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8/9/2019 Us 7498471 http://slidepdf.com/reader/full/us-7498471 1/7 US007498471B2 12) United States Patent 10) Patent N0.: US 7,498,471 B2 Schultz et a]. 45) Date of Patent: *Mar. 3, 2009 (54) PROCESS FOR PRODUCING CUMENE 6,762,334 B1 7/2004 Stewart 61 a1. ............ .. 585/323 (75) Inventors: Michael A. Schultz, Des Plaines, IL (US); Steven P. Lankton, Des Plaines, IL (US); Constante P. Tagamolila, Des (Continued) Plaines, IL (US) FOREIGN PATENT DOCUMENTS (73) Assignee: UOP LC, Des Plaines, IL (US) EP 0 806 406 A1 11/1997 * ) Notice: Subject to any disclaimer, the term of his patent is extended or adjusted under 35 U.S.C. 154 b) by 0 days. (Commued) OTHER PUBLICATIONS This patent is subject to a terminal dis claimer. Schultz, Michael A. et al., “Reduce Costs With Dividing-Wall C01 umns” WWW.cepmagaZine.0rg May 2002 pp. 64-71. 21) Appl.No.: 11/752,514 Continued) 22) Flled: May 3’ 2007 Primary ExamineriThuan Dinh Dang 74) Attorney, Agent, or FirmiMaryann Maas (65) Prior Publication Data US 2008/0293982 A1 Nov. 27, 2008 (57) ABSTRACT (51) Int. C1. C0 7C 15/0 73 (2006.01) In an alkylation Zone, a benZene recycle stream and propy C 7C 2/64 (2006.01) lene feed stream are contacted With an alkylation catalyst to (52) U.S. Cl. ...................... . 585/323; 585/450; 585/470 Convert the propylene and benzene into cumene. In a tran (58) Field of Cl assi?cation Search ............... .. 585/323, Salkylation Zone, 4 pol yisopropylb enlene Stream and 4 ben 58 5 /4 50, 470 Zene recycle stream are contacted With a transalkylation cata See application ?le for Complete Search history lyst to convert the polyisopropylbenZene and benZene into _ cumene. The lkylation and ransalkylation Zone ef?uents are (56) References Clted passed into a dividing Wall fractionation column. U.S. P TENT DOCUMENTS _ _ _ A umene product stream 1s removed from an 1ntermed1ate 2,471,134 A 5/1949 Wright ..................... .. 196/100 point of he dividing Wall fractionation column, A enzene 4,230,533 A 10/1980 GifOuX 203/1 recycle stream is removed from a ?rst end, and another ben 5902917 A 5/1999 Collins et a1~ 585/323 Zene recycle stream s removed from an intermediate point of 6,348,637 B1 2/2002 Herris ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ 585/820 the dividing Wall fractionation column. olyisopropylben 6,395,950 B1 5/2002 Rice 5 85/738 Zene stream s removedfrom second end f he dividi ng Wall 6395951 Bl 5/2002 Hamm 585/827 fractionation column. The polyisopropylbenZene stream is 6’4l7’420 B1 7/2002 Stewart et a1‘ 585623 passed to a polyisopropylbenZene fractionation column to 6,479,720 B1 11/2002 O’Brien et a1. 585/448 6,483,002 B1 11/2002 O’Brien .................... .. 585/826 Separatethepolylsopropylbenzene fromaheavy endsstream' 6,551,465 B1 4/2003 Van ile et a1. ........... .. 202/158 6,740,789 B1 5/2004 Bozzano et a1. ........... .. 585/323 9 Claims, 1 Drawing Sheet
Transcript
Page 1: Us 7498471

8/9/2019 Us 7498471

http://slidepdf.com/reader/full/us-7498471 1/7

US007498471B2

1 2 )

United States Patent

1 0 )

P a t e n t

N 0 . : U S 7 , 4 9 8 , 4 7 1 B2

S c h u l t z

e t a ] . 4 5 )

Date

o f

P a t e n t : *Mar. 3 , 2009

(54) PROCESS

FOR

PRODUCINGCUMENE 6,762,334

B1

7/2004

S t e w a r t

6 1 a 1 . . . . . . . . . . . . .

. .

585/323

( 7 5 ) I n v e n t o r s :

M i c h a e l

A . S c h u l t z ,

D e s

P l a i n e s , I L

( U S ) ;

S t e v e n

P .

L a n k t o n , D e s

P l a i n e s ,

I L

( U S ) ; C o n s t a n t e

P .

T a g a m o l i l a ,

D e s

( C o n t i n u e d )

P l a i n e s ,

I L

( U S ) FOREIGN

PATENT

DOCUMENTS

( 7 3 )

A s s i g n e e :

UOP LC, Des P l a i n e s , I L ( U S ) EP 0 8 0 6

4 0 6

A1

1 1 / 1 9 9 7

*

) N o t i c e : S u b j e c t t o a n y

d i s c l a i m e r ,

t h e t e r m

o f

h i s

p a t e n t i s extended o r a d j u s t e d under 35

U . S . C .

1 5 4 b ) b y 0 d a y s . ( C o m m u e d )

OTHER PUBLICATIONS

T h i s p a t e n t

i s

s u b j e c t t o a t e r m i n a l

d i s

c l a i m e r .

S c h u l t z , M i c h a e l A . e t a l . , “ R e d u c e C o s t s W i t h D i v i d i n g - W a l l C 0 1

umns” W W W . c e p m a g a Z i n e . 0 r g May 2 0 0 2 p p .

6 4 - 7 1 .

2 1 ) A p p l . N o . : 1 1 / 7 5 2 , 5 1 4

C o n t i n u e d )

2 2 ) F l l e d :

May

3 ’

2 0 0 7 P r i m a ry ExamineriThuan D i n h D a n g

7 4 )

A t t o r n e y ,

A g e n t , o r FirmiMaryann Maas

( 6 5 ) P r i o r P u b l i c a t i o n

Data

U S

2 0 0 8 / 0 2 9 3 9 8 2 A1 N o v . 2 7 , 2008 ( 5 7 )

ABSTRACT

( 5 1 )

I n t .

C 1 .

C0 7C 1 5 / 0 7 3 ( 2 0 0 6 . 0 1 ) I n an a l k y l a t i o n Z o n e , a

benZene

r e c y c l e s t r e a m and

propy

C

7C

2 / 6 4 ( 2 0 0 6 . 0 1 ) l e n e f e e d s t r e a m a r e c o n t a c t e d W i t h an a l k y l a t i o n c a t a l y s t t o

( 5 2 )

U.S.

C l . . . . . . . . . . . . . . . . . . . . . . .

. 585/323; 585/450; 585/470

C o n v e r t

t h e

propylene

and benzene i n t o cumene.

I n

a

t r a n

( 5 8 ) Field of Cl assi?cation

Search

. . . . . . . . . . . . . . . . . 585/323, S a l k y l a t i o n Z o n e ,

4

pol yisopropylb enlene Stream

and

4

ben

5 8

5 / 4 5 0 , 470 Zene r e c y c l e

s t r e a m

a r e c o n t a c t e d

W i t h

a t r a n s a l k y l a t io n c a t a

S e e a p p l i c a t i o n ? l e f o r C o m p l e t e S e a r c h h i s t o r y l y s t t o c o n v e r t

t h e

p o l y i s o p r o p y l b e n Z e n e

a n d

b e n Z e n e i n t o

_

cumene. The l k y l a t i o n and r a n s a l k y l a t i o n

Zone ef?uents

a r e

( 5 6 )

R e f e r e n c e s C l t e d

p a s s e d

i n t o a d i v i d i n g W a l l

f r a c t i o n a t i o n c o l u m n .

U.S.

P TENT

DOCUMENTS _ _ _

A

umene

product stream 1 s removed

fr o m an

1 n t e r m e d 1 a t e

2 , 4 7 1 , 1 3 4

A

5 / 1 9 4 9

W r i g h t

. . . . . . . . . . . . . . . . . . . . .

. .

