Fluid Catalytic Cracking II - American Chemical Society

Chapter 11

Fluid Cracking Catalyst Metals Passivation Development and Application Robert W. Bohmer, Dwight L. McKay, and Kelly G. Knopp

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Phillips Petroleum Company, Bartleville, OK 74004

Passivation of metals on equilibrium catalytic cracking catalyst is widely and successfully applied operating practice within the refining industry. The technology is effective over a broad range of catalysts metals concentrations, oil feed compositions, operating conditions and types of catalytic cracking units. Practice of antimony metals passivation technology increases FCC unit oil feed capacity, significantly decreases the yields of hydrogen and coke and increases the yield of gasoline. Lower quality oil feedstocks can be cracked. Options for maximizing metals passivation benefits are illustrated with examples from refinery units. The u s e o f m e t a l s p a s s i v a t i o n t o reduce t h e u n d e s i r e d e f f e c t s o f n i c k e l and vanadium on f l u i d c a t a l y t i c c r a c k i n g c a t a l y s t s has become an e s t a b l i s h e d operating practice within the refining industry. S e v e r a l o p e r a t i n g t r e n d s w i t h i n t h e i n d u s t r y , such a s increased resid cracking and h i g h e r regenerator temperature operation, are related t o the benefits provided by metals p a s s i v a t i o n ( 1 ) . Over t h e 14 y e a r s s i n c e i t was f i r s t c o m m e r c i a l l y i n t r o d u c e d , m e t a l s p a s s i v a t i o n has p l a y e d a key r o l e i n a l l o w i n g r e f i n e r s t o maximize p r o f i t s w h i l e c r a c k i n g r e s i d . Phillips Petroleum Company d i s c o v e r e d and d e v e l o p e d t h e antimony m e t a l s p a s s i v a t i o n p r o c e s s i n the early 1970's, and s u c c e s s f u l l y a p p l i e d t h e p r o c e s s a t i t s B o r g e r , Texas heavy o i l cracker (HOC) i n 1976 (2) . For c a t a l y t i c cracking units with contaminant metals problems, metals p a s s i v a t i o n with antimony significantly d e c r e a s e s t h e y i e l d s o f hydrogen and coke, and increases the y i e l d of gasoline. For a unit operating against a l i m i t e d g a s compressor o r r e g e n e r a t o r a i r blower, decreases i n yields o f hydrogen and coke a l l o w f o r any o f t h e f o l l o w i n g

0097-6156/91/0452-0183$06.00/0 © 1991 American Chemical Society

Occelli; Fluid Catalytic Cracking II ACS Symposium Series; American Chemical Society: Washington, DC, 1991.


184

FLUID CATALYTIC CRACKING II: CONCEPTS IN CATALYST DESIGN

benefits: increased throughput, increased conversion, or s u b s t i t u t i o n o f low v a l u e r e s i d f o r some gas o i l f e e d . With these performance benefits, metals passivation is widely used and accepted. Optimizing passivation performance is an important c o n s i d e r a t i o n as r e f i n e r s maximize t h r o u g h p u t t o c a t a l y t i c c r a c k i n g u n i t s and c h a r g e g r e a t e r q u a n t i t i e s o f r e s i d . M e t a l s p a s s i v a t i o n s h o u l d now be i n t e g r a t e d i n t o o v e r a l l r e f i n i n g o p t i m i z a t i o n models. Models u s e d t o p r e d i c t c a t a l y t i c c r a c k i n g y i e l d s b a s e d on f e e d s t o c k p r o p e r t i e s and o p e r a t i o n a l p a r a m e t e r s can be used e f f e c t i v e l y t o e v a l u a t e t h e r e a l b e n e f i t s o f a d d i t i v e s and methods f o r e n h a n c i n g the performance o f metals p a s s i v a t i o n . Models a r e b e i n g u s e d as w e l l as advanced l a b o r a t o r y methods t o d e v e l o p t e c h n i q u e s for i m p r o v i n g t h e commercial p e r f o r m a n c e o f m e t a l s p a s s i v a t i o n . S p e c i f i c commercial p e r f o r m a n c e b e n e f i t s o b t a i n e d w i t h the antimony m e t a l s p a s s i v a t i o n p r o c e s s and methods u s e d f o r e v a l u a t i n g p o t e n t i a l b e n e f i t s are discussed. Options f o r maximizing b e n e f i t s are a l s o presented. E a r l y Development and

