Adsorption Databank

-2010-

Moscow State University, Chemistry Dept.

Head supervisor: prof. Tolmachev A.M.

Executive supervisor: Godovikov I.A.

Executors: Kuznetsova T.A., Kruchenkova N.G., Godovikova M.I., Borodulina M.V.

http://www.adsorption.ru, http://www.chem.msu.ru/~Adsorption

This databank is interactive system of browsing and searching for adsorption data. Currently there are more than 110 isotherms of individual gas adsorption on macroporous adsorbents, more than 760 individual systems on microporous sorbents, more than 80 binary systems from solutions on macroporous and more than 60 binary systems from solutions on microporous sorbents, more than 100 binary gas systems on different adsorbents, 10 ternary systems and data on more than 230 adsorbents produced not only in Russia but also in other countries. The bank is constantly expanding.

For user convenience the results of calculation of experimental data by different physical-chemical equations are also shown.  The constants of corresponding equations give us important information about adsorption systems [1-3].

The adsorption of individual compounds on macroporous adsorbents.   For physical-chemical characterization of these adsorption systems the equations of BET [4] (1) and Aranovich  [5] (2) were used.:

      (1)

The values of am,C and correspondent charts are presented

             (2)

The values of am*,C* and correspondent charts are presented

From here and further: a – the adsorption under the pressure P, am, am* - the limit adsorption (the adsorption capacity), C, C*- the adsorption constants, - the saturated vapor pressure of the adsorbtive.

The adsorption of individual compounds on microporous adsorbents.   We used the equations of Dubinin-Radushkevich (n=2, adsorption on carbons, ps<10bar) or Dubinin-Astachov (n=3, adsorption on zeolites, ps<10bar) [6]  (3):

                       (3)

The values of following constants are presented: the value of adsorption capacity a0 under the pressure of saturation Ps and E0 – characteristics adsorption energy.

With the values of  Рs exceeding 10 bar all calculations were done only if the volatility data for compounds were available.

If the temperature exceeded Tкр (critical temperature) of the compound we made (if it was possible) the calculation of equation (3) with using as standard pressures the values of [7] which were obtained by extrapolation to overcritical temperature region of the following dependence:.

(A and B – constants)

In case we could obtain the values of vapor densities () and liquid densities () of the compound under certain temperatures we use also the numeric solution of the Tolmachev- Aranovich equation system [8, 9], based on the grid model by Ono-Kondo [10]. In the majority of cases the real sizes of micropores could contain one or two layers of adsorbat and thus, the corresponding equations for mono-(4,6) and bilayer-(5,6) models are [7,9]:

        (4)

     (5)

            , n=1 or 2                 (6)

                             (7)

From here and further: - the value of absolute  adsorption of the first component, - the adsorption capacity of the first component (mmol*g-1), Y1, X1 - molar parts of the first component in equilibrium volume (in this case vacancy solution [8,9]) and equilibrium adsorption solutions respectively,  - coupled interaction energies of components in adsorption solution, vacancy solution and with adsorbent respectively.

The equations (4-7) give us opportunity to describe absolute adsorption isotherms for both gases and vapors in broad intervals of temperatures and pressures

The values of the following constants are presented: a01, .  If it is necessary (at T>Tcr) in field “Notes” we present additionally the values of  . Below critical temperatures this parameter practically equals to zero and that’s why it is not presented.

Isotherms of exceed adsorption of the components from binary solutions on macroporous adsorbents were described by the Aranovich-Tolmachev equation system [1,11] for monolayer adsorption model. In this case interexchange energies  are practically the same and the equation system has only 3 parameters:

             (8)

            (9)

a1.m- the monolayer adsorption capacity of the first component, Г1- the value of exceed adsorption

 With the following parameter:

,

 - peer energies of interaction in volume solution

The values of the following constants are presented: a1m, B, (D/kT in forms)

Isotherms of exceed adsorption of the components from binary solutions on microporous adsorbents were described by the 4-parametric Tolmachev-Aranovich equation system [1,7,12] for bilayer adsorption model:

                  (10)

                  (11)

,   

The values of the following constants are presented: a1m, B,  (D1/kT),  (D2/kT)

In this case a1m parameter is formal and it corresponds not to the value of adsorption capacity [12].

The values of separation coefficient S for gas mixtures were also presented:

                                                                                                                    (12)

 

Apriori calculations for thernary systems

Because of very limited number of experimental data for thernary adsorption systems in databank we present the results of theoretical calculations for thernary adsorption systems based on experimental data for corresponding binary adsorptions systems. The possibility of such calculation was proved by  A.M. Tolmachev and coworkers [1,13]. There it was shown that the calculation of equilibria for adsorption of threecomponent solutions based on experimental data for correspondent binary solutions could be done with as high  precision as it  is for experimental data receipt (2-5%).

