Hydrodemetallization with Phosphorus Compounds over Aluminas in

Chapter 17

Hydrodemetallization with Phosphorus Compounds over

Aluminas

in

a

Trickle-Bed

Reactor

S. G. Kukes, A. W. Aldag, and S. L. Parrott

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on December 13, 2016 | http://pubs.acs.org Publication Date: July 6, 1987 | doi: 10.1021/bk-1987-0344.ch017

Phillips Petroleum Company, Bartlesville, OK 74004

Oil soluble phosphorous compounds were found to be active and selective for vanadium removal i n hydroprocessing resids over either high or low surface area aluminas. The phosphorus compounds preferent i a l l y reacted with the low molecular weight species in the resin fraction of the oil resulting i n the i n t e r s t i t i a l deposition of a vanadium - phosphorus material. No effect was observed on the rate of nickel removal and the HDS a c t i v i t y was actually inhibited by phosphorus.

E a r l i e r we r e p o r t e d e x t e n s i v e s t u d i e s i n the a r e a o f c h e m i c a l d e m e t a l l i z a t i o n o f heavy o i l s and r e s i d s (_1_, 2_). A v a r i e t y o f c h e m i c a l r e a g e n t s , such as s t r o n g i n o r g a n i c a c i d s , c h l o r i n a t i n g compounds, c h e l a t i n g a g e n t s , s t r o n g o x i d a n t s , e t c . , e x h i b i t e d some a c t i v i t y f o r m e t a l s and heteroatom removal. Most of these reagents were o i l s o l u b l e c h e m i c a l s which were heated w i t h o i l i n a b a t c h reactor without c a t a l y s t present. U n f o r t u n a t e l y , the most a c t i v e of these c h e m i c a l s a l s o produced s i d e r e a c t i o n s i n c l u d i n g element i n c o r p o r a t i o n , c r a c k i n g , p o l y m e r i z a t i o n , e t c . , and i n f a c t r e s u l t e d i n a degraded o i l . Phosphorous compounds were unique i n showing h i g h a c t i v i t y f o r vanadium removal w i t h r e l a t i v e l y low l e v e l o f s i d e r e a c t i o n s (_3, 4 ) . I t was found that both o r g a n i c and some i n o r g a n i c phosphorous compounds were e f f e c t i v e f o r vanadium removal from heavy o i l s and r e s i d s at temperatures i n excess o f 370 C (Table I ) . Vanadium removal c a n occur a t lower temperatures a t lower a s p h a l t e n e c o n c e n t r a t i o n ( T a b l e I I ) as t y p i c a l l y seen i n heavy o i l e x t r a c t s .

0097-6156/87/0344-0265$06.00/0 © 1987 American Chemical Society

Filby and Branthaver; Metal Complexes in Fossil Fuels ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

266

METAL COMPLEXES IN FOSSIL FUELS

Table I


E f f e c t o f Phosphorous Compounds on M e t a l Removal From Monagas Pipe L i n e O i l ( B a t c h R e a c t o r )

Run

A d d i t i v e and Concentration

1 2 3 4 5 6 7 8 9 10 11

None 3.0% Pi^S 3.0% P S 3.0 Red Ρ 3.0% ( P h O ) P ( 0 ) H 1.0% (CH 0) P None 1.0% ( C H 0 ) P 0.7% ( P h 0 ) P ( 0 ) H 3.0% P S 1.0% ( P h 0 ) P ( 0 ) H 3

2

5

2

3

3

3

3

2

i+

3

2

% N i Removed

% V Removed

Temp C

64 90 80 59 71 58 10 12 20 18 8

71 99 99 97 99 99 15 84 69 90 65

417 417 417 417 417 417 400 400 400 400 388

Residence Time: 1 hour

Table I I E f f e c t o f Phosphorous Compounds on Vanadium Removal From Heavy O i l E x t r a c t ( B a t c h R e a c t o r ) Additive

None 10% 2% 2% 11% 11% 2% 10% 10% 2%

(CH (CH (CH (CH (CH (CH (CH (CH (CH

3

3

3

3

3

3

3

3

3

0) 0) 0) 0) 0) 0) 0) 0) 0)

