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					16th International Environmental Project Olympiad




             The Research of Optimal Mixing Ratio of

 ACF (Activated Carbon Fiber) and AC (Activated Carbon)

      for Removal of VOC (Volatile Organic Compound) s

                                in Crude Oil




                              Republic of Korea




                                    Author
                      Dong-sung, Choi, Su-jin, Kim



                           Supervising Instructor

                               Chun-jeong, Lee
                                          - Abstract -
 A great amount of crude oil leaked in the ocean after a barge carrying a crane slammed into an oil

tanker in Tae-an, Chung-nam, Republic of Korea on December 7th, 2007. VOC (Volatile Organic

Compound) s from crude oil can caused people to have skin or respiratory problems. So it has become

necessary to develop an efficient method of adsorbing harmful gases in crude oil. What is especially

important is developing masks which have good absorption ability to VOCs. The purpose of this

study is to find the ways to reduce the harm of VOCs on people.


First, for the research, I developed a creative machine which can help measure the concentration of

gases and the efficiency of removal harmful gases easily. And I made experiments with the adsorption

of harmful gases using SEM and gas detectors. ACF (Activated Carbon Fiber) has large surface area

ratio, and its pores are exposed on the surface so it absorbed 25.4% of Benzene and 46.67% of

Toluene and this result shows that ACF have a better adsorption capacity for Benzene and Toluene

which have Benzene ring structure. However, ACF turned out to be a poor adsorbent of n-Hexane

which has a chain form structure. This research also shows that AC, which has a variety of pore sizes,

adsorbs 41.18% of n-hexane and this shows that AC adsorbs more n-hexane compared to other

adsorbents. According to approximate calculations of the molecular length of Benzene and n-Hexane,

the diameter of a Benzene ring is shorter than the molecular length of n-Hexane. It is analyzed in

probability aspect by comparing the molecular length of Benzene and n-Hexane that ACF which has

15 Å sized poles adsorb more Benzene than n-Hexane in the activated gas state. In the experiment

about the removal efficiency of harmful gases, results indicated that a mixture of ACF and AC has the

greatest synthetic removal efficiency of harmful organic gases which include both compounds which

have ring or chain form. According to the results, the optimal ratio of ACF to AC is 4:3.


 Through this research, we developed a creative machine which can help measure the adsorption

ability of absorbents and we suggested an innovative way to reduce the damage of volatile organic

compounds.




                                                 -2-
                               - Contents -
Ⅰ. Introduction……………………………………………………………………5

1. Background reason for the research…………………………………………..…….…..…5
2. The purpose of the research……………………………………………………………..…5



Ⅱ. Theoretical Background………………………………………………...……6

1. The mechanism and classification of adsorption………………………………………….6
2. The structure of pores……………………………………………………………...………7
3. Adsorbents: ACF, AC, Zeolite 5A …………………………………………………….….7



Ⅲ. Experimental Procedure………………………………………………..……8

1. Measuring the concentration of gases in the instrument…………………………………..8
2. Analysis of the surface through Scanning electron microscope (SEM)……………….…10



Ⅳ. Results and Considerations………………………………………………...12

1. VOCs removal by cotton wool.…………………………………………………….…….12
2. VOCs removal by adsorbent (ACF, AC and Zeolite 5A)………………………………..13
3. Optimal ratio of ACF and AC for removing VOCs…………………………………..….17



