Continuous noncatalytic esterification of lower formates
by Ih-Cheo Yang
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 Ih-Cheo Yang (1951)
Abstract:
It was found that the rate of esterification of lower alcohols (n-propyl, n-butyl, iso-butyl, n-amyl,
iso-amyl alcohol) with formic acid is increased by the raising of temperature.
The use of increased temperature obtained by rectifying at 60 psig pressure was investigated as a means
of carrying out the continuous non-eatalytic esterification of n-propyl, n-butyl, iso-butyl, n-amyl, and
iso-amyl alcohol with formic acid.
The non-catalytic esterification rates at the atmospheric pressure and at 60 psig pressure were
determined for n-propyl, n-butyl, iso-butyl, n-amyl and iso-amyl alcohol with formic acid. The ternary
azeotropic composition at 60 psig pressure was determined for each formate system and a continuous
non-catalytic esterification carried out for each ester. 
COHTiMJOUS HONCATALYTIG ESTERIFICATION OF 
LOWER FORMATES
by
H-CHEO YANG
A THESIS
S u bm itte d  t o  t h e  G rad u a te  F a c u l ty  
I n
p a r t i a l  f u l f i l lm e n t  o f  th e  r e q u i r em e n ts  \
f o r  th e  d e g re e  o f
M a s te r  o f  S c ie n c e  i n  C hem ica l E n g in e e r in g
a t
. M ontana S t a t e  C o lle g e
A pproved :
H ead , M ajo r D.ep&ptmspit
C hairm an , E xam in ing  C d ^ n i t te eB zPe
U ehn , '"'Graduate D iv i s io n
(
Bozeman', M btitana 
August,11951
- 2 -y  o
cT * TABLE OF CONTENTS Bags
A b s t r a c t 3
I .  I n t r o d u c t i o n .................................. ......................................................... ....  .  4
I I .  P r o c e s s e s .................... .... ................................................................................. 6
A. D e te rm in a t io n  o f  th e  e s t e r i f i c a t i o n
r a t e  a t  a tm o sp h e r ic  p r e s s u r e .  . . . . . . . . . . .  6
( I )  Equipm ent (2) M a te r ia l s  (3 ) P ro ­
c e d u re .
B. P r e p a r a t i o n  o f  60 p s ig  p r e s s u r e
t e r n a r y  and  a n a ly s i s  o f  i t s  c o m p o s i t i o n .................... ....  6
( I )  Equ ipm ent (2 ) P ro c e d u re .
C. E s t im a t io n  o f  th e  e s t e r i f i c a t i o n
r a t e  u n d e r  60 p s ig  p r e s s u r e  ..............................................................9
I I I .  R e s u l t s  ..................  . . . . . . . . . .  ......................... . . . 1 1
IV . Summary o f  R e s u l t s .  ............................................................... ....  . . .  11
V. D is c u s s io n ................................................................................  12
V I . L i t e r a t u r e  C i t e d ...................................   . 1 2
V I I .  A ppend ix ................................     13
103009
ABSTRACT
I t  was found  t h a t  th e  r a t e  o f  e s t e r i f i c a t i o n  o f  low e r  a lc o h o l s  
( n - p r o p y l ,  n - b u t y l ,  i s o - b u t y l ,  n -am y l, i s o -am y l  a lc o h o l )  w i t h  fo rm ic  
a c id  i s  in c r e a s e d  b y  th e  r a i d i n g  o f  tem p e ra tu re *
- ■ ' . ' -
T h e .u se  o f  in c r e a s e d  tem p e ra tu re  o b ta in e d  b y  r e c t i f y i n g  a t  60 p s ig  
p r e s s u r e  was i n v e s t i g a t e d  a s  a  means o f  c a r r y in g  o u t th e  c o n tin u o u s  n o n -  
c a t a l y t i c  e s t e r i f i c a t i o n  o f  n -p ro p y l: , n - b u t y l ,  i s o - b u t y l ,  n -am y l, and 
is o -am y l a lc o h o l  w i th  fo rm ic  a c id .