Initial

Application

R e s e a r c h and Development. R e s e a r c h s t u d i e s were c a r r i e d o u t i n l a b o r a t o r y u n i t s d e s i g n e d t o meet p a r t i c u l a r needs i n t h e a r e a o f heavy o i l c r a c k i n g and c o n t a m i n a n t m e t a l s on c r a c k i n g c a t a l y s t s . These r e a c t o r systems were d e s c r i b e d i n e a r l y p a p e r s ( 3 - 5 ) . Metals p a s s i v a t i o n a g e n t s were e v a l u a t e d i n s c r e e n i n g t e s t s . Commercial e q u i l i b r i u m c a t a l y s t s and c a t a l y s t s c o n t a m i n a t e d w i t h n i c k e l and vanadium i n t h e l a b o r a t o r y were used t o c r a c k gas o i l s o r r e s i d s . The p a s s i v a t i o n a g e n t s were p r i m a r i l y organo m e t a l compounds o r o x i d e s o f the elements s t u d i e d . The effectiveness of several e l e m e n t s f o r t h e r e d u c t i o n o f t h e y i e l d o f hydrogen i s shown i n Table I. Antimony c o n t a i n i n g compounds were t h e most e f f e c t i v e metals p a s s i v a t i o n agents. Although not d i s c u s s e d i n t h i s paper, m e t a l s p a s s i v a t i o n s t u d i e s have been made u s i n g c o m b i n a t i o n s o f elements. E q u i l i b r i u m c a t a l y s t from a heavy o i l c a t a l y t i c c r a c k e r was u s e d t o c r a c k 20 API g r a v i t y West Texas Long R e s i d . The c a t a l y s t c o n t a i n e d 3100 ppm n i c k e l and 4500 ppm vanadium; t h e concentration o f antimony was v a r i e d . E v a l u a t i o n r e s u l t s f o r 75 volume p e r c e n t conversion are illustrated i n Figure 1. The d i s t r i b u t i o n of c r a c k e d p r o d u c t s improved as antimony on t h e c a t a l y s t i n c r e a s e d . A d d i t i o n o f 0.25 w e i g h t p e r c e n t antimony r e d u c e d t h e y i e l d of h y d r o g e n about 50 p e r c e n t , r e d u c e d t h e y i e l d o f coke about 20 p e r c e n t , and t h e y i e l d o f g a s o l i n e i n c r e a s e d 10 p e r c e n t . Larger scale tests i n a transfer l i n e c a t a l y t i c cracking p i l o t plant c o n f i r m e d t h e o u t s t a n d i n g r e s p o n s e when t h e m e t a l s on t h e c a t a l y s t were p a s s i v a t e d w i t h a compound c o n t a i n i n g antimony. A p l a n aimed a t commercial a p p l i c a t i o n o f m e t a l s p a s s i v a t i o n t e c h n o l o g y was implemented. Toxicology, i n d u s t r i a l hygiene, and environmental questions r e l a t i v e to the use of antimony or p a s s i v a t i o n o f m e t a l s on c a t a l y s t i n FCC u n i t s were a d d r e s s e d . P r o c e d u r e s f o r i n j e c t i o n o f antimony compounds i n t o FCC u n i t s were


11.

BOHMERETAL.

185

FCC Metals Passivation


Table I. Passivation of Metals on FCC Catalysts Ranking of Elements f o r Reduction of Hydrogen

Hydrogen Reduction Relative To Antimony Passivation

Element Sb TI Bi P Sn In Ca Te Ba Oe Al Si

0

0.1

1.0 .8 .7 .6 .5 .4 .4

.3 .3 .2 .2 .2

0.2

0.3

0.4

0.5

ANTIMONY ON CATALYST, WT.% F i g u r e 1. 75 V o l % c o n v e r s i o n i n p i l o t p l a n t o p e r a t i o n . (Reproduced w i t h p e r m i s s i o n from r e f . 2. C o p y r i g h t 1977 G u l f P u b l i s h i n g Co.)