Ⅴ. Conclusion and Suggestion…………………………………………………19

1. Conclusion.……………………………………………………………………………….19
2. Suggestion………………………………………………………………………………..20



Ⅵ. References……………………………………………………...…………..21



Ⅶ. Appendix………………………………………………………...…………21

                                     -3-
                                    -Figure contents-
Fig. 1 Satellite picture of oil in Tea-an……………………………………..…………………………..5
Fig. 2 Volunteers for removing oil…………………………..……………………………………...…..5
Fig. 3 Mechanism of adsorption………………………………………………………………………..6
Fig. 4 ACF………………………………………………………………………………………..…….7
Fig. 5 AC………………………………………………………………………………………….……7
Fig. 6 Variety sizes of pole in AC………………………………………………………………….…..7
Fig. 7 Zeolite…………………………………………………………………………………..……….8
Fig. 8 Instrument……………………………………………………………………………….….……8
Fig. 9 The experiment procedure for the VOCs adsorption………………………………….…….….10
Fig. 10 SEM…………………………………………………………………………………………...10
Fig. 11 The procedure of analyzing the surface with SEM…………………………………...………11
Fig. 12 SEM photo of cotton wool…………………………………………………………………….12
Fig. 13 Removal efficiencies of benzene by adsorbents………………………………..……………..13
Fig. 14 Removal efficiencies of toluene by adsorbents……………………………………………….14
Fig. 15 Removal efficiencies of n-hexane by adsorbents………………………………….………….14
Fig. 16 SEM photo of ACF……………………………………………………………………..…..…15
Fig. 17 SEM photo of AC…………….………………………………………………………….…....15
Fig. 18 SEM photo of Zeolite 5A………………………………………………………………....…..15
Fig. 19 Removal efficiencies of benzene by the mixed adsorbent……………………................……18
Fig. 20 Removal efficiencies of toluene by the mixed adsorbent……………………………………..18
Fig. 21 Removal efficiencies of n-hexane by the mixed adsorbent………………………...................18
Fig. 22 Average removal efficiency of all VOCs by the mixed adsorbent……………………………19
Fig. 23 Diagram of benzene ring…………………………………………………….………………..21
Fig. 24 Diagram of n-hexane……………………………………………………...……….………….22



                                     -Table contents-
Table 1. Concentration of remained VOCs after adsorbing with cotton wool as time going…...…….12

Table 2. Concentration of remained VOCs and their removal efficiencies after adsorbing with
       ACF, activated carbon and Zeolite 5A as time going………………………………….……..13
Table 3. Concentration of remained VOCs and their removal efficiencies after adsorbing with
        the mixed adsorbent as time going…………………………………………………………...17
Table 4. Average removal efficiency of VOCs by adsorbing with the mixed adsorbent……...……...17


                                               -4-
Ⅰ Introduction
 .
1. Background reason for the research
  A large amount of crude oil leaked in December 2007 due to the collision of an oil tanker and a
 crane in Tea-An, Chung-Nam, Republic of Korea. Crude oil contained many organic compounds
 some of which are volatile. These compounds can cause significant health problems. Although they
 wore masks, people mobilized to clean up the spill reported experiencing headaches, vomiting, and
 other acute symptoms. Scientists have discovered that VOC (Volatile Organic Compound) s can be
 carcinogenic. Due to the harmful effects of VOCs on human beings it has become necessary to
 develop an efficient method of adsorbing harmful gases in crude oil. What is especially important is
 developing masks which can adsorb VOCs. It is also important to do research on ability of ACF
 (Activated Carbon fiber), AC (Activated Carbon) and Zeolite 5A to adsorb VOCs.




      Fig. 1 Satellite picture of oil in Tea-an              Fig. 2 Volunteers for removing oil



2. The purpose of the research
   We researched the optimum condition for efficient adsorption of volatile organic compounds
  using ACF, AC and Zeolite 5A. The specific purposes of the research are explained below:


   First, develop a machine which can easily measure the concentration of gases and have the
  ability to conduct experiments under various parameters.
   Second, compare the adsorption ability of ACF, AC and Zeolite 5A to Benzene, Toluene and n-
  Hexane according to various properties of adsorption.
   Third, crude oil is a mixture of volatile organic compounds, so research the optimum blending
  ratio of ACF and AC to adsorb harmful gases.


   The ultimate purpose of the research is to suggest ways to reduce damages to human health
  caused by harmful volatile organic compounds in crude oil.




