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Can Sucrose Compete with Hydrocarbons as a Chemical Feedstock? W. J. SHEPPARD and E. S. LIPINSKY Battelle Columbus Laboratories, 505 King Ave., Columbus, Ohio 43201
Many c h e m i c a l u s e s f o r s u c r o s e a n d i t s d e r i v a t i v e s have been r e p o r t e d i n c l u d i n g t h e making o f e t h y l a l c o h o l , g l y c e r i n , u r e t h a n e foam i n t e r m e d i a t e s , d e t e r g e n t s , and p l a s t i c i z e r s . These o p p o r t u n i t i e s have been d i s cussed i no t h e r papers i n t h i s volume, i n t h e ISRFp u b l i s h e d b o o k b y V a l e r i e K o l l o n i t s c h (1^) / a n d e l s e w h e r e . With t h e r i s e o f o i l and gas p r i c e s t h a t have o c c u r r e d r e c e n t l y and t h a t a r e expected i nt h e f u t u r e , updated comparisons a r e needed o f c o s t s o f making v a r i ous c h e m i c a l s f r o m h y d r o c a r b o n s v e r s u s s u c r o s e . In t h e l o n g r u n , o i l a n d g a s may b e i n v e r y s h o r t s u p p l y at any p r i c e . A t t h a t t i m e t h e c o m p e t i t i o n may b e among s u c r o s e , c e l l u l o s e , a n d c o a l . This paper address e s t h e c o s t o f e t h a n o l p r o d u c t i o n i n some d e t a i l a n d takes a b r i e f look a t acetone, b u t a n o l , and g l y c e r i n from hydrocarbons and sucrose, s i n c e these a r e cases where s i g n i f i c a n t v o l u m e s o f s u c r o s e m i g h t be u t i l i z e d . Before a comparison o f hydrocarbons and sucrose f o r c h e m i c a l u s e i s made, a l o o k i s i n o r d e r a t t h e a l t e r n a t e uses o f sucrose. There i s no p o i n t l o o k i n g at markets f o r sucrose as a chemical f e e d s t o c k even a t a l o w c o s t i f i t s u s e a s f o o d o r a n i m a l f e e d commands a better price. The c o m p a r i s o n a l s o s h o u l d i n c l u d e f u e l a s w e l l a s c h e m i c a l u s e s o f t h e p r o d u c t s made f r o m sucrose, s i n c e t h i s use a l s o i s i n f l u e n c e d by t h e i n creased p r i c e s f o rhydrocarbons. I n t h i s comparison t h e v a l u e o f t h e m a t e r i a l t o t h e u s e r must be c o n s i d e r ed. As a s t a r t , l e t u s compare f o o d and f u e l v a l u e s . Sugar a t 20C/lb i nt h e supermarket s e l l s f o r $28/mill i o n Btu. Gasoline a t 62C/gal ( i n c l u d i n g taxes) i s equivalent t o $ 5 / m i l l i o n Btu. The h i g h e r v a l u e f o r t h e s u g a r c a n be a t t r i b u t e d t o t h e f a c t t h a t i t h a s e x t r a v a l u e , namely n u t r i t i o n a l , p r e s e r v a t i v e , and f l a v o r values. Thus, u n t i l a l l food markets f o r sugar a r e s a t i s f i e d a t a l l p r i c e s down t o t h e f u e l v a l u e , n o s u g 336
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
25.
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337
a r w i l l be o f f e r e d t o p r o d u c e f u e l a t t h e f u e l - v a l u e d price. Of c o u r s e , o n c e t h e f o o d m a r k e t a t t h e c u r r e n t p r i c e i s s a t i s f i e d a n d p r i c e s d r o p , o t h e r m a r k e t s may be a b l e t o u s e s u g a r b e f o r e t h e p r i c e r e a c h e s t h e f u e l price. A n o t h e r l a r g e m a r k e t t h a t can a f f o r d t o pay a n u t r i t i o n a l premium i s t h e a n i m a l f e e d i n d u s t r y , w h i c h now i s a l a r g e u s e r o f m o l a s s e s . Thus, t h e r e i s a h i e r a r c h y o f needs and w i l l i n g n e s s t o pay, i n t h e o r d e r food, feed, then f u e l s . Further consideration of o t h e r m a r k e t s l e a d s t o t h e e x t e n d e d h i e r a r c h y shown i n Table I (with apologies f o r the forced a l l i t e r a t i o n ) . Table 1. 2. 3. 4. 5. 6.