186



d e v e l o p e d , and extended p i l o t p l a n t t e s t s d e m o n s t r a t e d o p e r a b i l i t y . Assessment o f a l l information indicated that, when applied p r o p e r l y , m e t a l s p a s s i v a t i o n w i t h antimony c o u l d be c a r r i e d o u t s a f e l y i n r e f i n e r y FCC u n i t s . The p o t e n t i a l economic b e n e f i t s were l a r g e , so a commercial t e s t i n a heavy o i l c a t a l y t i c c r a c k e r was undertaken. A p r o j e c t team p r e p a r e d t h e commercial t e s t p l a n , participated i n conduction o f t e s t s , and e v a l u a t e d the t e s t information. Commercial A p p l i c a t i o n . The commercial t e s t showed outstanding benefits. Comparison o f i n f o r m a t i o n from t h e heavy o i l c r a c k e r f o r s e v e r a l months b e f o r e and a f t e r p a s s i v a t i o n o f t h e m e t a l s on t h e c a t a l y s t d e m o n s t r a t e d l o n g term, t r o u b l e - f r e e a p p l i c a t i o n o f m e t a l s p a s s i v a t i o n technology. P a s s i v a t i o n o f t h e m e t a l s on t h e c a t a l y s t with antimony improved catalyst selectivity to gasoline, and reduced p r o d u c t i o n o f gas and coke. Many d e t a i l s o f t h e t e s t program and t h e d e m o n s t r a t e d b e n e f i t s a c h i e v e d have been r e p o r t e d (2, 6-8) . Commercial b e n e f i t s o f m e t a l s p a s s i v a t i o n were s i m i l a r to the benefits predicted from research and development information. E f f e c t s on Environment, I n d u s t r i a l Hygiene, and M e t a l l u r g y . The e f f e c t s o f m e t a l s p a s s i v a t i o n w i t h antimony on t h e environment, industrial hygiene and m e t a l l u r g y were studied by Phillips P e t r o l e u m Company and by i n d e p e n d e n t t e s t i n g l a b o r a t o r i e s . The t o x i c o l o g i c a l and e n v i r o n m e n t a l i n f o r m a t i o n r e l a t e d t o antimony m e t a l s p a s s i v a t i o n has been s t u d i e d by s p e c i a l i s t s representing over seventy r e f i n e r i e s . The g u i d e l i n e s f o r safe p r a c t i c e o f metals passivation with antimony have been demonstrated i n commercial e x p e r i e n c e . (6, 9 ) . Mechanism. The i n t e r a c t i o n o f antimony w i t h supported n i c k e l p a r t i c l e s was s t u d i e d w i t h X-ray d i f f r a c t i o n (XRD) ( 1 0 ) . These s t u d i e s s u g g e s t e d t h a t a h i g h l e v e l o f antimony i s p r e s e n t on t h e s u r f a c e o f Ni-Sb a l l o y s . F u r t h e r s t u d i e s o f t h e Ni-Sb a l l o y , u s i n g X-ray photoelectron spectroscopy (XPS) and Auger electron s p e c t r o s c o p y (AES), c o n f i r m e d t h e p r e s e n c e o f an antimony e n r i c h e d surface (11) • The s u r f a c e e n r i c h m e n t o f antimony on t h e N i - S b a l l o y would be e x p e c t e d t o s i g n i f i c a n t l y alter the c a t a l y t i c a c t i v i t y o f n i c k e l , as i n d e e d o c c u r s when antimony i s added t o n i c k e l laden cracking c a t a l y s t s . E f f e c t o f Antimony on CO Combustion Promoters and S0 Catalysts. Partial passivation o f CO combustion c a t a l y s t may o c c u r when antimony-containing metals p a s s i v a t i o n agents a r e i n j e c t e d i n t o c a t a l y t i c cracking units. A d e c r e a s e i n CO combustion may be most n o t i c e a b l e d u r i n g t h e f r o n t end l o a d i n g p e r i o d o f h i g h antimony injection (12)• T e c h n o l o g y has been d e v e l o p e d t o overcome t h e d e c r e a s e d a c t i v i t y o f t h e combustion c a t a l y s t s . Passivation of metals on c a t a l y s t w i t h antimony i s routinely practiced i n c a t a l y t i c c r a c k i n g u n i t s u s i n g CO combustion c a t a l y s t f o r complete X


11.

or


BOIIMER ET A L .

partial

not

affect

Industry

Passivation of of

performance

of

passivation

FCC u n i t

9).

In

proven

concentrations. revealed 45%

as

to

chemical cell

sizes,

Case

Studies.

the

A s shown i n

with

benefits

antimony

of

The

at

600

vanadium; hydrogen.

improved

the coke

unit in

and

with

value

lower

improvements Table

II,

throughput.

The

vanadium, and

gas

and

control.

FCCU unit

it

affected

the

When

a

was high

state

antimony

SCF/BFF,

and

was the

on

as

the

decrease

the the

17°F

decreased the

the

gas

ratio

31%, 1.5%.

wet

gas

oil

feed

of

benefits

both

production of

hydrogen

these

the

hydrogen of

the

metals maximize

and

its was

in

of

to

ppm n i c k e l

and

unit

hydrogen the

evidenced

c o m p r e s s o r was

effective,

Overall,

of

injected, load

decreased

and

on

significant

operating

490

maintain

operation

production load

gas

nickel

1200

air 92

the

ppm

blower SCF

gas

per

to

the

compressor governor in

the

heat

fuel

gas

control

of

on

also other

units.

blower was

amount

to

the

against

Hydrogen

concentration

steady

shows

contained

this

difficult

wet

increased

cost

refinery

operating

limits. with

units

dramatically

unloaded of

FCC

ppm

a

gasoline

to

utilized Specific

its

900

antimony

2.5%

benefit

example, in

was

against

production

of

is

30.

FCC c a t a l y s t

the

The

processing 58

second

a

FCCU f e e d ;

compressor,

The than

antimony

below.

catalyzed of

of

and unit

transfer

that

refinery

contained

production

substitution

resid.

two

operating

yield

FCC

lower

6000 ppm.

discussed

Hydrogen

and

at

passivation

for

metals

of

technology

hydrogen

than

FCC c a t a l y s t

5%,

greater

compressor

of

FCC u n i t

ppm

(9).

less

passivation

hydrogen

the at

metals

Introduction

enabled

was

passivation

2,

a

from

6000

generations

zeolite of

Figure

performance.

compressor,

improved

demonstrated

size

these

decreased

decrease

have

cell

The

of

yield

barrel

is

ppm

production

The

example

the

commercial

than

equilibrate

6 0 0 0 ppm 4 N i + V a r e

constraint.