                                                  -5-
Ⅱ Theoretical Background
 .
1. The mechanism and classification of absorption
 A. Mechanism of adsorption
   Adsorption is a phenomenon where gases stick to the surface of a solid through a physical or
  chemical interaction. Materials which contain lots of pores to adsorb are called adsorbents. A
  phenomenon where gases stick to around shaped hole is explained below.

   a. Gases move to the surface of a pore in the adsorbent.

   b. Gases approach the pore by molecular diffusion when close to the surface of a pore.

   c. Gases pass through the spaces in the adsorbent by movement of the inner particles or
    molecular diffusion and move towards an adsorption point.

   d. Gases become fixed to the inner surface of an adsorbent.

   In these adsorption processes, the last process is the Rate Limiting Step which can dominate the
  speed of adsorption. Therefore adsorption is limited by the former process. Finally, adsorption rate
  is determined by diffusion and the movement rate of molecules in the adsorbent.




                                    Fig. 3 Mechanism of adsorption


 B. Classification of adsorption
   The main form of adsorption is classified in two ways; physical adsorption and chemical
  adsorption. Physical adsorption occurs according to Van der Waals force which is relatively weak
  in comparison to other bonds. Chemical adsorption occurs through ionic or covalent bonds. In
  physical adsorption, there is no bond between the surface of the adsorbent and the gases, which
  mean gases are in a temporary fixed state near the surface of the adsorbent. These molecules can
  become separated easily by changes in pressure or concentration, therefore physical adsorption is
  reversible. Most gas adsorption processes have similar characteristics. However, in chemical
  adsorption, gases are caught on the surface of the adsorbent by covalent force so chemical
  adsorption is irreversible.


                                               -6-
2. Structure of pores
  A pore is a space in a solid construction. There are two types of pores: space between particles and
 space in particles. The structure of pore can be described by its shape, size and its connection state
 to other pores. Compared to the size of molecules, pores are much larger. According to the size of
 pores, if the size of the pore is larger than 50nm, it is called macro pore, if the size of the pore is
 smaller than 2nm, it is called micro pore. Pores which are middle sized are called meso pores.
 Although the activated point on the surface of an adsorbent can participate in the reaction, the effect
 is very small since the total surface area of the outer surface of the adsorbent is much smaller than
 that of the inner surface.


3. Adsorbents: ACF, AC, Zeolite 5A
 A. ACF (Active Carbon Fiber)
   ACF is an activated carbon which is made by manufacturing
  during carbonized rayon. After heating rayon with deoxygenating,
  the fixed carbon frame remains, and all other chemical elements
  are eliminated. At that time, if we add water to it and oxidize it,
  pores will form and it will turn into fiber form. ACF is very
  efficient in adsorption because its pore size is 15 Å uniformly                Fig. 4 ACF
  and its pores are exposed on the outside more than activated carbon and other adsorbent.


 B. AC (Activated Carbon)
   AC, an aggregate of amorphous carbon which has many small
  pores (and it has a large inner surface area because small pores
  are made during activation), is classified into powder or lump
  state by the size of the pores. The pores of AC are complex and
  contain many capillaries which mean these pores have a large
  surface area. Shown in Fig. 6, there are various sizes (micro pore
  – meso pore - macro pore) the pores inside of activated carbon.                 Fig. 5 AC




                                   Fig. 6 Variety sizes of pole in AC

                                                 -7-
 C. Zeolite 5A
    Zeolite is a general term used for crystallized aluminum silicate. The
   synthesis Zeolite from nature is usually used Zeolite A, Zeolite X type
   and Zeolite Y type are classified by the formation of the bonds and
   Al2O3, SiO2. The front number of Zeolite A is classified with valid
   pore's size.
                                                                                   Fig. 7 Zeolite



Ⅲ. Experimental Procedure

 1. Measurement of the concentration of VOCs
   A. Development of the standard instrument for removing VOCs
    The commercial standard device for removing VOCs cannot be applied because it is difficult to
   use this. Therefore, the standard device for removing VOCs was developed for this study. The
   developed device was similar to one in the real field but the size was only small.


   a. Instrument
     The instrument for investigating the adsorption of VOCs was made out of acrylic (30 cm x 21
    cm x 19 cm). This box was composed with a heating plate, fan, a gas detector hall and an
    adsorbent column. The liquid pollutant was evaporated by the heating plate. The pollutant gas
    flowed in the column by the fan. The gas detector hall had a valve for air tightness and the
    various-sized detectors could be installed in the hall.