1 9 6 / 1 0 0 p o i n t

of

h e d i v i d i n g

W a l l

f r a c t i o n a t i o n

column,

A

enzene

4 , 2 3 0 , 5 3 3 A

1 0 / 1 9 8 0

G i f O u X 2 0 3 / 1 r e c y c l e s t r e a m i s removed

from

a ? r s t e n d , and a n o t h e r

ben

5902917

A 5 / 1 9 9 9 C o l l i n s

e t a 1 ~

5 8 5 / 3 2 3

Zene r e c y c l e stream

s removed from an i n t e r m e d i a t e

p o i n t of

6,348,637

B1

2/2002 Herris ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

585/820

the

dividing

Wall fractionation

column. olyisopropylben

6,395,950 B1 5/2002 Rice 5 85/738 Zene stream s

removedfrom

second

end

f

he

dividing Wall

6395951 Bl 5/2002

Hamm 585/827

fractionation column. The polyisopropylbenZene stream

is

6 ’ 4 l 7 ’ 4 2 0 B1

7 / 2 0 0 2

S t e w a r t

e t

a 1 ‘ 58 5 6 2 3 passed t o

a

polyisopropylbenZene f r a c t i o n a t i o n c olumn t o

6,479,720

B1

11/2002 O’Brien e t

a 1 . 5 85 / 448

6 , 4 8 3 , 0 0 2

B1

11/2002 O’Brien

. . . . . . . . . . . . . . . . . . . .

. . 585/826 Separatethepolylsopropylbenzene fromaheavy endsstream'

6 , 5 51 , 4 6 5 B1 4/ 2003 Van

ile

e t a 1 . . . . . . . . . . . . . . 202/ 15 8

6 , 7 4 0 , 7 8 9 B1

5/2004

Bozzano e t a 1 . . . . . . . . . . . . . .

585/323

9 Claims,

1 Drawing

Sheet

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US 7 , 4 9 8 , 4 7 1 B2

P a g e

2

6 , 9 2 7 , 3 1 4

6 , 9 7 9 , 3 9 4

7 , 0 6 0 , 8 5 2

2001/0052453

2002/0017480

2002/0019576

2004/0011706

2004/0020757

2004/0254411

2006/0052630

2006/0101852

U . S . PATENT DOCUMENTS

B1

8 / 2 0 0 5

B2 1 2 / 2 0 0 5

B2 6/2006

A1 12/2001

A1

2/2002

A1 2/2002

A1

1 / 2 0 0 4

A1 2/2004

A1 1 2 / 2 0 0 4

A1 3/2006

A1 5 / 2 0 0 6

chultz et a 1 .

. . . . . . . . . . . .

.. 585/734

BoZZano et a l . . . . . . . . . . . . . . . . 208/12

M aas e t a l .

562/94

Rust et a l . . . . . . . . .. 202/158

Emmrich t

a 1 .

. . 2 0 8 /3 1 3

Emmrich t

a 1 .

. . 5 8 5 / 8 6 6

Kaibel

et a l . . . . . .. 208/347

Deibele

et a l . . . . . .

. . 203/21

Steinbrenner

e t

a 1 .

5 8 5 / 3 2 3

Narbeshuber

e t

a 1 . 5 6 2 / 8 1

Porter

.......................

. 62/620

200 6 /0178 544 A1*

8 /2 0 0 6

Murray

t

a l .

. . . . . . . . . . . .

. . 5 85 / 467

FOREIGN PATENT DOCUMENTS

EP

1

205

460

A1 5/2002

W0 W0

3/051799

A1 6 / 2 0 0 3

OTHER

PUBLICATIONS

R u d d , Howard “ T h e r m a l c o u p l i n g

f o r e n e r g y e f ? c i e n c y ”

S u p p l e m e n t

t o T h e C h e m i c a l E n g i n e e r A u g . 2 7 , 1 9 9 2 p p . s 1 4 - s 1 5 .

M u r a l i k r i s h n a ,

K . e t a l . , “ D e v e l o p m e n t

o f

D i v i d i n g W a l l D i s t i l l a t i o n

Column D e s i g n S p a c e

f o r a

S p e c i ? e d

S e p a r a t i o n ”

T r a n s IChemE o l .

8 0 , PartA M a r .

2002 p p .

1 5 5 - 1 6 6 .

*

c i t e d by

examiner

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US

7 , 4 9 8 , 4 7 1

B2

1

PROCESS

FOR PRODUCING CUMENE

FIELD

OF THE INVENTION

A

p r o c e s s

f o r p r o d u c i n g

cumene

Where t h e p r o d u c t

cumene s

s e p a r a t e d

u s i n g

a d i v i d i n g

W a l l

d i s t i l l a t i o n

c o l u m n .

BACKGROUND

OF THE INVENTION

Cumene, o r

i s o p r o p y l b e n Z e n e , i s

a v a l u a b l e

p r o d u c t t h a t i s

u s e d

m a i n l y f o r t h e m a n u f a c t u r e o f p he n o l a n d a c e t o n e .

Cumene h a s

b e e n p r o d u c e d

by

a c a t a l y t i c p r o ce s s u s i n g a

s o l i d p h o s p h o r i c

a c i d

t h a t

i s

made

b y

i m p r e g n a t i n g k i e s e l

g u h r W i t h p h o s p h o r i c a c i d . NoW, e o l i t i c c a t a l y s t s a r e u s e d t o

p r o d u c e h i g h e r

q u a l i t y

cumene t a

l o W e r

i n v e s t m e n t

c o s t .

I n a t y p i c a l c o m m e r c i a l p r o c e s s f o r t h e

p r o d u c t i o n o f

c u m e n e ,

l i q u i d

b e n Z e n e a n d

l i q u i d

p r o p y l e n e a r e

c h a r g e d

i n t o

an l k y l a t i o n

Zone

containing

one

or

more

e a c t o r s containing

a n a l k y l a t i o n c a t a l y s t . I n o r d e r t o

m i n i m i Z e

t h e p r o d u c t i o n o f

p o l y a l k y l a t e d

p r o d u c t s

o f b e n Z e n e i t h a s

b e e n t h e p r a c t i c e

t o

m a i n t a i n

a

molar

e x c e s s

of benZene t h r o u g h o u t

t h e r e a c t i o n

Zone r a n g i n g from a b o u t 4 : 1 t o a b o u t 1 6 : 1 , and more p r e f e r

a b l y

a b o u t

8 : 1

o f b e n Z e n e t o p r o p y l e n e . TWo c o m p e t i n g r e a c

t i o n s

W i t h

t h e

d e s i r e d p r o d u c t i on o f i s o p r o p y l b e n Z e n e h a v e

c r e a t e d problems i n some commercial p r o c e s s e s .

One o f

t h e s e h a s b e e n t h e f o r m a t i o n o f

p o l y a l k y l a t e d

b e n Z e n e s

s u c h

a s d i - and

t r i i s o p r o p y l b e n Z e n e r a t h e r

t h a n t h e

d e s i r e d

m o n o a l k y l a t e d p r o d u c t . T h i s c o m p e t i n g r e a c t i o n may e p a r

t i a l l y

c o n t r o l l e d b y e m p l o y i n g l a r g e m o l a r

e x c e s s e s

o f b e n

Z e n e . However, a

t r a n s a l k y l a t i on r e a c t o r i s

employed

o

r e a c t

p o l y a l k y l a t e d b e n Z e n e s W i t h b e n Z e n e t o

form

a d d i t i o n a l

c u m e n e . The o t h e r c o m p e t i n g

r e a c t i o n c a u s i n g

l o s s e s i n

t h e

y i e l d o f cumene b a s e d

on

p r o p y l e n e

r e a c t a n t c h a r g e d

i s t h e

f o r m a t i o n

o f

o l i g o m e r s

o f

p r o p y l e n e s u c h a s p r o p y l e n e d i m e r

and r i m e r W hich

occur

o a l i m i t e d e x t e n t even With h e

l a r g e

molar e x c e s s e s o f b e n Z e n e p r e s e n t . P r o p y l e n e t r i m e r s and

some of h e propylene

t e t r a m e r s b o i l

With

cumene.

S i n c e t h e

p r e s e n c e o f t h e s e o l e ? n s i n t e r f e r e

W i t h

t h e o x i d a t i o n r e a c t i o n

u s e d t o make p h e n o l from

c u m e n e ,

t h i s

o l i g o m e r i Z a t i o n

s i d e

r e a c t i o n must b e m i n i m i z e d t o make a h i g h

p u r i t y

p r o d u c t .

T h e a l k y l a t o r a n d t r a n s a l k y l a t o r e ? l l u e n t s u n d e r g o s e p a r a

t i o n

o p e r a t i o n s

t o s e p a r a t e b e n Z e n e ,

cumene p r o d u c t ,

p o l y

i s o p r o p y l b e n Z e n e , a n d b y - p ro d u c t s t r e a m s u s i n g d i s t i l l a t i o n

c o l u m n s .

T r a d i t i o n a l l y

t h r e e d i s t i l l a t i o n columns

a r e

u s e d .