The n o n - c a t a l y t i c  e s t e r i f i c a t i o n  r a t e s  a t  t h e ; a tm o sp h e r ic  p r e s s u r e  
and  a t  60 p s i g  p r e s s u r e  w ere  d e te rm in e d  f o r  n - p r o p y l ,  n - b u t y l ,  i s o - b u t y l  
n -am y l and is o -am y l a lc o h o l  w i th  fo rm ic  a c id .  The t e r n a r y  a z e o t r o p ic  
c om p o s i t io n  a t  60 p s ig  p r e s s u r e  was d e te rm in e d  f o r  e a c h  fo rm a te  sy s tem  
and a  c o n tin u o u s  n o n - c a t a l y t i c  e s t e r i f i c a t i o n  c a r r i e d  o u t  f o r  e a ch  e s t e r
L , INTRODUCTION
' The m ost im p o r ta n t  f a c t o r s  c a u s in g  an  in c r e a s e d  r a t e  o f  e s t o r i f i -
( '
c a t i o n  a r e  c a t a l y s t  and  r i s e  i n  t e m p e ra tu r e e
C a t a l y s t s ,  su ch  a s  h y d r o c h lo r ic  and  s u l f u r i c  a c id s  a r e  u sed  in  
comm erc ia l p r e p a r a t i o n s  o f  e s t e r s  b e c a u s e  o f  t h e i r  r e l a t i v e  low  c o s t .
The raw  m a t e r i a l s  a r e  o rg a n ic  a c i d ,  low e r  a l c o h o l  i n  e x c e s s ,  and a  l i t t l e  
s u l f u r i c  a c i d .  They a r e  m ix ed , c o n d u c ted  th ro u g h  h e a t  e x c h an g e rs  and 
p a s s e d  th ro u g h  an  e s t e r i f i c a t i o n  column a t  a tm o sp h e r ic  p r e s s u r e .  The 
o v e rh ead  from  t h i s  column i s  t h e  t e r n a r y  a z e o tro p e  and  c o n s i s t s  o f  a lc o h o l  
e s t e r  and  w a te r .
The r a t e  o f  c h em ic a l  r e a c t i o n  i n c r e a s e s  r a p i d l y  w i th  in c r e a s e d  
t e m p e r a tu r e .  The e m p i r i c a l  A r rh e n iu s  E q u a t io n :
a  l a  k  5  A 
dT RTzr
i s  t h e  r e l a t i o n  b e tw een  th e  s p e c i f i c  r e a c t i o n  v e l o c i t y  c o n s ta n t  K and 
t e m p e r a tu r e .  T i s  th e  a b s o lu te  t e m p e r a tu r e ,  R i s  th e  g a s  law  c o n s ta n t ,  
and  A i s  t h e  e n e rg y  o f  a c t i v a t i o n .  I f  t h e  r e a c t i o n  can  be e f f e c t e d  a t  a  
s u f f i c i e n t l y  h ig h  t e m p e r a tu r e ,  a  s a t i s f a c t o r y  r a t e  c a n  be o b ta in e d  i n  th e  
a b sen ce  o f  any  c a t a l y s t .  A s u i t a b l e  tem p e ra tu re  may be  o b ta in e d  by  
c a r r y in g  o u t  t h e  e s t e r i f i c a t i o n  i n  a  r e c t i f i c a t i o n  column o p e ra te d  u n d e r  
s u f f i c i e n t  p r e s s u r e  t o  g iv e  t h e  d e s i r e d  b o i l i n g  tem p e ra tu r e .