                                            Fig. 8 Instrument




                                                  -8-
 b. The gas detectors
   The gas detector was the narrow glass column with the chemicals whose color was changed by
  the reaction with VOCs. And this detector could measure the concentration of VOCs with the
  length of the changed color in the column. This method is widely applied in the real field. The
  concentration of Benzene, Toluene and n-Hexane in the instrument were measured with this gas
  detector.


 c. Pump
  The gas in the instrument flowed into the gas detector column by the pump.


B. Experimental procedure
 a. Fill the adsorbent in the column.
 b. Lay a slide glass on the heating plate and drop some quantity of liquid VOCs on the slide glass
  with a micro pipette.
 c. After evaporating the liquid VOCs, remove the glass in the both side of the gas detector. And
  put the detector into the pump.
 d. Open the valve of the gas detector hall and turn on the pump for inhale the VOCs into the gas
  detector.
 e. If the color in the detector does not change, close the valve and measure the length of the
  changed color in the column.




              1. Fill the adsorbent in the column         2. Drop the liquid VOCs




                                                    -9-
               3. Evaporate the liquid VOCs                  4. Remove the glass in detector




                   5. Measure the VOCs                      6. Measure the length of the color
                       Fig. 9 The experiment procedure for the VOCs adsorption




2. Analysis of surface with SEM
A. Scanning Electron Microscope (SEM)




                                              Fig. 10 SEM
   SEM is an instrument in which the specimen is examined point by point directly in a moving
  electron beam, and electrons reflected by the specimen are used to form a magnified, three-
  dimensional image on a television screen.

                                                - 10 -
B. Analytical procedure
 a. Fix a sample on the stove.
 b. Coat the sample with platinum and prevent the sample in SEM.
 c. Put the sample into SEM and turn on the vacuum pump.
 d. Adjust the brightness and the focus and the position of the computer connected to SEM.
 e. Capture the picture.




                   1. Prepare samples                         2. Put the sample




                                        Capture the picture


                    Fig. 11 The procedure of analyzing the surface with SEM




                                              - 11 -
Ⅳ Results and Discussion
 .
 1. VOCs removal by cotton wool
   People who were mobilized to remove crude oil in Tea-an wore masks and most of the masks are
  made of cotton wool. But they experienced health problem because of VOCs from crude oil. First
  of all, the adsorbent efficiency of cotton wool was investigated. The VOCs removal efficiency of
  cotton wool is presented in Table 1.


  Table 1. Concentration of remained VOCs after adsorbing with cotton wool as time going

                                                       Concentration (ppm)
    Adsorbent     VOCs
                                 0 min              5 min             10 min               15 min

                 Benzene           60                  58                59                 58

   Cotton wool   Toluene           83                  76                76                 76

                 n-Hexane          190               190                190                 190




                            X100                                        X1000

                                   Fig. 12 SEM photo of cotton wool


   As we can know that the inner formation of cotton wool is the tangled formation of fiber.
   We could get these results through upper figures.


   Table 1 show all VOCs were not almost removed by cotton wool. Cotton wool had sparsely
 cellulose fiber and its pore was slightly developed (Fig. 12). Therefore, cotton wool could not
 adsorb VOCs.




                                                 - 12 -
2. VOCs removal by adsorbent (ACF, AC and Zeolite 5A)
 Three kinds of adsorbents were used in this study. Removal efficiencies of Benzene, Toluene and
n-Hexane were investigated as time going. The VOCs removal efficiency of ACF, AC and Zeolite
5A is presented in Table 2.