The r s t

i s

t y p i c a l l y a benZene column, used

o

r e c o v e r e x c e s s

benZene

from

h e r e a c t o r e ? l l u e n t s . The benZene column v e r

h e a d , W h i c h

i s

l a r g e l y b e n Z e n e ,

i s t y p i c a l l y

r e c y c l e d t o

t h e

a l k y l a t o r

a n d

r a n s a l k y l a t o r . The e c o n d d i s t i l l a t i o n column s

t y p i c a l l y

a cumene

column

used o recover h e cumene prod

u c t

from

h e benZene column o t t o m s .

The

cumene r o d u c t

i s

t y p i c a l l y t h e n e t o v e r h e a d

from

t h e cumene

column.

The

cumene

r o d u c t

may

be used

n

a p p l i c a t i o n s

s u c h

a s

p h e n o l

o r

a c e t o n e p r o c e s s e s , o r may e

s e n t

t o

s t o r a g e . The t h i r d d i s

t i l l a t i o n

column i s

u s u a l l y a p o l y i s o p r o p y l b e n Z e n e

column

used

t o

r e c o v e r

p o l y i s o p r o p y l b e n Z e n e

r e c y c l e s t r e a m from

t h e cumene

column

o t t o m s . PolyisopropylbenZene s recov

e r e d a s o v e r h e a d from h e

p o l y i s o p r o p y l b e n Z e n e

column and

i s

t y p i c a l l y r e c y c l e d t o

t h e

t r a n s a l k y l a t o r . T h e h i g h b o i l i n g

b o t t o m s , t h e

h e a v y

e n d s , i s u s u a l l y

c o o l e d a n d s e n t

t o

s t o r a g e .

C u r r e n t

p r o c e s s H o w s c h e m e s a r e i m p r o v e d b y r e p l a c i n g

t h e

benZene

column

and

t h e cum ene colu mn With a s i n g l e

d i v i d i n g

W a l l

c o l u m n .

The r e s u l t i n g

a d v a n t a g e s

i n c l u d e a

s i g n i ? c a n t

s a v i n g s

i n t h e e n e r g y

r e q u i r e m e n t

a n d

t h e t o t a l

number o f

s t a g e s ,

a h i g h e r cumene

p u r i t y and

a r e d u c t i o n i n

benZene l o s s . A d d i t i o n a l a d v a n t a g e s

i n c l u d e

a r e d u c t i o n i n

25

3 0

35

40

45

50

55

60

6 5

2

c a p i t a l c o s t s

a s s o c i a t e d W i t h

t h e r e d u c e d

number o f

s t a g e s ,

r e d u c t i o n

i n e x c h a n g e r

s u r f a c e

a r e a , and

a r e d u c t i o n

i n t h e

e q u i p m e n t c o u n t .

The

d i v i d i n g

W a l l

o r P e t y l u k c o n ? g u r a t i o n

f o r

f r a c t i o n

a t i o n columns

Was

n i t i a l l y i n t r o d u c e d

some

50 y e a r s ago by

P e t y l u k

e t a l . A e c e n t

c o m m e r c i a l i z a t i o n o f

a f r a c t io n a t i o n

column e m p l o y i n g

t h i s

t e c h n i q u e

p r o m p t e d

more

r e c e n t

i n v e s t i g a t i o n s a s

d e s c r i b e d i n t h e a r t i c l e a p p e a r i n g a t page 1 4

o f a

S u p p l e m e n t t o T h e C h e m i c a l E n g i n e e r , 2 7 A u g . 1 9 9 2 .

The

u s e o f d i v i d i n g

W a l l c o l u m n s i n

t h e s e p a r a t i o n o f

h y d r o c a r b o n s i s a l s o d e s c r i b e d n t h e p a t e n t l i t e r a t u r e . F o r

i n s t a n c e , U . S . P a t . N o . 2 , 4 7 1 , 1 3 4 i s s u e d t o R . 0 . W r i g h t

d e s c r i b e s t h e

u s e

o f a d i v i d i n g W a l l column

i n

t h e s e p a r a t i o n

o f l i g h t h y d r o c a r b o n s r a n g i n g

f r o m m e t h a n e t o

b u t a n e . U . S .

P a t . No.

4 , 2 3 0 , 5 3 3 i s s u e d

t o V . A. Giroux d e s c r i b e s a c o n t r o l

system

o r a d i v i d i n g

W a l l

column and l l u s t r a t e s t h e u s e o f h e

c l a i m e d

i n v e n t i o n i n t h e s e p a r a t i o n

o f a r o m a t i c s

c o m p r i s i n g

b e n Z e n e , t o l u e n e a n d

o r t h o x y l e n e .

Using

a

d i v i d i n g

W a l l

column

i n t h e a cumene p r o d u c t i o n

p r o ce s s p r ov i d e s

s i g n i ? c a n t a d v a n t a g e s o v e r

cumene

r o d u c

t i o n

p r o c e s s e s t h a t

do n o t employ

a

d i v i d i n g

W a l l

f r a c t i o n

a t i o n

c o l u m n ,

a s

shoWn

b e l o W .

SUMMARY OF THE INVENTION

A umene g e n e r a t i o n p r o ce s s u s i n g

a

d i v i d i n g W a l l f r a c

t i o n a t i o n

Zone

a s

been

e v e l o p e d . The r o c e s s

i n v o l v e s con

t a c t i n g , i n an a l k y l a t i o n

Z o n e , a f e e d s t r e a m

c o m p r i s i n g a t

l e a s t

p r o p y l e n e a n d a ? r s t b e n Z e n e

r e c y c l e s t r e a m

c o m p r i s i n g

a t

l e a s t b e n Z e n e

W i t h a n a l k l y a t i o n

c a t a l y s t u n d e r

a l k y l a t i o n

c o n d i t i o n s

t o

c o n v e r t

a t

l e a s t

a

p o r t i o n o f

t h e

p r o p y l e n e a n d

benZene i n t o cumene and form an a l k y l a t i o n

Zone

e?luent

c o m p r i s i n g b e n Z e n e and c u m e n e . A l s o , i n a t r a n s a l k y la t i o n

Z o n e ,

a

p o l y i s o p r o p y l b e n Z e n e r e c y c l e s t r e a m c o m p r i s i n g

a t

l e a s t

p o l y i s o p r o p y l b e n Z e n e

and a s e c o n d b e n Z e n e r e c y c l e

stream co mprising

a t

l e a s t benZene

a r e contacted

With

t r a n

s a l k y l a t i o n c a t a l y s t

u n d e r

t r a n s a l k y la t i o n c o n d i t i o n s t o c o n

v e r t a t l e a s t a

p o r t i o n

o f t h e p o l y i s o p r o p y l b e n Z e n e and ben

Zene i n t o

cumene

and f o r m

a

t r a n s a l k y l a t i o n Zone

e?luent

c o m p r i s i n g benZene and cum ene. The

a l k y l a t i o n

Zone e ? l u

e n t and

t h e

t r a n s a l k y l a t i o n Zone

e ? l u e n t

a r e

passed

i n t o

a

d i v i d i n g

W a l l

f r a c t i o n a t i o n

column

Which

s

o p e r a t e d

a t

f r a c

t i o n a t i o n c o n d i t io n s .

The

d i v i d i n g W a l l f r a c t i o n a t i o n column

i s d i v i d e d

i n t o a t

l e a s t a ? r s t

and

a second p a r a l l e l

f r a c t i o n

a t i o n Z o n e by

a d i v i d i n g W a l l ,

W i t h

t h e

? r s t and

t h e

s e c o n d

f r a c t i o n a t i o n Zones each having an upper and

a

loWer end

l o c a t e d

W i t h i n

t h e f r a c t io n a t i o n

c o l u m n , W i t h

t h e ? r s t

a n d

second

f r a c t i o n a t i o n Z o n e s b e i n g i n

open

communication

a t

t h e i r upper

e n d s

With an

u n d i v i d e d

upper s e c t i o n of h e f r a c

t i o n a t i o n column

and i n open

communication t

t h e i r

l o W e r

e n d s W i t h

an

u n d i v i d e d

loWer s e c t i o n of t h e

f r a c t i o n a t i o n

c o l u m n .

The

a l k y l a t i o n

Z o n e e f ? u e n t

a n d t h e t r a n s a l k y la t i o n

Zone

e?luent stream

enters

the

c o l u m n

a t

one

or

more

n t e r

m e d i a t e

p o i n t ( s ) o f t h e ? r s t f r a c t i o n a t i o n

Z o n e .