7. 8. 9.
I.
H i e r a r c h y o f Farm P r o d u c t s
Farmaceutical Firewater Fragrance Flavorant F u n c t i o n a l a i d f o r food Food Flesh, fowl, fish F a t s and o i l s Fillers Feed Fiber F i l m and s h e e t
10. 11. 12. 13. 14.
Uses
F r a m i n g and l u m b e r Feedstock f o r chemicals Fertilizer F r i a b i l i t y aid, erosion control, etc. Fuel For f a m i l y f l i v e r Flying Family furnace F a c t o r y and e l e c t r i c i t y generation
I n t e r m e d i a t e b e t w e e n f e e d and f u e l u s e s a r e t h o s e t h a t u t i l i z e t h e one, two, and t h r e e d i m e n s i o n a l p r o p e r t i e s of cane f i b e r o r s u c r o s e d e r i v a t i v e s , f o r example, r a y o n o r p o l y e t h y l e n e , f i b e r , p a p e r , and C e l o t e x board. The c h e m i c a l a n d b u l k p h y s i c a l p r o p e r t i e s a r e r e f l e c t e d i n u s e s as a c h e m i c a l f e e d s t o c k , f e r t i l i z e r , and a i d t o i m p r o v e t h e q u a l i t y o f t h e s o i l , p r e v e n t e r o s i o n , and h o l d m o i s t u r e i n t h e s o i l . These a l l have a g r e a t e r v a l u e p e r l b t h a n j u s t u s i n g the chemic a l b o n d i n g e n e r g y r e l e a s e d on c o m b u s t i o n . Also, there are values higher than the n u t r i t i v e value of food. These are r e l a t e d t o h i g h e r p h y s i o l o g i c a l a c t i v i t i e s o f t h e m a t e r i a l s u c h a s , use as a d r u g o r medicine, f l a v o r , or fragrance. The b e v e r a g e u s e o f a l c o h o l , t a x p a i d a t r e t a i l , commands a t l e a s t $ 4 0 / g a l , which i s e q u i v a l e n t t o $60/gal f o r g a s o l i n e . Thus, s u c r o s e as a s w e e t e n e r i s w o r t h more p e r l b t h a n c o r n s t a r c h , w h i c h p r o v i d e s c a l o r i e s b u t no f l a v o r . Funct i o n a l a i d s , t h a t i s i n g r e d i e n t s which improve the p r o p e r t i e s of food, s h e l f l i f e , or p r e p a r a t i o n ease have a premium. S u c r o s e as a p r e s e r v a t i v e i n marmalade i s w o r t h more t h a n a f o o d t h a t o n l y p r o v i d e s c a l o r i e s .
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
338
SUCROCHEMISTRY
I t s h o u l d be n o t e d t h a t t h e h i g h e r v a l u e p r o d u c t s u s u a l l y are s o l d i n s m a l l e r volumes than the lower valued products. For example, the annual per c a p i t a c o n s u m p t i o n i n t h e U n i t e d S t a t e s i s 90-100 l b o f s u g a r v e r s u s 2700 l b o f g a s o l i n e . Economic i n c e n t i v e s l e a d the producer t o f i l l the h i g h e s t v a l u e market even a t low volumes, t h e n t o " s p i l l o v e r " t o the n e x t lower p r i c e , l a r g e r volume market. Frequently, product d i f f e r e n t i a t i o n i s used t o a v o i d l o s s o f t h e premium p r i c e i n the f i r s t market w h i l e g a i n i n g s a l e s volume i n the second. For example, a l c o h o l i s s o l d i n beverage ( t a x a b l e and t a x f r e e ) and d e n a t u r e d grades. W i t h i n each category there a l s o i s a h i e r a r c h y . Meat i s w o r t h more t h a n f a t s and o i l s , w h i c h i n t u r n a r e w o r t h more t h a n s t a r c h y f o o d s , w h i c h p r o v i d e m e r e l y calories. In the f u e l s category, t r a n s p o r t a t i o n f u e l a n d home h e a t i n g h a v e h i g h e r v