I n  o r d e r  t o  c a r r y  o u t  t h e  r e a c t i o n  c o n t in u o u s ly ,  th e  e s t e r  m ust be 
removed from  th e  r e a c t i o n  m ix tu re  i n  th e  fo rm  o f  a  t e r n a r y  c o n s ta n t  
b o i l i n g  m ix tu r e .  The t e r n a r y  c o n s i s t s  o f  a l c o h o l ,  e s t e r  and  w a te r ,  and 
th e  f e e d  c h a rg e  i s  c a l c u l a t e d  from  th e  c om p o s i t io n  o f  t h i s  t e r n a r y .  The
f e e d  c h a rg e  m ust b e  o f  su ch  a  c om p o s i t io n  t h a t  no  component w i l l  b u i ld  up 
a s  e x c e s s  in  th e  s t i l l  p b t e B e fo re  th e  c o n tin u o u s  e s t e r i f i c a t i o n  i s  
c a r r i e d  o u t ,  i t  i s  n e c e s s a r y  t o  d e te rm in e  a  tem p e ra tu re  and  p r e s s u r e  a t  
w h ich  th e  e s t e r i f i c a t i o n  r a t e  i s  s u f f i c i e n t l y  h ig h ,  a s  w e l l  a s  th e  compo­
s i t i o n  o f  t h e  lo w e s t  b o i l i n g  t e r n a r y  a z e o t ro p e  a t  t h a t  p r e s s u r e ,
• I t  w as th e  p u rp o se  o f  t h i s  w ork  t o  d e te rm in e :
(1 ) th e  non-r’c a t a l y t i c  e s t e r i f i c a t i o n  r a t e  (e x p re s s e d  a s  p e r  c e n t  
. . c o n v e rs io n  p e r  h o u r )  a t  th e  b o i l i n g  p o in t  u n d e r  a tm o sp h e r ic
p r e s s u r e  o f  n - p r o p y l ,  n - b u t y l ,  i s o - b u t y l ,  n -am y l, and  iso -am y l 
a lc o h o l  w i th  fo rm ic  a c id ,
(2 ) th e  n o n - e a t a l y t i e  e s t e r i f i c a t i o n  r a t e  a t  th e  b o i l i n g  tem p e ra tu re  
c o r r e s p o n d in g  t o  60 p s i g  p r e s s u r e  o f  e a c h  o f  th e  a l c o h o l s  named 
ab o v e ,
(3 ) t h e  c om p o s i tio n  o f  th e  t e r n a r y  a z e o t ro p e  form ed i n  e a c h  c a se  a t  
th e  tem p e ra tu re  c o r r e s p o n d in g  t o  60 p s ig  p r e s s u r e ,
(4 ) th e  p r o p e r  c h a rg e  f o r  e a c h  o f  th e  sy s tem s  named ab o v e , c o r r e c t  
f o r  60 p s i g  p r e s s u r e ,  and t o  o p e r a te  th e  e s t e r i f i c a t i o n . p r o c e s s  
c o n t in u o u s ly  a t  t h i s  60 p s i g  p r e s s u r e .
“ 6 ~
Ho. PROCESSES
A0 D e te rm in a t io n  o f  t h e  e s t e r i f i c a t i o n  r a t e  a t  a tm o sp h e r ic  p ressu re®
I 0 E qu ipm en t:
The equ ipm en t c o n s i s t e d  o f  250 m l. E r lenm ey e r  f l a s k ,  a  P y re z  
g l a s s  L ie b ig  c o n d e n se r , a  1 1 0 - v o l t ,  500 W att h e a t e r  c o n t r o l l e d  
by  an  a u t© tra n s fo rm e r , a n  i c e  b a th ,  and a  50 ml* buret®
. 2o M a t e r i a l s ;
The fo rm ic  a c id  u sed  was 98^-100% p u r e ,  o b ta in e d  from  G en e ra l ■
.................  . C hem ica l ..D iv is io n ,.. A l l i e d  ..C hem ica l.& .Dye C o rp o r a t io n ,  (The
c a l c u l a t i o n  i n  t h i s  . i n v e s t i g a t i o n . i s  ..based on 99$.; p u re  ) .  The 
n - p r o p y l ,  n - b u t y l , n -am y l, i s o - b u t y l ,  and is o -am y l  a lc o h o ls  
used , w ere  -C„p, g r a d e , . o b ta in e d .f r o m  S h a r p ie s ,  E im er and Aofend,
........................and  E astm an  Kodak Co*
........  So P ro c e d u r e :
E q u a l m ol p o r t i o n s  o f  a lc o h o l  and  fo rm ic  a c id  w ere  p la c e d  in  