A t r e a m comprising cumene

s removed from

an i n t e r m e

d i a t e

p o i n t

o f t h e s e c o n d f r a c t i o n a t i o n Z o n e o f t h e d i v i d i n g

W a l l f r a c t i o n a t i o n c o l u m n . A

r s t

b e n Z e n e

r e c y c l e

s t r e a m i s

removed from

a ? r s t end

o f t h e d i v i d i n g W a l l f r a c t i o n a t i o n

c o l u m n . The s e c o n d

b e n Z e n e r e c y c l e

s t r e a m i s removed from

an

i n t e r m e d i a t e

p o i n t

o f

t h e second

f r a c t i o n a t i o n

Zone of

h e

d i v i d i n g W a l l

f r a c t i o n a t i o n

c o l u m n , a n d

a

p o l y i s o p r o p y l b e n

Zene

t r e a m

i s

removed

from second

end

of h e

d i v i d i n g

W a l l

f r a c t i o n a t i o n c o l u m n . The p o l y i s o p r o p y l b e n Z e n e s t r e a m i s

p a s s e d t o

a

p o l y i s o p r o p y l b e n Z e n e

f r a c t i o n a t i o n

column t o

s e p a r a t e t h e p o l y i s o p r o p y l b e n Z e n e r e c y c l e s t r e a m

f r o m

a

h e a v y

a r o m a t i c s s t r e a m .

Page 5: Us 7498471

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http://slidepdf.com/reader/full/us-7498471 5/7

US

7 , 4 9 8 , 4 7 1

B2

3

BRIEF

DESCRIPTIONOF THE DRAWING

The FIGURE s a

schematic

i l l u s t r a t i o n of

one

embodi

ment of h e

p r e s e n t i n v e n t i o n . The

FIGURE does n o t s h o w a

number

of e t a i l s f o r t h e p r o c e s s arrangement s u c h a s pumps,

c o m p r e s s o r s , v a l v e s , s t a b i l i z e r s and r e c y c l e l i n e s Which a r e

W e l l

knoWn o

t h o s e

s k i l l e d

i n

t h e

a r t .

DETAILED DESCRIPTION OF THE

INVENTION

R e f e r r i n g t o t h e FIGURE, t h e p r o c e s s o f t h e i n v e n t i o n

r e q u i r e s tWo

r e a c t o r s , a n

a l k y la t i o n r e a c t o r 2 , o r a l k y l a t o r , and

a t r a n s a l k y l a t i on r e a c t o r 4 , o r t r a n s a l k y l a t o r .

P r o p y l e n e

and

benzene f e e d s t o c k s

6

and

an excess of benzene 8 a r e

i n t r o

d u c e d

t o

a l k y l a t o r 2 .

A y p i c a l p r o p y l e n e f e e d s t o c k

may

e a n

a l m o s t p u r e polymer

r a d e

m a t e r i a l or

c a n

c o n t a i n s i g n i ? c a n t

amounts o f p r o p a n e , a s

t y p i c a l l y

f o u n d i n r e ? n e r y - g r a d e p r o

p y l e n e . A

y p i c a l b e n z e n e

f e e d s t o c k

may

c o n t a i n

b e n z e n e

9 9 . 9 W t . - % m i n . )

a n d

t o l u e n e 0 . 0 5

W t . - %

m i n ) . A l k y l a t i o n

r e a c t o r s may

b e

o p e r a t e d i n

t h e

v a p o r

p h a s e , l i q u i d - p h a s e o r

m i x e d - p h a s e .

I t i s

p r e f e r r e d t o o p e r a t e

t h e

a l k y l a t i o n

r e a c t o r

i n

t h e l i q u i d p h a s e . A t t h e l o W e r t e m p e r a t u r e s o f t h e l i q u i d

p h a s e

o p e r a t i o n ,

x y l e n e

i m p u r i t i e s a r e

n o t

p r o d u c e d a n d

a

cumene p r o d u c t o f s u p e r i o r q u a l i t y i s p r o d u c e d .

I n

o n e

e m b o d i m e n t , t h e t e m p e r a t u r e

o f

t h e a l k y la t i o n r e a c t o r i s

s e l e c t e d from

h e

r a n g e of100° C . t o

3 1 0 °

C .

( 2 1 2

t o 5 9 0 ° F . )

and

h e p r e s s u r e i s

s e l e c t e d from

h e r a n g e

of 800 o 5100

kPa

( 1 1 6 t o 740 p s i a ) . I n a

more s p e c i ? c

embodiment t h e tem

p e r a t u r e

i s

i n t h e r a n g e

o f

1 2 0

t o 2 8 0 °

C .

( 2 4 8 t o 5 3 6 ° F . )

and

t h e

p r e s s u r e

i s

i n

t h e

r a n g e of from a b o u t 1000 t o 3900 kPa

( 1 4 5

t o

5 6 5

p s i a ) .

A l k y l a t i o n

r e a c t o r

2

c o n t a i n s

a n

e f f e c t i v e

a m o u n t o f a l k y l a t i o n

c a t a l y s t .

S u i t a b l e a l k y l a t i o n c a t a l y s t s

i n c l u d e

s o l i d a c i d c a t a l y s t s and p r e f e r a b l y a s o l i d o x i d e z e o

l i t e .

E x a m p l e s

a r e

z e o l i t e b e t a , z e o l i t e X , z e o l i t e Y , m o r d e n i t e ,

f a u j a s i t e ,

z e o l i t e o m e g a ,

UZM-8, MCM-22, MCM-36,

MCM-49 nd M CM - 5 6 .

A l k y l a t i o n

r e a c t o r s , o p e r a t i n g

c o n

d i t i o n s and c a t a l y s t s a r e knoWn i n t h e a r t and n o t

f u r t h e r

d i s c u s s e d

h e r e .

I n a l k y la t i o n r e a c t o r

2 ,

t h e

b e n z e n e

i s a l k y l a t e d W i t h t h e

p r o p y l e n e

t o form

i s o p r o p y l b e n z e n e ,

o r cumene. Some

p o l y

i s o p r o p y l b e n z e n e s , Which

a r e

m a i n l y d i - and t r i - s u b s t i t u t e d

p r o p y l b e n z e n e s ,

a r e

a l s o f o r m e d .

O t h e r h e a v y

a r o m a t i c

b y p r o d u c t s

h a v i n g

from 1 6 t o a b o u t

2 4 c a r b o n

a t o m s may

a l s o be

f o r m e d .

Benzene

i s

f e d t o t h e

a l k y l a t o r

i n e x c e s s s o

t h a t v i r t u a l l y a l l t h e p r o p y l e n e i s r e a c t e d . T h e r e f o r e , a l k y l a

t i o n r e a c t o r e ? ° l u e n t 1 0 c o n t a i n s p r i m a r i l y b e n z e n e , cumene

a n d

p o l y i s o p r o p y l b e n z e n e s .

T r a n s a l k y l a t i o n

r e a c t o r 4 i s u s e d t o form a d d i t i o n a l

c u m e n e

t h r o u g h t r a n s a l k y l a t i n g t h e p o l y i s o p r o p y l b e n z e n e

p r o d u c e d i n

t h e a l k y la t i o n r e a c t o r

a n d

r e c y c l e d

i n

l i n e

4 3

W i t h

b e n z e n e

r e c y c l e d

i n

l i n e 2 0 . S u it a b l e c o n d i t i o n s a n d

c a t a l y s t s

may be t h e same

a s

d e s c r i b e d f o r t h e a l k yl a t i o n

r e a c t o r .

E x a m p l e s

o f s u i t a b l e

t r a n s a l k y l a t i o n

c a t a l y s t s a r e z e o l i t e

b e t a , z e o l i t e

X ,

z e o l i t e Y ,

m o r d e n i t e ,

f a u j a s i t e , z e o l i t e

o m e g a ,

U ZM -8 , MC M - 2 2 , MC M - 3 6 ,

MCM-49

nd MC M - 5 6 .

n

one

e m b o d i m e n t ,

t h e t e m p e r a t u r e i s

s e l e c t e d from

t h e r a n g e

o f

1 0 0 ° C . t o 2 7 0 ° C . ( 2 1 2 t o 5 1 8 ° F . ) and h e p r e s s u r e i s s e l e c t e d

from t h e

r a n g e

o f 800 t o 5100 kPa

( 1 1 6

t o 740 p s i a ) . I n

a n o t h e r

more

s p e c i ? c

e m b o d i m e n t ,

t h e t e m p e r a t u r e i s a b o u t

1 2 9 °

C . ( 2 6 4 °

F . )

a n d

t h e

p r e s s u re r a n g e s from a b o u t 1000

o

3 9 0 0 k P a ( 1 4 5

t o 5 6 5 p s i a ) . T r a n s a l k y l a t i o n r e a c t o r s , o p e r a t

i n g c o n d i t i o n s

and c a t a l y s t s

a r e

knoWn i n t h e a r t and n o t

f u r t h e r d i s c u s s e d h e r e . The

t r a n s a l k y l a t i o n e ? ° l u e n t 1 2 f r o m

t r a n s a l k y l a t i o n

r e a c t o r 4

c o n t a i n s

p ri m a r il y b e n z e n e , e t h y l

b e n z e n e a n d

p o l y e t h y l b e n z e n e .

