Reduction of sulfur dioxide to elemental sulfur using methane as the reducing agent
by Willard F Davis
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Chemical Engineering
Montana State University
© Copyright by Willard F Davis (1956)
Abstract:
An investigation was conducted to determine what effect temperature, mol ratio of feed, and total mols
of feed would have on the reduction of sulfur dioxide with methane using a semi-continuous flow
fixed-bed catalytic process unit.
Sulfur dioxide was reduced with methane over 400 grams of catalyst while operating conditions were
varied between the following limits; temperature — 525°to 595°C., mol ratio of methane to sulfur
dioxide — 1.32 to 7.14, total mols of feed per hour — 6.06 to 9.09.
When operating at a mol ratio of 3.6 and 8.0 total mols of feed, a temperature of 562°C. gave a
maximum conversion to sulfur of 62 percent with fresh catalyst but after extended catalyst use a
temperature of 550°C. gave a maximum yield of 58 percent. In both cases a decrease in conversion to
sulfur was accompanied by an increase in the percent sulfur dioxide converted to other products at
temperatures above 562°and 550°C., and by an increase in percent sulfur dioxide which was unreacted
at temperatures below 562°and 550°C.
A 3.6 mol ratio of methane to sulfur dioxide produced a 62 percent maximum reduction to sulfur when
temperature and total mols of feed were held constant at 562°C. and 8.0 mols, respectively. A decrease
in reduction to sulfur was accompanied by an increase in percent sulfur dioxide converted to other
products at mol ratios greater than 3.6 and an increase in percent sulfur dioxide which passed unreacted
when mol ratios less than 3.6 were used.
The rate of feed which appeared most favorable for conversion to sulfur when used with a temperature
of 562°C. and a mol ratio of 3.6 was 8.4 total mols per hour and feed rates both greater and less than
this value gave a sharp reduction in percent conversion to sulfur accompanied by a corresponding sharp
increase in percent sulfur dioxide converted to other products.
It is believed that greater ultimate yield of sulfur may be obtained by operating at a temperature below
560°C, and a mol ratio less than 3.6 with subsequent recycle of the unreacted sulfur dioxide.
Extended use of the catalyst produced a definite change in its activity as indicated by a decrease in
maximum, conversion to sulfur from 62 to 58 percent, while the temperature at which these maximums
occurred shifted from 562°C. for fresh catalyst to 550°C. for catalyst which had been in service for 160
hours.
Time required to stabilize operating conditions was felt to be a source of experimental error since it
was included in the actual run. REDUCTION OF SULFUR DIOXIDE TO ELEMENTAL SULFUR
USING METHANE AS THE REDUCING AGENT
by
WILLARD F . DAVIS
A THESIS
S u b m itte d t o t h e G r a d u a te F a c u l t y
in
p a r t i a l f u l f i l l m e n t o f t h e r e q u i r e m e n ts
f o r th e d e g re e of
M a s te r o f S c ie n c e i n C h e m ic a l E n g in e e r in g
at
M ontana S t a t e C o lle g e
■A p p ro v e d ;
Bozeman
Bozem
anj M ontana
S e p te m b e rj 1956
-
3)
2
-
TABLE OF CONTENTS
-2P ag e
A b s t r a c t ..........................................................................................................
,
■
3
I n t r o d u c t i o n .....................................................................................................
•
4
A.
B a c k g ro u n d
..................................................................................
.
4
B.
P r e v io u s W o r k ........................................................................ ....
.
6
T herm odynam ic C o n s i d e r a t i o n s ..............................................................
.
9
9
A.
M ethods ............................................................................................
.
B.
C o n c lu s io n s ..................................................................................
. 11
E q u ip m e n t D e s ig n a n d C o n s t r u c t i o n
................................................
. 12
..................................................................................
. 12
A.
F low S h e e t
B.
D e s ig n a n d S p e c i f i c a t i o n s o f Com ponent P a r t s
.
. 13
P r o c e d u r e s a n d M a t e r i a l s ........................................................................
. 18
E x p e rim e n t D e s ig n
. 22
.......................................................................................
D is c u s s io n o f R e s u lts
.............................................................................
. 24
A.
T e m p e ra tu re ..................................................................................
• 24
B.
Mol R a t i o .......................................................................................
• 25
C.
T o t a l M ols o f F e e d
...............................................................
• 25
D.
T h e o r e t i c a l R e c y c le o f U n r e a c te d S u l f u r D io x id e
. 25
E.
C a ta ly s t A c tiv ity
...................................................................
. 26
F.
L in e o u t
............................................................................................
. 27
Summary
B ib lio g r a p h y
. 28
.
. 29
Acknow ledgem ent
. 30
A ppendix
. 31
119225
-3 ABSTRAOT
An i n v e s t i g a t i o n w as c o n d u c te d t o d e te r m in e w h a t e f f e c t te m p e r a tu r e ,,
m ol r a t i o o f f e e d , a n d t o t a l m o ls o f f e e d w o u ld h a v e on t h e r e d u c t i o n
o f s u l f u r d i o x i d e w i t h m e th a n e u s i n g a s e m i- c o n tin u o u s f l o w f i x e d - b e d
c a ta ly tic p ro ce ss u n it.
' S u l f u r d i o x i d e was r e d u c e d w i t h m e th a n e o v e r AOO g ram s o f c a t a l y s t
w h i l e o p e r a t i n g c o n d i t i o n s w e re v a r i e d b e tw e e n t h e f o l l o w i n g l i m i t s :
t e m p e r a t u r e — 525 ° t o 5 9 5 ° C ., m ol r a t i o o f m e th a n e t o s u l f u r d i o x id e —
1 .3 2 t o 7 . IA 5 t o t a l m o ls o f f e e d p e r h o u r — 6 .0 6 t o 9 . 0 9 .
.When o p e r a t i n g a t a m o l r a t i o o f 3 . 6 a n d 8 .0 t o t a l m o ls o f f e e d , a
t e m p e r a t u r e o f $ 6 2 °C . g a v e a maximum c o n v e r s i o n t o s u l f u r o f 62 p e r c e n t
w i t h f r e s h c a t a l y s t b u t a f t e r e x te n d e d c a t a l y s t u s e a t e m p e r a t u r e o f
5 5 p °C . g a v e a maximum y i e l d o f 58 p e r c e n t . I n b o th c a s e s a d e c r e a s e i n
c o n v e r s i o n t o s u l f u r w as a c c o m p a n ie d b y a n i n c r e a s e i n t h e p e r c e n t s u l f u r
d i o x i d e c o n v e r t e d t o o t h e r p r o d u c t s a t t e m p e r a t u r e s a b o v e 562° a n d SSO0C . ,
a n d b y a n i n c r e a s e i n p e r c e n t s u l f u r d i o x i d e w h ic h w as u n r e a c t e d a t
t e m p e r a t u r e s b e lo w 5 6 2 °a n d 550°C .
A 3 .6 m o l r a t i o o f m e th a n e t o s u l f u r d i o x i d e p r o d u c e d a 62 p e r c e n t
maximum r e d u c t i o n t o s u l f u r when t e m p e r a t u r e an d t o t a l m o ls o f f e e d w e re
h e l d c o n s t a n t a t 5 6 2 °C . a n d 8 .0 m o ls , r e s p e c t i v e l y . A d e c r e a s e i n r e ­
d u c t i o n t o s u l f u r w as a c c o m p a n ie d b y a n i n c r e a s e i n p e r c e n t s u l f u r
d i o x i d e c o n v e r t e d t o o t h e r p r o d u c t s a t m o l r a t i o s g r e a t e r t h a n 3 .6 a n d a n
i n c r e a s e i n p e r c e n t s u l f u r d i o x i d e w h ic h p a s s e d u n r e a c t e d when m ol r a t i o s
l e s s t h a n 3 . 6 w e re u s e d .
■The r a t e o f f e e d w h ic h a p p e a r e d m o st f a v o r a b l e f o r c o n v e r s i o n t o
s u l f u r when u s e d w i t h a t e m p e r a t u r e o f 562 ° C . a n d a m o l r a t i o o f 3 .6 was
8 . A t o t a l m o ls p e r h o u r a n d f e e d r a t e s b o t h g r e a t e r a n d l e s s t h a n t h i s
v a l u e g a v e a s h a r p r e d u c t i o n i n p e r c e n t c o n v e r s io n t o s u l f u r a c c o m p a n ie d
b y a c o r r e s p o n d in g s h a r p i n c r e a s e i n p e r c e n t s u l f u r d i o x i d e c o n v e r te d t o
o th e r p ro d u c ts .
I t i s b e l i e v e d t h a t g r e a t e r u l t i m a t e y i e l d o f s u l f u r m ay b e o b t a i n e d
b y o p e r a t i n g a t a t e m p e r a t u r e b e lo w 560 ° C „ a n d a m ol r a t i o l e s s t h a n 3 ,6
w ith su b se q u e n t r e c y c le o f th e u n re a c te d s u lf u r d io x id e .
E x te n d e d u s e o f t h e c a t a l y s t p ro d u c e d a d e f i n i t e c h a n g e i n i t s
a c t i v i t y a s i n d i c a t e d b y a d e c r e a s e i n maximum, c o n v e r s io n t o s u l f u r fro m
62 t o 56 p e r c e n t , w h ile t h e t e m p e r a t u r e a t w h ich t h e s e maximums o c c u r r e d
s h i f t e d fro m 5 62°C . f o r f r e s h c a t a l y s t t o S50°C . f o r c a t a l y s t w hich h a d
b e e n i n s e r v i c e f o r 160 h o u r s .
Time r e q u i r e d t o s t a b i l i z e o p e r a t i n g c o n d i t i o n s was f e l t t o b e a
s o u r c e o f e x p e r i m e n t a l e r r o r s i n c e i t w as i n c l u d e d i n t h e a c t u a l r u n .
I
“4INTRODUCTION
A.
B a c k g ro u n d
I n t h e y e a r s f o l l o w i n g W orld War I I ,
a n d p a r t i c u l a r l y t h e y e a r s 1950
t o 1 9 5 2 , t h e r e d e v e lo p e d i n t h e s u l f u r m a r k e t a " t i g h t " s i t u a t i o n i n w h ic h
i n d u s t r i a l s u p p l i e s w e re s u f f i c i e n t t o m e e t consum er n e e d s f o r o n ly t h r e e
to
s e v e n m o n th s ..
T h is w as n o t c o n s i d e r e d a h e a l t h y c o n d i t i o n a n d s t e p s
w e re t a k e n b y v a r i o u s G overnm ent a g e n c i e s t o rem edy t h e s i t u a t i o n .
D u rin g
t h i s p e r i o d p r i c e s o f s u l f u r r a n g e d fro m $21 t o $24 p e r t o n a t t h e m in e s
t o a s m uch a s $100 t o $200 p e r t o n on t h e e x p o r t m a r k e t .
The u p sw in g o f t h e v a l u e o f s u l f u r l e d t o i n c r e a s e d e f f o r t i n t h e
s e a r c h f o r a d d i t i o n a l s o u r c e s o f t h i s co m m odity.
O ld m in e s w e re r e o p e n e d
a n d new d e p o s i t s o f s u l f u r o r e s w e re s u r v e y e d an d d e v e lo p e d , b u t t h e s e
g a v e o n l y a 3 0 t o 40 y e a r r e s e r v e a t p r e s e n t c o n su m p tio n r a t e s .
The h ig h
m a r k e t v a l u e o f e l e m e n t a l s t i l f u r m ade r e c o v e r y o f t h i s m a t e r i a l a s a b y -'
p r o d u c t fro m f u e l s a n d s ta c k , g a s e s e c o n o m ic a lly a t t r a c t i v e .
The n e e d f o r
re m o v a l o f s u l f u r fro m i n d u s t r i a l g a s e s t o im p ro v e t h e i r u t i l i t y a s f u e l
o r t o r e d u c e a i r p o l l u t i o n e n c o u ra g e d t h i s t y p e o f s u l f u r p r o d u c t i o n , b u t
t h e g r e a t e s t i m p e tu s w as g iv e n b y t h e s u l f u r s h o r t a g e .
Many c o m p a n ies
t h a t consum e s u l f u r , p a r t i c u l a r l y t h o s e i n t h e p e tr o le u m i n d u s t r y , saw a n
o p p o r t u n i t y t o im p ro v e t h e i r i n d i v i d u a l s u p p ly p o s i t i o n s b y i n s t a l l i n g
e q u ip m e n t t o r e c o v e r . s u l f u r fro m t h e i r w a s te g a s e s .
T h e se p l a n t s g a v e a
35 p e r c e n t i n c r e a s e i n t h e r e c o v e r e d - s u l f u r o u t p u t .
S in c e 1952 e x t e n s i v e d e p o s i t s o f e l e m e n t a l s u l f u r h a v e b e e n l o c a t e d
a n d d e v e lo p e d i n M exico a n d m in in g m e th o d s h a v e b e e n im p ro v e d i n o t h e r
-
5
“
p a r t s o f t h e w o r ld a n d , a s a r e s u l t , t h e p r i c e o f s u l f u r h a s t a k e n a
s h a r p d r o p , t h u s re m o v in g much o f t h e i n c e n t i v e f o r t h e e x p e n d i t u r e s o f
c a p i t a l on s u l f u r r e c l a m a t i o n e q u ip m e n t a t t h i s t i m e .