a l u e s t h a n f u e l f o r r u n ning factories or generating e l e c t r i c i t y . O c c a s i o n a l l y , t h e r e i s an i n v e r s i o n o f t h e o r d e r , b u t o n l y i n u n u s u a l c i r c u m s t a n c e s , f o r e x a m p l e , t h e snowbound c a b i n d w e l l e r b u r n i n g h i s f u r n i t u r e f o r warmth. For chemical uses of sucrose t o rank h i g h e r than food a n d f e e d w o u l d r e q u i r e q u i t e a r e v o l u t i o n i n human values. On t h e o t h e r h a n d , a t t h e f o o d a n d f e e d p r i c e f o r s u c r o s e , e c o n o m i c i n c e n t i v e s w o u l d be more l i k e l y t o l e a d t o t h e use o f s u c r o s e as a c h e m i c a l i n t e r m e d i a t e t h a n as a s o u r c e o f f u e l . Looking f u r t h e r at chemical o p p o r t u n i t i e s , a s e a r c h was made f o r l a r g e v o l u m e c h e m i c a l s t h a t c o u l d a f f o r d t h e c o s t o f s u c r o s e as a raw m a t e r i a l . When the volume of o r g a n i c c h e m i c a l p r o d u c t i o n i s graphed a g a i n s t p r i c e p e r l b f o r 150 l e a d i n g o r g a n i c c h e m i c a l s (2) i n a l o g - l o g p l o t , a n e a r l y s t r a i g h t band i s found a s shown i n F i g u r e 1. However, i f the type o f chemic a l i s c o n s i d e r e d , t h e d i s p l a y no l o n g e r i s a b a n d b u t a s e r i e s o f o v e r l a p p i n g p a t c h e s , a s shown i n F i g u r e 2. H e r e , a h i e r a r c h y c a n be s e e n , s i m i l a r t o t h a t d e s c r i b ed p r e v i o u s l y . Most primary p e t r o c h e m i c a l s are i n the high volume-low p r i c e category. Chemicals w i t h macromolecular s t r u c t u r e , that i s , p l a s t i c s , r e s i n s , and e l a s t o m e r s , a r e i n t h e m e d i u m - t o - l a r g e v o l u m e and at a higher average p r i c e than b a s i c petrochemicals. M a t e r i a l s w i t h p h y s i o l o g i c a l a c t i v i t i e s such as m e d i c i n a l c h e m i c a l s , f l a v o r a n t s , a n d some p e s t i c i d e s h a v e low volumes and h i g h v a l u e s . Chemicals w i t h other f u n c t i o n a l v a l u e s , s u c h as r u b b e r p r o c e s s i n g c h e m i c a l s , p l a s t i c i z e r s , and s u r f a c e a c t i v e a g e n t s , s e l l i n modera t e v o l u m e s a t p r i c e s b e t w e e n t h e two e x t r e m e s . W i t h t h e i d e a o f u t i l i z i n g l a r g e amounts o f s u c r o s e and r e l e a s i n g l a r g e amounts o f p e t r o l e u m f o r
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
25.
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U n t i l t h e p e t r o c h e m i c a l a n d n a t u r a l g a s boom, i n d u s t r i a l e t h a n o l was m a n u f a c t u r e d p r i m a r i l y b y f e r m e n t a t i o n of molasses. The p r o d u c t i o n o f e t h y l e n e w i t h a s e l l i n g p r i c e o f o n l y 3C/lb combined w i t h i n c r e a s e d use o f molasses i n animal feed l e d i n t h e U n i t e d S t a t e s t o t h e manufacture o f e t h a n o l p r i m a r i l y by h y d r a t i o n o f ethylene. The c u r r e n t m a r k e t f o r i n d u s t r i a l e t h a n o l e x c e e d s 7 0 0 , 0 0 0 t o n s / y e a r (3). A d d i t i o n a l ethanol i s used c a p t i v e l y b y some p r o d u c e r s t o m a n u f a c t u r e a c e t i c
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
25.