B o t h a l k y l a t i o n

e ? ° l u e n t 1 0

a n d t r a n s a l k y l a t i o n

e ? ° l u e n t 1 2

a r e

i n t r o d u c e d

t o cumene/benzene i v i d i n g W a l l f r a c t i o n a t i o n

20

25

3 0

35

40

45

50

55

60

6 5

4

d i s t i l l a t i o n column 1 4 . W i t h i n t h e d i v i d i n g W a l l

f r a c t i o n a t i o n

d i s t i l l a t i o n

column a r e tWo p a r a l l e l f r a c t i on a t i o n z o n e s . A

? r s t

f r a c t i o n a t i o n

z o n e

o c c u p i e s

a l a r g e p o r t i o n o f t h e l e f t

hand

s i d e

o f

t h e

m i d - s e c t i o n o f t h e f r a c t i on a t i o n d i s t i l l a t i o n

column. Note h a t t h e

terms

“ l e f t - h a n d ” and “ r i g h t - h a n ”

a r e

u s e d h e r e i n a s r e l a t i v e t o t h e d r a W i n g s . I n a c t u a l p r a c t i c e t h e

placement o f h e z o n e s a s t o t h e l e f t s i d e o r t h e r i g h t s i d e o f h e

column

i s

n o t c r i t i c a l . T h i s ? r s t f r a c t i o n a t i o n zone i s s e p a

r a t e d

from p a r a l l e l

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

zone o c c u p y i n g t h e

o t h e r h a l f o f t h e column

c r o s s s e c t i o n

by a s u b s t a n t i a l l y ? u i d

t i g h t v e r t i c a l W a l l

1 6 .

The

v e r t i c a l W a l l i s n o t n e c e s s a r i l y

c e n t e r e d

i n

t h e

column and

t h e tWo

f r a c t i o n a t i o n zones m ay

d i f f e r i n c r o s s s e c t i o n a l

a r e a

o r s h a p e . The v e r t i c a l W a l l

d i v i d e s a

l a r g e

v e r t i c a l p o r t i o n o f h e

column n t o

tWo a r a l l e l

f r a c t i o n a t i o n zones. The tWo

zones

a r e

i s o l a t e d

f r o m each

o t h e r f o r t h e

h e i g h t

o f h i s W a l l ,

b u t

communicate t

b o t h

t h e

t o p and bottom

n d s

of h e column. There s no d i r e c t vapor

r

l i q u i d ? o W betWeen

t h e

tWo f r a c t i o n a t i o n

z o n e s

t h r o u g h t h e

d i v i d i n g W a l l ,

b u t

t h e

u p p e r

end

o f

t h e

f r a c t i o n a t i o n z o n e i s

open t o t h e

i n t e r n a l

volume of h e d i s t i l l a t i o n column con

t a i n i n g

a n u n d i v i d e d

f r a c t i o n a t i o n z o n e p r e f e r a b l y

h a v i n g

a d d i t i o n a l

t r a y s .

L i q u i d may p a s s u n d e r

t h e d i v i d i n g

W a l l

a t

t h e

b o t t o m

o f

t h e

tWo

f r a c t i on a t i o n s e c t i o n s

a l t h o u g h

v a p o r

H o w i s p r e f e r a b l y r e s t r i c t e d

o r

c o n t r o l l e d . T h u s , v a p o r and

l i q u i d can

f r e e l y

move around

t h e W a l l

betWeen

t h e

tWo

p o r t i o n s o f t h e c o l u m n .

D u r i n g o p e r a t i o n ,

t h e

c o m p o n e n t s o f b o t h e f ? u e n t s a r e

s e p a r a t e d i n t h e ? r s t f r a c t i o n a t i o n

zone

With h e more o l a t i l e

compounds

moving u p W a r d o u t

o f

h e l e f t - h a n d

? r s t

f r a c t i o n

a t i o n

z o n e and e m e r g i n g i n t o t h e u n d i v i d e d

u p p e r

p o r t i o n

o f

t h e d i s t i l l a t i o n

c o l u m n . As W i t h

t h e ? r s t

f r a c t i o n a t i o n

z o n e ,

t h e

u p p e r

end

o f

t h e r i g h t - h a n d

s e c o n d z o n e i s

i n open c o m

m u n i c a t i o n W i t h t h e u p p e r s e c t i o n o f t h e d i s t i l l a t i o n

column

Which

may

o p t i o n a l l y

c o n t a i n a d d i t i o n a l f r a c t i o n a t i o n t r a y s

e x t e n d i n g a c r o s s

t h e

e n t i r e column

c r o s s

s e c t i o n .

The c o m p o n e n t s o f

t h e e ? ° l u e n t

W i l l

s e p a r a t e a c c o r d i n g t o

b o i l in g p o i n t o r r e l a t i v e

v o l a t i l i t i e s ,

Which s t h e main

f a c t o r

i n

d e t e r m i n i n g

t h e i r

b e h a v i o r

i n t h e

d i s t i l l a t i o n

c o l u m n .

The

c o m p o n e n t

h a v i n g a r e l a t i v e l y

l o W

b o i l i n g p o i n t i s t h e b e n

z e n e

from e a c h o f t h e e ? l l u e n t s .

The

m i d - r a n g e b o i l i n g c o m

p o n e n t

i s t h e d e s i r e d p r o d u c t , c u m e n e .

The

components h a v

i n g r e l a t i v e l y h i g h b o i l i n g p o i n t s a r e t h e

p o l y i s o p r o p y l b e n z e n e a n d

a n y

h e a v y a r o m a t i c s .

The t r a n s a l k y l a t i o n

e ? ° l u e n t

1 2 a n d t h e a l k y la t i o n

e ? ° l u e n t

10 a r e

introduced

i n t o a ? r s t v e r t i c a l f r a c t i o n a t i o n zone occu

p y i n g

a

l a r g e

p o r t i o n o f h e l e f t - h a n d

s i d e

o f h e m i d s e c t i o n o f

t h e f r a c t i on a t i o n d i s t i l l a t i o n

c o l u m n .

The e ? ° l u e n t

may be

c o m b i n e d b e f o r e

b e i n g

i n t r o d u c e d , b u t

a d v a n t a g e s

may b e

r e a l i z e d b y i n t r o d u c i n g t h e e ? l l u e n t s a t d i f f e r e n t h e i g h t s a l o n g

t h e

d i v i d i n g

W a l l f r a c t i o n a t i o n

d i s t i l l a t i o n c o l u m n .

The a l k y

l a t i o n

r e a c t o r

e f ? u e n t

m ay

c o n t a i n a h i g h e r c o n c e n t r a t i o n

of

p o l y i s o p r o p y l b e n z e n e

a n d t h e r e f o r e

i t may b e a d v a n t a g e o u s

t o i n t r o d u c e

t h e

a l k y l a t i o n r e a c t o r e ? ° l u e n t a t

a

r e l a t i v e l y

l o W e r h e i g h t a l o n g t h e c o l u m n a s c o m p a r e d

t o

t h e t r a n s a l k y

l a t i o n

r e a c t o r

e ? i u e n t .

I n

one embodiment t h e d i v i d i n g W a l l

f r a c t i o n a t i o n

d i s t i l l a t i o n

column s

o p e r a t e d s o t h a t t h e

o v e r

h e a d p r e s s u r e i s 7 k P a 1

p s i a )

a n d

3 8 °

C .

( 1 0 0 °

F . ) .

The e n z e n e p r e s e n t

i n t h e

e f ? u e n t s i s d r i v e n upWard

n t h e

? r s t f r a c t i o n a t i o n

zone

and n t e r t h e

t o p

s e c t i o n of h e

column

Where

t

i s removed n

o v e r h e a d 1 8

and i d e draW 2 0 . Benzene

i n o v e r h e a d 1 8 i s removed from t h e t o p o f t h e d i v i d i n g

W a l l

column and a s s e d

t h r o u g h

an v e r h e a d c o n d e n s e r 38 o form

l i q u i d d e l i v e r e d t o r e c e i v e r 2 2 .