The e x i s t i n g . r e ­
s e r v e s o f s u l f u r a r e n o t u n l i m i t e d a n d t h e tim e w i l l come w hen o t h e r
s o u r c e s w i l l h a v e t o be d e v e lo p e d t o
s u p p le m e n t t h e n a t u r a l d e p o s i t s .
I n t h e m e t a l l u r g i c a l i n d u s t r y m any o f t h e o r e s o f i r o n , c o p p e r ,
s i l v e r , l e a d , a n d o t h e r m e t a l s a r e fo u n d a n d m in e d a s t h e r e s p e c t i v e
s u lf i d e s i n v a ry in g fo rm s.
One o f t h e m e th o d s u s e d f o r r e c o v e r i n g t h e s e
m e t a l s fro m t h e i r o r e s , w h ic h h a s b e e n i n u s e f o r c e n t u r i e s an d i s
s till
u se d e x te n s iv e ly to d a y , in v o lv e s c o n v e rtin g th e s u lf id e o re t o i t s
c o r r e s p o n d in g o x id e a n d t h e n r e d u c i n g t o t h e m e t a l w i t h c a rb o n o r some
o th e r m a te ria l.
To c o n v e r t t h e m e t a l l i c s u l f i d e s t o o x i d e s , t h e o r e s a r e l i t e r a l l y
b u r n e d , o r s i n t e r e d , a t r e l a t i v e l y h i g h t e m p e r a t u r e s i n a n a i r a tm o s p h e re .
P a r t o f t h e o x y g en fro m t h e a i r r e p l a c e s t h e s u l f u r i n t h e o r e , t h u s
f o r m in g m e t a l l i c o x i d e s , a n d t h e d i s p l a c e d s u l f u r t h e n r e a c t s w i t h s u f ­
f i c i e n t q u a n t i t i e s o f t h e r e m a i n i n g ■o x y g en t o fo rm s u l f u r d i o x i d e o r
s u lfu r tr io x id e .
T h e se s u l f u r com pounds, b e in g g a s e o u s , e n t e r t h e f l u e ­
g a s s tr e a m a n d p a s s t o t h e s t a c k w h e re t h e y a r e d i s s i p a t e d i n t o th e
a tm o s p h e r e .
M ost s m e l t e r s h a v e f o r som etim e r e c o v e r e d enough s u l f u r d i o x id e fro m
t h e i r s t a c k g a s e s t o m a n u f a c tu r e t h e s u l f u r i c a c i d r e q u i r e d i n t h e i r own
p l a n t a n d i n t h e im m e d ia te a r e a .
To a t t e m p t t o s u p p ly a m a r k e t l o c a t e d
a n y d i s t a n c e fro m t h e p l a n t i s p r o h i b i t e d b y t h e fiig h c o s t o f t r a n s p o r t i n g
th e a c id .
Some p l a n t s h a v e f o u n d i t p r o f i t a b l e t o i n s t a l l f e r t i l i z e r
p l a n t s a n d o t h e r r e l a t e d p r o c e s s e s w h e r e in a d d i t i o n a l a m o u n ts o f s u l f u r i c
a c id can be u s e d .
T h e se p r o c e s s e s a r e g e n e r a l l y s e a s o n a l i n n a t u r e a n d
.
.
a t b e s t u s e o n l y a s m a l l p o r t i o n o f t h e s u l f u r d i o x id e w h ic h i s p ro d u c e d
i n t h e s m e l ti n g o p e r a t i o n .
I f some e c o n o m ic a l m eth o d w e re a v a i l a b l e b y
w h ic h t h i s w a s te d s u l f u r d i o x i d e c o u ld b e c o n v e r t e d t o e l e m e n t a l s u l f u r ,
a new s o u r c e o f r e v e n u e w o u ld b e a v a i l a b l e t o t h e s m e l t e r s a n d a v a l u a b l e
c o n t r i b u t i o n w o u ld b e a d d e d t o o u r s u l f u r r e s e r v e s .
B.
P r e v io u s Work
I n c o n s i d e r i n g t h e p ro b le m o f r e d u c t i o n o f s u l f u r d i o x i d e t o o b t a i n
e l e m e n t a l s u l f u r , t h e l i t e r a t u r e w as c o n s u l t e d t o d e te r m in e w h a t p r e v i o u s
w o rk , i f a n y , h a d b e e n do n e a lo n g t h e s e l i n e s .
w h ic h a p p e a r e d i n t h e l i t e r a t u r e p r i o r t o 1 9 2 9 .
No s u r v e y w as made on w ork
I t was f o u n d t h a t c o n s id ­
e r a b l e w ork h a d b e e n d o n e on t h e p ro b le m ., b o t h i n t h e U n ite d S t a t e s a n d i n
o th e r c o u n trie s .
A r t h u r J . C a d d ic k ( l )
c a r r i e d o u t e x p e r im e n ts i n w h ic h a b e d o f i n ­
c a n d e s c e n t c o k e w as u s e d t o p ro d u c e e l e m e n t a l s u l f u r fro m g a s e s o f v a r y i n g
s u l f u r d io x id e c o n te n t.
C a d d ic k 1s r e s u l t s i n d i c a t e d t h a t t h e r e was a
maximum r e c o v e r y o f s u l f u r a n d a minimum c o n su m p tio n o f c o k e when t h e f e e d
g a s e s c o n t a i n e d s e v e n p e r c e n t s u l f u r d i o x i d e b y v o lu m e .
I n a h e x p e rim e n t
i n w h ic h s te a m w as i n j e c t e d w i t h t h e SOg, C a d d ic k r e p o r t e d t h e r e c o v e r y
o f 7 4 .1 4 p e r c e n t o f t h e
s u l f u r c o n t e n t , w i t h a c o n s u m p tio n o f 1 .1 2 t o n s
o f c o k e a n d 0 .0 8 t o n s o f s te a m p e r t o n o f r e c o v e r a b l e s u l f u r .
“7I n e x p e r im e n ts c a r r i e d o u t b y t h e R u s s i a n s ,
(5) ,
s u l f u r d i o x id e was
r e p o r t e d t o r e a c t w e l l . w i t h m e th a n e a t 9 00°C . o v e r a b a u x i t e c a t a l y s t t o
fo rm s u l f u r , h y d ro g e n s u l f i d e , w a t e r , a n d c a rb o n m o n o x id e .
At h ig h e r
t e m p e r a t u r e s h y d ro g e n a n d c a rb o n m o n o x id e w e re fo rm e d , w h i l e a t lo w e r
t e m p e r a t u r e s t h e m e th a n e was r e p o r t e d t o r e a c t i n c o m p l e t e l y .
TfiZhen u s in g
a m e th a n e t o s u l f u r d i o x i d e r a t i o of" Q.4 3 a n d a t e m p e r a t u r e o f 9 0 0 °C .,
t h e i r y i e l d o f s u l f u r , b a s e d on m e th a n e , w as 8 9 .2 t o 9 6 .5 p e r c e n t .
J . ¥ . Beckman ( 3 ) r e d u c e d s u l f u r d i o x i d e i n t h e p r e s e n c e o f a
" s im p le " c a t a l y s t b y p a s s i n g a m ix t u r e o f s u l f u r d i o x i d e a n d n a t u r a l g a s
o r c a rb o n m o n o x id e t h r o u g h a c y l i n d r i c a l c h am b er w h ic h c o n t a i n e d t h e
c o n t a c t m a s s , a n d w h ic h w as e l e c t r i c a l l y h e a t e d t o m a i n t a i n t h e " c o n t a c t
m a ss a t 4 2 7 ° t o 4 7 0 °C .
The s u l f u r p ro d u c e d w as c o n d e n se d fro m t h e d i s ­
c h a r g e g a s e s a n d w as c o l l e c t e d a s a l i q u i d .
The r e d u c t i o n r e a c t i o n was
f o u n d t o b e e x o th e r m i c .
The r e d u c t i o n o f s u l f u r d i o x id e w as r e p o r t e d t o b e c a t a l y z e d by
b a u x i t e ( 7 ) ( 5 ) o r v a n a d iu m p e n to x i d e ( 2 ) , a n d t h e c a t a l y t i c a c t i o n o f
b a u x i t e w as r e p o r t e d t o b e im p ro v e d b y t h e a d d i t i o n o f i r o n o r m anganese
com pounds ( l ) .
A s m e l t e r l o c a t e d a t T r a i l , B r i t i s h C o lu m b ia , ( 4 ) , o p e r a t e d a p l a n t
w h ic h u t i l i z e d a n i n c a n d e s c e n t b e d o f c o k e t o re d u c e t h e s u l f u r diopd.de
fro m t h e i r s t a c k g a s e s t o e le m e n t a l s u l f u r .
T h is p l a n t w as o p e r a t e d on a
c o m m e rc ia l s c a l e .
A f te r s tu d y in g th e in fo r m a tio n fo u n d i n th e l i t e r a t u r e an d c o n s id e r­
i n g t h e v a r i o u s r e d u c i n g a g e n t s w h ic h w e re r e a d i l y a v a i l a b l e , i t was
d e c id e d t h a t p r e l i m i n a r y s t u d i e s o f t h e r e d u c t i o n o f s u l f u r d i o x i d e w ould
-8 ~
b e m ade u s i n g n a t u r a l g a s a s a s o u r c e o f m e th a n e a n d a c t i v a t e d a lu m in a a s
a ’c a t a l y s t .
T h is p a p e r i s a d i s c u s s i o n o f t h e e x p e r i m e n t a l r e d u c t i o n o f s u l f u r
d i o x i d e b y m e th a n e a n d t h e e f f e c t s on t h a t r e d u c t i o n p r o d u c e d b y v a r y i n g
t e m p e r a t u r e , m ol r a t i o o f r e a c t a n t s , a n d t o t a l m o ls o f r e a c t a n t s p a s s e d
p e r h o u r.
'I
-9 THERM ODm M IC CONSIDERATIONS
A.
M ethods
I n c o n s id e r in g t h e r e d u c tio n o f s u l f u r d io x id e w ith m e th a n e , i t was
f e l t t h a t some p r e l i m i n a r y s tu d y o f t h e therm odynam ic a s p e c t s o f th e
p ro b lem s h o u ld be c a r r i e d o u t .
To do t h i s , a number o f r e a c t i o n e q u a tio n s
in v o l v in g s u l f u r d io x id e an d m ethane w ere p o s t u l a t e d .
T h ese e q u a tio n s
w ere chosen t o g iv e v a r io u s r e a c t i o n p r o d u c ts and t o t e s t how some o f th e
p r o d u c ts m ig h t p o s s i b l y be e x p e c te d t o b eh av e i n th e p r e s e n c e o f s u l f u r
d io x i d e .
The s u g g e s te d r e a c t i o n s w ere s e t f o r t h a s o n ly a p o r t i o n o f
th o s e w hich c o u ld be w r i t t e n .
I t i s p o s s i b l e t h a t t h e r e d u c t io n i s b y a
r e a c t i o n w h ich h a s n o t b een p r e s e n te d .
The s i x r e a c t i o n s w hich w ere
considered are:
(I )
2802(g) +
(2 )
4S02 (g) + 3GH4 (g )
CS2 (g) + 2C02 (g) + 4H2° ( g ) + 2H2S(g)
(3)
5802(g) + 3OH^g) —
°^2 (g) + 3 / 2 8g (g ) + 2002(g) + &H20(g)
U)
3 S02 (g) + 2CH4 (g )
^Sgfg) + 2H2S(g) + 2002(g) + 2^ O fg )
(5)
^ ( g ) + GS2 (g)
(6)
S02 (g) + 2H2S (g) —■>
8 2(g) + 0 0 2 (g) + %2 0(g)
3Z2 8 2(g) + 002(g)
3Z2 8 2 (g) + 2Ha0 (g)
I n t h e s e e q u a tio n s t h e f i r s t f o u r d e a l w ith r e a c t i o n b etw een m ethane
and s u l f u r d io x id e , w h ile t h e l a s t two s u g g e s t some p o s s i b l e r e a c t i o n s
betw een s u l f u r d io x id e and some o f th e p r o d u c ts o b ta in e d i n t h e f i r s t
f o u r e q u a tio n s .
I
-
10-
D ata fro m T a b le I was u s e d t o c a l c u l a t e a change o f e n th a lp y a t
s ta n d a r d c o n d i tio n s (A Hgog) by s u b t r a c t i n g t h e t o t a l h e a t s o f fo rm a tio n
(A H f 2 ^ )
o f t h e r e a c t a n t s fro m t h e t o t a l h e a t s o f f o r m a tio n o f th e
p r o d u c ts .
S i m i l a r l y , t h e change i n e n tr o p y {A S2
s u b t r a c t i n g t h e sum o f Sc
p r o d u c ts .
298
was c a l c u l a t e d by
o f th e r e a c t a n t s from th e Sc
o f th e
7
.............
298
A te m p e r a tu r e o f n e u t r a l 1 e q u ilib r iu m (Tn e ) , a t w hich th e
e q u ilib r iu m c o n s ta n t (Kg q ) e q u a ls o n e , was c a l c u l a t e d b y d i v i d i n g th e
o f an e q u a tio n b y i t s c o rre s p o n d in g A
T hese r e s p e c t i v e
v a lu e s o f A H2^g and A S2 ^ were then used t o c a lc u la te th e change in
fr e e energy ( A F ) f o r each o f the, p o stu la te d r e a c tio n s a t tem peratures of
2 9 8 °, 4 0 0 ° , 6 0 0 °, 1 0 0 0 °, an d I g 0 0 %
u s in g th e e q u a tio n
A F t = AH2^d - T (A S 298)
where
T = te m p e r a tu r e b e in g s t u d i e d , i n d e g re e s K e lv in , ( 0K ).
