Desulfurization of Diesel by Selective Adsorption of Sulfur Compounds over Zeolite and Activated Carbon

제올라이트와 활성탄에서의 황화합물 선택 흡착에 의한 경유 탈황

박정근·고창현·Vinay M. Bhandari^{·이용택*·김종남†}

한국에너지기술연구원분리공정연구센터

305-343

71-2

*

305-764

220 (2005

7

20

, 2005

9

1

)

Desulfurization of Diesel by Selective Adsorption of Sulfur Compounds over Zeolite and Activated Carbon

Jung Geun Park, Chang Hyun Ko, Vinay M. Bhandari, Yongtaek Lee* and Jong-Nam Kim^†

Separation Process Research Center, Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343, Korea

*Department of Chemical Engineering, Chungnam National University, 220, Gung-dong, Yuseong-gu, Daejeon 305-764, Korea (Received 20 July 2005; accepted 1 September 2005)

요 약

흡착식경유탈황을위하여

Y

. n-

BT, DBT, 4,6- DMDBT

50 ppmw

(Cu

, Ni

)

.

,

Ni-Y

,

.

1 g

186 ppmw

15 ml

.

.

Abstract −

We have investigated Y zeolite and activated carbon for an adsorptive desulfurization of diesel. In batch experiments, cation (Cu

, Ni

) exchanged Y zeolites showed high equilibrium adsorption capacity for sulfur compounds in model diesel, which contained BT, DBT and 4,6-DMDBT of each 50 ppmw in n-octane. But the cation exchanged Y zeolites lost its capacity in commercial diesel (186 ppmw). On the other hand, activated carbon showed reasonable adsorption capacity for sulfur compounds in both model and commercial diesel. The adsorption capacity of sulfur on Ni- Y zeolite was decreased with the increase of benzene concentration in model diesel but the sorption capacity on acti- vated carbon was insensitive to aromatic concentration. In breakthrough test, activated carbon of 1 g could treat 15 ml of commercial diesel with 186 ppmw sulfur. Toluene showed good solvent for regenerating activated carbon among sev- eral solvents.

Key words: Desulfurization, Diesel, Y Zeolite, Adsorption, Activated Carbon

1. 서 론

대도시대기오염은자동차배기가스가주원인

(

85

)

.

2006

430 ppmw

30 ppmw

[1],

2010

15 ppmw

.

현재널리사용되고있는수송용연료의황성분제거기술은수첨

탈황공정

(HDS: hydrodesulfurization)

(300

C

),

(20-100

)

Co-Mo/Al

O

Ni-Mo/Al

O

환하여제거한다

[2].

thiol

sulfide

4,6-dimethyldibenzothiophene

4, 6

용이치않다

. HDS

기위해서는촉매반응기의부피를

3

[3],

더높은온도및압력에서의운전

,

,

.

†

To whom correspondence should be addressed.

E-mail: [email protected]

따라서수첨탈황공정을대체할여러기술들중의하나로흡착탈황 공정이개발되고있다

.

미국의

Conoco-Phillips

(S-Zorb)

2001

.

,

,

SO

.

(400-440

C),

(7-35 atm)

.

1,500 ppmw

FCC

10 ppmw

[4].

최근

Yang

π

-

[5].

-

(complexation)

서주로일어나는

Van der Waals Force

큰흡착능력과높은선택성을가진다

.

,

이하다

[6].

,

-

적용할경우

,

[7].

Yang

guard bed

.

-

합체기반의

Cu-Y

했다

.

-

[5].

본연구에서는경유의고심도흡착탈황에적합한흡착제개발을 위하여금속이온

(Cu

, Ni

)

Y

.

2. 실 험

2-1.흡착제제조

본연구에서사용된흡착제는

Y

Y

,

,

,

.

Ni-Y

Cu-Y

Na-Y

(Si/Al=2.37, Aldrich)

(Ni(NO

)

),

(Cu(NO

)

)

.

Y

3

3

.

되지않았던여분의금속질산염을제거해주기위해충분한양의증 류수

(

2L)

.

3

.

Cu

, Ni

pH 5

를유지하도록하였다

[8].