25

less

latest

unit

metals

than

been

increases,

over

a

metals

reduction

minimization tests

has

catalyst

from

USY

catalysts

4Ni+V c o n c e n t r a t i o n s

less

first

of

in

zeolite

effectively

compressor

Octane

of

in

catalysts

2.

the on

FCC

level

study

Figure

based

Commercial

affect

operating

does

(13).

utilized

of

of

metals

compliments

catalysts

resulting

not

antimony

passivation

increased

(4Ni+V),

been

range

hydrogen

levels

9 0 0 0 ppm

(15).

does

with

catalysts

range

metals

A

average

dealumination.

reactions

and

the

has

wide

broad

catalyst

metals

octane

a

improves.

passivation

catalysts:

with

a

the

that

the

over

Metals


As

35%

(4Ni+V)

metals

reduction

x

antimony

over

performance

trials to

SO

technology

designs,

addition,

commercially passivation

the

Acceptance

metals

variety (14,

CO c o m b u s t i o n . the

Wide

Antimony

187

this

operated

in

eased,

by

a

the to

was

decreased

regenerator

stabilized closer

production

compressor

refinery

steady

load

on

temperature.

compressor the

decreased eased.

state,

speed

the

air

As

the

controller

steam and

to

Coke

balance.

this


helped

188

FLUID CATALYTIC CRACKING H: CONCEPTS IN CATALYST DESIGN

1 H2, SCF/BFF

| 1


140

1

r ^ ^ j

NO MP

H2, SCF/BFF

WITH MP

1

< 6000

6000 - 9000

>90O0

4NI • y PPM Figure

2.

Hydrogen

make w i t h m e t a l s p a s s i v a t i o n .

Table I I . Antimony Metals Passivation E f f e c t s on Charge Rate

Before Charge, B/D Feed API Gravity Feed Carbon Residue, Wt% Regenerator Bed, F Metals on Catalyst, PPM Nickel Vanadium Hydrogen, $CF/BFF C & Lighter, LB/BFF C & C O l e f i n s , LV%FF I C 4 , LV%FF Oasoline, LV%FF LCO, LV%FF Coke, LB/BFF 2

3

4

After Passivation

30,774 28.2 0.38 1302

32,943 27.5 0.63 1285

489 1203

611 1585

92 14.3 12.8 3.1 56.2 24.3 19.7

58 14.7 13.2 2.9 54.3* 26.5 18.3

*Separations conditions were changed t o increase the y i e l d of LCO during the l a t e f a l l and winter months.


11.

smooth load

out

the

on the

33,000 feed

to

The

the

on

of

antimony

Metals value

Texas

HOC

crack

decreased

HOC f e e d

blended the

hydrogen

the

with

to

maximize

into

10%

500

to

did

the

after

the

a

change

in

the

the

charge

of

Phillips

and

rpm.

percent

of

Texas

its

crude

it

had

been

crude

Metals

prior

to from

refinery

HOC.

the

difficult

increased significantly,

than

the

enabled

Oriente

Borger,

Sweeny,

decreased

This

and p r o c e s s a more

Phillips

dry

Other

types

injection FCCU

production

and

Thermofor

operating the In

in

but

the

yield

to

metals

a

TCCU as

and

a

application,

evidenced

decreased

by

70 ° F

H2/CH4

the

56%

of of

liquid

ratio

been A

volume

in

hydrogen

liquid

products

antimony

decrease

mole

has

(TCCU).

60

decrease

Yields

of

distillate

Units

than

injection a

Yield

maximize

Cracking

was

through

0.7.

passivation

conversions less observed

refiner 8°F

passivation.

to

C4

increasing

Another

metals

passivation.

by

increased

operate

reactor

increased

temperature

metals

where

increase

17.2%

RON c l e a r

Catalytic

feed

to

refinery

antimony.

that

FCCU a t

metals

coke,

temperature,

a oil

with

increased.

units

One

outlet

with

operations

FCC

of

of

and g a s o l i n e

of

refiners feed)

riser

production

are

production

allows

conversion.

alkylation

the

gas

also

FCCU

the

increased,

of

to

BPD

quality

as

less

primarily

passivation at

less

successful

yield

poorer

was

production

about

HOC c a t a l y s t

still

increase

percent

hydrogen

metals

(valuable

conversion

refiner

due

a

increased

gasoline

antimony

Fifteen

into

increase

production

gasoline

feed

of

refiners

of

speed

passivation

to

decreased

charge

decreased

31,000

(6).

Metals

to

unit

use of

was

passivation

able

allows

(JL4) .

and on t h e

severity

unit,

increase throughput

was

with

to

the

the

the

products.

compressor

to

in

yield

With

i n c r e a s e d from

able

The

Injection

feedstock

slate

to

liquid

feeds.

gas

Ecuador

of

of

also

metals

passivation

lower

refinery

the

189

operations.

c h a r g e was

was

catalyst.

fractionation

process

refinery

refinery

unit;

the

addition

overall

compressor, the

BPD.

metals



BOHMER ET AL.

decreased

in

regeneration

in

the

off

gas

of

the

13.7%. Catalyst

V/Ni

literature antimony

on

antimony coking

on

Ratio

Effects

antimony

nickel.