 Table 2. Concentration of remained VOCs and their removal efficiencies after adsorbing with ACF, AC and
        Zeolite 5A as time going

                                      Concentration (ppm)                   Removal efficiency (%)
   absorbent     VOCs
                              0 min     5 min   10 min      15 min   0 min     5 min    10 min   15 min

                Benzene        63        56       51         47      0.00      11.11    19.05    25.40
     ACF        Toluene       150        120      90         80      0.00      20.00    40.00    46.67

               n-Hexane       190        170      150        140     0.00      10.53    21.05    26.32

                Benzene        59        53       48         47      0.00      10.17    18.64    20.34

     AC         Toluene        72        54       50         48      0.00      22.22    30.56    33.33

               n-Hexane       170        150      130        100     0.00      10.17    23.53    41.18

                Benzene        63        58       55         53      0.00       7.94    12.70    15.87
  Zeolite 5A    Toluene        81        72       66         63      0.00      11.11    18.52    22.22

               n-Hexane       200        190      180        170     0.00       5.00    10.00    15.00



 The VOCs removal efficiency of ACF, AC and Zeolite 5A is presented in Fig. 13, Fig. 14, and Fig.
15. X axis of the graph presents time and y axis of the graph presents the removal efficiency.




                          Fig. 13 Removal efficiencies of benzene by adsorbents




                                                  - 13 -
                       Fig. 14 Removal efficiencies of toluene by adsorbents




                       Fig. 15 Removal efficiencies of n-hexane by adsorbents


 As we can know in Fig. 13 and Fig. 14, ACF has the greatest total Benzene and Toluene removal
efficiency. However, in Fig. 15 AC has the greatest total n-Hexane removal efficiency.


 We could get these results through upper figures.
 - The removal efficiency of Benzene and Toluene with benzene ring by ACF was higher than
 other adsorbents because ACF with the larger surface area had the high physical adsorption ability
 of VOCs.




                                              - 14 -
      - These are the SEM pictures of absorbents.




                               X1000                                      X100, 0001

                                           Fig. 16 SEM photo of ACF




                                X100                                        X1000

                                            Fig. 17 SEM photo of AC




                                X100                                       X1000

                                        Fig. 18 SEM photo of Zeolite 5A

1
    We could not take the second picture of Fig. 16 because of the capacity of SEM. So we got that picture at a
specialty website which deals AFC.

                                                     - 15 -
     Fig. 16 shows the pores of ACF were uniform (15 Å ) and exposed much. However, AC and
    Zeolite 5A had the complex surface and multiform pores (Fig. 17 and 18). Therefore, ACF could
    adsorb more VOCs because the pores of ACF were exposed more than of other adsorbents.


     - However, more n-Hexane was removed by AC differently to other VOCs. While ACF had only
     small pores, the pore size of AC was various (from micro pore to macro pore). According to
     approximate calculation of length of Benzene and n-Hexane2, the length of Benzene (4.62 Å) is
     shorter than the length of n-Hexane (9.08 Å). And in the probability aspect, gases molecular are in
     activated state, so n-Hexane could not be adsorbed in AFC which has very small pores (15 Å) well
     than Benzene and Toluene. On the other hand, although Zeolite 5A had various sized pores like
     AC, the removal efficiency of n-hexane by this was lower than by ACF. This was why the surface
     area of Zeolite 5A was smaller than of ACF. To conclude, n-Hexane was well removed by
     adsorbent with large sized pore and the large surface area.