A m ore r ig o r o u s d e te r m in a tio n o f th e v a l u e s o f A F was n o t a tte m p te d ,
s in c e h e a t c a p a c i t i e s f o r some o f th e p r o d u c ts form ed w ere n o t a v a ila b le *
E q u ilib r iu m c o n s t a n t s (K
eq
) w ere c a l c u l a t e d f o r each r e a c t i o n a t each
o f th e te m p e r a t u r e s , u s in g t h e e q u a tio n
lo g IO
w here
T = te m p e r a tu r e i n 0K.
R = g a s c o n s ta n t (1 .9 8 7 )
A F = chapge i n f r e e e n e rg y a t te m p e r a tu r e T.
-
11
-
A sa m p le o f t h e s e c a l c u l a t i o n s i s g iv e n i n T a b le I I a lo n g w i t h t h e
A
c a lc u la te d v a lu e s o f
3 A
A
a n d Ke q (T j f o r e a c h o f t h e
p o s tu la te d r e a c tio n s .
Zh
C o n c lu s io n s ;
I n t h e f i r s t f i v e s u g g e s t e d r e a c t i o n s th e - A -^(t ) v a l u e s a r e a l l
n e g a tiv e and th e
^^
e q u ilib r iu m , v a l u e s a r e a l l g r e a t e r t h a n o n e ,
i n d i c a t i n g t h a t i f t h e s e w e re t h e r e a c t i o n s i n v o l v e d , t h e y s h o u ld p r o c e e d
to w a r d t h e r i g h t a t r e a s o n a b l e o p e r a t i n g t e m p e r a t u r e s .
a p o s itiv e
R e a c ti o n s i x h a s
A F ^ ^ v a l u e i n t h e lo w e r t e m p e r a t u r e r a n g e b u t c h a n g e s t o a
n e g a t i v e v a l u e a t S l l 0K. (5 3 8 ° C . ) , w h ic h m ig h t i n d i c a t e t h a t t h e r e a c t i o n
w as q u e s t i o n a b l e .
The r e c o v e r y o f t h e s u l f u r a s a l i q u i d r a t h e r t h a n a
g a s m ig h t h a v e g iv e n m ore f a v o r a b l e v a l u e s f o r
.
The v a l u e s o b t a i n e d f o r t h e s e s u g g e s t e d r e a c t i o n s i n d i c a t e d t h a t a
r e d u c t i o n r e a c t i o n s h o u ld t a k e p l a c e b e tw e e n s u l f u r d i o x i d e a n d m e th a n e
i n t h e t e m p e r a t u r e r a n g e c o n s i d e r e d , an d t h a t e x p e r i m e n t a l s t u d i e s o f t h e
p ro b le m w e re j u s t i f i e d .
-1 2 -
EQUIPMENT DESIGN AND CONSTRUCTION
A.
Flow S h e e t .
I n p r e p a r in g f o r r e s e a r c h i n v e s t i g a t i o n s o f th e ' r e d u c t io n o f s u l f u r
d io x id e w ith m ethane a t v a r io u s te m p e r a tu r e s , m ol r a t i o s , an d sp ace v e lo c ­
i t i e s , a sem i—c o n tin u o u s —flo w , f i x e d b e d , c a t a l y t i c p r o c e s s u n i t was
d e s ig n e d an d b u i l t „
The e a r l y o p e r a tio n o f t h e u n i t n e c e s s i t a t e d d e s ig n
ch an g e s i n w hich th e o r i g i n a l u n i t s w ere r e p la c e d o r m o d if ie d t o overcome
s p e c i f i c o p e r a t in g p ro b lem s a s th e y w ere e n c o u n te re d .
A b lo c k flo w
d ia g ra m o f t h e u n i t a s i t em erged i n i t s f i n a l fo rm i s shown i n F ig , I ,
and a d e t a i l e d f lo w s h e e t o f t h e u n i t i s shown i n F ig . 2 .
As t h i s u n i t
was s e t u p , s u l f u r d io x id e and m eth an e w ere m e te re d b y o r i f i c e s and manom­
e t e r s from t h e i r r e s p e c t i v e s o u r c e s i n t o a p ip e w hich c a r r i e d them t o th e
to p o f th e r e a c t o r .
The m ixed g a s e s th e n p a s s e d down th r o u g h th e p r e h e a t
s e c t i o n c o n ta in in g o n e - h a l f in c h B e r l s a d d le s and th e n o v e r t h e c a t a l y s t
bed.
The h o t r e a c t e d g a s e s th e n p a s s e d t o t h e c o n s ta n t- te m p e r a tu r e
c o n d e n s e r w here th e s u l f u r v a p o r was co n d en sed t o t h e l i q u i d s t a t e , a f t e r
w hich t h e l i q u i d s u l f u r and t h e p a r t i a l l y c o o le d g a s e s p a s s e d down th e
c e n t e r o f th e s u l f u r r e c e i v e r . t o a cup i n t h e b o tto m w here t h e s u l f u r was
c o lle c te d .
The re m a in in g g a se o u s m a t e r i a l s th e n p a s s e d upw ard th ro u g h a
g la s s - w o o l f i l t e r w here an y e n t r a i n e d s u l f u r p a r t i c l e s w ere rem oved.
From
t h e s u l f u r r e c e i v e r t h e g a s e s w ere c a r r i e d t o a w a te r c o o le d co n d e n se r
w here m ost o f t h e w a te r t h e y c o n ta in e d was co n d en sed o u t an d c o l l e c t e d i n
t h e w a te r r e c e i v e r .
A f te r th e w a te r was rem oved, th e g a s e s w ent t o th e
low te m p e ra tu r e c o n d e n s e r w here an y u n r e a c te d s u l f u r d io x id e was c o l l e c t e d .
-1 3 a n d t h e y t h e n p a s s e d o u t t h e v e n t l i n e t o t h e a tm o s p h e r e .
B.
D e s ig n a n d S p e c i f i c a t i o n s o f Com ponent P a r t s
R e a c to r:
The r e a c t o r was made from , a 2 7 - in c h l e n g t h o f 2 - i n c h ,
s c h e d u le 4 0 , b l a c k - i r o n p i p e .
c lo s e th e e n d s.
S ta n d a r d c a s t - i r o n p i p e c a p s w e re u s e d t o
S ee F i g . 3 f o r d e t a i l s o f r e a c t o r c o n s t r u c t i o n .
T h re e
n i chrom e c o i l s w e re s p a c e d a lo n g t h e l e n g t h o f t h e r e a c t o r t o s u p p ly t h e
o u ts id e h e a t n e c e s s a ry t o m a in ta in an y d e s ir e d r e a c to r te m p e ra tu re .
The
r e s i s t a n c e o f t h e t o p c o i l w as su c h t h a t i t w ould draw 9 A .C . am p eres
when c o n n e c te d t o a 2 2 0 - v o l t pow er s u p p ly .
The r e s i s t a n c e s o f t h e m id d le
a n d b o tto m c o i l s w e re su c h t h a t t h e y d re w 5 .5 a n d 4 .5 A .C . a m p e re s ,
r e s p e c t i v e l y , when c o n n e c te d t o a 1 1 0 - v o l t pow er s u p p ly .
A s in g le la y e r
o f a s b e s t o s t a p e w as w ra p p e d t h e f u l l l e n g t h o f t h e r e a c t o r , t h e n t h e
c e ra m ic b e a d - s t r u n g h e a t i n g c o i l s w e re wound i n t o p l a c e , c o v e r e d w ith a
s e c o n d l a y e r o f a s b e s t o s t a p e , a n d f i n a l l y i n s u l a t e d w i t h a b o u t one i n c h
o f 85 p e r c e n t m a g n e s ia .
To p e r m i t f i l l i n g
and in s p e c tio n o f th e r e a c to r ,
t h e t o p c a p w as n o t i n s u l a t e d , b u t t h e b o tto m c a p a n d t h e e x i t g a s l i n e
w e re c o v e r e d w i t h t h e o n e - i n c h m a g n e s ia l a y e r .
A ^ -in c h s ta n d a rd b la c k -
i r o n p i p e , w e ld e d c l o s e d a t t h e t o p e n d , w as p a s s e d th r o u g h t h e c e n t e r o f
t h e b o tto m c a p t o s e r v e a s a th e r m o w e ll i n t h e r e a c t o r .
A m e ta l b a f f le
w as p l a c e d i n t h e t o p o f t h e r e a c t o r t o m ix a n d d i f f u s e t h e f e e d g a s e s a n d
t o p r e v e n t t h e i r im p in g in g d i r e c t l y upon t h e end o f t h e t h e r m o w e ll .
A
s t a i n l e s s - s t e e l s c r e e n w as p l a c e d i n t h e b o tto m o f t h e r e a c t o r t o s e r v e a s
a c a t a l y s t s u p p o r t a n d g i v e a n open s p a c e f o r f r e e g a s p a s s a g e t o t h e
o u t l e t o p e n in g .
■' - 1 4 S u l f u r C o n d e n se rs
A w a t e r - c o o l e d c o n d e n s e r made o f m e t a l was f i r s t
t r i e d , b u t t h e s u l f u r s o l i d i f i e d i n t h e t u b e a n d so o n p lu g g e d i t ,
th u s
An i n s u l a t e d 3 / 8 - i n c h g l a s s t u b e a p p ro x ­
s to p p in g th e flo w o f g a s e s .
i m a t e l y 24 i n c h e s i n l e n g t h w as t h e n t r i e d , b u t i t a l s o p lu g g e d w ith
s o lid ifie d s u lfu r.
A c o n s t a n t - t e m p e r a t u r e c o n d e n s e r w as t h e n b u i l t w h ic h
w o u ld c o n d e n se t h e s u l f u r a n d m a i n t a i n i t i n a l i q u i d s t a t e u n t i l i t w as
d e liv e re d to th e s u lf u r r e c e iv e r .
F ig . 4 .
D e t a i l s o f t h e c o n d e n s e r a r e shown i n
The c e n t e r t h b e was m ade fro m a 3 0 - i n c h l e n g t h o f 1 - i n c h d i a m e te r
t h in - w a l l e l e c t r i c a l c o n d u it.
A 2 6 - in c h s e c t i o n o f 1 - i n c h d i a m e te r t h i n -
w a l l e l e c t r i c a l c o n d u it w as u s e d f o r t h e c o n d e n s e r j a c k e t a n d was s e c u r e d
i n p la c e b y b ra z in g a t each en d .
I n l e t a n d o u t l e t c o n n e c t io n s f o r c o o l a n t
w e re p r o v id e d b y b r a z i n g s e c t i o n s o f 1 - i n c h b l a c k - i r o n p i p e i n t o h o l e s
d r i l l e d a t t h e t o p a n d b o tto m o f t h e c o n d e n s e r j a c k e t .
The c e n t e r t u b e
w as p a c k e d w i t h j j - i n c h c e ra m ic e l e c t r i c a l i n s u l a t i n g b e a d s t o g iv e a
g r e a t e r c o n ta c t s u rf a c e f o r th e h o t g a s e s and t o c o a le s c e th e f in e p a r t ­
i c l e s o f s u l f u r w h ic h w ere s u s p e n d e d i n t h e g a s s tr e a m .
A c e r a m ic - b e a d -
s t r u n g n i chrom e h e a t i n g c o i l w as wound on t h e lo w e r p o r t i o n o f t h e con­
d e n s e r t o p r o v id e s u f f i c i e n t h e a t t o c o n s t a n t l y b o i l t h e c o o l a n t i n t h e
c o n d e n se r.
A p p r o x im a te ly 400 - w a t t s o f h e a t was f o u n d t o b e s u f f i c i e n t
pow er t o m a in ta in b o i l i n g .
A ^ - i n c h s t a n d a r d p i p e w as u s e d t o c o n n e c t t h e
c o o la n t o u t l e t t o th e to p o f a o n e -q u a rt c o o la n t r e s e r v o i r , and a n o th e r
s e c t i o n o f p i p e w as u s e d t o c o n n e c t t h e b o tto m o f t h e r e s e r v o i r t o t h e
i n l e t , o r b o tto m , o f t h e c o n d e n s e r .
A w a t e r - c o o l e d g l a s s c o n d e n s e r was
c o n n e c te d t o t h e t o p o f t h e c o o la n t r e s e r v o i r t o c o n d e n se a n d r e t u r n t o
-
15
-
t h e s y s te m a n y v a p o r s fo rm e d b y t h e b o i l i n g i n t h e c o n d e n s e r .
A 3/4 -in c h
l a y e r o f 85 p e r c e n t m a g n e s ia w as u s e d t o i n s u l a t e t h e c o n d e n s e r , r e s e r v o i r
and l in e s o f th e u n i t .
An e t h y l e n e - g l y c o l - w a t e r s o l u t i o n , a d j u s t e d t o b o i l
a t 317 ° F . , w as u s e d a s t h e h e a t t r a n s f e r medium, i n t h e c o n d e n s e r .