Little

and vanadium. activity

interaction

to

came

of

by

from

vanadium

antimony

the

on

percentage

hydrogen

commercial

units

data is

indicate not

a

antimony

metals

in

and with

FCC c a t a l y s t

the

significant

ratio

of

the

shown t o

studies of

antimony vanadium

vanadium t o

controlling

factor

effect

of

interaction

of

stabilize

the

vanadium

direct will

Figure metals

3

the

on

and of

effect

influence shows

passivation

nickel

nickel in

this

Stabilization

to

to

nickel

for

diffraction,

(16).

nickel.

the

Evidence

X-ray

addition

presence

antimony

vs.

that

the

about

experiments,

that

Much

focuses on

deactivation.

reduction

decrease

Generation.

mentioned

steam

suggests

of

is

coking

vanadium,

interaction

Hydrogen

passivation

Vanadium has been

mild

temperature-programmed nickel

on

metals

ratios. the

the in The

catalyst

performance

passivation.


of

190

FLUID CATALYTIC CRACKING II: CONCEPTS IN CATALYST DESIGN A

study

showed

of

the

antimony

dehydrogenation in

the

catalyst

was

then

oil.

yield

percent

Technology Based a

such

production, economic

plant

metals

the

metals

the

the

In

of

Maintenance benefits correlated (Figure

the

38%

of

with

been

of

antimony

additives al.

in

additive, better

curve.

generally

a

shape

type

the

a

pilot

of

of

the

plant

decreases

Close

will

in

39%

decreases In

in

case

in

4

hydrogen of

yields

of

monitoring

of

assure that

commercial

tests

to

a in

additive

passivation as o r g a n i c

performance

performance

(14). benefits

The than

curve

1).

The beyond

to

allow

yields

selected

of

will

Antimony

inorganic. an

trisdipropyldithiophospate, plant

the

program.

or of

been

operations

point

desired

increases

antimony

The

has

production

(Figure is

maximum

program.

catalyst

hydrogen

"cushion" major

categorized

passivation

and

and

Estimations

Changes

corresponds

metals

pilot

41%

respectively.

passivation

plant A

passivation

fluidized

predicted plant,

36%,

respectively.

production

system without

of

benefits decrease

plant pilot

were

equilibrium

the

antimony in

pilot

and

28%

metals the

pilot

The

of

in

benefits

Benefits

concentration

performance are

a

on

magnitude

the

catalyst

of

compared

pentoxide

from

observed of

Concentration.

the

Antimony. the

potential

estimate.

on the

ratio

benefits

acceptable.

to

Antimony

confirmed

coke.

affect

plant

hydrogen

determine

commercial,

36%

Passivation

hydrogen

hydrogen and Type

FCCU

magnitude

production

were

non-linear

breakpoint

and

the

commercial

and

coke

Proper

in

gave

2,

plant,

34%,

The

commercial

utilizes

hydrogen production

predicted

fluctuations

et.

hydrogen

derived

5).

recommended the

42%,

in

3,

the

and

antimony-to-nickel

has

was

concentration

are

and

case

Metals

of

antimony

to

of

the

commercial

In case

to

plant

the

p r o d u c t s were d i f f i c u l t

Optimization

magnitude

pilot

yield

averaged

evaluations,

potential

severity

to gas

Use

procedure

and

were

in

catalyst

passivation

46%

changes

compound cracking

catalyst.

Commercial

hydrogen were

production

the

1,

decreases of

to

contaminated

by

concentrations,

close

pilot

35%.

commercial,

other

the

is

passivation

yield

evaluated

estimation

reactor

that

case

was

with

(17).

shows

respectively. in

and

its

contaminated this

passivated

reaction

decreases

containing

estimating

catalyst

operations

predicted

for

as

In

of

and commercial metals

type,

was

unpassivated

Transferred

The

4

were

for

the

process.

in

decrease

portion antimony

the

Figure observed

for

developed

feed

predicted.

A an

hydrogen than

and

catalyst

catalysts

Effectively

benefits

commercial

with

of

was

of

with

The

less

on p i l o t

benefits


is

procedure

data

laboratory.

denydrogenation

vanadium

Cracking

treated

vanadium.

The

fifteen

catalyzed with

activity.

vanadium passivate

vanadium

interacts

Gall,

organo-antimony with

antimony

organo-antimony the

inorganic



BOHMER ET AL.

80


z 2

iu$

60

g

40

20 % H2 DECREASE IN COMMERCIAL UNITS 0.0

Figure

3.

1 1.5 2 2.5 3 FCC CATALYST V/NI RATIO

C a t a l y s t V / N i e f f e c t s on h y d r o g e n

PILOT PLANT

CASE 1 F i g u r e 4. benefits.

3.5

PREDICTED

CASE 2

Comparison o f p i l o t

generation.

COMMERCIAL

CASE 3

CASE 4

p l a n t , p r e d i c t e d , and c o m m e r c i a l


192


compound.