an  E rle nm ey e r  f l a s k  and b o i l e d  u n d e r  a tm o sp h e r ic  p r e s s u r e  a t  t o t a l  
' ..re f l u x  ..by u s in g  a  P y rex  g l a s s - L i e b i g  condenser®  A f t e r  one h o u r
b o i l i n g ,  th e  f l a s k  was p la c e d  i n  a n  i c e  b a th  and th e  u n re a c te d  
a c id  was t i t r a t e d  w i th  a  s ta n d a r d  s o lu t i o n  o f  sod ium  h y d ro x id e  
u s in g  p h e n o lp h th a le i n  a s  th e  in d ic a to r®  The p e r c e n t  o f  e s t e r i f i ­
c a t i o n  c o u ld  t h e n  be c a lc u la te d®
B® P r e p a r a t i o n  o f  60 p s lg  p r e s s u r e  t e r n a r y  and a n a ly s i s  o f  i t s  composition®
(a )  The 60 p s ig  p r e s s u r e  e s t e r i f i c a t i o n  u n i t  i s  shown in  Pig®
1® The u n i t  c o n s is te d ,  o f  a  c o p p e r  p r e c i s i o n  column l | r  in c h e s  i n  -
d iam e te r  by  52 in c h e s  Io n g e The column was p acked  w i th  ^  in c h , 
g l a s s  h e l i c e s .  The s t i l l  p o t  w h ich  was s i l v e r  s o ld e r e d  t o  th e  
■ co p p e r  co lum n, was c o n s t r u c te d  from  a  s t a i n l e s s  s t e e l  oxygen t a n k  
w i th  a  c a p a c i ty  o f  ab o u t 1800 m le The co p p e r  column was j a c k e te d  
by  48 mm, g l a s s  tu b in g  in s i d e  64 mm, g l a s s  t u b in g ,  w i th  a  h e a t in g  
c o i l  s p i r a l i n g  th e  l e n g th  o f  th e  i n s id e  t u b e .  Power was s u p p l ie d  
t o  th e  h e a t i n g  e lem en t th ro u g h  an  a u to t r a n s f o rm e r .  The co n d en se r  
s e c t i o n  c o n s i s t e d  o f  a  w a te r  j a c k e t  c o n s t r u c te d  o f  an  I l= I n c h  
s e c t i o n  o f  tw o - in c h  s ta n d a r d  i r o n  p ip e  and  a  c o ld  f i n g e r  12 in c h e s  
lo n g  c o n s t r u c te d  .o f  ^ i n c h -  co pp e r tu b in g  ( I ) ,  The f low  o f  w a te r  
th ro u g h  th e  c o ld  f i n g e r  was c o n t r o l l e d  by  u s in g  a  l a b o r a to r y  
-b e l lo w s  pump. The c o n d e n se r  m o to r  was s u p p l ie d  from  a  c o n s ta n t  
h e a d .s o u r c e .  The r e f l u x  r a t i o  o b ta in e d  i n  th e  c o ld  f i n g e r  was 
e s t im a te d  t o  be i n  t h e  ra n g e  o f  5 -1  t o  10=1,
C onnec ted  to  t h e  s t i l l  p o t  was a  co p p e r  f e e d  t a n k  w i th  a- . 
c a p a c i ty  o f  a b o u t f i v e  l i t e r s ,  and  a  r e c e i v e r  c o n s t r u c te d  o f  l | -  
in c h  s ta n d a rd  i r o n  p ip e .  B o th  t h e  fe e d b a c k  and  r e c e i v e r  were k e p t  
u n d e r  th e  same o p e r a t in g  p r e s s u r e  a s  t h e  co lum n.
The d e s i r e d  p r e s s u r e  was o b ta in e d  by  means o f  an  a i r  com p resso r 
a n d .a  B eV ilb is s  P r e s s u r e .R e g u la t o r ,  Two 1 1 0 -v o l t  550 w a t t  h e a t e r s  
c o n t r o l l e d  by  a u to - t r a n s f o rm e r s  s u p p l ie d  th e  h e a t  t o  ‘th e  s t i l l  p o t  
and  th e  co lum n , ' . -
(b )  F o r . th e  p u r p o s e . o f . a n a l y s i s :
A g l a s s  p r e c i s i o n  co lum n, one in c h  in  d iam e te r ,  w i th  a  3 6 - in c h
s e c t i o n ,  p ack ed  w i th  ^ = in £ h  g l a s s - h e l i c e s  and e q u ip p ed  w i th  a  Cqfad
,
tyfce c o n d e n s in g  h ead  was u sed  t o  make a tm o sp h e r ic  s e p a r a t i o n s .