S u l f u r R e c e iv e r s
A 3 0 0 - m l. F lo r e n c e f l a s k , t o w h ic h a s i d e arm h ad
b e e n a t t a c h e d , was f i r s t u s e d a s a s u l f u r r e c e i v e r , b u t d i f f i c u l t i e s w e re
e n c o u n te r e d i n t h a t t h e s u l f u r c o u ld n o t b e rem o v e d , a n d some s u l f u r p a r t ­
i c l e s w e re e n t r a i n e d i n t h e g a s e s a n d s u b s e q u e n t ly s e t t l e d o u t i n t h e
lin e s .
To overcom e t h e s e d i f f i c u l t i e s a s u l f u r r e c e i v e r w as c o n s t r u c t e d
fro m a 1 3 - i n c h s e c t i o n o f 2 ^ - i n c h d i a m e te r g l a s s t u b i n g .
Two l a r g e r u b b e r
c o r k s w e re u s e d t o c l o s e t h e e n d s , t h e t o p one b e in g b o r e d t o t a k e a n i n e i n c h s e c t i o n o f o n e - i n c h d i a m e te r g l a s s t u b i n g w h ich e x te n d e d down i n t o
th e r e c e iv e r t o c a r r y th e g a s e s and an y e n tr a in e d s u l f u r p a r t i c l e s to th e
lo w e r s e c t i o n o f t h e r e c e i v e r .
The lo w e r s e c t i o n o f t h e r e c e i v e r h e ld a
s m a l l , e a s i l y rem o v e d , a lu m in u m - f o i l cup i n w h ic h t h e l i q u i d s u l f u r
c o lle c te d and s o l i d i f i e d .
From t h e b o tto m t h e g a s e s p a s s e d upw ard th r o u g h
g l a s s w o o l l o o s e l y p a c k e d b e tw e e n t h e c o n c e n t r i c w a l l s o f t h e tw o g l a s s
t u b e s w h e re a n y e n t r a i n e d s u l f u r p a r t i c l e s w e re f i l t e r e d o u t .
A se c o n d
s m a ll h o le i n th e to p c o rk , f i t t e d w ith a g l a s s tu b e , s e rv e d a s an o u t l e t
f o r th e g a s e s p a s s in g t o th e w a te r c o n d e n se r.
When i n o p e r a t i o n , t h e
s u l f u r r e c e i v e r w as s u r r o u n d e d b y a b o i l i n g w a t e r b a t h t o p r e v e n t a n y
w a t e r fro m c o n d e n s in g i n i t .
W a te r C o n d e n s e r:
1
See F i g . 4-A f o r d e t a i l s o f s u l f u r r e c e i v e r .
A 3 6 - i n c h l o n g w a t e r - c o o l e d g l a s s c o n d e n s e r h a v in g
a 3 / 8 - i n c h c e n t e r t u b e w as u s e d t o rem ove m o st o f t h e w a t e r v a p o r fro m
th e g a se s.
W a te r R e c e iv e r ;
A o n e - l i t e r E r le n m e y e r f l a s k , a t t a c h e d t o t h e b o tto m
o f t h e w a t e r c o n d e n s e r , w as u s e d a s a w a t e r r e c e i v e r .
C o ld C o n d e n s e r;
A 6 0 0 -m l. d i s t i l l a t i o n f l a s k w ith t h e g a s i n l e t t u b e
e x t e n d i n g n e a r l y t o t h e b o tto m w as im m erse d i n a n a e e t o n e - d r y - i c e b a th a s
a f i r s t t r i a l l o w - te m p e r a tu r e c o n d e n s e r .
The s m a ll am ount o f w a t e r v a p o r
p r e s e n t i n t h e g a s e s b e in g c o o le d c o l l e c t e d i n t h e i n l e t t u b e i n t h e fo rm
o f i c e a n d so o n s to p p e d t h e f l o w o f g a s e s .
An a tt e m p t t o i n s u l a t e t h e
i n l e t t u b e w as made b y w ra p p in g i t w i t h a 3 / l 6 - i n c h l a y e r o f g l a s s w ool
f o ll o w e d b y a s e c o n d g l a s s t u b e , w ith t h e a n n u l a r s p a c e s a t t h e en d s c lo s e d
w ith b o re d c o rk s .
T h is a f f o r d e d l i t t l e
a n d t h e t u b e so o n p l u g g e d .
r e l i e f , fro m t h e f o r m a t i o n o f i c e
A n i chrom e h e a t i n g c o i l was t h e n wound on t h e
i n l e t tu b e , fo llo w e d b y a g la s s - w o o l i n s u l a t i o n and a seco n d tu b e , b u t i c e
s t i l l fo rm e d i n t h e s e c t i o n c o v e r e d b y t h e c o r k a t t h e lo w e r e n d and p l u g ­
ged th e tu b e .
A l a r g e r f l a s k w i t h m ore room i n t h e n e c k w as s e c u r e d .
A
new i n l e t t u b e w as c o n s t r u c t e d i n w h ic h a n i chrom e h e a t i n g c o i l was s p a c e d
a t 3 / l 6- i n c h p e r t u r n a lo n g i t s
e n t i r e i n s i d e s u r f a c e a n d t h e o u t s i d e was
i n s u l a t e d Tya 3 / l 6 - i n c h l a y e r o f g l a s s w o o l c o v e re d b y a s e c o n d t u b e .
ta ils
o f c o n d e n s e r c o n s t r u c t i o n a r e , shown i n F i g . 5 .
De­
A p p r o x im a te ly 12
v o l t s a p p l i e d b y a n a u t o t r a n s f o r m e r w as s u f f i c i e n t t o p r e v e n t f o r m a ti o n o f
'
ic e in th e tu b e .
V en t L in e ;
O n e -h a lf-in c h s a ra n tu b in g .
S u l f u r D io x id e F e e d ;
F e e d was s t a r t e d fro m a 1 5 0 -p o u n d s u p p ly i n a
s t e e l t a n k , b u t i n o r d e r t o o b t a i n a m ore a c c u r a t e d e t e r m i n a t i o n o f f e e d
-11t o t h e r e a c t o r , a s t e e l t a n k o f 2 , 500 -gram , c a p a c i t y w as f i l l e d fro m t h e
l a r g e t a n k a n d u s e d a s a f e e d s u p p ly .
T h is t a n k was s m a ll en o u g h t o be
w e ig h e d on t h e l a b o r a t o r y b a la n c e t o d e te r m in e t h e am ount u s e d d u r in g e a c h
ru n .
S u l f u r D io x id e M e te r in g :
A g l a s s v e n t u r i - t y p e o r i f i c e w as u s e d i n
c o n j u n c t i o n w i t h a w a t e r - f i l l e d m a n o m e te r.
C a l i b r a t i o n w as d o n e by
w e ig h in g t h e f e e d b o t t l e t o d e te r m in e t h e am ount p a s s e d i n u n i t tim e,.
M ethane M e te rin g s
A g l a s s v e n t u r i - t y p e o r i f i c e was u s e d i n c o n ju n c ­
t i o n w i t h a d i e s e l - o i l - f i l l e d B a c h a ra c h i n c l i n e d m a n o m e te r.
C a lib ra tio n
w as d o n e w i t h a P r e c i s i o n S c i e n t i f i c 2 0 - c u . f t . Wet T e s t M e te r .
S u l f u r D io x id e M e te r in g V a lv e s
M ethane M e te r in g V a lv e s
L o w -T e m p e ra tu re B a th s
Id e a l-A e ro s m ith n e e d le v a lv e .
.Hoke b r a s s b l u n t - s p i n d l e n e e d l e v a l v e .
S o l i d c a rb o n d i o x i d e a n d a c e t o n e i n a f o u r -
l i t e r vacuum b o t t l e .
A u to tra n s fo rm e rs s
One 2 2 0 -v o l t P o w e r s ta t f o r t h e t o p r e a c t o r c o i l ,
tw o 1 1 0 - v o l t P o w e r s t a t s f o r t h e m id d le a n d b o tto m r e a c t o r c o i l s , one
1 1 0 - v o l t P o w e r s ta t f o r t h e c o n s t a n t t e m p e r a t u r e c o n d e n s e r , a n d one 1 1 0 v o l t P o w e r s ta t f o r t h e lo w t e m p e r a t u r e c o n d e n s e r .
T h e rm o c o u p le s :
T h ree ir o n - c o n s t a n ta n .
Q u ic k -d is c o n n e c ts
One s i x - p o l e , s e l f - a l i g n i n g d i s c o n n e c t f o r th e rm o ­
c o u p le l e a d s .
T e m p e r a tu r e I n d i c a t o r s
p o te n tio m e te r.
A L e e d s a n d W o rth ru p 1 8 - p o i n t i n d i c a t i n g
PROCEDURES M D MATERIALS
P ro ced u res
R e a c to r A sse m b ly ;
W ith t h e r e a c t o r s u p p o r te d i n u p r i g h t p o s i t i o n ,
t h e i n s i d e o f t h e r e a c t o r w as i n s p e c t e d t o b e s u r e t h e s t a i n l e s s s t e e l
s c r e e n w as i n p o s i t i o n a t t h e b o tto m .
N e x t, 400 g ram s o f c a t a l y s t w ere
c a r e f u l l y p o u r e d i n so t h a t a u n if o r m b e d w as o b t a i n e d .
c a t a l y s t ' b e d 13 i n c h e s i n d e p t h .
T h is g a v e a
The r e m a in in g s p a c e w as f i l l e d w ith
|~ - in c h B e r l s a d d l e s w h ic h w e re d ro p p e d i n a fe w a t a t im e , a f t e r w h ic h t h e
m e t a l b a f f l e p l a t e w as p u t i n t o p l a c e . i n t h e t o p a n d t h e c a p sc re w e d o n .
A g r a p h i t e —i n - o i l t h r e a d d r e s s i n g w as u s e d t o p r e v e n t s e i z u r e o f t h e
th re a d s .
to i t .
The r e a c t o r w as t h e n s e t i n . p l a c e a n d t h e f e e d l i n e s c o n n e c te d
H e a tin g c o i l l e a d s w e re p lu g g e d i n t o t h e i r r e s p e c t i v e p o w e r s t a t s
a n d t h e th e r m o c o u p le d i s c o n n e c t w as s e c u r e d i n i t s
s o c k e t.
The c o n s t a n t - t e m p e r a t u r e c o n d e n s e r w as t h e n s e c u r e d i n p l a c e a n d
c o n n e c te d t o t h e r e a c t o r , a f t e r w h ic h i t w as f i l l e d w i t h c o o l a n t a n d t h e
c o o l a n t c o n d e n s e r w as f i t t e d i n t o p l a c e .
C o o lin g - w a te r l i n e s a n d h e a t i n g -
c o i l p o w e r s t a t w e re t h e n c o n n e c te d t o i t .
S ta rt-u p ;
tu rn e d o n .
C o o lin g w a t e r t o t h e tw o w a t e r - c o o l e d c o n d e n s e r s was
P o w e rs ta ts f o r th e h e a tin g c o i l s o f th e r e a c t o r an d th e
c o n s t a n t - t e m p e r a t u r e c o n d e n s e r w e re t u r n e d on a n d a d j u s t e d t o t h e i r p r o p e r
s e ttin g s .
A c l e a n s u l f u r r e c e i v e r , w a t e r r e c e i v e r , a n d ,■lo w - te m p e r a tu r e —
c o n d e n s e r f l a s k w e re e a c h w e ig h e d a n d p l a c e d i n t h e u n i t , a n d t h e i r r e ­
s p e c t i v e w e i g h ts w e re r e c o r d e d .
A l l l i n e s w e re c o n n e c te d a n d a l l con­
n e c t i o n s w e re c h e c k e d t o m ake s u r e t h e y w e re g a s - t i g h t .
A fiv e -lite r
—19**"
b e a k e r w as p l a c e d a ro u n d t h e s u l f u r r e c e i v e r an d f i l l e d w i t h h o t w a t e r .
An e l e c t r i c h o t - p l a t e w as p l a c e d u n d e r i t t o k e e p t h e w a t e r b o i l i n g .
S m a ll p i e c e s o f d r y - i c e w e re a d d e d t o t h e a c e t o n e b a t h o f t h e lo w -te m p e r­
a t u r e c o n d e n s e r u n t i l t h e b a t h t e m p e r a t u r e d ro p p e d t o t h a t o f t h e d r y i c e ,
a f t e r w h ic h a n e x c e s s o f d r y i c e w as a d d e d .
The low —te m p e r a t u r e - c o n d e n s e r
p o w e r s t a t w as t u r n e d on a n d a d j u s t e d t o 12 v o l t s .
The r e a c t o r w as h e a t e d t o t e m p e r a t u r e o v e r a t h r e e - h o u r p e r i o d .
When t h e t e m p e r a t u r e o f t h e p r e h e a t s e c t i o n r e a c h e d SlO 0C ., t h e m eth a n e
f lo w w as s t a r t e d th r o u g h t h e s y s te m .
S u l f u r d i o x id e f lo w w as s t a r t e d a n d
t h e p o w e r s t a t s w e re a d j u s t e d t o o p e r a t i n g s e t t i n g s when t h e tw o c a t a l y s t
t e m p e r a t u r e s w e re 20 d e g r e e s b e lo w t h e d e s i r e d o p e r a t i n g t e m p e r a t u r e ,
s i n c e i t w as f o u n d t h a t t h e s e tw o t e m p e r a t u r e s w ould r i s e 20 d e g r e e s a n d
s t a r t t o l e v e l o f f i n t h e f i r s t 10 m in u t e s a f t e r t h e s u l f u r d i o x id e f lo w
w as s t a r t e d .