Temp C

3

3

3

3

3

3

3

3

3

0 83 50 32 54 45 21 82 79 61

60 60 60 20 60 20 20 60 20 20

360 360 360 360 317 317 317 317 317 317

P0 PO P0 PO PO PO P P P

% Removal Ni V

Residence Time (min)

0 0 2 0 0 0 0 0 0 0

The s o l u b i l i t y o f the phosphorous compounds and p a r t i c u l a r l y the s t e r i c e f f e c t s o f groups a t t a c h e d to the phosphorous a r e v e r y i m p o r t a n t p a r a m e t e r s . The e f f e c t i v e n e s s o f the a d d i t i v e s d e c l i n e d i n the f o l l o w i n g o r d e r : ( RO) P>( ArO) P ( 0) H>( ArO) P>Ar P0>( N H ^ H P 0 3

2

3

3

2

H

where R - a l k y l and Ar - p h e n y l .


17.

Hydrodemetallization with Phosphorus Compounds

KUKES ET AL.

267

I n i t i a l studies also indicated that phosphorous compounds were effective in a t r i c k l e bed reactor packed with alundum (low surface area alumina

750 ppm Ρ Ο

% Vanadium Removed

90 80 ο

:

70

°

0

•

Ο

°

60

Ο

50

Ο ++

+

+

+

• • +

+

° +

+

α

ο

0

++

+

+

40 30

+

20

-

•

+D

10 0]

100

200

300

400

500

600

700

Time on Stream (Hours) Maya 400F+, 2250 pel. 2500 SCF/Bbl, 1 LHSV, 400C

Figure 4. E f f e c t of Ρ on Vanadium Removal (Alumina Packing)



KUKES ET AL.

No Ρ ο

750 ppm Ρ +

% Nickel Removed


30

200

300

400

500

Time on Stream (Hours) Maya 400F+, 2250 pel, 2500 SCF/Bbl, 1 LHSV, 400C Figure 5.

E f f e c t of Ρ on Nickel Removal (Alundum Packing) No Ρ •

Λ Λ

20

750 ppm Ρ +

% Sulfur Removed

200 300 400 Time on Stream (Hours) Maya 400F+. 2250 pel, 2500 SCF/Bbl, 1 LHSV, 400C Figure 6.

500

E f f e c t of Ρ on Sulfur Removal (Alundum Packing)