S 0 P r o c e d u r e :
«a0ca
I t  was f i r s t  assum ed t h a t  th e  t e r n a r y  a z e o tro p e  c om p o s itio n  
u n d e r  60 p s i g  p r e s s u r e  w ould  be  th e  same a s  a t  a tm o sp h e r ic  p re s s u re *  
From th e  a tm o sp h e r ic  t e r n a r y  c om p o s itio n  d a t a ,  T ab le  I ,  t h e  p ro p o r ­
t i o n s  o f  a l c o h o l ,  a c id  and  w a te r  ( i f  n e c e s s a ry )  r e q u i r e d  t o  fo rm  th e  
t e r n a r y  a z e o t ro p e  w e re . c a lc u la te d *  F o r  ex am p le :
A tm osphe ric  t e r n a r y  o f  i s o - b u t y l  fo rm a te  c o n s i s t s  o f  th e  f o l lo w ­
in g :
■ I s o b u ty l ,  
fo rm a te
I s o b u ty l
a lc o h o l
.W ater
Wto <fo 76 6*7 1 7 ,3
Mdls wt* 103*13 74*13 18 -
Mols 0*7435 0*0904 0 ,9605
Mols I 0*133 1 ,3 95
...................  Feed  Charge
Mois Grams
Form ic  a c id  I  46
I s o b u ty l  a lc o h o l  I  + 0*1SS 83* S
W ater I*  395 -1  5*3
About 100 gm* o f  t h i s  m ix tu re  was th e n  c h a rg ed  t o  th e  u n i t  
and  b o i l e d  u n d e r  60 p s ig *  p r e s s u r e  a t  t o t a l  r e f l u x  f o r  one hour*  
P roduct, w as th e n  ta k e n  o f f  a t  a  h ig h  r e f l u x  r a t i o  u n t i l  th e  tem p e r­
a tu r e  in  th e  s t i l l  p o t  b egan  t o  c l im b , i n d i c a t i n g  e x h a u s t io n  o f  th e  
t e r n a r y  a z e o tro p e *
T h is  p ro d u c t  was th e n  r e d i s t i l l e d  i n  th e  g l a s s  p r e c i s io n  
column u n d e r  a tm o sp h e r ic  p r e s s u r e *  The a tm o sp h e r ic  t e r n a r y  a z e o ­
t r o p e  came o f f  f i r s t  and c o n tin u e d  t o  come, o f f  u n t i l  one o f  th e  
c o n s t i t u e n t s  was e x h a u s te d ,  when th e  tem p e ra tu re  o f  th e  f Iasdc b e -
- 9 -
gan to  c l im b . The n e x t  h ig h e r  b o i l i n g  a z e o t r o p e ,  a lw ay s  a  b in a r y ,  th e n  
came o f f  u n t i l  one o r  b o th  o f  i t s  c o n s t i t u e n t s  were e x h a u s te d ,  when th e  
tem p e ra tu re  o f  th e  f l a s k  a g a in  began  t o  c lim b . The c om p o s i tio n  o f  th e  
t e r n a r y  o b ta in e d  u n d e r  60 p s ig  p r e s s u r e  c o u ld  th e n  be c a l c u l a t e d .
F o r ex am p le : A n a ly s is  o f  th e  i s o b u ty l  fo rm a te  t e r n a r y  u nde r 60
p s ig  p r e s s u r e  was 63.3% a tm o sp h e r ic  t e r n a r y ,  (76% i s o b u ty l  fo rm a te ,
6.7% i s o b u ty l  a l c o h o l ,  17.3% w a t e r ) , 21.9% b in a r y  (67% i s o b u ty l  a lc o h o l
33% w a te r )  and  14.8% w a te r .
I s o b u ty l I s o b u ty l
fo rm a te a lc o h o l W ater
Atm. t e r n a r y  63 .3x76  = 4 8 .1 6 3 .3 x 6 .7  I  4 .2 6 3 .3 x 1 7 .3  
— 1 1 .0
A lc o h o l-w a te r  b i n a r y  0 21 .9x67  = 1 4 .7 21 .9x33  = 7 . 2
W ater 0 ) 1 4 .8
T h e re fo re  60PSIG TERNARY = 4 8 .1 1 8 .9 3 3 .0
Ce E s t im a t io n  o f  th e  e s t e r i f i c a t i o n  r a t e  u n d e r  60 p s ig  p r e s s u r e  
P ro c e d u r e :
The p ro p e r  f e e d  ch a rg e  was c a l c u l a t e d  from  th e  f i n a l  60 p s ig  
t e r n a r y  a z e o tro p e  c om p o s i t io n . F o r  ex am p le , 60 p s ig  i s o b u ty l  t e r n a r y  
c o n s i s t s  o f  48.1%  i s o b u ty l  f o rm a te ,  18.9% i s o b u ty l  a l c o h o l ,  and 33.0%
w a te r .