It

down o n t h e Miller,

has been

catalyst

et.

pentoxide

al.

and

antimony

improvement

Phillips

uses

applications Commercial Metals and

Metals

Passivation


Commercialized plus

the

reactor

also

in

compared

with

catalyst

to

of

antimony

of

Future

assure

remain

an

continues dichotomy

at

benefits (27). would

high

and

result

in

been

in

With

in

been

Another are

reduces

the used

metals

proprietary, the

of

The

be

2.4

of

catalyst

up

the The

activity

feedstock

to

percent,

of when

improved.

comparable

increased

yield

gasoline

resistance

also

maintain

gasoline of

three

and

The

the

in

the

the

unit

the

the

and

percent, yield

of

catalysts Work

passivation

process.

The

levels

of

between

has

between

must of

antimony

documented

on the

optimum the

increasing

been

antimony

efficiency new

increased

industry.

operations of

and

cracking

refining

economic

dynamics

laydown

tests

on

efficiency

retention of

octane

metals

concentration

shifting

in

changes

diluents has

plus Other

percent.

to

the

antimony

observed

23.).

catalyst

as

yield

may

helped

laydown

improve

and

Improvements

or

that

tin

the

tin

technology

concentration.

mechanisms

(22,

(26).

cases.

higher

antimony

the

and

antimony,

phosphorous

systems.

alone.

passivation

decreasing to

as

Development

for

that

plus

Antimony

and

vanadium

improvements

Methods

antimony

and

elements

such

changes

these

antimony

weight

of

ingredients

i n c r e a s e d up t o

important

on

with

development,

commercialized.

bismuth

(25).

conversion

0.5

pressures

throughput will

the

gasoline

Application

Economic

traps

and

the

costs.

commercial

and

been

hydrocarbons

increases

commercial

d e c r e a s e d up t o

and

process

light

by

research

antimony

antimony

of

that

its

a

the

additive

in

addition

commercially

and

use

conditions,

yield

coke

have

the

several

process the

coke,

for

optimization.

catalysts,

.14),

containing of

showed

concluded lower

have

(19-21) ,

or

deactivation

combination for

(6,

conjunction

introduced

and

active

FCC

include

combination

hydrogen

of

to

vanadium

to

economic

systems

tin

steam

additive,

been

The

of

and

successfully passivation has

systems

use

(£4)

tin,

antimony

data

efficiency

additives

include

phosphorus

of

The

lay

compounds.

Systems

area

elements

plus

commercialized as

an

systems of

antimony

such

is

(18).

authors due

cost/benefit

passivation

combinations

the

organo-antimony

passivation

antimony

but

additives

inorganic

comparisons

lay-down

preferred

based on a

several

tin,

was

the

additive

in

compound,

pentoxide

than

commercial

organo-antimony

organo-antimony

organo-antimony

effectively

presented

an

significant

suggested that

more

to

catalyst a

higher

antimony be 35

laydown

considered. to

40

containing

percent additive

systems. Studies utilized

to

mechanisms.

which develop

apply a

Transport

surface

better

science

understanding

experiments

in

the

technology of lab

metals have

are

being

passivation shown


that

11.

during

steam-aging

intraparticle

migrating

V

can

be

sepiolite

in

the

form

V

passivation

V-catalyst

and

by

Agreement

with

lab

partially

imaging

free

to

particle.

structure

data

suggest

condition catalyst

by

trends

of

include

plant

and

tests

10,000

ppm

yields

of

to

and

nickel of

V

V+5

play

a

shift

the

as

In

(33) . a

be

within

state

and

Their

sufficient

factors the

FCC

found to

well

not

in

desired

passivation reactor

temperatures

higher

such

as

deactivation

of

reactor

temperature

revealed and

90%,

that,

coke,

increased 10%.

customize

A

the

in

a the

be

with

used

propylene

to

yield

slate

for

Pilot

containing in

reduced

20%,

passivation

product

improve

reductions

agent

and

the total

techniques

a

to

quality

to

catalyst

addition

of

1000°F)

lower

temperatures.

passivation

variety

total

can

the

Industry

than

and

reactor

slate,

change.

(greater

technology high

yield

also

throughput,

1050°F

hydrogen

FCC

program

at

increased

is

role

quality

yield

as

Other

Raman

(SIMS).

oxidation

of

during

laser

FCC c a t a l y s t

deactivation.

as

equilibrium

v a n a d i u m was

in

to

formed

spectrometry

the

that

such

mechanism

XPS a n d

particle

and

trap

The

studied

investigated

passivation

metals

XRD,

(28)

product

at

to

by

mass

particle

occurs

metal

compound

(32)

Occelli

al.

olefins,

butylenes used

the

ion

V

a

vanadate.

studied

mobility

higher

butadiene be

of

of

by

(28).