80

C

5

. Ni/Al

O

20

였다

. Na-Y(Aldrich),

, TAKEDA

GH

X(AC1)

CALGON

C30-53(AC2)

200

C

24

.

2-2.시약및모사경유 제조

,

경유에함유된황화합물중에서

HDS

않은내화황화합물

(refractory sulfur compound)

benzothiophene (BT), dibenzothiophene(DBT), 4,6-dimethyldibenzothiophene(4,6-DMDBT)

등에대한여러흡착제의흡착특성을분석하기위하여

n-

BT(Aldrich, 95

), DBT(Aldrich, 98

), 4,6-DMDBT (Aldrich, 97

)

를각각

50 ppmw

150 ppmw

경유를제조하였다

.

.

2-3.회분식흡착실험

충분히건조된흡착제들은원하는입자크기

(300-425

m)

성한후

0.5 g

Table 1

라열처리를하였다

.

다음에제조된황농도

150 ppmw

186 ppmw

용경유

10 ml

.

기는상온

,

1

GC- FPD(flame photometric detector)

.

2-4.파과실험

황화합물의활성탄에대한동적흡착특성을파악하고자파과실험 을수행하였다

.

Fig. 1

in-situ

.

0.4 cm,

0.6 cm,

30 cm

.

300-425

m

1 g

200

C

.

Table 1. Activation condition of each adsorbent used in batch test

Adsorbents Activation condition

Na-Y 350

C, Helium

Cu-Y 450

C, Helium

Ni-Y 350

C, Helium

Silica gel 150

C, Helium

AC1 AC2 200

C, Helium

200

C, Helium

20 wt

Ni/Alumina 200

C, Helium

Fig. 1. Schematic diagrams of adsorption experimental apparatus;

(a) batch experimental apparatus, (b) breakthrough experimen-

tal apparatus.

제거시키기위해서황성분이제거된

n-

.

석영관내부의공기제거가완료되면밸브조작으로상용경유를주 입하여실험을진행하였다

.

,

0.2 ml/min

.

GC-FPD

.

2-5. GC 분석

회분식흡착실험과파과실험동안얻어진샘플의황농도분석은

SUPELCO 24158 SPB-1

flame photometric detector(FPD)

가장착된

HP6890

(GC)

.

황화합물인

BT, DBT, 4,6-DMDBT

n-

GC

,

.

50 ppmw

n-

. Fig. 2

GC-FPD

.

BT

DBT

4,6-DMDBT

지하였다

.

GC-FPD

,

.

,

상용경유의초기

total area

C

total area

를

C

C

/C

. 3. 결과 및 고찰

3-1.회분식흡착실험을통한황흡착특성 분석

다양한종류의흡착제중에서우수한황제거능력을가지는흡착

제를선별하기위해서회분식흡착실험을하였다

. Fig. 3

가

150 ppmw

력을나타냈다

.

. Y

(Na-Y)

,

Y

트

(Ni-Y, Cu-Y)

인하였다

.

,

BT, DBT, 4,6-

DMDBT

.

(

림에서

AC1, AC2)

BT

DBT, 4,6-DMDBT

.

(Ni/

Al

O

)

.

반면에

Fig. 4

탄이가장높은황화합물흡착능력을나타냈으며

, AC1

AC2

.

.

n-

,

,

.

.

Fig. 2. GC-FPD chromatogram of model and commercial diesel.

Fig. 3. Effect of adsorbents on sulfur adsorption of treated model die-

sel in batch adsorption: vertical axis represented remaining

sulfur concentration.

3-2.방향족화합물의영향분석

본실험에서는선행된회분식흡착실험에서나타난결과를보다 정확히이해하고자니켈이온이교환된

Y

(Ni-Y)

사하였다

. Fig. 5

150 ppmw

인벤젠농도를

0.0, 0.5, 5.0, 25 v/v

Ni-Y

.

Ni-Y

.

0.5 vol

72

. 5 vol

벤젠첨가시약

98

, 25 vol

합물의흡착능력을완전히상실하는것으로나타났다

.

.

합물과도π

-

[9].

Yang

Y

교환된

Cu

, Cu

Y

,

다

[10].