O p e r a ti o n :
T e m p e r a tu r e s w e re c o n t r o l l e d b y a d j u s t i n g t h e pow er i n p u t
t o th e r e a c t o r h e a tin g c o i l s w ith th e p o w e r s ta ts ,
The p r e h e a t s e c t i o n w as
h e l d a t $ 10 ° t o $ 1 $°G . e x c e p t when i t becam e n e c e s s a r y t o c h a n g e i t t o
c o n tr o l a d i f f i c u l t te m p e ra tu re s it u a ti o n i n th e c a ta ly s t b e d .
An a t t e m p t
w as m ade t o h o l d t h e tw o c a t a l y s t t e m p e r a t u r e s t h e sam e, a n d t h i s te m p e r ­
a t u r e w as d e te r m in e d b y t h e c o n d i t i o n s o f o p e r a t i o n .
M ethane a n d s u l f u r
d i o x i d e f lo w w e re r e g u l a t e d b y a d j u s t i n g t h e i r c o n t r o l n e e d l e - v a l v e s t o
g i v e t h e d e s i r e d m an o m eter r e a d i n g s .
The s u l f u r d i o x i d e s u p p ly b o t t l e
w as w e ig h e d b e f o r e a n d a f t e r e a c h r u n a n d t h e w e ig h t u s e d d u r i n g t h e r u n
w as o b t a i n e d b y t h e d i f f e r e n c e .
Enough d r y i c e was p e r i o d i c a l l y a d d e d t o
—
20
~
k e e p i t i n e x c e s s i n t h e a c e t o n e b a t h of t h e low —te m p e r a t u r e c o n d e n s e r .
R e a d in g s w e re t a k e n and" a d j u s t m e n t s w e re m ade a t 1 0 - m in u te i n t e r v a l s
d u r in g t h e r u n .
S h u t-d o w n :
To s h u t t h e u n i t down, t h e v a l v e o n . t h e s u l f u r d i o x id e
t a n k w as c l o s e d , a n d p o w er t o t h e r e a c t o r h e a t e r s , c o n s t a n t - t e m p e r a t u r e
c o n d e n s e r a n d t h e h o t - w a t e r b a t h .were t u r n e d o f f .
M ethane w as l e f t f lo w -
i n g f o r 10 m in u te s t o sw eep a l l o f t h e s u l f u r d i o x id e fro m t h e u n i t .
The
p o w e r t o t h e l o w - te m p e r a tu r e c o n d e n s e r w as t u r n e d o f f a n d t h e f l a s k was
rem oved fro m t h e a c e t o n e b a t h a n d w e ig h e d , t h e n c o rk e d a n d c o n n e c te d t o
t h e v e n t l i n e t o p e r m i t a n y s u l f u r d i o x i d e w h ich h ad b e e n c o l l e c t e d t o
b o i l aw ay .
The f l a s k w as t h e n w e ig h e d a g a i n a n d t h e am ount' o f s u l f u r
d i o x i d e c o l l e c t e d w as o b t a i n e d b y t h e d i f f e r e n c e b e tw e e n t h i s w e ig h t an d
t h e w e ig h t a t t h e end o f t h e r u n .
The d i f f e r e n c e b e tw e e n t h e f l a s k ' s
f i n a l w e ig h t a n d i t s w e ig h t a t t h e s t a r t o f t h e ru n g a v e t h e am ount o f
w a t e r w h ic h h a d c o l l e c t e d i n i t .
The s u l f u r a n d w a t e r r e c e i v e r s w e re '
w e ig h e d a n d t h e am ount o f m a t e r i a l c o n t a i n e d i n e a c h w as o b t a i n e d b y
d iffe re n c e .
M a te ria ls
The s u l f u r d i o x i d e u s e d i n t h i s r e s e a r c h was a c o m m e rc ia l g r a d e ,
o b t a i n e d fro m M a th e so n Company o f J o l i e t , I l l i n o i s .
M ethane u s e d a s a r e d u c i n g a g e n t f o r t h e s u l f u r d i o x i d e w as o b t a i n e d
fro m t h e n a t u r a l g a s l i n e s o f t h e l o c a l u t i l i t y com pany.
P e l l e t i z e d a c t i v a t e d a lu m in a c a t a l y s t m a n u f a c tu r e d b y t h e H arshaw
C h e m ic a l Company" w as u s e d f o r t h i s s t u d y .
O n e - e ig h t h - i n c h e x tr u d e d
-
21
-
p e l l e t s w e re u s e d .
The m a t e r i a l u s e d f o r p a c k in g i n t h e p r e h e a t s e c t i o n
w as
g - in c h
c e ra m ic B e r l s a d d l e s .
O n e - f o u r t h - i n c h c e ra m ic i n s u l a t i n g b e a d s w ere u s e d f o r p a c k in g i n t h e
c o n s ta n t-te m p e ra tu re c o n d e n se r.
-ZZEXPERIMMT DESIGN
A s e r i e s o f r u n s w as m ade t o O b ta in d a t a r e g a r d i n g t h e r e d u c t i o n o f
s u l f u r d i o x i d e w ith m e th a n e a n d t o s t u d y t h e e f f e c t v a r i a t i o n s i n te m p e r ­
a t u r e 5 m ol r a t i o o f r e a c t a n t s , a n d t o t a l m o ls o f r e a c t a n t s p a s s e d p e r h o u r
h a d on t h e r e a c t i o n .
The f i r s t r u n s m ade w e re o f a p u r e l y e x p l o r a t o r y
n a t u r e an d w e re Made a t c o n d i t i o n s w h ic h a s t u d y o f t h e m a t e r i a l s in v o lv e d
h a d i n d i c a t e d m ig h t b e f a v o r a b l e t o t h e r e a c t i o n .
A f te r s e v e r a l ru n s had
b e e n m ade, t h e d a t a w as a r r a n g e d i n t o g ro u p 's i n w h ic h o n l y o n e o f t h e op­
e r a tin g c o n d itio n s v a rie d .
T h is w as d o n e i n a n a tt e m p t t o f i n d t r e n d s i n
th e e f f e c t s e x e rte d by v a r ia tio n in o p e ra tin g c o n d itio n s .
When t h e s e
t r e n d s w e re a s c e r t a i n e d a d d i t i o n a l r u n s w e re made i n t h e r a n g e w h ich
a p p e a r e d m o st f a v o r a b l e i n an a t t e m p t t o m ore c l o s e l y p i n p o i n t t h e co n ­
d i t i o n s g iv in g th e g r e a t e s t r e d u c tio n t o
s u lfu r.
C o n d i t io n s f o u n d t o g i v e f a v o r a b l e r e a c t i o n s w e re t h e n u s e d t o s e t u p
r u n s i n w h ic h e a c h v a r i a b l e w as s t u d i e d i n d i v i d u a l l y .
A f t e r enough d a t a
h a d b e e n c o l l e c t e d t o p l o t ro u g h c u r v e s o f t h e e f f e c t o f e a c h v a r i a b l e ,
t h e l e n g t h o f t h e r u n s w as e x te n d e d fro m tw o h o u r s t o t h r e e - a n d - o n e - h a l f
h o u r s t o m in im iz e t h e e f f e c t o f e x p e r i m e n t a l e r r o r i n t r o d u c e d b y l i n e - o u t
tim e ,
( tim e r e q u i r e d t o s t a b i l i z e o p e r a t i n g c o n d i t i o n s ) , a n d a n e x t e n s i v e
s t u d y w as m ade i n w h ic h o n l y one o p e r a t i n g c o n d i t i o n w as v a r i e d w h ile t h e
o t h e r tw o w e re h e l d a t t h e p r e v i o u s l y d e te r m in e d o p tim u m s.
p e rc e n t re d u c tio n t o
A maximum
s u l f u r w as s o u g h t a s t h e d e s i r a b l e r e s u l t .
I n t h e s e r i e s o f r u n s m ade t o c h e c k t h e e f f e c t o f t e m p e r a t u r e , t h e
r e s u l t s o b t a i n e d d i d n o t c o r r e s p o n d w ith r e s u l t s o b t a i n e d fro m r u n s made
a t t h e b e g in n i n g o f t h e t e s t w h ic h w ere made u n d e r i d e n t i c a l o p e r a t i n g
c o n d itio n s .
To c h e c k a p o s s i b l e c h a n g e i n c a t a l y s t a c t i v i t y d u e t o e x ­
t e n d e d u s e , t h e c a t a l y s t w as rem oved a n d r e p l a c e d w i t h f r e s h m a t e r i a l ,
a f t e r w h ic h a n o t h e r s e r i e s o f r u n s w as m ad e.
I n t h i s s e r i e s , te m p e r a tu r e
w as v a r i e d w h i l e o t h e r c o n d i t i o n s w e re h e l d a t t h e same v a l u e s u s e d f o r
th e p re v io u s te m p e ra tu re s tu d y .
I n t h i s s t u d y , t e m p e r a t u r e w as v a r i e d b e tw e e n 5 2 5 °C . a n d 5 9 5 °G .,
m o l r a t i o o f m e th a n e t o
s u l f u r d i o x i d e w as v a r i e d b e tw e e n o n e a n d s e v e n ,
a n d t o t a l f e e d w as v a r i e d fro m s i x t o t e n m o ls p e r h o u r .
c a t a l y s t b e d w as u s e d f o r t h e r u n s .
A 40 0 -g ram
-2 4 DISCUSSION OF RESULTS
A.
T e m p e ra tu re
A d e f i n i t e e f f e c t w as f o u n d t o be e x e r t e d on t h e r e a c t i o n b y te m p e r ­
a tu re .
The p l o t o f d a t a o b t a i n e d when u s i n g f r e s h c a t a l y s t } shown i n
F i g . 6 , g i v e s a maximum o f 62 p e r c e n t c o n v e r s i o n o f s u l f u r d i o x i d e t o
s u l f u r p e r p a s s i n t h e r a n g e o f $60° t o 5 6 5 °C .
Above t h i s t e m p e r a t u r e
r a n g e t h e r e d u c t i o n t o s u l f u r d r o p s o f f r a p i d l y w i t h a c o r r e s p o n d in g r a p i d
i n c r e a s e o f s u l f u r d i o x i d e w h ic h w as c o n v e r t e d t o o t h e r m a t e r i a l s .
a t u r e s b e lo w 560 C . g a v e a s h a r p d e c r e a s e i n c o n v e r s io n t o
s u l f u r and i n ­
c r e a s e i n p e r c e n t s u l f u r d io x id e u n r e a c te d , b u t th e d e c re a s e i n
d i o x i d e c o n v e r t e d t o o t h e r p r o d u c t s w as s m a l l .
T em per­
s u lfu r
A t $ 2 $ °C . t h e r e was 4 1 .5
p e r c e n t o f t h e s u l f u r d i o x i d e r e c o v e r e d u n r e a c t e d a s co m p ared w ith two
p e rc e n t a t $6$ C.
The s u l f u r d i o x id e c o n v e r t e d t o o t h e r p r o d u c t s d ro p p e d
fro m a p p r o x i m a t e ly 36 p e r c e n t a t $ 6 $°C . t o 28' p e r c e n t a t 5 2 5 °C .
TOien t h e c a t a l y s t h a d b e e n i n s e r v i c e f o r 160 h o u r s t h e maximum p e r ­
c e n t c o n v e rs io n o f s u l f u r d io x id e t o s u l f u r had d e c re a s e d t o
58 p e r c e n t
a n d t h i s maximum h a d s h i f t e d fro m t h e 56 O0 t o 565°C . r a n g e f o r hew c a t a l y s t
to
55 0 °C .
Above 560°C . t h e p e r c e n t r e d u c t i o n t o s u l f u r d ro p p e d o f f v e r y
r a p i d l y , a s shown i n P i g . 7 , an d w as l e s s t h a n t e n p e r c e n t a t 5-7 5°C . a s
co m p ared t o 52 p e r c e n t f o r f r e s h c a t a l y s t a t t h i s t e m p e r a t u r e .
th e
At 525°C .
s u l f u r d i o x i d e w h ic h re m a in e d u n r e a c t e d w as 2 9 .5 p e r c e n t f o r u s e d
c a t a l y s t , a n d 2 8 ,0 p e r c e n t f o r f r e s h c a t a l y s t .
-
B0
25
-
Mol R a t i o
A m o l r a t i o o f m e th a n e t o
s u l f u r d i o x i d e o f 3 «6 g a v e t h e g r e a t e s t
p e rc e n t s u l f u r d io x id e re d u c e d t o
s u l f u r on a s i n g l e p a s s b a s i s .
Above
t h i s m ol r a t i o r e d u c t i o n t o s u l f u r d ro p p e d o f f .v e r y r a p i d l y t o f o u r p e r ­
c e n t a t m ol r a t i o s o f f i v e o r g r e a t e r , a s shown i n F i g . 8 .
l e s s t h a n 3 .6 c o n v e r s io n t o
F o r m ol r a t i o s
s u l f u r d ro p p e d o f f v e r y r a p i d l y t o 1 5 .5 p e r ­
c e n t a t 1 .3 2 m ol r a t i o , w h i l e t h e p e r c e n t s u l f u r d i o x id e w h ic h re m a in e d
u n r e a c t e d i n c r e a s e d v e r y r a p i d l y fro m e i g h t t o s i x t y p e r c e n t a s t h e m ol
r a t i o w as d e c r e a s e d fro m 3 - 6 t o 1 .3 2 .