2
    Calculation is in Appendix.

                                                  - 16 -
3. Optimal ratio of ACF and AC for removing VOCs
  From previous experimental results, removals of Benzene and Toluene were dependent on the
 surface area and the exposure of pores. And the removal of n-hexane was also dependent on the
 diversity of pore size. In VOCs from crude oil, both chain and ring form compounds exist.
 Therefore, in order to removal both chain form and ring form VOCs more efficiently, a mixed
 adsorbent with ACF and AC was applied. This chapter studied the optimal mixing ratio of two
 adsorbents according to comparing the average removal efficiency of all VOCs with variously
 mixed adsorbents. The VOCs removal efficiency of absorbent which is mixed with ACF and AC is
 presented in Table 3. And the average value of final VOCs removal efficiency is presented in table
 4.


Table 3. Concentration of remained VOCs and their removal efficiencies after adsorbing with the mixed
        adsorbent as time going

 Mixing Ratio                                Concentration (ppm)                   Removal efficiency (%)
                      VOCs
  (ACF : AC)                       0 min       5 min    10 min     15 min   0 min     5 min    10 min    15 min

                     Benzene            68      64        58        54      0.00       5.88    14.70       20.60

       2:5           Toluene            80      66        53        52      0.00      17.50    33.80       35.00

                     n-Hexane         179       143      136        114     0.00      20.11    24.02       36.31

                     Benzene            64      57        54        49      0.00      10.94    15.63       23.44

       3:4           Toluene            80      72        61        46      0.00      10.00    23.75       42.50

                     n-Hexane         186       171      157        123     0.00       8.06    15.59       33.87

                     Benzene            63      56        50        46      0.00      11.11    20.63       26.98

       4:3           Toluene            83      65        63        46      0.00      21.69    24.10       44.58

                     n-Hexane         233       180      179        157     0.00      22.75    23.18       32.62

                     Benzene            66      58        56        48      0.00      12.12    15.15       27.27

       5:2           Toluene            92      68        56        50      0.00      26.09    39.13       45.65

                     n-Hexane         217       179      171        157     0.00      17.51    21.20       27.65


Table 4. Average removal efficiency of VOCs by adsorbing with the mixed adsorbent
      Mixing Ratio
                                2:5                    3:4                   4:3                   5:2
      (ACF : AC)

        Average                 30.63                  33.27                34.73                  33.52




                                                       - 17 -
 The VOCs removal efficiency of each mixed absorbents is presented in Fig. 19, Fig. 20, and Fig.
21. X axis of the graph presents time and y axis of the graph presents the removal efficiency.




                   Fig. 19 Removal efficiencies of benzene by the mixed adsorbent




                    Fig. 20 Removal efficiencies of toluene by the mixed adsorbent




                   Fig. 21 Removal efficiencies of n-hexane by the mixed adsorbent




                                               - 18 -
  The total VOCs removal efficiency of mixed adsorption is presented in Fig. 22. X axis of the
 graph is ACF:AC, y axis of the graph presents averaged removal efficiency.




                Fig. 22 Average removal efficiency of all VOCs by the mixed adsorbent


  As we can see in Fig. 19 and Fig. 20, the mixing rate which has the greatest Benzene and Toluene
 removal efficiency is 5:2. As we can see in Fig. 21, the mixing rate which has the greatest n-
 Hexane removal efficiency is 2:5. The result has the same tendency that as the rate of ACF
 increases, total Benzene and Toluene removal efficiency increases, and as the rate of AC increases,
 total n-Hexane removal efficiency increases. As we can see in Fig. 22, the synthetic Benzene,
 Toluene and n-Hexane removal efficiency is the greatest in ACF:AC=4:3


 We could get these results through upper graphs.
  - As previous results, the higher ratio of ACF, the higher removal efficiency of Benzene and
   Toluene. And as the ratio of AC is high, removal efficiency of n-Hexane increases.
  - The optimal mixing ratio of ACF:AC was 4:3 for the high removal efficiency of all VOCs.
  - The mixed adsorbent included the both advantages of ACF and AC. Therefore this mixed
   adsorbent could more efficiently remove the VOCs than each adsorbent.