 

All mentioned equation constants, table data for experimental isotherms and isotherm charts were presented in the databank.

The adsorbent characteristics correspond to the published in specialized catalogs or technological  production data by manufacturing firms (see corr. references).

 

References

1. А.М.Толмачев. // Физикохимия поверхности и защита материалов. 2010. Т. 46. № 3. С. 291. Protection of  Metals and Physical Chemistry of Surfaces.2010. V. 46. 3. P.242. А.М.Толмачев, И.А.Годовиков // Вестн.Моск. Ун-та.Сер.2.Химия.2001. Т. 42. №4. С. 241.

2. И.А.Годовиков, Т.А.Кузнецова, А.М.Толмачев // Журн. Физич. химии.2001.Т.75. №11. С. 2030.

3. А.М.Толмачев, О.И.Трубников, И.А.Годовиков, Т.А.Кузнецова // Вестн. Моск. Ун-та. Сер. 2. Химия. 2001. Т.42. №4. С. 247.

4. S. Brunauer, P.H. Emmett, E .Teller. // J. Am. Chem. Soc. 1938. V. 60. P. 309.

5. Г.Л. Аранович. // Журн. физич. химии. 1988. Т. 62. №11. С. 3000.

6. M.M. Dubinin. // Progress in surface and membrane Sci. New York:Acad. Press. 1975. V. 9. P. 1. М.М.Дубинин,В.А.Астахов. Изв. АН СССР. Сер.хим. 1971. С. 5,11,17.

7. А.М.Толмачев, М.М.Дубинин, М.Е.Белоусова, А.А.Фомкин. // Изв. АН СССР. Сер. Хим. 1987. C. 19. А.М. Толмачев, Т.А. Кузнецова, И.А. Годовиков. // Физикохимия поверхностных явлений и защита материалов. 2011. (в печати).

8.      A.M.Tolmachev, O.I. Trubnikov. // Carbon. 2002. V. 40 (9). P. 1401.

9.      А.М.Толмачев, Ф. Стекли, О.И.Трубников., Т.А.Кузнецова. // Журн. физич. химии. 1999. Т. 73. № 7. С. 1267.

10. С.Оно, С.Кондо. // Молекулярная теория поверхностного натяжения в жидкостях. Пер. с англ. М.:МИР. 1963. С. 262.

11.  А.М.Толмачев, Е.М.Еремина, О.И.Трубников, Н.А.Окишева // Журн. физич. химии, 1997. Т. 71. № 4. С.682.

12. А.М.Толмачев, М.И.Годовикова, Т.С.Егорова. // Журн.физич.химии. 2005. Т. 79. № 1. С. 1.

13.  А.М Толмачев.// Adsorption, Science and Technology.  1993. V. 10. P. 155.  Вестн. Моск. Ун-та. Сер. 2. Химия. 1994. Т. 35. № 2. С. 115.

 

The realized databank is not a quiet complete system.  The authors will appreciate every experimental data of different substance adsorption or of the mixture of substances adsorption on every absorbents from every source or person. We accept all the information through our contact mailbox: amtolmach@yandex.ru.

 

As it was mentioned above currently presented databank system from one side is the database of adsorption systems and from the other one is the system of search requests building as standard web-forms. After the start of corresponding site division user could see the following initial form (Fig. 1):

 

Fig 1.

This basic form divided on to three main zones: 1. Browsing in the base zone.  2. The result output zone.  3. Searching in the base zone – the zone for search request building. So in order to browse the base one should choose interested division of the base (table to browse) from the following listbox:

Adsorbents (absorbent data)

Binvapor (experimental isotherm data for adsorption of binary gas (vapor) mixtures on different adsorbents)

Binsmi (experimental isotherm data for adsorption of binary mixtures from solutions on microporous adsorbents)

Binsma (experimental isotherm data for adsorption of binary mixtures from solutions on macroporous adsorbents)

Macro (experimental isotherm data for adsorption of individual compounds on macroporous adsorbents)

Micro (experimental isotherm data for adsorption of individual compounds on microporous adsorbents)

Ternary (experimental isotherm data for adsorption of triple (ternary) gas or solution mixtures on different adsorbents)

and press “browse table” button. After that in the second (output) zone the table output will appear as following:  (for example we choose “Micro” table – the table of experimental isotherm data for adsorption of individual compounds on microporous adsorbents and press “browse table” button):

Fig 2

In the second zone the table per 10 has been appeared. User could move through the table by pressing management links (Next, Next100, Last, Previous, Previous100, First) or choose interested system record by clicking on the correspond system link. After that action all common information for chosen adsorption system will be presented in separate window as following (Fig 3):

Fig 3.