SHEPPARD AND LiPiNSKY
Sucrose as a Chemical Feedstock
341
a c i d and a c e t a l d e h y d e , thus l e a d i n g t o a s t i l l l a r g e r production than the s a l e s f i g u r e s d i r e c t l y a t t r i b u t e d to ethanol. The s e l l i n g p r i c e o f i n d u s t r i a l e t h a n o l h a s r i s e n r a p i d l y i n t h e l a s t few y e a r s , r e f l e c t i n g ethylene p r i c e i n c r e a s e s f r o m t h e r a n g e o f 3C t o 4C/lb t o IOC t o 12C/lb. The p r e s e n t s e l l i n g p r i c e o f e t h a n o l i s a p p r o x i m a t e l y $1.15/gal, o f w h i c h t h e e t h y l e n e c o s t i s a p p r o x i m a t e l y 50C a n d t h e n o n - r a w m a t e r i a l c o s t s t o t a l 65C/gal. The non-raw m a t e r i a l c o s t s i n c l u d e m a r k e t i n g c h a r g e s a n d p r o f i t i n a b u s i n e s s t h a t h a s many s m a l l customers w i t h s p e c i a l i z e d requirements. E t h a n o l from Cane J u i c e . R e s e a r c h c o n d u c t e d by B a t t e l l e Columbus L a b o r a t o r i e s f o r t h e F u e l s from Biomass P r o g r a m O f f i c e o f t h e D i v i s i o n o f S o l a r E n e r g y o f t h e US E n e r g y R e s e a r c h a n d D e v e l o p m e n t A d m i n i s t r a t i o n (ERDA) has f o c u s e d on t h e p o s s i b l e m a n u f a c t u r e o f e t h a n o l from sugar c r o p s . The p r o s p e c t s f o r m a n u f a c t u r e o f ethylene from fermentation ethanol i s i n c l u d e d i n t h i s r e s e a r c h p r o j e c t . Ethylene p r o d u c t i o n from sugar crops i s considered a long-range o p p o r t u n i t y because t h e p r i c e o f p e t r o l e u m would have t o n e a r l y t r i p l e b e f o r e i t would begin t o appear economically a t t r a c t i v e . A c c o r d i n g l y , ethylene from f e r m e n t a t i o n e t h a n o l i s n o t discussed i n t h i s paper. The c o n s o l i d a t e d m a n u f a c t u r i n g c o s t s f o r a n e t h a n o l f e r m e n t a t i o n f a c i l i t y t h a t i s capable o f making a b o u t 70 m i l l i o n g a l p e r y e a r o f 190 p r o o f a l c o h o l i s shown i n T a b l e I I . The m a j o r c o s t e l e m e n t i n f e r m e n t a t i o n e t h a n o l i s t h e sugar s o l u t i o n t h a t i s t h e raw material. J u i c e s t h a t c o u l d be e x t r a c t e d f r o m s u g a r cane, sugar b e e t s , and sweet sorghum were i n v e s t i g a t e d by B a t t e l l e . S u g a r c a n e j u i c e a p p e a r s t o be most promi s i n g f o r l a r g e - s c a l e o p e r a t i o n s because the co-operat i o n a l b a g a s s e c a n be u s e d t o a c h i e v e f u e l s e l f - s u f f i ciency. F o r s m a l l e r s c a l e o p e r a t i o n s , by-product mola s s e s may b e a s g o o d o r b e t t e r b u t t h e p r i c e v o l a t i l i t y o f t h i s b y - p r o d u c t c o u l d be a s o u r c e o f c o n c e r n . Batt e l l e e s t i m a t e s t h a t c l o s e t o 15 l b o f f e r m e n t a b l e soli d s w o u l d b e r e q u i r e d t o make o n e g a l e t h a n o l . A r e a s o n a b l y o p t i m i s t i c cane j u i c e c o s t i s a p p r o x i m a t e l y 6C/lb ( f e r m e n t a b l e s o l i d s b a s i s ) . Therefore, the s u g a r s a l o n e w o u l d c o s t a b o u t 90C/gal o f e t h a n o l . The m a j o r c a p i t a l c o s t i s f o r a l a r g e n u m b e r o f fermentation tanks. T h e r e f o r e , s m a l l e r p l a n t s may have n e a r l y a s l o w c a p i t a l c o s t p e r g a l b e c a u s e one simply uses fewer, l a r g e - s i z e fermentation tanks. The major o p e r a t i n g c o s t i s t h e steam r e q u i r e d t o d i s t i l l the e t h a n o l and t o p e r f o r m v a r i o u s cane j u i c e concen-
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
SUCROCHEMISTRY
342 Table I I . Consolidated (In
Basis:
Manufacturing Costs - Ethanol m i l l i o n s o f 1976 d o l l a r s )
70 m i l l i o n g a l l o n s d r i e d stilläge
o f 95 p e r c e n t
ethanol
Plant
and 224,400
tons
ia Annualized Estimated
Capital
Charges
Operating Costs
14.9 including
dénaturant
22.2
Sugarcane J u i c e
55.8
TOTAL
92.9
Stillage
By-Product
Credit
NET
MANUFACTURING
C O S T
NET
M A N U F A C T U R I N G ;
C O S T
(a)
Based on c a p i t a l a f t e r taxes.