I s o b u ty l
fo rm a te
I s o b u ty l
a lc o h o l W ater
w t .  % 4 8 .1 1 8 .9 33
Mol. w t. 1 0 2 .1 3 7 4 .1 2 18
Mols 0 .4 7 0 0 .2 55 1 .835
Mols I . 0 .5 4 2 3 .9 1
- 1 0 -
Feed  Charge
Mols Grams
Form ic a c id I 46
I s o b u ty l  a lc o h o l  I  + 0 .5 4 2 1 1 4 .4
W ate r  ^ 3 e' 91 -  I  5Ss4
A cco rd in g  t o  th e  f e e d  ch a rg e  r a t i o ,  a b o u t 100-150  gms0 o f  t h i s  
m ix tu re  (b a sed  on §- mol o f  fo rm ic  a c id )  was th e n  ch a rg ed  t o  th e  u n i t  and  
b o i l e d  u n d e r  60 psig®  p r e s s u r e  a t  t o t a l  r e f l u x  f o r  one h o u r .  The head  was 
c h a n g ed .f rom  t o t a l  r e f l u x  t o  z e ro  r e f l u x  u n t i l  t h e  tem p e ra tu re  i n  th e  s t i l l  
p o t  b eg an  t o  c l im b , i n d i c a t i n g  e x h a u s t i o n .o f  th e  t e r n a r y  a z e o t ro p e  (ab o u t 
1 2 -15  min®) The w e ig h t o f  th e  t e r n a r y  and th e  e s t e r i f i c a t i o n  r a t e  u nd e r 
60 p s i g  p r e s s u r e  w ere  c a lc u la te d®  Fo r ex am p le , from  th e  f e e d  ch a rg e  r a t i o  
shown ab o v e , f e e d  23 gms® fo rm ic  a c id ,  57®2 gms. i s o b u ty l  a lc o h o l  and 
26®2 gms. w a te r  t o  th e  un it®  The w e ig h t  o f  th e  t e r n a r y  o b ta in e d  from  th e  
above m ethod i s  55 gms® From  a n a l y s i s ,  th e . c om p o s itio n  o f  i s o b u t y l  fo rm a te  
i i  60 p s ig .  t e r n a r y  i s  48®1%. So th e  i s o b u t y l  fo rm a te  fo rm ed  i s  55 x  0 .4 8 1  
"  2 6 .4  gms®
.HCOOH + (CH3 ) 2 CHCH2OH — ^  ..HcOOCH3CH(CH3 )3 + H2O
46 : 102
x  : 2 6 .4  - -, ■...< . ■ ■ ■
o ° .  x  1 1 .9  gms® o f  HCOOH u sed  t o  fo rm  2 6 .4  gms.
I s o b u ty l . f o rm a t e .  T h e f d fo r e , th e  e s t e r i f i c a t i o n  r a t e  u n d e r
60 p s ig  p r e s s u r e  ”  x  100 “  51.8% ' v
The p ro c e d u re  c a n  be r e p e a te d  s e v e r a l  t im e s  t o  g e t  th e  mean v a lu e .
\
■=11"
' A p r e s s u r e  o f  60 P s i g 9 w h ich  w ould  g iv e  a  s u b s t a n t i a l  tem p e ra tu re  r i s e  
compared t o  th e  a tm o sp h e r ic  b o i l i n g  p o i n t ,  was a b ou t th e  maximum p r e s s u r e  
a t  w h ich  th e  equ ipm en t u sed  c o u ld  h e  o p e r a t e d .  The c o n tin u o u s  n o n - c a t a l y t i e  
e s t e r i f i c a t i o n  o f  n -=propy l9 n - b u t y l ,  i s o b u t y l ,  n -am y l, and  iso am y l a lc o h o l s  
w i th  fo rm ic  a c id  c o u ld  be s u c c e s s f u l l y  o p e r a te d  in  t h i s  u n i t .
The e s t e r i f i c a t i o n  r a t e  a t  a tm o sp h e r ic  p r e s s u r e  and 60 p s ig  p r e s s u r e  
o f  U =P ropy l9 n = b u ty l , i s o b u t y l ,  n=am yl, and  iso am y l a lc o h o l s  w i th  fo rm ic  
a c id  g iv e n  i n  T ab le  I I  w ere  c a lc u l a t e d  from  e x p e r im e n ta l  d a t a .