R e c e i v e r

22 may have a v e n t

s t r e a m

2 1 . A i q u i d p h a s e

s t r e a m

o f b e n z e n e 2 6 i s removed

from h e r e c e i v e r

and

d i v i d e d i n t o a ? r s t

p o r t i o n

28

Which

s

r e t u r n e d t o

t h e

t o p

o f t h e

d i v i d i n g W a l l

f r a c t i o n a t i o n

column

a s re?ux and

a

second p o r t i o n

8 Which

i s

r e c y c l e d

t o

t h e

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7 , 4 9 8 , 4 7 1

B2

5

a l k y l a t i o n r e a c t o r

2 . Benzene may

a l s o be removed from

d i v i d i n g

W a l l column i n

s t r e a m

20

Which i s a

s i d e d r a W .

Benzene t r e a m 2 0 may

be

r e c y c l e d t o t r a n s a l k y l a t i o n r e a c t o r

4 . T W o benzene

s t r e a m s

a r e WithdraWn fro m

t h e

benzene

c o l u m n b e c a u s e t h e c a t a l y s t s t y p i c a l l y u s e d i n t h e a l k y l a t i o n

r e a c t o r

can o l e r a t e

some

W a t e r p r e s e n t

d u r i n g t h e

a l k y l a t i o n

r e a c t i o n ,

b u t

t h e

c a t a l y s t s t y p i c a l l y u s e d i n t h e t r a n s a l k y l a t i o n

r e a c t o r a r e

l e s s t o l e r a n t

o f

W a t e r . T h e r e f o r e ,

t h e overhead

c o n t a i n s benzene Which may be

s a t u r a t e d

W i t h W a t e r and s

a p p r o p r i a t e

f o r

t h e a l k y la t i o n r e a c t o r ,

W h i l e

t h e

s i d e

d r a W

c o n t a i n s d r y o r s e m i - d r y

b e n z e n e

Which s a p p r o p r i a t e

f o r

t h e

t r a n s a l k y l a t i o n

r e a c t o r . As u s e d

h e r e i n t h e

t e r m

“ r i c h ”

i s

intended t o

i n d i c a t e

a

c o n c e n t r a t i o n

of t h e i n d i c a t e d com

pound

o r

c l a s s

o f

compounds g r e a t e r

t h a n 5 0

a n d

p r e f e r a b l y

g r e a t e r t h a n 7 5 mol-%.

The b o t t o m

o f t h e d i v i d i n g

W a l l

f r a c t i o n a t i o n

column

1 4

a l s o

comprises an undivided

f r a c t i o n a t i o n

z o n e . This

zone

c a n r e c e i v e l i q u i d d r a i n i n g f r o m b o t h t h e ? r s t and s e c o n d

f r a c t i o n a t i o n

z o n e s .

The l i q u i d

i s

s u b j e c t e d t o f r a c t i o n a t i o n

d i s t i l l a t i o n Which r i v e s t h e cumene

upWards

a s

vapor Wh ile

c o n c e n t r a t i n g t h e l e s s v o l a t i l e p o l y i s o p r o p y l b e n z e n e a n d

h e a v y a r o m a t i c s

i n t o a

b o t t o m s l i q u i d 3 4 t h a t

i s

removed from

d i v i d i n g W a l l

f r a c t i o n a t i o n

c o l u m n

1 4 .

T h i s

s e p a r a t i o n

i s

e f f e c t e d t h r o u g h t h e u s e o f r e b o i l e r 36 p r o v i d i n g v a p o r t o t h e

bottom

undivided

f r a c t i o n a t i o n z o n e .

The

p r o d u c t cumene

s t r e a m 3 2 i s

WithdraWn

from

t h e d i v i d i n g W a l l f r a c t i o n a t i o n

column i n a

s i d e

draW from h e r i g h t - h a n d s i d e f r a c t i on a t i o n

z o n e . Bottoms s t r e a m 34 i s p a s s e d t o p o l y i s o p r o p y l b e n z e n e

s e p a r a t i o n column 4 0 .

I n

o n e embodiment

t h e

d i v i d i n g W a l l

f r a c t i o n a t i o n d i s t i l l a t i o n column s o p e r a t e d s o t h a t t h e

o v e r

head p r e s s u r e

i s

i n t h e

r a n g e o f

from 7 t o 1 4 kPa

1

t o 2 p s i a )

a n d 3 0

t o 4 5 ° C . ( 8 6 t o 1 1 3 ° F . ) . I n a n o t h e r embodiment t h e

d i v i d i n g W a l l

f r a c t i o n a t i o n

d i s t i l l a t i o n column s o p e r a t e d

s o

t h a t t h e

o v e r h e a d p r e s s u r e i s

7 k P a

1 p s i a ) a n d 3 8 ° C . ( 1 0 0 0

F . ) .

I n a more s p e c i ? c

embodiment of

h e

i n v e n t i o n ,

t h e

u n d i

v i d e d

b o t t o m s e c t i o n

o f t h e d i v i d i n g W a l l

f r a c t i o n a t i o n

c o l

umn

s

d e p i c t e d

a s

s e p a r a t e d

from

t h e

tWo

p a r a l l e l

f r a c t i o n

a t i o n z o n e s

by

a g a s

? o W

c o n t r o l o r g a s t r a p - o u t

t r a y

l o c a t e d

j u s t

b e l o W t h e b o t t o m o f t h e

W a l l .

A

l i g h t

g a p a t t h i s p o i n t

a l l o W s h o r i z o n t a l

l i q u i d ? o W

b e t W e e n t h e

p a r a l l e l f r a c t i o n

20

25

3 0

35

40

6

vapor

t o

t h e bottom o f t h e tWo p a r a l l e l f r a c t i o n a t i o n z o n e s

s e p a r a t e l y . The

g a s

H o w m a y

be c o n t r o l l e d by one

o r

more

H o w o n t r o l

v a l v e s o r by d j u s t i n g t h e

r e l a t i v e l i q u i d

l e v e l s i n

t h e bottom of h e tWo

z o n e s .

T h i s

i s d e s c r i b e d i n some d e t a i l

i n U s. a t . No. 4 , 2 3 0 , 5 3 3 .

A e t p o r t i o n o f b o t t o m s s t r e a m 3 4 c o n t a i n i n g p r i m a r i l y

p o l y i s o p r o p y l b e n z e n e a n d h e a v y

a r o m a t i c s i s

p a s s e d t o p o l y

i s o p r o p y l b e n z e n e c o l u m n

4 0 f o r t h e

s e p a r a t i o n o f p o l y i s o

p r o p y l b e n z e n e

i n t o p o l y i s o p r o p y l b e n z e n e c o l u m n

o v e r h e a d

4 2 , a n d h e a v y

a r o m a t i c s

i n t o p o l y i s o p r o p y l b e n z e n e c o l u m n

b o t t o m s 4 4 . P o l y i s o p r o p y l b e n z e n e column o v e r h e a d 42 con

t a i n i n g p r i m a r i l y

p o l y i s o p r o p y l b e n z e n e i s

p a s s e d

t h r o u g h

r e c e i v e r

4 6

and a p o r t i o n

i s

r e t u r n e d t o t h e t o p p o r t i o n

o f

p o l y i s o p r o p y l b e n z e n e column

4 0

a s r e ? u x . The

r e m a i n d e r o f

t h e s t r e a m 4 3 i s

r e c y c l e d

t o t r a n s a l k y l a t i on r e a c t o r

4 .

I n one

embodiment t h e column i s o p e r a t e d s o t h a t t h e

o v e r h e a d

t e m p e r a t u r e i s from b o u t 8 5 °

C .

t o a b o u t 1 0 5 °

C .

( 1 8 5 t o 2 2 1

°

F . )

and h e p r e s s u r e

i s from

b o u t 1 6

t o

a b o u t 1 9 kPa

( 2 . 3

t o

2 . 7

p s i a ) .

I n

a more s p e c i ? c

embodiment

h e

column

s

o p e r

a t e d

s o t h a t t h e

o v e r h e a d

t e m p e r a t u r e

i s 9 5 ° C . ( 2 0 3 °

F . )

a n d

t h e p r e s s u r e i s

1 7 k P a 2 . 5 p s i a ) .