Ⅴ Conclusion and Suggestion
 .
1. Conclusion
  This study was conducted for finding the optimal adsorbent for removing VOCs produced from
 petroleum because the people had a headache by inhaling VOCs, who were cleaning up spilled oil
 on the coast near Tae-an in Republic of Korea.
  - Adsorption of VOCs by ACF, AC and Zeolite 5A was dependent on the surface area, the degree
  of pore exposure and pore size of adsorbents.

                                               - 19 -
  - Because ACF had the larger surface area and its pores were more exposed than AC and Zeolite
  5A, ACF had the good physical adsorption ability. Therefore, Benzene and Toluene could adsorb
  on ACF well.
  - Because the pore size of AC was various (from micro pore to macro pore), n-Hexane which has
  long molecular length could be adsorbed on AC than on ACF with only small pores very well.
  However, ACF could absorb more n-Hexane than Zeolite 5A which had various sized pore
  because ACF had much larger surface area. Therefore, n-Hexane was well removed by adsorbent
  with various sized pore and the large surface area.
  - ACF and AC were better adsorbent for removing Benzene and Toluene, and n-Hexane,
  respectively. Therefore, the mixed adsorbent with them was applied for removing VOCs and
  could efficiently remove them. There was the optimal mixing ratio of ACF to AC (4:3).
  Finally, this mixed adsorbent can be usefully applied in the oil spill accident in the ocean, a gas
  station, an oil tank and so on.


2. Suggestion
 A. In experiments, the VOCs removal efficiency of each adsorbent is under 50%. If we conduct
  experiments until saturated physical adsorption state, we can get more credible VOCs removal
  efficiency.
 B. If we conduct experiments with compounds which is adsorbed by chemical adsorption such as
  radical compound, Ammonia, we can find other factors which is related to adsorption mechanism
  except large surface area, the size of pores and revealed degree of pores.
 C. After conducting experiments which is about other VOCs such as Formaldehyde, we can apply
  these results to another problems for instance Sick House Symptom.
 D. ACF has a great amount of Benzene and Toluene adsorption ability since it has large surface
  area and revealed pores. However, it cannot adsorb n-Hexane which has long molecular length
  very well because its pores are so small. To replenish this disadvantage, AC which has variety size
  of pores can be mixed with ACF so mixed adsorbent synthetically and efficiently adsorbs chain
  and ring form VOCs. Therefore, the using possibility of mixed adsorbent is very high in crude oil
  work place, house and gas station. And it is expected using its adsorption ability in many fields for
  example impurities removal, moisture removal and separation of materials, etc.




                                               - 20 -
Ⅵ References
 .

1. Oxtoby, Gillis, Nachtrieb, Principle of modern chemistry, Thomson, 2003, pp.148-154

2. Peter Atkins, Julio de Paula, Physical Chemistry, Oxford, 7th Edition, pp. 1096-1115

3. Son Jae-Ik, An introduction of new carbon materials, KIER, 2000, pp. 94-96.

4. Dong Yang Carbon, Activated carbon, Dong-Yang Carbon, 1999, pp. 37~39.

5. Dae Dong A.C., Optimal design of activated carbon, p.11.




Ⅶ. Appendix

The calculation of molecular length

1. The length of Benzene Ring




                                      Fig. 23 Diagram of benzene ring



Let’s put the covalent bond radius of Carbon, r. The angle of the benzene ring is 120°. So the length of

Benzene ring is
                                        2  2r cos60  4r  6r .
r is 0.77Å. So the length of Benzene ring is 4.62 Å




                                                  - 21 -
2. The length of n-Hexane




                                      Fig. 24 Diagram of n-hexane



Let’s put the covalent bond radius of Carbon, r. The angle of the benzene ring is 109.5°. The length

which faces to 109.5° angle in the triangle can be calculated by the second cosine law.

                       ( Length)2  4r 2  4r 2  2  2r  2r cos109.5  10.66r 2

So the length of n-Hexane can be calculated like below.

                                      3  10.66r  2r  11.79r

r is 0.77Å. So the length of n-Hexane is 9.08 Å




                                                  - 22 -

				
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