Metals

end

stable

Kugler

oxidation

metals

C2-C4

light

from

demands

a

feedstocks. the

of

et.

vanadium

market

maximize

and

catalyst

location

As

been

Lea

vanadium

that

vanadium

economics

has

move

sorbed

nature

results

of

for

heat

secondary

Woolery,

local

a

the

(28-31).

catalysts

a

of

193

transfer

irreversibly

interaction

spectroscopy



BOHMERETAL.

particular

may unit

configuration. The M o d e l i n g Models

have

operating aided

in

Miller

of

Metals

been

developed

parameters application the the

passivation

In feed, not

need

for

instances

observed as

expected.

yield

coke

hydrogen allowing

yields would

a

actual

had

one with

with there

passivation

yields

(^34) .

based

These

passivation and

models Teran

and m e t a l s

on

have

benefits.

mathematical

passivation,

the

to (27)

tracking

to

metals been

an

removed to

These were

the

passivation,

benefits

metals were

antimony,

FCCU

to

the when

compressor

what

had III

yields

and

influenced the

there

yields been

compares projected

This the

the The

conversion

project

passivation.

greater

gas

changes

Table

but

result.

FCCU

feedstock,

second column of

no

hydrogen

of

expected

to

quality

application,

increase

used

lower

sometimes

operational

in

of

are

addition not

change

The

charge

passivation

commercial

refinery feed.

with

the

5.6%,

Models

with

antimony.

yields

model

metals

of

In 34%

the

quality

been

metals use of

maximize

changes

production

significantly. have

injection the

lower

refiners

increased

restraint,

cracker

FCCU h y d r o g e n m o d e l i n g

where

decreased

of

the

vanadium

selectivity

decreased

charge

of

cat

properties

benefits.

production of

predict

feedstock reported

benefits

reported

Effects

and e v a l u a t i o n (35)

optimize

to

and

and P a w l o s k i

calculate

Passivation

shows

lower


no the by that

quality

194


1800 PPM < Nl< 2000 PPM + 100

•SO-


IL CO CM X

BASE

-50

SB/NI F i g u r e 5. C o m m e r c i a l r e s p o n s e o f h y d r o g e n p r o d u c t i o n t i o n s i n c a t a l y s t Sb/Ni r a t i o .

to varia-

Table I I I . The E f f e c t s of Feedstock Quality on Passivation

With Metals Passivation

Percent Change With Metals Passivation Considering Feed Quality Changes

+1.3 +17.2 +5.6 -13.6 -33.6

+3.8 +9.6 -8.9 +7.1 -33.6

6.4

17.9

Percent Change

Gasoline C LPG Gas Coke LCO H 4

2

Benefits/Costs


11. BOHMERETAL. feed

was

considered.

passivation operational

was

trial,

models

and t i n

additional gasoline

of

the

percent

Incorporation expected

only

ratio

when

with

o f metals and

of

metals

accounting

for

the

in

passivation overall extend

data

technology refinery

evaluated in

with

to

4.4

yield

of

0.3

weight

percent.

into

plant

FCC u n i t

economics

t h e documented

of

r e c y c l e and

improved

increase

increased

system i n the

i n the yield

slurry

system

of

commercial

increase

increase

percent

only

one

antimony-tin

properties,

included

2.6

the benefits

In

2.2 percent

antimony-tin

coke

into

significantly

with

feed

were

the

of

alone.

a 0.2 percent

conversion,

models to

achieved

i n fresh

and the y i e l d

operation

antimony

conversion,

conditions

benefits

higher

gasoline,


with

processing

model,

cost

6.4,

to a i d i n evaluating

with

higher

When v a r i a t i o n s

other

used

benefits

yield

to

vs.

changes. were

2.9 percent

benefit

17.9

compared

included coke.

The

better,

and feed

Similar antimony

195


models

benefits

of

is

metals

passivation. Summary Passivation an

o f metals

established

The

technology

contaminant types

of

Commercial

benefits

over

a

hydrogen

quality

and coke o i l

are

range

Practice FCC u n i t

with

catalyst

refining

broad

of

of

feed

can

with

for

metals

capacity, the

be

practice

o f models

illustrated

catalyst

antimony

and increases

the

is

industry.

c o n d i t i o n s and

o i l

feedstocks

and the a p p l i c a t i o n

benefits

cracking

the

process operating

units.

obtained

technology

catalytic within

increases

of

Lower

passivation

refinery

cracking

the yields

passivation metals

effective

technology

gasoline.

practice

concentrations,

catalytic

decreases of

is

metals

passivation

on equilibrium

operating

yield

cracked.

of

metals

maximizing

examples

from

units.

Literature Cited

1. 2. 3. 4. 5. 6.

7. 8.

Stokes, O. M., Davison Catalagram No. 77 (1988). Dale, O. H., and McKay, D. L . , Hydrocarbon Processing, 56 (9), 97-102 (1977). McKay, D. L., and Bertus, B. J., PREPRINTS, Div. of Petrol. Chem., ACS, 24 (2), 645 (1979). McKay, D. L . , Schaffer, A. M., and Bertus, B. J., Southwest Catalysis Society Symposium, Fall 1980 Meeting, Houston, TX. Lee, F. M., Ind. Eng. Chem. Res., 28, 920-925 (1989). Dale, G. H., Rogers, C. L . , Nielsen, R. H., McKay, D. L., and Davis, E. D., API 43rd Midyear Meeting, Toronto, Canada, May 8-11, 1978, Proceedings-Refining Department, 57, 432-438 (1978). Rush, J . B., Chemical Engineering Progress, 77 (12), 29-32 (1981). Rush, J . B., AM-81-43, NPRA Annual Meeting, March 29-31, 1981, San Antonio, TX.