The h e o r e t i c a l m o d e l i n g r e s u l t s shoWn i n T a b l e 2

i n d i c a t e

t h a t

t h e s e p a r a t i o n

p e r f o r m e d

i n

t h e p re s e n t i n v e n t i o n

W o u l d

compare

f a v o r a b l y

t o t h a t a c h i e v e d u s i n g

a c o n v e n t i o n a l

scheme employing

a

benzene

column f o l l o W e d by a cumene

c o l u m n . T h e

d a t a i s b a s e d s o l e l y

u p o n e n g i n e e r i n g

d e s i g n

c a l c u l a t i o n s and n d i c a t e s t h a t tWo

c o n v e n t i o n a l

f r a c t i o n a t i o n

c o l u m n s t h e b e n z e n e column n d

t h e

cumene c o l u m n ) c o u l d

b e

r e p l a c e d W i t h a

d i v i d i n g

W a l l column

o p r o v i d e s i g n i ? c a n t

b e n e ? t s

and c o s t s s a v i n g s . Energy c o s t s a s W e l l a s t h e t o t a l

number o f s t a g e s a r e r e d u c e d W i t h

t h e d i v i d i n g

W a l l

column

a s compared o t h e c o n v e n t i o n a l tWo columns i n s e r i e s .

When d e s i g n i n g d i s t i l l a t i o n u n i t s , o f t e n t h e number

o f

s t a g e s

i n a u n i t must be b a l a n c e d W i t h t h e e n e r g y r e q u i r e

ments o f

t h e

u n i t . I n

t h e t h e o r e t i c a l

modeling d e s c r i b e d

h e r e i n ,

t W o

d i f f e r e n t

d i v i d i n g

W a l l c o l u m n (DWC)

d e s i g n s

Were m o d e l e d . One ( c a s e 1 ) h a s

a g r e a t e r

number

o f s t a g e s

a n d

a

l o W e r e n e r g y

r e q u i r e m e n t ,

W h i l e

t h e o t h e r ( c a s e 2 )

h a s

a l o W e r number

o f

s t a g e s b u t a h i g h e r

e n e r g y

r e q u i r e m e n t .

The e s i g n d a t a f o r

e a c h o f h e

s y s t e m s modeled

r e

p r o v i d e d

i n T a b l e

1 .

TABLE

2

Column

D e s i g n

DWC

e s i g n

Benzene Column Cumene

Co lumn

Case

1

Case 2

o v e r h e a d p r e s s u r e k P a ,

p s i a )

5 5

8 )

7

1 )

7 1 ) 7 1 )

o v e r h e a d t e m p e r a t u r e

°

C . , ° F . ) 3 8 ( 1 0 0 ) 1 5 5 ( 3 1 1 ) 3 8 ( 1 0 0 ) 3 8 ( 1 0 0 )

C o n d e n s o r Work

M W ,

(MMBTU/hr) 4 . 5 7 1 5 . 6 ) 4 . 8 9 1 6 . 7 ) 4 . 5 0 2 5 . 6 ) 7 . 7 6

2 6 . 5 )

B o t t o m s t e m p e r a t u r e

°

C . , °

F . )

1 9 9 ( 3 9 1 ) 2 3 3 ( 4 5 2 ) 2 3 5 ( 4 5 5 )

2 3 4

( 4 5 4 )

R e b o i l e r

Work M W , (MMBTU/hr)

4 . 6 6

1 5 . 9 )

4 . 4 2

1 5 . 1 ) 7 . 4 1 2 5 . 3 )

7 . 7 0

2 6 . 3 )

T o t a l # S t a g e s 36 42 6 7 6 2

Column

D i a m e t e r

cm

1 1 . )

1 8 3 6 )

2 1 3

7 ) 2 5 9 8 . 5 ) 2 7 4 9 )

a t i o n z o n e s . T h i s

t r a y

may h a v e

l i q u i d

s e a l e d p e r f o r a t i o n s

a l l o W i n g t h e n o r m a l doWnWard H o w f i q u i d , b u t i t s

s t r u c t u r e

i s s u c h t h a t t h e upWard H o w o f v a p o r i s a t l e a s t

g r e a t l y

r e s t r i c t e d o r

c o n t r o l l e d . The t r a y may t o t a l l y b l o c k

t h e

upWard vapor

H ow .

The u s e of

h i s

t r a y

m ay

r o v i d e a means

t o

p o s i t i v e l y c o n t r o l t h e d i v i s i o n o f t h e

upWard g a s

? o W

betWeen h e

tWo

f r a c t i o n a t i o n z o n e s , Which s a prime means

o f c o n t r o l l i n g p e r f o r m a n c e o f t h e t W o z o n e s . O p t i on a l l y ,

r e ? u x may

a l s o b e

s e p a r a t e l y

c o n t r o l l e d . The

t o t a l

column

b o t t o m s may

b e ,

t h e r e f o r e ,

p r e f e r a b l y

r o u t e d

f r o m

t h e c o l

umn i a a

l i n e and s p l i t

betWeen tWo

l i n e s

Which f e e d t h e

55

60

6 5

T a b l e 2

s h o W s

t h e

r e s u l t s

o f h e m o d e l i n g . As

c l e a r l y

shoWn

b y

t h e d a t a , e a c h o f t h e

d i v i d i n g

W a l l

c o l u m n

d e s i g n s p r o

v i d e d both

an

n e r g y s a v i n g s and r e d u c t i o n i n t h e

number

of

s t a g e s a s compared o t h e c o n v e n t i o n a l

tWo

column d e s i g n .

F o r e x a m p l e ,

t h e

d i v i d i n g W a l l column c a s e 1 r e q u i r e s

a

t o t a l

c o n d e n s e r d u t y o f

2 5 . 6

MMBTU/hr,

a n d

t h e d i v i d i n g W a l l

column c a s e 2 r e q u i r e s a t o t a l c o n d e n s e r d u t y

o f

2 6 . 5

MMBTU/hr versus 32.3 MMBTU/hr o r

t h e

tWo conven

t i o n a l

c o l u m n s .

S i m i l a r l y , t h e d i v i d i n g

W a l l column c a s e

1

r e q u i r e s a t o t a l

r e b o i l e r

d u t y o f 2 5 . 3

MMBTU/hr, a n d

t h e

d i v i d i n g

W a l l column c a s e 2

r e q u i re s a

t o t a l r e b o i l e r d u t y o f

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7 , 4 9 8 , 4 7 1

B2

7

2 6 . 3

MMBTU/hr

ersus

31

MMBTU/hr

o r

t h e

tWo

conven

t i o n a l c o l u m n s .

As

o t h e

number

o f

s t a g e s ,

t h e d i v i d i n g W a l l

column c a s e 1

r e q u i r e s

6 7 s t a g e s , a n d t h e d i v i d i n g W a l l c o l

umn a s e 2 r e q u i r e s

6 2

s t a g e s

v e r s u s

78 t o t a l s t a g e s f o r t h e

tWo

c o n v e n t i o n a l

c o l u m n s . F i n a l l y ,

t h e d a t a

shoWs t h e r e i s

a

s m a l l i n c r e a s e

i n cumene p u r i t y

and d e c r e a s e i n t h e

amount

of

enzene o s t

t o

v e n t . T h e r e f o r e , t h e u s e

of

h e d i v i d i n g

W a l l

column r e d u c e s t h e c a p it a l c o s t s a s t o t h e number of r a ys a s

W e l l a s t h e u t i l i t y

c o s t s

a s compared o a

s e t of

c o n v e n t i o n a l

f r a c t i o n a t i o n

c o l u m n s .