The c om p o s i t io n s  o f  60 p s ig  p r e s s u r e  a z e o tro p e  t e r n a r i e s  w ere a n a ly z e d  
and c a l c u l a t e d  a s  g iv e n  i h  T ab le  I I I ,
F o r  c o n tin u o u s  o p e r a t i o n ,  th e  f e e d  c h a rg e s  were c a l c u l a t e d  a c c o rd in g  
t o  th e  c om p o s i t io n s  o f  60 p s ig . .p r e s s u r e  t e r n a r y .  The f e e d  c h a rg e  compo­
s i t i o n s  ...are g iv e n  in  T ab le. 1 7 . The p ro d u c t  was removed a t  th e  r a t e  a s  
h ig h  a s  th e  e s t e r i f i c a t i o n  f a t e ,  u n d e r  60 p s i g .  p r e s s u r e ,
1 7 . SUMMRY OF "RESULTS -
The f o l lo w in g  sm spary  may be drawn from  th e  r e s u l t s  found  in  t h i s  
i n v e s t i g a t i o n :
I .  The e s t e f i f i c a t i o n  r a t e  u n d e r  60 p s i g  p r e s s u r e  i s  much h ig h e r  th a n  
t h a t  a t  a tm o sp h e r ic  p r e s s u r e .
B o  E s t e r i f i c a t i o n  o f  n - p r o p y l ,  n - b u ty l ,  i s o b u t y l ,  n -am y l, iso am y l 
a l c o h o l s  by  fo rm ic  a c id  may be c a r r i e d  o u t c o n t in u o u s ly  i n  th e  
a b sen ce  o f  a  c a t a l y s t  i n  a  r e c t i f i c a t i o n  c o lumn u n d e r  60 psijg
. I I I .  RSSPLTS
p re s s u re . .
oIB=
5o The 60 p s ig  p r e s s u r e  t e r n a r y  c om p o s itio n  i s  d i f f e r e n t  from  t h a t  
a t  a tm o sp h e r ic  p r e s s u r e  i n  a l l  c a se s*
4« The p.e? c e n t  o f  e s t e r  i n  th e  t e r n a r y  a z e o tro p e  i s  l e s s  a t  60 p s ig  
p r e a s p rp  tMan a t  a tm o sp h e r ic  p r e s s u r e  in  a l l  c a se s*
V* DlgOUSSIOH
From A r r e h e n iu s - e q u a t io n  I n  (S  -  4  ) ' we can  c a l c u l a t e  th e
K1 1I  l 2
e n e rg y  o f  a c t i v a t  ioh.-.f-rom e x p e r im e n ta l  d a t a .  F o r n -p ro p y l  fo rm a te  A -  7410 
c a l / g .  m o l; n - b u ty l  f o rm a te ,  A s  6890 c a l /g *  m ol; i s o b u t y l  fo rm a te  A 5 5880 
e a l o / g .  m o l; n -am y l fo rm a te  A = 8500 c a l / g .  m o l; Isoam y l fo rm a te  A = 1780 
c a l / g .  m o l.
•,
From A r rh e n iu s  e q u a t io n  th e  r e a c t i o n  r a t e - c o n s t a n t  c an  a l s o  be found* 
F o r  ex am p le , t o  f i n d  th e  r e a c t i o n  r a t e  o f  i s o b u ty l  fo rm a te  a t  1550C.
From  e x p e r im e n ta l  d a t a ,  s . «1)1*6 a t  ISS0Oo
° m  R -  ;  , 5 8 8 0 ,  ( — 3 ---------  ,■ , , 1 . _
5 1 .6  ' 1 .9 8 6  V 873 158 873 155
Oe e - K 2 = 67.8% ' ' a t  I ^ S 0O0
From l i t e r a t u r e ,  K =.61*69% a t  155°C . (8 )
V I. LITERATURE CITFD 
( I )  B e r g . a n d .S m i th , . I n d u s t r i a l  E n g in e e r in g  Chem.