A g re a te r
u ltim a te
y ie ld
of
s u l f u r m ig h t p o s s i b l y b e r e a l i z e d by o p e r a t i n g ^a t lo w e r m o l r a t i o s an d
r e c y c lin g th e u n r e a c te d s u l f u r d io x id e a s i s
C.
shown i n F i g . 1 1 .
T o t a l M ols o f F e e d
A p l o t o f d a t a o b t a i n e d b y v a r y i n g t o t a l m o ls o f f e e d p e r h o u r ,
F i g . 9 , i n d i c a t e s t h a t a maximum c o n v e r s i o n t o
s u l f u r w as o b t a i n e d w i t h
8 . 4 m o ls o f f e e d p e r h o u r u s i n g 400 g ram s o f c a t a l y s t .
No e x t e n s i v e s tu d y
w as m ade u s i n g t h i s v a l u e f o r an o p e r a t i n g c o n d i t i o n a n d s l i g h t l y h i g h e r
y i e l d s o f s u l f u r m ig h t h a v e b e e n o b t a i n e d u s i n g i t i n c o n j u n c t i o n w i t h a
m o l r a t i o o f 3 - 6 a n d a t e m p e r a t u r e o f 5 65 0G.
F r e s h c a t a l y s t m ig h t a l s o
have g iv e n b e t t e r r e s u l t s , s in c e th e c a t a l y s t u sed t o o b ta in t h i s d a ta
h a d b e e n i n s e r v i c e i n e x c e s s o f 125 h o u r s .
D.
T h e o r e t i c a l R e c y c le o f U n re a c te d S u l f u r D io x id e
A c o m p a ris o n o f t h e g r a p h show ing p e r c e n t' s u l f u r d i o x i d e r e d u c e d t o
s u l f u r p e r p a s s v e r s u s te m p e r a tu r e , F ig . 6, w ith a g ra p h o f u ltim a te y i e l d
-
26 -
o f s u lf u r v e rs u s te m p e ra tu re . F ig . 10, in d ic a te s t h a t a s li g h t in c re a s e in
u l t i m a t e y i e l d o f s u l f u r m ig h t b e e f f e c t e d b y p e r f o r m in g t h e r e d u c t i o n a t
5 55°C . a n d r e c y c l i n g t h e u n r e a c t e d s u l f u r d i o x i d e r a t h e r t h a n u s in g a
s i n g l e p a s s o p e r a t i o n a t $ 6 3 °C .
S i m i l a r l y , a c o m p a ris o n o f t h e g ra p h o f
p e r c e n t c o n v e r s io n t o s u l f u r p e r p a s s v e r s u s m ol r a t i o , F i g . 8 , w ith t h e
g r a p h o f u l t i m a t e y i e l d o f s u l f u r v e r s u s m ol r a t i o , F i g . 1 1 , i n d i c a t e s
t h a t a c o n s i d e r a b l e i n c r e a s e i n u l t i m a t e y i e l d o f s u l f u r c o u ld b e o b t a i n e d
o v e r s i n g l e p a s s o p e r a t i o n b y u s i n g a m e th a n e t o s u l f u r d i o x i d e m ol r a t i o
o f 2 .7 a n d r e c y c l i n g t h e u n r e a c t e d s u l f u r d i o x i d e .
E.
C a ta ly s t" A c tiv ity
The d a t a f o r t h e tw o t e m p e r a t u r e s t u d i e s , shown i n T a b l e s IV a n d V
and p l o tt e d i n F ig s . 6 and 7 , in d ic a te t h a t th e c a t a l y s t had a d e f i n i t e
c h a n g e i n a c t i v i t y w i t h e x te n d e d u s e .
A c o m p a ris o n o f t h e s e tw o s e r i e s
r e v e a l s t h a t t h e f r e s h c a t a l y s t g a v e a maximum r e d u c t i o n t o
s u l f u r w h ich
w as f o u r p e r c e n t h i g h e r t h a n t h e c a t a l y s t w h ic h h a d b e e n i n
s e r v i c e m ore
t h a n 160 h o u r s .
The maximum y i e l d f o r t h e f r e s h c a t a l y s t w as o b t a i n e d
u s i n g a n o p e r a t i n g t e m p e r a t u r e o f 5 6 2 ° C ., b u t 551°C . g a v e t h e b e s t y i e l d s
o f s u l f u r a f t e r e x te n d e d c a t a l y s t u s e .
An i n c r e a s e i n t e m p e r a t u r e ab o v e
562 ° C . w i t h a f r e s h c a t a l y s t g a v e a c o r r e s p o n d in g d e c r e a s e i n y i e l d w h ic h
a p p e a r e d t o b e a n e a r l y s t r a i g h t l i n e f u n c t i o n , w h ile a v e r y s h a r p d ro p i n
re d u c tio n to
s u l f u r a c c o m p a n ie d a t e m p e r a t u r e i n c r e a s e fro m 5 6 0 ° t o 5 70°C .
i n r u n s w i t h c a t a l y s t w h ic h h a d b e e n i n u s e m ore t h a n 160 h o u r s .
A t 525 ° C .
t h e f r e s h c a t a l y s t g a v e o n l y 3 0 .5 p e r c e n t r e d u c t i o n t o s u l f u r b u t a f t e r
-
27 -
e x b e n d e d u s e t h e c o n v e r s i o n t o s u l f u r w as 4 1 .0 p e r c e n t a t t h e same te m p e r ­
a tu re .
The s u l f u r d i o x i d e w h ic h w as c o n v e r t e d t o o t h e r p r o d u c t s was
v i r t u a l l y t h e same f o r f r e s h a n d u s e d c a t a l y s t a t 5 2 5 ° C ., b u t t h e p e r c e n t
c o n v e r t e d t o p r o d u c t s o t h e r t h a n s u l f u r i n c r e a s e d much m ore r a p i d l y f o r
th e u sed c a t a l y s t a t te m p e ra tu re s above 5 6 0 ° C .
T h is i n d i c a t e s t h a t w i t h
e x te n d e d c a t a l y s t u s e t h e r e w as a s h i f t i n a c t i v i t y w h ic h f a v o r e d i n c r e a s e d
r e d u c tio n t o
s u l f u r a t t e m p e r a t u r e s b e lo w 5 60 °C . a n d a s h a r p i n c r e a s e i n
p r o d u c t s o t h e r t h a n s u l f u r a t t e m p e r a t u r e s g r e a t e r t h a n 5 60°C .
F.
L in e o u t
No p r o v i s i o n w as made t o s e p a r a t e l i n e o u t tim e ( tim e r e q u i r e d t o
s t a b i l i z e o p e r a t i n g c o n d i t i o n s ) fro m t h e r e s t o f t h e r u n ; c o n s e q u e n t ly ,
t h is w ill p rese n t a d e fin ite
so u rc e o f e x p e rim e n ta l e r r o r .
An a v e r a g e o f
20 m in u te s was r e q u i r e d t o b r i n g o p e r a t i n g c o n d i t i o n s t o t h e d e s i r e d l e v e l ,
b u t some r u n s r e q u i r e d a s l o n g a s one h o u r f o r l i n e o u t .
T h is t e n d s t o
m ake t h e e x p e r i m e n t a l e r r o r g r e a t e r f o r some r u n s t h a n f o r o t h e r s .
.
—28—
SUMMARY
T e m p e ra tu re was- f o u n d t o a f f e c t r e d u c t i o n t o s u l f u r a n d h i g h e s t
y i e l d s o b t a i n e d p e r p a s s w e re 62 p e r c e n t r e d u c t i o n t o s u l f u r a t 562°C .
w i t h f r e s h c a t a l y s t a n d 58 p e r c e n t r e d u c t i o n t o s u l f u r a t 5 50°C . w ith
c a t a l y s t w h ic h h a d b e e n i n s e r v i c e 8ISO h o u r s .
A m ol r a t i o o f m e th a n e t o s u l f u r d i o x i d e o f 3 .6 g a v e t h e h i g h e s t
s u lf u r y ie ld s f o r s in g le p a ss o p e ra tio n b u t a g r e a te r u ltim a te y ie ld
a p p e a r e d t o be p o s s i b l e on a r e c y c l e b a s i s a t lo w e r m ol r a t i o s .
The f e e d r a t e w h ic h a p p e a r e d t o g iv e t h e b e s t s u l f u r r e c o v e r y was
3 . 4 t o t a l m o ls p e r h o u r u s i n g 400 g ram s o f c a t a l y s t , b u t n o e x t e n s i v e
s t u d i e s w e re made u s i n g t h i s v a l u e .
A s l i g h t i n c r e a s e i n u l t i m a t e y i e l d m ig h t be r e a l i z e d b y o p e r a t i n g
a t lo w e r t e m p e r a t u r e s a n d r e c y c l i n g t h e u n r e a c t e d s u l f u r d i o x i d e .
The
g r e a t e s t i n c r e a s e i n u l t i m a t e y i e l d m ade p o s s i b l e b y r e c y c l e seem ed t o
b e when o p e r a t i n g a t a m o l r a t i o o f m e th a n e t o s u l f u r d i o x i d e o f 2 . 7 .
A c h a n g e i n c a t a l y s t a c t i v i t y a p p e a r s t o accom pany e x te n d e d c a t a l y s t
.u s e .
The c h a n g e f a v o r e d t h e f o r m a t i o n o f m ore g a s e o u s p r o d u c t s a n d l e s s
s u l f u r a b o v e 560°C .
A t t e m p e r a t u r e s b e lo w 5 6 0 ° C ., c a t a l y s t w h ic h h ad b e e n
u se d e x te n s iv e ly gave g r e a t e r s u l f u r r e c o v e r y and l e s s u n r e a c te d s u l f u r
d i o x i d e t h a n w as o b t a i n e d w i t h f r e s h c a t a l y s t a t t h e same t e m p e r a t u r e s .
L in e o u t tim e w as b e l i e v e d t o i n t r o d u c e e x p e r i m e n t a l e r r o r i n t o t h e
d a t a s i n c e no p r o v i s i o n w as m ade f o r s e p a r a t i n g i t fro m t h e a c t u a l r u n .
-2 9 -
BIBLIOGMPHY
(1 )
B r i t . P a t . N o. 4 2 7 ,9 9 9
May 3 ,
(2 )
C an. P a t .
J u ly I ,
(3 )
E n g . M in in g J . 1 3 I
(4 )
I n d . E n g . Chem.
(5 )
J . Chem. I n d . (Moscow)
(6 )
O la f A-. Hougen a n d K e n n e th M. W a tso n , C h e m ic a l.P r o c e s s P r i n c i p l e s .
Jo h n W ile y & S o n s , I n c . , P a r t One
71 I 2 , ( 1 9 5 2 ) .
(7 )
U. S . P a t .
N o. 3 0 1 ,5 5 4
(1 9 3 $ )
(1930)
7 , ( 1931 )
J2
9 1 0 -1 4 ( 1940 )
2
3 3 -7 ,
( 193 ^ )
N o. 1 ,7 7 1 ,4 8 0 , O f f i c i a l G a z e tt e
3 9 6 -5 , 973, J u ly 29,
ACKNOWLEDGEMENT
The a u t h o r w is h e s t o t h a n k t h e E n g i n e e r in g E x p e rim e n t S t a t i o n ,
M ontana S t a t e C o l l e g e , f o r t h e i r c o u r t e s y i n s p o n s o r in g t h e w ork on t h i s
p r o b le m I a l s o , P r o f e s s o r s L lo y d B e rg , H. A l b e r t S a n e r , a n d L e w is G.. M a y f ie ld
f o r t h e i r g u id a n c e a n d a s s i s t a n c e .
-3 1 APPENDIX
T a b le I
Thermodynamic D ata ............................................................................... ....
32
T a b le I I
Sample C a l c u l a t i o n s and C a lc u la te d V alu es o f AHpqn,
A S2 9 8 > t NE*
and" Ke q ^ o r R e a c tio n E q u a t i o n s " .................... 33
T a b le I I I
O p e ra tin g C o n d itio n s and P ro d u c t Y ie ld ..........................................
TABLE IV
P e r c e n t Y ie ld s W ith V ary in g T em p eratu re
(F re s h C a t a l y s t ) . • ............................................................ 40
T a b le V
P e r c e n t Y ie ld s W ith V ary in g T em p eratu re
( C a t a ly s t Used 160 H o u rs)
...................................................40
T a b le H
P e r c e n t Y ie ld s W ith V ary in g Mol R a tio
T a b le V II
P e r c e n t Y i e l d s W ith V a ry in g T o t a l M ols o f F e e d ........................ 42
T a b le V I I I
P e r c e n t S u l f u r D io x id e C o n v e rte d t o S u lf u r D iv id e d
b y P e r c e n t S u l f u r D io x id e R e a c te d a t V a rio u s
Mol R a tio s . .......................................... .... ............................................. .... .
43
P e r c e n t S u l f u r D io x id e C o n v e rte d t o S u lf u r D iv id e d
by P e r c e n t S u l f u r D io x id e R e a c te d a t V a rio u s
T e m p e r a t u r e s ................................ ....................................................... ....
43
F ig u r e I
B lo ck Flow D iagram
44
F ig u r e 2
D iagram o f S u l f u r R e d u c tio n U n i t ....................... - ..............................45
F ig u r e 3
D iagram o f R e a c to r . . . . . . . . . . . . . . . . . . . . .