TABLE

2 Column

Design DWC

ase

1

DWC

ase

2

T o t a l Cond QMW

9 . 4 5

3 2 . 3 )

7 . 5 0

2 5 . 6 )

7 . 7 6

2 6 . 5 )

( M M B T U / h r )

T o t a l Reb QMW 9 . 0 8

3 1 )

7 . 4 1

2 5 . 3 )

7 . 7 0

2 6 . 3 )

( M M B T U / h r )

T o t a l # of t a g e s 7 8 6 7

6 2

%

a v i n g s in

Cond

Q

20.74%

17.96%

%

a v i n g s

in Reb

Q 18.39% 15.16%

% a v i n g s

in #

S t a g e s 14.10% 20.51%

Cumene P u r i t y

( W t %)

9 9 . 9 4 4 9 9 . 9 5 5 9 9 . 9 5 5

Benz n

Cumene

( W t

ppm)

4 4 4

Cymenes n Cumene

( W t

ppm)

1 6 1 6

1 5

Benzene L o s t

t o

V e n t * ( W t

% )

1 . 3 7

0 . 1 8

0 . 1 8

*based on benzene

in

f r e s h f e e d

The i n v e n t i o n

c l a i m e d i s :

1 . A umene g e n e r a t i o n p r o c e s s u s i n g

a d i v i d i n g

W a l l f r a c

t i o n a t i o n z o n e , s a i d

p r o c e s s c o m p r i s i n g :

c o n t a c t i n g ,

in a n a l k y l a t i o n z o n e , a t l e a s t p r o p y l e n e , ben

z e n e , and a ? r s t benzene

r e c y c l e

s t r e a m W i t h a n a l k y l a

t i o n

c a t a l y s t u n d e r a l k y l a t i o n c o n d i t i o n s t o c o n v e r t

a t

l e a s t a

p o r t i o n o f

h e p r o p y l e n e and benzene i n t o cumene

and

form

an

a l k y l a t i o n zone e f ? u e n t

c o m p r i s i n g

ben

zene and cumene;

c o n t a c t i n g ,

i n a

t r a n s a l k y l a t i o n

z o n e , a

p o l y i s o p r o p y l b e n

z e n e - r i c h r e c y c l e

s t r e a m

c o m p r i s i n g

a t

l e a s t

p o l y i s o p r o

pylbenzene

and a second benzene

r e c y c l e s t r e a m

c o m

p r i s i n g a t l e a s t b e n z e n e W i t h

a t r a n s a l k y la t i o n

c a t a l y s t

under

t r a n s a l k y l a t i o n

c o n d i t i o n s t o c o n v e r t a t l e a s t a

p o r t i o n

o f t h e p o l y i s o p r o p y l b e n z e n e

a n d b e n z e n e i n t o

cumene and for m a t r a n s a l k y l a t i o n zone ef?uent com

p r i s i n g b e n z e n e a n d c u m e n e ;

p a s s i n g t h e a l k y la t i o n

z o n e e f ? u e n t a n d

t h e t r a n s a l k y la t i o n

zone e ? l u e n t

i n t o

a d i v i d i n g

W a l l

f r a c t i o n a t i o n

column

o p e r a t e d a t

f r a c t i o n a t i o n c o n d i t i o n s and d i v i d e d

i n t o

a t

l e a s t a ? r s t and

second

a r a l l e l f r a c t i o n a t i o n

zone

by a

d i v i d i n g

W a l l , W i t h

t h e

? r s t a n d

t h e s e c o n d

f r a c t i o n a t i o n

zones

each

having an

upper

and a loWer end l o c a t e d

W i t h i n t h e

f r a c t i o n a t i o n

c o l u m n ,

W i t h t h e ? r s t and s e c

ond

r a c t i o n a t i o n z o n e s b e i n g i n open comm unication t

t h e i r upper e n d s With

an

u n d i v i d e d upper s e c t i o n of h e

f r a c t i o n a t i o n column and i n open communication a t

20

30

35

40

45

50

8

t h e i r loWer e n d s With

an

u n d i v i d e d loWer s e c t i o n of h e

f r a c t i o n a t i o n c o l u m n ,

and

i t h

t h e a l k y la t i o n

z o n e e ? l u

e n t and t r a n s a l k y l a t i o n

z o n e

e ? l u e n t

e n t e r i n g t h e

c o l

umn t

i n t e r m e d i a t e

p o i n t s of h e

? r s t f r a c t i o n a t i o n zone

Wherein

t h e

t r a n s a l k y l a t i o n zone e f ? u e n t i s i n t r o d u c e d

i n t o

t h e d i v i d i n g W a l l

f r a c t i o n a t i o n column t

an

i n t e r

m e d i a t e

h e i g h t o f h e d i v i d i n g W a l l f r a c t i o n a t i o n c o l u m n

Which

s

betWeen t h e i n t e r m e d i a t e h e i g h t a t Which t h e

a l k y l a t i o n zone e f ? u e n t i s i n t r o d u c e d and a ? r s t end of

t h e

d i v i d i n g

W a l l f r a c t i o n a t i o n c o l u m n ;

removing a

stream

comprising cumene from

an

i n t e r m e d i

a t e

p o i n t

o f

h e

s e c o n d f r a c t i o n a t i o n z o n e o f

h e d i v i d i n g

W a l l f r a c t i o n a t i o n

c o l u m n ;

r e m o v i n g t h e ? r s t b e n z e n e r e c y c l e

s t r e a m

f r o m t h e ? r s t e n d

o f t h e d i v i d i n g

W a l l f r a c t i o n a t i o n

c o l u m n ;

removing h e s e c o n d b e n z e n e

r e c y c l e

s t r e a m

from n i n t e r

m e d i a t e p o i n t

o f t h e s e c o n d f r a c t i o n a t i o n

z o n e o f

t h e

d i v i d i n g

W a l l

f r a c t i o n a t i o n c o l u m n ;

removing a polyisopropylbenzene-rich stream fr o m a s e c

o n d e n d

o f

t h e d i v i d i n g

W a l l f r a c t i o n a t i o n c o l u m n ;

a n d

p a s s i n g t h e p o l y is o p r o p yl b e n z e n e - r i c h s t r e a m t o a p o l y

i s o p r o p y l b e n z e n e f r a c t i o n a t i o n

column

o s e p a ra t e t h e

p o l y i s o p r o p y l b e n z e n e r e c y c l e s t r e a m

from heavy

a r o

m a t i c s - r i c h

s t r e a m .

2 .

The

p r o c e s s

o f c l a i m

1

Wherein

t h e a l k y l a t i o n

zone i s

o p e r a t e d

a t

a p r e s s u r e

i n

t h e

r a n g e of 800 o 5100

kPa

1

1 6

t o

740 p s i a ) and a t e m p e r a t u r e

i n

t h e r a n g e o f 120

t o 2 8 0 °

C .

( 2 4 8

t o 5 3 6 °

F . ) .

3 . The

p r o c e s s

o f

c l a i m 1 Wherein h e t r a n s a l k y l a t i o n zone

i s o p e r a t e d

a t

a p r e s s u r e i n t h e r a n g e

o f

800 o 5100 kPa 1 1 6

t o 740 p s i a ) and

t e m p e r a t u r e

i n t h e r a n g e of 100 o 270° C .

( 2 1 2 t o

5 1 8 0

F . ) .

4 .

The

p r o c e s s

o f c l a i m

1 f u r t h e r c o m p r is i n g c o n d e n s i n g

t h e ? r s t

b e n z e n e

r e c y c l e

s t r e a m u s i n g

a

c o n d e n s e r o p e r a t e d

a t

a t e m p e r a t u r e in

t h e

r a n g e

of30 o 4 5 ° C .

( 8 6

t o 1 1 3 ° F . ) and

a

p r e s s u r e

i n

t h e r a n g e of7 t o

1 4 kPa

1

t o 2 p s i a ) .

5 .

The p r o c e s s o f c l a i m

1 W h e r e i n t h e p o l y i s o p r o p y l b e n

z e n e

column

i s

o p e r a t e d

s o

t h a t

t h e

t e m p e r a t u r e of

h e

? r s t

benzene

e c y c l e

s t r e a m

i s

i n

t h e

r a n g e o f 8 5 t o 1 0 5 °

C .

( 1 8 5 t o

2 2 1 °

F . )

and h e

p r e s s u r e i s 1 6 t o 1 9 kPa 2 . 3 t o

2 . 7

p s i a ) .

6 .

The p r o c e s s

o f c l a i m 1 W h e r e i n t h e s t r e a m c o m p r i s i n g

cumene from

an

i n t e r m e d i a t e p o i n t of t h e second

f r a c t i o n

a t i o n zone of t h e d i v i d i n g W a l l f r a c t i o n a t i o n

column

com

p r i s e s 9 9 . 9 5 5 Wt umene.

7 . The p r o c e s s o f c l a i m 1 W h e r e i n t h e s t r e a m

c o m p r i s i n g

cumene from

an

i n t e r m e d i a t e p o i n t of t h e second

f r a c t i o n

a t i o n zone of t h e d i v i d i n g

W a l l f r a c t i o n a t i o n

column com

p r i s e s no more t h a n about 4 W t . ppm enzene.

8 . The p r o c e s s o f

c l a i m 1

f u r t h e r c o m p r i s i n g p a s s i n g

t h e

s t r e a m c o m p r i s i n g cumene t o a p h e n o l

g e n e r a t i o n

p r o c e s s .

9 . The p r o c e s s o f

c l a i m 1

f u r t h e r c o m p r i s i n g p a s s i n g

t h e

stream co mprising

cumene o

an a c e t o n e g e n e r a t i o n p r o c e s s .

* * * * *


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