Table 2

에제시된

15.7-47.2 vol

, ppm

비해

1,000

.

다더큰선택성을가진다하더라도방향족화합물의농도가상대

적으로매우높기때문에

, Ni-Y

-

향족화합물이차지하게되어

,

.

-

20

.

반면활성탄은모사경유내방향족화합물인벤젠의농도가증가 하더라도황화합물의흡착량감소는크지않았다

.

5 vol

95

25 vol

90

.

,

.

3-3.파과실험을통한활성탄의황 흡착특성분석

회분식실험에서상용경유의황화합물흡착에효과를보인활성 탄의동적흡착특성을파악하기위해서파과실험을실시하였다

. Fig. 6

은활성탄의상용경유파과곡선이다

.

, 0.2 ml/min

,

활성탄단위

g

5 ml

.

를

5 ml

.

속된실험에서황화합물이흡착제에포화한상태에서파과되었는지 를확인하기위하여상용경유의누적통과량이

7 ml

16

,

.

,

Fig. 5. Effect of benzene content in model diesel on sulfur reduction.

Table 2. Typical aromatic composition of commercial diesel fuels[5]

Typical Composition (vol

)

Total Aromatics Benzene Toluene Xylene Ethylbenzene Cumene

15.7-47.2 0-0.02 0-0.18 0.04-0.71 0.02-0.7 0.01-0.06

(31.8) (0.01) (0.05) (0.15) (0.04) (0.02)

*Average values are shown in parentheses.

Fig. 4. Effect of adsorbents on sulfur adsorption of treated commer-

cial diesel in batch adsorption: vertical axis represented rela-

tive sulfur concentration of remaining commercial diesel.

을의미한다

. Fig. 7

Fig. 6

.

Fig. 6

건과동일하게

0.2 ml/min

.

,

을진행하지않고

15

3 ml

2

.

, ‘0.2 ml/min

3 ml

2

’

.

활성탄

1 g

186 ppmw

15 ml

수있었다

.

험에비해활성탄의흡착량이약

3

. Hernandez-

Maldonado

Yang

성이매우적다고보고했다

[5].

착속도로인해이러한결론에도달한것으로판단된다

.

,

본실험에서흡착속도를고려한파과실험을통해서활성탄의우수 한흡착능력을확인하였다

.

.

(turbostratic structure)

,

결정이불규칙적으로배열되는것에의하여생긴세공과비결정부 분이흡착에관여한다고생각된다

.

진다고판단된다

[11].

가증가할수록황화합물의구조는활성탄의구조와유사해지므로

,

계면에서더강한상호작용이일어날것이며

,

. n-

BT, DBT, 4,6-DMDBT

50 ppmw

씩녹여제조된

150 ppmw

BT

다큰분자인

DBT

4,6-DMDBT

근거를뒷받침해주고있다

.

3-4.용매의용출에의한활성탄재생

흡착질로포화흡착된활성탄은압력강하

,

,

(

),

[11-15].

생방법이가장많이사용되나

,

,

[16].

본활성탄의재생실험은화학적용매에의한추출방법을이용 하였다

.

6

(

,

, MTBE,

, n-

,

)

.

1 g

200

C

유를흡착탑으로주입시켜황화합물로활상탄을포화흡착시켰다

.

그후

,

0.4 ml/min

로주입시켜서배출되는용매의황화합물농도를

GC-FPD

.

Fig. 8

6

이가장우수한재생제였다

.

g

20 ml

90

, 60 ml

100

.

,

MTBE,

, n-

,

.

,

.

3-5.톨루엔을이용한반복재생

가장우수한재생능력이있는톨루엔을이용한반복재생과그에

따른황화합물흡착량변화를

Fig. 9

.

과실험과같은한조건에서이루어졌으며

,

.

,

,

n-

Fig. 6. Breakthrough curve of sulfur for commercial diesel using acti- vated carbon.

Fig. 7. Breakthrough curve of sulfur for commercial diesel using acti-

vated carbon with interruption of feeding for two hours after

every sampling treated diesel of 3 ml.

히흘려보냈다

.

,

n-

0.2 ml/

min

경유를채취하여

GC-FPD

.