(8 ) G ro g g in s , P.H... tlU n i t  .P ro c e s s e s  i n  O rgan ic  S y n th e s i s ” , 3 rd  E d . p .  685 , 
. . . .  ...Hew. Y o rk , M cG raw -H ill Book Co. I n c .  1947*
(.3) .H o r s le y ,  L .H . T ab le  ■ o f  ..A zeo trope  .and  H on -A zeo trb p e s , A n a ly t i c a l  
. C h em is try , 1 9 , 508 -600  (.1947)
■13“
V I I . APPSKDIX
Page
F ig u re  I  -  S ch em a tic  D iagram  o f  E qu ipm en t. ...........................................  14
T ab le  t  A tm o sph e r ic  A z eo tro p e  C om po s it io n s , . . . . . . . . . . .  . 1 5
T ab le  I I  ■? E s t e r i f i c a t i o n  R a te s .  . . . . . . . . . . . . . . . . . . . 1 6
T ab le  I I I ?  60 p s i g .T e rn a ry  A zeo tro p e  C om po s it io n s . . . . . . . . . . .  16
T ab le . IV, -  Feed  C om po sitio n s , f o r  C on tin u ou s  O p e ra t io n . 17
—1 4—
H^O
COL D FINGER
PRESSURE 
REGULATOR
PUMP
SARAN
SIGHT
TUBE
SARAN
SIGHT
TUBE
FEED
TANKl/ 4  GLA S S  
HE LICES
> - GLASS 
^  JACKETS
1/4' COPPER 
TUBING
DRAI N
F ig u re  I  S ch em a tic  D iagram  o f  Equipm ent
TABLE I  -  ATMOSPHERIC AZEOTROPE COMPOSITIONS ( 3 )
Ethyl Formate 
n-Propyl Formate 
Isopropyl Formate 
n-Butyl Formate 
Isobu ty l Formate 
n-Amyl Formate 
Isoamyl Formate
E -
A E Binary Binary
E-W A-W
B.P. B.P. B.P. w t. % B.P. ■wt. %
°C 0C OC W OQ W
78.3 54.1 78.15 4 .4
79.2 81 71.6  2 .3 87.7 28.3
82.5 Tl No data 80 .4 12 .1
117.7 106.9 83 .8  15 92 .4 38
107.9 98.5 80 .4  7 .8 89 .9 33
137.8 132 91.6  23 .4 95.9 54
131.6 123.3 90 .2  21. 95 .2 49.6
Ester A -  Alcohol
Binary
E-A
B.P. w t. % B.P. wt.% wt. % w t. %
OC A OC E A W
No Azeo. No data
80.6  9 .8 70.8 82 5 13
No data No data
105 .8  23 .7 83.6 68 .7  10 „ 21.3
97.8  20.6 80 .2 76 6 .7  17.3
130.4  43 91 .4 41 .2  21 .2  37.6
123.6 26 89 .8 48 19.6  32 .4
W - Water
tL
Ul
I
-16'
TABLE I I  -  ESTERIFICATION RATES
E s t e r A tm osphe ric  R a te  
Temp. °C R a te
60 p s ig  R a te  
Temp. °C R a te
n -P ro p y l  Form ate 90 1 1 .0 134 2 6 .3
n -B u ty l  Form ate 1 0 4 .5 2 8 .9 144 3 1 .6
I s o b u ty l  Form ate 98 2 4 .6 138 5 1 .6
n-Amyl Form ate 108 1 3 .9 144 .5 1 8 .6
Iso am y l Form ate 106 2 1 .0 143 2 3 .3
(From l i t e r a t u r e  th e  e s t e r i f i c a t i o n  r a t e  
a t  155°C . i s  61.69%) (2)
o f  I s o b u ty l  Fo rm ate
TABLE I I I -  60 PSIG TERNARY AZEOTROPES
E s t e r B .P .°C w t . % A lco h o l w t. % E s t e r  wt . % W ater
n -P ro p y l  Form ate 134 3 0 .7 3 2 .4 3 6 .9
n -B u ty l  Form ate 144 2 7 .3 3 9 .0 33 .7
I s o b u ty l  Form ate 138 1 8 .9 4 8 .1 33 .0
n-Amyl Form ate 1 44 .5 2 0 .2 24 .5 5 5 .3
Iso am y l Form ate 143 2 7 .6 1 8 .3 5 4 .1
■17
TABLE IV . -  FEED COMPOSITION FOR CONTINUOUS OPERATION
E s t e r w t. % Acid
n -P ro p y l  Form ate 1 7 .0
n -B u ty l  Form ate 1 7 .5
I s o b u ty l  Form ate 2 1 .6
n-Amyl Form ate 9 .6
Iso am y l Form ate 7 .3
w t. % A lco h o l w t. % W ater
5 2 .9 3 0 .1
5 5 .7 2 6 .8
5 3 .9 2 4 .5
3 9 .5 5 0 .9
4 0 .7 5 2 .0
103009
10022724 6
«5*‘
105009
author
J-c : Ih-Cheo
TITLE u 0 n ^ l i i U U U d  1 ) 0 !'}C 'T l
___e8torificatinn of I
d a t e  d u e
ower om a
BORROWER 'S  NAME
103009