46
F ig u r e 4
D iagram o f C o n s ta n t T em p e ra tu re C ondenser
47
F ig u r e A-A
D iagram o f S u lf u r R e c e i v e r ...................■. . ■.................................. ....
48
F ig u r e 5
D iagram o f Low T em p eratu re C o n d en ser . . . . .
49
F ig u r e 6
P e r c e n t Y ie ld W ith V ary in g T em p eratu re When U sing
F r e s h C a t a l y s t ................................. . . . . . . . . . . . . . .
50
P e r c e n t Y ie ld W ith V ary in g T em p eratu re When C a t a ly s t
Used More Than 160 H ours . . . . . . . . . . . . . . . . . .
$1
T a b le IX
F ig u r e 7
. . . . . . . . . .
...................................................
. . . . . . . . .
.......................
37
41
—31a-—
APPENDIX ( c o n tin u e d )
F ig u r e 8 P e r c e n t Y ie ld W ith V ary in g Mol R a t i o ....................................................$2
F ig u r e 9
P e r c e n t Y ie ld W ith T o ta l M ols o f F eed P e r H o u r ..................... 53
F ig u r e 10
U ltim a te Y ie ld o f S u lf u r W ith V ary in g T e m p e ra tu re .
F ig u r e 11
U ltim a te Y ie ld o f S u lf u r W ith V ary in g Mol R a t io . . . . . .
. . . .
54
55
-3 2 -
TABLE I
THERMODYNAMIC DATA
¥
5■
Compound
?
^ 2 (g )
P
S
' ' (Rom M c)
8 2 (g)
C( g r )
. c o (g>
CV
'bO
O
U
CS2 ( g )
GH4(g)
H2 S ( g )
H2 ° ( g )
Hf 2 9 8
s ° 298
K cal
E .U .
°K .
-7 0 .9 6
59.24
430.3
0 .0
7 .6 2
———
3 1 .0 2
54.41
0 .0
1 .3 6
—2 6 .4 2
-9 4 .0 $
T
C
Atm.
7 7.7
1 3 1 3 .2
234.5*
———
———
4 7 .3 0
1 3 4 .4
3 4 .6
5 1 .0 6 '
3 0 4 .1
7 2 .9
22.08
5 7 .1
5 46.2
76.0
-1 7 .8 9
# .5
1 9 1 .1
- 4 .8 1 5
49.15
373.5
88 .9
- 5 7 .8 0
4 5 .1 1
647.3
218.2
C a l c u l a t e d b y P a r a c h o r s fro m E ougen a n d W atson ( 6 ) .
f
P
C
■
4 5 .8
:
-
33-
TABLE I I
°f
SAMPLE CALCULATIONS AND CALCULATED VALUES
AH298> A S298> TNE■’ a f T= an d Keq f o r REACTION EQUATIONS
(I)
^ 2 (g )
A H
+ 0 ^ 4 (6 )
S g fg ) + O O g ^ ) + ZHgO^g)
2 ( - 7 0 .9 6 ) - 17.89 —>
298
A
4 S293
3 1 .0 2 - 94.05 + 2 ( - 5 7 .8 0 )
^298 = —E8 .3 2 K c a l
2 ( 5 9 .2 4 ) + 4 4 .5 —
5 4 . 4 1 + 5 1 .0 6 + 2 ( 4 5 .1 1 )
A S 2 9 8 = 3 2 .7 1
E .U .
Tm„ = A H = - 18820 = -555°K
AS
3 2 .7 1
A
F29d = AiH29d - T (A S 29d). = 18820 - 298(32.71) = 18820 - 9740
= -2 8 5 6 0 c a l = - 2 8 .5 6 K c a l
Log
K=
1U
-A F
=
2 .3 HT
28560
28.5
( 2 .3 ) ( l.9 8 7 ) ( 2 9 8 )
, ^
20
Keqn = 6 .8 0 x 10
Temp. 0K
A F K cal
Ke=
A H29d = —1 8 .8 2 K c a l
298
.- 2 8 .5 6
A S29d =
400
-3 1 .9 0
2 .4 6 x IO17
600
-3 8 .3 7
8 .9 2 x 10^3
1000
-5 1 .5 3
1 .7 8 x IO11
1500
-6 7 .9 2
7 .6 0 x IO?
3 2 .7 1 E .U .
?NE - -555°%"
6 .8 x.lO^O
-3 4 TABLE L I ( c o n t i n u e d )
SAM PLE C A L C U L A T IO N S AND CALCULATED VA LU ES
of
AH298,
(2 )
A S2 9 8 ,
+ 3CH^(g)
Tw e ,
AFt ,
and
K
fo r
R E A C T IO N E Q U A T IO N S
CS2 (g ) +2C02 (g ) + 4H20 ( g ) + 2H2S (g )
Temp. °K.
AF K cal
^eq
^ ^ 2 9 8 = ~ 7 4 °7 4 K c a l
298
- 9 5 .1 4
3 .9 8 x I O ^
A S 298 =
400
- 1 0 2 .1 4
6 .3 0 x IO ^^
600
- 1 1 5 .8 4
1 .2 6 x IO4 ^
1000
- I 4 3 .2 4
1500
- 1 7 7 .5 4
1 .5 8 x I O ^ l
25
6 .3 0 x 10
--1 0 9 0 °K .
SSOg^g) + 3CH ^(g)
CS2 ( g ) + 3 / 2 s 2 ( g ) * 2C° 2 ( g ) + &H20 ( g )
Temp. 0K.
A F K cal
CD
X!
1NE
6 8 .5 0 E .U .
AH 298 = -7 3 .1 4 8 Kcal
298.
-7 7 .2 5
3 .9 8 x IO ^
A S 298 =
400
-7 8 .6 6
7.9 5 % IO42
600
- 8 1 .4 1
3 .8 0 x i o 29
1000
-8 6 .9 3
8.93 x IO18
1500
-9 3 .8 3 -
4 .4 6 X IO13
Tb e
1 3 .7 8 E .U .
- -5 3 0 0 ° k .
-:3 5 TABLE I I
(c o n tin u e d )
SAM PLE C A L C U L A T IO N S AND CALCULATED V A LU ES
of
(4 )
Z lH 2 9 8 ,
A S2 9 8 ,
Tn e ,
3S02 (g ) + 2CH^(g) —>
V
and
K
fo r
R E A C T IO N E Q U A T IO N S
&S2(g) + 2H2S (g ) +fCOg^) + ZHgOfg)
Temp. °K .
A F K cal
J
. >'
*1■
Z IF t ,
4 H298 = —4 9 .1 6 K c a l
298
—6 4 .4 0
1.26 x IO^?
^ S 298 =
400
-69.61
7.9$ x IO3^
600
-79.86
1 ,0 0 x IO29'
1000
- 1 0 0 .2 9
7 .9 5 x IO21
1500
- 1 2 5 .7 6
1.78 x
t NE
5 1 .1 3 E .U .
- - 96l°K-
SOz(g)
+
•.
/
I
^^298 =
A S 298 =
TNE
OSg^g) - >
K cal
1 6 .3 2 E .U .
= ^ ° K-°
IO18
3/2 s2(g) + C02(g)
Temp. 0K.
AF K cal
298
-3.43
3.24 x IO2
400
- 5 .1 0
6.03 x IO2
600
-8.37
1 .1 2 x IO3
1000
-14.89
1 .7 4 x IO3
1500
-23.07
2 .2 9 x IO3
Keo
-3 6 table
of
(6)
AH2 9 8 ,
II
(c o n tin u e d )
SAM PLE C A L C U L A T IO N S AND CALCULATED VA LU ES
A -S 3 9 8 , T ^ ,
A Ft , an d K
f o r R E A C T IO N E Q U A T IO N S
SOgfg) + 2H2S (g) —>
3 /2 S2 ^ ) + 2H20 (g )
Temp. °K.
AiF K c a l
Kea
= 1 1 .5 8 K c a l
298
7340
4 .2 6 x 10 “ 5
4S
= 1 4 .2 8 E . U.
4P0
5870
7 .4 2 x 10 ~^
^NE
=
600
3020
8.15 x IO"1
1000
-2690
3 .8 6
1500
-9810
2 .6 9 x 10
TA B LE I I I
O PER A TH Cr CO N D IT IO N S AND PRODUCT H E L D
I
Bun
N o.
A v e ra g e
Temp. 0C .
560.2
560.5
573.2
569.6
574.5
573.2
568.9
570:8
M E-I
MR-2
MR-3
MR-A
MR-5
558.9
559.2
566.6
562.9
564.5
%SO2
C o n v e r te d
to - S
6A9.A
174
4 .6
643.5
3A3
375
329
128
316
326
256
239
274
227
2?8
2.92
30.9
27.4
18.75
41.8
15.95
55.5
27.6
43.1
42.25
33.69
5 8 1 .8
583.9
59A.5L
563.2
52A.7
566.9
579.4
559.7
562.1
575.9
575.7
550.6
5 6 6 .9
217
5 1 .6
235
329
42.6
54.1
57.74
37.6
18.05
44.55
33.32
42.5
13.35
39.5
218
282
565
229
204
315
165
314
370
513
. 363
480
598
52.5
57.3
56.7
49.2
38.4
%SOg
re a c te d
1 .1 5
.58
45.1
18.85
1 .5 6
32.9
62.20
14.45
0.4
14.95
0.44
0.366
# SOg
t o O th e r
P ro d u c ts -
94.25
96.5
24.0
53.85
79.7
75.3
21.95
3 0 .1
.461
72.0
42.0
57.3
67.3
47.94
D e t
e r m i n e d
.4 6
41.8
21.3
67.85
33.65
0.49
29.85
4 1 .1
1 4 .1
0 .6
24.5
1 1 .1
11.9
15.14
30.4
42.2
21.8
66.19
27.65
86.05
36.0
3 6 ,4
30.8
. 28.16
20.4
19.2
Mol R a t io
2 y § 2 2_
4.58
2.28
1 .9 1
2.85
3.83
2.83
2.73
2.95
3.93
4.27
3.63
4.72
3.78
3.5
3.74
3.77
.1.98
0.9
1 .3
T o ta l
M ols
p e r Hr
7.77
8.52
8.90
7.89
8.79
9.43
9.52
7.89
9.22
9.07
8.19
9.91
8.12
8.25
8.14
8 .1 2
6.55
8.53
4 .1 1
1.92.
1.98 '
4.42
1.99
3.53
7.34
5.98
7.33
3.62
3.62
3.23
2.47
1.87
8.23
8.23
8.00
8 .1 4
7.94
-37-
E -I
E -2
E -3
E-A
E -5
E -6
E -7
E -S
E -9
E -IO
E -Il
E -1 2
E -1 3
E—IA
E -1 5
E -1 6
E -1 7
E -IS
E -1 9
E -2 0
E -2 1
E -2 2
E -2 3
Grams SOU sed
^
TA B LE I I I
(c o n tin u e d )
OPERATING CONDITIONS AND PRODUCT YIELD
# SOg
Run
No.
A v e ra g e
Temp. 0C.
565.9
564.4
563.3
563.1
561.0
562.4
563.3
563.6
Grams S0„
U sed
MR—6
MR-7
MR-8
MR-9
MR-10
MR-11
MR-12
MR-13
MR-14
MR-15
MR-16
MR-17
564.5 ,
562.8
564.5
763
330
360
333
328
243
313
220
350
340
330
308
TM-I
TM-2
TM-3
TM-4
TM-5
TM-6
TM-7
563.3
563.4
552.2
562.5
562.3
560.3
562.5
383
386
463
347
347
304
429
T -I
T -2
T -3
T -4
T -5
T -6
553.6
542.8
535.0
524.3
582.6
571.0
408
.399
384
381
394
390
5 6 4 .1
C o n v e rte d
to S
26.0
63.0
, 54.4
34.3
33.6
4 .1 2
5 .1 2
4.55
48.00
35.3
32.8
3.9
39.2 43.5
52.3
3 1 .1
61.7
8,55
57.3
57.8
56.2
49.5
4 1 .0
3.56
10.25
# SOg
U n re a c te d
59.9
1.8
0 .0
0.6
0.2
0.41
0.32
0.91
0.0
0.3
0.0
0.0
0.2
0.5
0.0
0.0
2.6
0 .6 6
0.7
.24
6.01
6.77
29.9
.5 1
0.25
* SOp
t o O tn e r
P r o d u c ts
Mol R a t io
C S ,/SO 9
1 4 .1
1»32
35.2
45.6
65.1
3.8
4.05
6 6 .2
95.5
94.56
94.54
52.00
6 4 .4
67.2
96.1
4 .4 4
4 .5 1
6 .4 4
4.69
7 .1 4
4 .1 4
4.32
4 .3 4
4.83
T o ta l
M ols
per Sr
7 .9 1
8 .2 8
8 .1 4
8.08
8.06
8.06
7.96
7.98"
8.02
8.03
8.08
7.99
6 0 .6
4 .1 2
56.0
47.7
68.9
35.7
90.8
42.0
4.2
3.87
3.65
7 .6 3
4 .1
3 .4 6
5 .1 7
6 .0 6
3.68
8.97
41.96
37.8
43.7
29.1
96.
89.50
3.44
3.6
3.65
3.68
3.56
3.6
8.08
8.00
7.98
8.76
8.73
9.96
7 .9 6
8 .0 2
8.00
TABLE I I I
(c o n tin u e d )
OPERATING CONDITIONS AND PRODUCT YIELD
Run
N o.
