371 patent/USRE31093E/en not_active Expired - Lifetime
Patent Citations (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US29560A (en) * | 1860-08-14 | Improvement in compounds used as decolorizers | ||
| US1619649A (en) * | 1927-03-01 | of london | ||
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| US2835343A (en) * | 1956-09-20 | 1958-05-20 | Standard Oil Co | Gas adsorption with an alkali metalactivated adsorbent |
| US3066099A (en) * | 1959-06-29 | 1962-11-27 | Nilok Chemicals Inc | Mineral active carbon and process for producing same |
| US3168485A (en) * | 1960-06-27 | 1965-02-02 | Standard Oil Co | Removal of metal contaminants from activated carbon |
| US3492244A (en) * | 1965-10-13 | 1970-01-27 | Takeda Chemical Industries Ltd | Method for the production of coke |
| US3479300A (en) * | 1965-10-22 | 1969-11-18 | Cabot Corp | Carbonaceous products |
| US3764561A (en) * | 1971-03-09 | 1973-10-09 | Takeda Chemical Industries Ltd | Activated carbon from admixture of coking coal and inorganic potassium salts |
| US3835064A (en) * | 1971-09-23 | 1974-09-10 | T Shinomiya | Process for manufacturing an activated carbon |
| US3923689A (en) * | 1972-11-29 | 1975-12-02 | Ici America Inc | Removal of iron contaminants from porous materials |
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| US4075282A (en) * | 1975-02-22 | 1978-02-21 | Laboratorium Fur Adsorptionstechnik Gmbh | Process for impregnating active carbon with iodine compounds |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5637339A (en) * | 1995-04-27 | 1997-06-10 | Hickory Specialties, Inc. | Method of making a tar-depleted liquid smoke |
| US20050035062A1 (en) * | 1999-11-23 | 2005-02-17 | Hiltzik Laurence H. | Coated activated carbon for contaminant removal from a fluid stream |
| US20050123763A1 (en) * | 1999-11-23 | 2005-06-09 | Hiltzik Laurence H. | Colored activated carbon and method of preparation |
| US20070012185A1 (en) * | 2005-07-14 | 2007-01-18 | Access Business Group International Llc | Air treatment filter and related method |
| US7316732B2 (en) | 2005-07-14 | 2008-01-08 | Access Business Group International Llc | Air treatment filter and related method |
| US20090056827A1 (en) * | 2006-04-10 | 2009-03-05 | Meadwestvaco Corporation | Control of vapor emissions from gasoline stations |
| US9533251B2 (en) | 2006-04-10 | 2017-01-03 | Ingevity South Carolina, Llc | Control of vapor emissions from gasoline stations |
| US20080236389A1 (en) * | 2006-04-24 | 2008-10-02 | Mead Westvaco Corporation | Impregnated Monoliths |
| EP2574618A1 (en) | 2011-08-19 | 2013-04-03 | EMD Millipore Corporation | Methods of reducing level of one or more impurities in a sample during protein purification |
| EP2942353A1 (en) | 2011-08-19 | 2015-11-11 | EMD Millipore Corporation | Methods of reducing level of one or more impurities in a sample during protein purificaton |
| WO2014133741A1 (en) | 2013-02-26 | 2014-09-04 | Emd Millipore Corporation | Selective removal of a protein from a mixture of proteins using activated carbon by adjusting solution conditions |
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