196 9. 10. 11. 12.

13. 14.


15. 16. 17.

18. 19.

20. 21. 22.

23. 24.

25. 26. 27. 28.

29.

FLUID CATALYTIC CRACKING II: CONCEPTS IN CATALYST DESIGN Bohmer, R. W., McKay, D. L., and Knopp, K. G., AM-89-51, NPRA Annual Meeting, March 19-21, 1989, San Francisco, CA. D r e i l i n g , M. J . , and Schaffer, A. M., J . Catal., 56, 130-133 (1979) . Parks, G. D., Applications of Surface Science, 5, 92-97 (1980) . Transcript of NPRA Question and Answer Session on Refining and Petrochemical Technology, 40-41 (1980), 50-51 (1982), 68 (1984), 62 (1987). Pettersen, F. A., and Blanton, W. A., Paper 37e, AICHE, Summer National Meeting, 1986, Boston, MA G a l l , J . W., Nielsen, R. H., McKay, D. L., and M i t c h e l l , N. W., AM-82-50, NPRA Annual Meeting, March 21-23, 1982, San Antonio, TX. Pine, L. A., Maher, P. J . and Wachter, W. A., J . Catal., 85, 466-476. Tatterson, D. F., and M i e v i l l e , R. L., Ind. Eng. Chem. Res., 27, 1595-1599 (1988). McCarthy, W. C., Hutson, T. J r . , and Mann, J . W., K a t a l i s t i k s 3rd Annual F l u i d Cat Cracking Symposium, May 1982, Amsterdam, The Netherlands. M i l l e r , R. F., Blaschke, M. W., and Pawloski, J . N., AM-88-72, NPRA Annual Meeting, March 20-22, 1988, San Antonio, TX. Denison, F. W. I I I , Hohnholt, J . F., English, A. R., and Krishna, A. S., AM-86-51, NPRA Annual Meeting, March 23-25, 1986, Los Angeles, CA. English, A. R., and Kowalczych, D. C., O i l and Gas J . , 127-128, (July 16, 1984). Anderson, M. W., O c c e l l i , M. L., and Suib, S. L., J . Catal., 118. 31-42 (1989). Ramamoorthy, P., English, A. R., Kennedy, J . V., Lossens, L. W., and Krishna, A. S., AM-88-50, NPRA Annual Meeting, March 20-22, 1988, San Antonio, TX. Kennedy, J . V., and Jossens, L. W., Paper 60a, AICHE, Spring National Meeting, 1990, Orlando, FL. Cabrera, C. A., Helmer, C. L., and Davis, J . P., Paper 14, K a t a l i s t i k s 8th Annual F l u i d Cat Cracking Symposium, June 1-4, 1987, Budapest, Hungary. Upson, L. L., Paper 18, K a t a l i s t i k s 8th Annual F l u i d Cat Cracking Symposium, June 1-4, 1987, Budapest, Hungary. Barlow, R. C., and L i p i n s k i , J . J . , AM-89-17, NPRA Annual Meeting, March 19-21, 1989, San Francisco, CA. Teran, C. K., AM-88-70, NPRA Annual Meeting, March 20-22, 1988, San Antonio, TX. O c c e l l i , M. L., i n " F l u i d C a t a l y t i c Cracking: Role i n Modern Refining," ACS Sympsoium Series, V o l . 375: M. L. O c c e l l i , Ed., ACS, Washington, D. C., p. 162 (1989). O c c e l l i , M. L. and Stencel, J . M. i n " F l u i d C a t a l y t i c Cracking: Role i n Modern Refining," ACS Sympsoium Series, V o l . 375: M. L. O c c e l l i , Ed., ACS, Washington, D. C., p. 195 (1989).


11. 30.

31.

32. 33.

34.


35.

BOHMER ET AL.


197

O c c e l l i , M. L. and Stencel, J . M. i n "Zeolites as Catalysts, Sorbents and Detergent Builders." H. O. Karge and J. Weitkamp Eds.; E l s e v i e r , p. 127 (1989). O c c e l l i , M. L. and Stencel, J . M. i n " Z e o l i t e s . Facts, Figures. Future." P. A. Jacobs, P. A. Vanjarter, Eds., E l s e v i e r , Part B, p. 1311, 1989. Let a, D. P., and Kugler, E. L., PREPRINTS, Div. o f P e t r o l . Chem., ACS, 33 (4), 636-641 (1988). Woolery, O. L., Chin, A. A., Kirker, G. W., Huss, A. J r . , and Chester, A. W., PREPRINTS, Div. of P e t r o l . Chem., ACS, 33 (4), 648. Wenig, R. W., White, M. G., and McKay, D. L., PREPRINTS, Div. of P e t r o l . Chem., ACS, 28 (4), 909-919 (1983). M i l l e r , R. F. and Pawloski, J . N., Paper 18b, AICHE., Spring National Meeting, 1988, New Orleans, LA.

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