A v e ra g e
Temp. 0C .
T -7
$62.0
T-B
T -9
T -IO
T -Il
T -1 2
525.5
574.
584.9
565.
545.
$ SOg
C o n v e rte d
to S
U n r e a c te d
t 6 O th e r
P ro d u c t's
380
52.00
0.0
48.00
400
382
397
390385
30.5
54.
34.8
61.5
52.
Grams SOp
U sed
$ SOg
$ SOg
4 1 .5
28.0
0.0
0.5
2.0
4 6 .0
1 6 .6
64.7
36.5
31.4
Mol R a t io
SS4-Se23.72
3.67
3.68
3,61
3.60
3.64
T o ta l
M ols
p e r H r.
8.03
7.97
7.97
7.99
8*00
7.98
TA B LE I V
PERCENT YIELDS WITH VARYING TEMPERATURE
(F re sh C a ta ly s t)
Run
N o.
E -5
E -1 3
T-B
T -9
T -IO
T -Il
T- 1 2
, A v e ra g e
Temp. 0C .
594.9
575.7
525.5
574.0
584.9
565.0
545.0
Grams SOp
U sed
# SOg C o n v e rte d
to S
18.75
51.60
30.50
54.00
34.80
61.50
52.00
128
21?
400
382
397
390
385
# SOg
$ SOg
U n r e a c te d
1.56
.4 6
41.5
t o O th e r
P ro d u c ts
79.7
47.94
28.0
0 .0
4 6 .O
0.5
2.0
64.7
36.5
31.4
1 6 .6
CH4ZSOa,
T o ta l
M ols
p e r H r.
3.83
3.78
3.67
3.68
3.61
3.60
3.64
8.79
8.12
7.97
7.97
7.99
8.00
7.98
Mol R a tio
?
TABLE V
PERCENT YIELDS WITH VARYING TEMPERATURE
( C a t a l y s t U sed 160 H o u rs )
Run
N o.
A v e ra g e
Temp. ° C .
T -I
T -2
T -3
T -4
T -5
T- 6
T -7
553.6
542.8
535.0
524.3
582.6
571.0
562.0
Grams SOg
U sed
408
399
384
381
394
390
380
# SOg
C o n v e rte d
- to S
57.8
56.2
49.5
41.0
3.56
10.25
52.00
# SOg
# SOg
U n re a c te d
.24
6.01
6.77
29.9
.5 1
0.25
0.0
t o O th e r
P r o d u c ts
Mol R a tio
Cl14So2-
T o ta l
M ols
p e r H r.
41.96
37.8
43.7
-29.1
96.
89.50
48.00
3.44
3.6
3.65
3.68
3.56
3.6
3.72
8.08
8.00
7.98
7.96
8.02
8.00
8.03
TABLE H
PERCENT YIELDS WITH VARYING MOL RATIO
% so
Run
N o,
MR-2
MR—4
MR-5
MR-6
MR-8
MR-9
MR-10
MR-11
MR-12
MR-13
MR-14
MR-15
MR-16
MR-17
A v e ra g e
Temp, 0C .
559.2
562.9
564.5
565.9
563.3
5 6 3.1
5 6 1 .0
5 6 2.4
563.3
563.6
5 6 4 .1
564.5
562.8
5 6 4 .5
Grams SOp
U sed
513
480
598
763
360
333
328
243
313
220
350
340
330
308
# SOg
2
C o n v e rte d
to S
57.3
4 9 .2
3 8 .4
2 6 .0
5 4 .4
3 4 .3
3 3 .6
% SOg
U n r e a e te d
1 1 .9
3 0 .4
4 2 .2
5 9 .9
0 .0
0 .6
0 .2
4 .1 2
0 .4 1
5 .1 2
4 .5 5
4 8 .0 0
3 5 .3
3 2 .8
3 .9
0 .3 2
0 .9 1
0 .0
0 .3
0 .0
0 .0
t o O th e r
P ro d u c ts
Mol R a t io
3 0 .8
2 0 .4
1 9 .2
1 4 .1
3 .6 2
2 .4 7
1 .8 7
4 5 .6
6 5 .1
6 6 .2
95.5
94.56
94.54
52.00
6 4 .4
67.2
96 .1
=S4M
-
1 .3 2
4 .0 5
4 .4 4
4 .5 1
6 .4 4
4 .6 9 .
7 .1 4
4 .1 4
4 .3 2
4 .3 4
4 .8 3
T o ta l
M ols
p e r H r,
8.23
8 .1 4
7 .9 4
7 .9 1
8 .1 4
8 .0 8
8 .0 6
8 .0 6
7 .9 6
7 .9 8
8 .0 2
8 .0 3
8 .0 8
7 .9 9
iL
y
TABLE
YlI
PERGEMT YIELDS WITH VARYING TOTAL MOLS OF FEED
TM-3
TM-A
TM-6
TM-7
T -I
A v e ra g e
Tenip. °C .
Grams SOg
U sed
552.2
562.5
560.3
562.5
553.6
463
347
304
429
408
% .SOg
C o n v e rte d
to S
52.3
3 1 .1
8.55
57.3
57.8
# SOg
SOg
U n r e a c te d
0 .0
0 .0
0 .6 6
0.7
.2 4
t o O th e r
P r o d u c ts
Mol R a tio
CHziZSO2 -
47.7
68.9
90.8
42.0
3.87
3.65
3.46
3.68
3.44
4 1 .9 6
T o ta l
M ols
p e r Hr
9.90
7.03
6 .0 6
8,97
8.08
-Z Y -
Run
N o.
-4 3 TA B LE H I I
PE R C E N T SU L FU R D IO X ID E CONVERTED TO SU LFU R
D IV ID E D BY P E R C E N T SU L FU R D IO X ID E REA CTED AT V A R IO U S MOL R A T IO S
Run
No.
MR-2
MR-4
MR-5
MR-6
MR-8
MR-9
MR-10
MR-11
MR-12
MR-13
MR-14MR-15
MR-16
MR-1?
% SOp t o
S u lfu r
57.3
49.2
38.4
26.0
54.4
34.3
33.6
4.12
5.12
4.55
48.00
35.3
32.8
3.9
$ SOg
R e a c te d
% SO0 t o
X
% SOg R e a c te d
88,10
69.60
57.80
40.10
100
¥ ° 1 R a t io
CH4ZSO2
3.62
2.47
1.8?
1.32
4.05
65.1,
70.6
.6 6 .4
64.8
54.4
34.5
33.7
1 0 0 .0 0
99.40
99.80
99.59
99.68
99.09
■
A- •>AA
4 -5 1
6 .4 4
4 ° 14
1 0 0 .0 0
99.7
100.0
1 0 0 .0
S u lfu r
■
5.14
4.58
48.00
35.4
32.8
3.9
4.69
7 -1 4
4.14
4.32
4 -3 4
4.83
TABLE IX
PERCENT SULFUR■DIOXIDE CONVERTED TO SULFUR
. DIVIDED BY PERCENT SULFUR DIOXIDE REACTED AT VARIOUS 'TEMPERATURES
Run
N o.
E -5
E -1 3
T -8
T -9
T -IO
T -Il
T -1 2
A v e ra g e
Temp. ° C .
594.9
575.7
525.5
574.0
584.9
565.0
545.0
% SO
to
S u lfu r
18.75
51.60
30.50
54.00
34.80
61.50
52.00
# SOg
R e a c te d
98.44
99.44
58.50
100.00
99.50 '
98.00
83.40
% SOg t o S u l f u r
* SOg R e a c te d
19.05
51.90
52.10
5 4 -0 0
35.00
62.80
62.40
X
1m -
-L U U
-4 4 -
SULFUR
DIOXIDE
VENT
S UP P L Y
LOW
METHANE
SUPPLY
T E MP E R A T U R E
CONDENSER
WA T E R
PREHEAT
RECEIVER
WA T E R
CATALYST
CONDENSER
CONSTANT
SULFUR
TEMPERATURE
RECEIVER
CONDENSER
FIG. I.
BLOCK
FLOW
DIAGRAM
MANOMETER
REACTOR
WATER
-----SO2
MANOMETER
SO2
CONDENSER
VENT
SUPPLY
CONSTANT TEMPERATURE
C ONDE N S E R -------------
SULFUR
RECEIVER
LOW TEMPERATURE
CONDENSER
WATER RECEIVER
FIG. 2
DIAGRAM
OF S UL F UR
DIOXIDE
REDUCTION
UNIT
—4 6 —
FEED
LINE
CAST
IRON PIPE CAP
THREADS
MAGNESIA INSULATION
FROM
CH4
MANOMETER
BERL
SADDLES
FROM S O g
MANOMETER
NICHROME
HEATING COILS
BAFFLE
CATALYST
BLACK IRON
PIPE
THERMOWELL
STAI NLESS
SCREEN
THERMOCOUPLE
NOT
TO
-CONSTANT
TEMPERATURE
CONDENSER
LEADS
S CALE
FIG.
3.
DIAGRAM
S TEEL
OF
REACTOR
-4 7 -
CONDENSER
COOLANT
RESERVOI R
1/ 8"
MAGNESIA
INSULATION
PI PE
1/4" CERAMIC
BEAD PACKING
COOLANT
NICHROME
HEATING COIL
SCREEN
NOT
FIG. 4
TO
PACKING
SUPPORT
SCALE
DIAGRAM
OF CON ST AN T
TEMPERATURE
CONDENSER
—4 8 —
HOT
CONSTANT TEMPERATURE
C O N D E N S E R -----------RUBBER
GASES
^ — LINE
TO
WATER
CONDENSER
CORK-
SULFUR
GLASS
2-1/4"
GLASS
TUBE
GLASS
TUBE
HOT
WOOL
GAS ES
AL UMI NUM- F OI L CUP
S ULF UR
RUBBER
NOT TO
FIG.
SCALE
4-A.
DIAGRAM
OF
SULFUR
R EC EI VE R
CORK
-4 9 -
POWER LEADS TO
AUTOTRANSFORMER
GAS FROM WATER
CONDENSER —
RUBBER
TO
CORK
VENT LINE
GLASS WOOL
INSULATION -
FOUR LITER
VACUUM BOTTLE
ACETONE
GLAS S
TUBE
NICHROME
HEATING COIL
DRY
CONDENSED S O 2
AND W A T E R --------
NOT TO
FIG.
5.
SCALE
DIAGRAM
OF
LOW
TEMPERATURE
CONDENSER
ICE
—5 0 —
CATALYST, FRESH
MOL RATIO,
3 . 6 0 - 3.83
TOTAL MOLS F E E D / HOUR ,
( 1 ) % SO2 TO SULFUR
(2) % S02
( 3 ) % SOg
8 79
PRODUCTS
W T.
PERCENT
S ULF UR
DIOXIDE
IOO-I
UNREACTED
TO OTHER
7.97 -
TEMPERATURE
FIG. 6.
PERCENT
WHEN
YI ELD
USI NG
WITH
FRESH
VARYING
CATALYST
TEMPERATURE
—SI —
CATA LYST1 USED 160
MOL RATIO,
3.44 TOTAL MO L S F E E D
HOURS
3.72
P ER HOUR,
7.98 -
8.03
( I ) % SO2 TO SULFUR
( 2 ) % S O 2 U NR E AC T E D
(3)%
S O 2 TO
OTHER
P RODUCTS
TEMPERATURE
FIG.
7.
P E RC E NT
WHEN
YI E L D
CATALYST
WITH
USED
eC
VARYING
MORE
TEMPERATURE
THAN
160
HOURS
—52 —
IOOh
D
TEMPERATURE, 5 5 9 - 5 6 6
C
TOTAL MOLS FEED
PER HOUR, 7.91 - 8. 23
DIOXIDE
80-
WT.
P ERCENT
SULFUR
( I ) % SO2 TO SULFUR
( 2 ) •/• SO2 UNREACTED
( 3 ) % SO2 TO OTHER PRODUCTS
-o -
-O -
rd-
=A-
MOL
FIG.
8
PERCENT
YI E LD
WI TH
VARYING
MOL
RATIO
—
53 —
TEMPERATURE, 5 5 2 - 5 6 3
MOL RATIO,
3.4 4 - 3.87
(1) %
(2) %
(3) %
I OOi
TOTAL
FIG. 9.
PERCENT
MOLS
OF
S O2 TO
SULFUR
SO2 UNREACTED
SO2 TO OTHER PRODUCTS
MOLS OF FEED
YI ELD
FEED
WI T H
PER
6C
PER
VARYING
HOUR
HOUR
TOTAL
—
54—
MOL RATIO, 3 . 4 4 TOTAL M O L S F E E D
3.68
P ER
HOUR,
7.96 -
T E MP E R AT UR E
FIG. 10.
ULTI MATE
VARYING
YIELD
OF
SULFUR
TEMPERATURE
WI TH
8.08
—5 5 —
TEMPERATURE, 5 5 9 - 5 6 5 ° C
MOLS OF FEED,
SOo TO SULFUR
TOTAL
mol
FIG.
II.
ULTI MATE
VARYING
ch V s o
ratio
YIELD
MOL
OF
R ATI O
1 1 9 2 2 5
2
SULFUR
WI TH
7.91 - 8 . 2 3
K57G
D299r
co p .2
119225
D a v i s , W. F .
R eduction of s u l f u r d io x id e
elem ental s u lf u r . . .
'T H S 'r X
--".'.1IVl
\» w - s =, y
119225
_,
to