272


Table IV % Vanadium Removed Alumina

Alundum Hours on stream


0 ppm phosphorus 750 ppm phosphorus

0

30

0 30

8 42

150

0

30

150

10 80

0 30

11 42

50 80

As these d a t a show, the h y d r o d e m e t a l l i z a t i o n (HDM) a c t i v i t y o f the h i g h s u r f a c e area alumina i n c r e a s e s w i t h time much f a s t e r than t h a t o f alundum i n the absence o f phosphorus. However, the HDM a c t i v i t y f o r both systems i s remarkably s i m i l a r and i n c r e a s e s w i t h time i n the presence o f l a r g e phosphorus c o n c e n t r a t i o n s . This i s a p p a r e n t l y due t o the development o f heterogeneous a c t i v i t y on vanadium s p e c i e s which have d e p o s i t e d i n t e r s t i t i a l l y . In b o t h cases severe p l u g g i n g problems o c c u r r e d a f t e r 200 - 300 hundred hours on stream. E l e c t r o n microprobe d a t a c o n f i r m e d t h a t o n l y a s m a l l f r a c t i o n o f the vanadium d e p o s i t e d i n the alumina p e l l e t s . A n a l y s i s o f the i n t e r s t i t i a l d e p o s i t s r e v e a l e d the presence o f h i g h c o n c e n t r a t i o n s o f phosphorus, vanadium, and c a r b o n . Low l e v e l s o f phosphorus i n the feed (20 ppm) d i d not a f f e c t the HDM a c t i v i t i e s o f alumina o r alundum even a f t e r 600 hours on stream and no p r e s s u r e drop was observed a t the end o f the r u n . The e f f e c t o f phosphorus c o n c e n t r a t i o n on the HDM a c t i v i t y o f the h i g h s u r f a c e area alumina a f t e r the heterogeneous r a t e became relatively constant (600 hours on stream, 10 wt.% m e t a l s accumulated) was i n v e s t i g a t e d ( F i g u r e 8 ) . N e i t h e r 135 nor 275 ppm phosphorus showed any e f f e c t on the r a t e o f vanadium r e m o v a l ; however, a f t e r 500 hours o f c o n t i n u o u s phosphorus a d d i t i o n , the r e a c t o r plugged. These r e s u l t s support the proposed mechanism o f a homogeneous r e a c t i o n o f t h e phosphorous compounds w i t h t h e low m o l e c u l a r weight vanadium s p e c i e s . These vanadium s p e c i e s are more r e a c t i v e than the c o r r e s p o n d i n g h i g h m o l e c u l a r weight vanadium s p e c i e s even under heterogeneous r e a c t i o n c o n d i t i o n s (6)· When the r a t e o f the heterogeneous r e a c t i o n i s h i g h and most o f t h e low molecular weight vanadium compounds a r e removed, phosphorus a d d i t i o n does not a f f e c t the r a t e o f vanadium removal. However, the p h o s p h o r y l a t i o n o f a s p h a l t e n e s was s t i l l observed a t these c o n d i t i o n s which r e s u l t e d i n a s p h a l t e n e p r e c i p i t a t i o n , and an e x c e s s i v e r e a c t o r p r e s s u r e drop. LC-ICP a n a l y s e s o f p r e c i p i t a t e showed presence o f phosphorous i n a h i g h m o l e c u l a r weight s p e c i e s (more than 5000 by p o l y s t y r e n e c a l i b r a t i o n ) . Conclusions Phosphorus promotes the r a t e o f vanadium removal d u r i n g h y d r o p r o c e s s i n g over h i g h and low s u r f a c e area a l u m i n a s . T h i s r e a c t i o n o c c u r s homogeneously and r e s u l t s i n the i n t e r s t i t i a l d e p o s i t i o n o f


17.

273


KUKES ET AL.

750 ppm Ρ +

NoP •


» % Vanadium Removed

400 200 300 Time on Stream (Hours) Maya 400F+, 2250 psi. 2500 SCF/Bbl, 1 LHSV. 400C

100

Figure 7.

E f f e c t of Ρ on Vanadium Removal (Alundum Packing) NoP •

100,

500

135 ppm Ρ +

275 ppm Ρ Ο

% Vanadium Removed

908070 6050-

•

•

4030 c

2010 ^ D D

D

° °

200

mLm

600 800 1000 Time on Stream (Hours) Blended feed (see text), 2250 psi, 2500 SCF/Bbl. 1 LHSV, 400C

Figure 8.

400

1200

E f f e c t of Ρ on Vanadium Removal (Alumina Packing)


274


a vanadium - phosphorous species which results in heterogeneous activity. Phosphorus preferentially removes low molecular weight vanadium species in the resin fraction. Phosphorus was found to have no effect on the rate of nickel removal and actually inhibits the HDS activity.


Acknowledgments The authors would like to acknowledge the assistance of M. D. Phillips for electron microprobe analysis. Literature Cited (1)

Kukes, S. G. 34th Can. Chem. Eng. Conf., Quebec, 1984, p. 146.

(2)

Kukes, S. G.; Aldag, A. W. Preprints, Div. of Petrol. Chem., ACS, 1985, 30 (1), 119.

(3)

Kukes, S. G. U. S. patent 4,529,503, 1985.

(4)

Kukes, S. G. et a l . U. S. Patents Nos. 4,419,225, 4,421,638, 1983; 4,522,702, 1985.

(5)

Hausler, D. W.; Carlson, R. S. Preprints, Div. of Petrol. Chem., ACS, 1985, 30 (1), 28.

(6)

Bridge, A. G.; Green, D. C. "Diffusional Considerations in Residium Hydrodemetallization", Chem Tech '80, Symposium 5.

RECEIVED October 30, 1986


1983;

Hydrodemetallization with Phosphorus Compounds over Aluminas in

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