루어지면

,

0.4 ml/min

,

총

3

2

.

을수행해본결과

13 ml/g

,

재생시

,

한

12 ml/g

.

서각각

87

80

,

.

,

.

4. 결 론

모사경유의회분식흡착실험을통해

,

.

, 4,6-

DMDBT

.

BT

다

DBT

4.6-DMDBT

.

반면상용경유의회분식흡착실험에서는

,

,

성을가진

Ni-Y

Cu-Y

나타났다

.

,

.

Ni-Y

,

Ni-Y

.

.

즉

, Ni-Y

,

할수록제올라이트내에더많은π

-

.

.

활성탄의동적흡착량

(

)

,

.

,

g

15 ml(2 mg S/g ads.)

다

.

1 g

2 mg

다

.

,

, 3

80

.

참고문헌

1. Clean Air Conservation Act, Table 30, Preparation Standard for Transportation Fuel and Its Additives, Ministry of Environment, Korea(2004)

2. Gates, B. C., Katzer, J. R. and Schuit, G. C. A., A Chemistry of Catalytic Processes , McGraw-Hill, New York(1979).

3. Song, C. and Ma, X., “New Design Approaches to Ultra-Clean Diesel Fuels by Deep Desulfurization and Deep Dearomatiza- tion,” Appl catal B: Environmental. ,

(1), 207-238(2003).

4. http://www.szorb.com/sulfur_removal.htm

5. Hernandez-Maldonado, A. J. and Yang, R. T., “New Sorbents for Desulfurization of Diesel Fuels Via

-Complexation,” AIChE. ,

50

(4), 791-801(2004).

6. King, C. J., Separation Processes Based on Reversible Chemical Complexation , In Handbook of Separation Process Technology, Rousseau, R.W., ed., Wiley, New York(1987).

7. Ma, X., Velu, S., Kim, J. H. and Song, C., “Deep Desulfuriza- tion of Gasoline by Selective Adsorption over Solid Adsorbents and Impact of Analytical Methods on ppm-level Sulfur Quanti- fication for Fuel Applications,” Appl Catal B: Environmental. ,

56

(1-2), 137-147(2005).

8. Baes, C. F. and Mesmer, R. E., The Hydrolysis of Cations , Wiley, New York(1976).

Fig. 9. Adsorption capacity of sulfur after regeneration of activated car- bon using toluene at 0.4 ml/min (with interruption and without reactivation).

Fig. 8. Effectiveness of regeneration with different regenerants.

9. Hernandez-Maldonado, A. J. and Yang, R. T., “Desulfurization of Liquid Fuels by Adsorption Via

-Complexation with Cu(I)-Y and Ag-Y Zeolites,” Ind. Eng. Chem. Res. ,

(1), 123-129(2003).

10. Yang, R. T., Hernandez-Maldonado, A. J. and Yang, F. H., “Des- ulfurization of Transportation Fuels with Zeolites Under Ambi- ent Conditions,” Science ,

(5629), 79-81(2003).

11. Park, Y. T., Principles and Application of Activated Carbon (1992).

12. Martin, R. J. and Ng, W. J., “Chemical Regeneration of Exhausted Activated Carbon-II,” Water Res. ,

(12), 1527-1535(1985).

13. Moreno-Castilla, C., Rivera-Utrilla, J., Joly, J. P., Lopez-Ramon, M. V., Ferro-Garcia, M. A. and Carrasco-Marin, F., “Thermal Regen-

eration of an Activated Carbon Exhausted with Different Substi- tuted Phenol,” Carbon .,

(10), 1417-1423(1995).

14. Salvador, F. and Sanchez Jimenez, C., “A New Method For Regenerating Activated Carbon by Thermal Desorption with Liquid Water Under Subcritical Conditions,” Carbon .,

(4), 511-516(1996).

15. Nakano, Y., Hua, L. Q., Nishijima, W., Shoto, E. and Okada, M.,

“Biodegradation of Trichloroethylene(TCE) Adsorbed on Gran- ular Activated Carbon(GAC),” Water Res .,

(17), 4139-4142(2000).

16. http://www.samchullyac.co.kr