 

Here one could see the basic parameters of chosen adsorption system – i.e. the system name, the name (names) and the formula (formulas) of adsorbat compounds, the adsorbent name, the temperature and the basic constants of calculation by different physical-chemical equations (depends on the system type) – as it was described above in the first section of this manual:

Adsorbents (adsorbent data): D - adsorbent density, VS - total pore volume, Vmicro micropores volume Vmeso- mesopores volume Vmacro macropores volume, w01,w02limit volumes of the sorption space, E01 - E02- characteristics sorption energies.

Binsmi (experimental isotherm data for adsorption of binary mixtures from solutions on microporous adsorbents): a1m, B, D/kT, D2/kT -  parameters of Tolmachev-Aranovich equation for adsorption of mixture components from solutions on microporous adsorbents (10,11), a01 a02 – adsorption capacities of components on current adsorbent, obtained from the Dubinin-Radushkevich (Dubinin-Astachov) equations if any available.

Binsma (experimental isotherm data for adsorption of binary mixtures from solutions on macroporous adsorbents): a1m, B, D/kT - parameters of Aranovich-Tolmachev equation for adsorption of mixture components from solutions on macroporous adsorbents (8,9),    a01, a02 – adsorption capacities of components on current adsorbent, obtained from the BET (Aranovich) equations if any available.

Macro (experimental isotherm data for adsorption of individual compounds on macroporous adsorbents): ps- the saturated vapor pressure of the compound under current temperature, am,C – BET equation parameters(1), am*,C*- Aranovich equation parameters (2).

Micro (experimental isotherm data for adsorption of individual compounds on microporous adsorbents): ps- the saturated vapor pressure of the compound under current temperature, rvap, rliq, rvap/rliq – densities of: vapor, liquid and their ration respectively, a0,E0 – parameters of Dubinin-Radushkevich (for carbons) or Dubinin-Astachov (for zeolites) equations, a01, e01/kT, e01/kT – parameters of Aranovich-Tolmachev equation for  adsorption of individual compounds on microporous adsorbents (4-6).

And finally literature reference and hyperlinks to the data table and data chart are shown. By pressing them user could open in separate windows the table of experimental isotherm data (Fig. 4) or isotherm chart (Fig. 5):

Fig 4.

Fig 5.

All presented data could be easily copied to another application executed or printed in standard way in operation system.

For searching in the base one should choose initial search criteria from the listbox available in the zone 3 (System name, Adsorbat name, Adsorbat formula, Adsorbent name, Temperature), then should enter search variable (or its fragment) in the corresponding textbox – i.e. what he exactly wants to find and then should choose the table in which he wants to search (Macro, Micro, Adsorbents, Binvapor, Binsmi, Binsma, Ternary). Thus for example the following combinations will output the following results:

Search criteria

Search variable

Search table

Result

Adsorbat name

Methane

Macro

All systems of CH4 adsorption on macroporous adsorbents

Adsorbat formula

CCl4

Binsmi

All systems of binary mixture adsorption from solution with carbon tetrachloride on all microporous adsorbents under all temperatures available

Adsorbent name

SKT

Micro

All systems of adsorption of all individual compounds available on microporous adsorbents which contain «SKT» in its name under all temperatures available

Temperature

303

Micro

All systems of adsorption of all substances available on all microporous adsorbents under 303K

System Name

303

Micro

All systems of adsorption of all substances available on all microporous adsorbents under 303K

System Name

СH4-SKT

Micro

All systems of CH4 adsorption on adsorbents which contain in its name «SKT» under all temperatures available.

System Name

CCl4-C6H6

Binsmi

All adsorption systems from the mixtures of carbon tetrachloride with benzene on all adsorbents available under all temperatures.

System Name

CCl4-C6H6-AC

Binsmi

All adsorption systems from the mixtures of carbon tetrachloride with benzene on AC adsorbent under all temperatures.

System Name

C3H8

Micro

All systems of adsorption of C3H8 on all microporous adsorbents available under all temperatures (Fig. 6)

 

After pressing “Search” button the search result will be output as table in the second zone. It consists of the names of adsorption systems which satisfy search conditions entered by user as following (Fig 6):

Fig 6

After that by clicking on the interested system link one could have isotherm common data, isotherm table data and isotherm chart from the obtained table as it was described above.

With all suggestions, notes and questions one could send mail to:

amtolmach@yandex.ru, pr0vider@yandex.ru, tchess54@mail.ru.