(11.2) 81.8
PER GALLON
investment
1.17
o f $127 m i l l i o n ,
60% d e b t ,
14% r e t u r n
tration operations. The a v a i l a b i l i t y o f cheap bagasse t o a c c o m p l i s h t h i s steam g e n e r a t i o n i s a d e f i n i t e a d vantage f o r sugarcane. However, b e e t j u i c e o r m o l a s s e s may b e a c c e p t a b l e i f a s u p p l y o f c h e a p s t e a m c a n b e assured. Another r e l a t i v e l y high cost item i s working c a p i t a l , because c o n c e n t r a t e d cane j u i c e must be s t o r e d d u r i n g t h e o f f season and c o n s i d e r a b l e ethanol invent o r i e s a r e r e q u i r e d t o s e r v i c e t h e market. S t i l l a g e , t h a t i s , s t i l l r e s i d u e and spent y e a s t , i s a n u t r i t i o u s animal feed concentrate. T h e stilläge from t h i s e t h a n o l p r o c e s s does n o thave a c o m p o s i t i o n as d e s i r a b l e a s t h a t o b t a i n e d f r o m g r a i n e t h a n o l o p e r a tions. P r o t e i n content i s l o wand s a l t s content i s high. T h i s stilläge w a s e s t i m a t e d t o b e h a l f t h e value o f the conventional grain-based products. The n e t c o s t s a r e c a l c u l a t e d t o b e a b o u t $ 1 . 1 7 / g a l . These c o s t s i n c l u d e a charge f o r a r e t u r n on e q u i t y o f 14% a f t e r t a x e s , a s s u m i n g t h a t 6 0 % o f t h e c a p i t a l f o r t h e v e n t u r e w e r e b o r r o w e d a t 8.75% i n t e r e s t . Marketi n g charges and other promotional expenses t h a t c o u l d a d d a p p r o x i m a t e l y 35£/gal a r e n o t i n c l u d e d . I f more c o n s e r v a t i v e f i n a n c i a l p o l i c i e s were used (e.g., 30% d e b t a n d 1 5 % a f t e r t a x e s r e t u r n o n e q u i t y ) , t h e manuf a c t u r i n g cost would r i s e t o about $1.30/gal and t h e
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
25.
SHEPPARD
A N D
LiPiNSKY
Sucrose as a Chemical Feedstock
343
s e l l i n g p r i c e m i g h t be c l o s e t o $1.70. These p r e l i m i n a r y c a l c u l a t i o n s i n d i c a t e t h a t e t h a nol by fermentation o f sugarcane j u i c e i s c l o s e t o equivalence w i t h ethanol d e r i v e d from petroleum o r n a t u r a l gas l i q u i d s a t $1.15/gal. As d e s c r i b e d above, the competitiveness o f sugarcane w i t h the nonrenewable r e s o u r c e s depends h e a v i l y o n the c o s t o f the fermentable sugars. I f one h a d t o p u r c h a s e m o l a s s e s on t h e open m a r k e t , t h e v e n t u r e c o u l d be i n deep t r o u b l e d u r ing times o f high molasses p r i c e s , occasioned, perhaps, by a c o r n c r o p f a i l u r e . The v a l u e o f t h e stilläge i s a n o t h e r c r i t i c a l f a c tor. I f t h i s p r o d u c t c o u l d b e u p g r a d e d t o s e l l more competitively with other d i s t i l l e r s dried solubles, the economics o f t h i s e t h a n o l process would improve but, i f the product proved unacceptable, a corresponding depressing e f f e c t would be observed. Another s e n s i t i v e element i s steam, the c o s t o f w h i c h i s m i n i m i z e d b y e m p l o y i n g b a g a s s e a s t h e r a w material. When new v a c u u m f e r m e n t a t i o n p r o c e s s e s , s u c h as t h a t u n d e r i n v e s t i g a t i o n b y t h e U n i v e r s i t y o f C a l i f o r n i a ( 4 ) , r e a c h f u l l development, steam w i l l be used more e f f i c i e n t l y a n d t h e c o m p l e x i t y o f t h e e t h a n o l f a c i l i t y and c a p i t a l c o s t c o u l d be reduced significantly. Ethanol from Petroleum. A t what r e l a t i v e p r i c e w i l l sugarcane r e p l a c e petroleum o r n a t u r a l gas l i q u i d s i n the manufacture o f i n d u s t r i a l ethanol? A sophisticated answer t o t h i s q u e s t i o n cannot be g i v e n i n p u r e l y e c o n o m i c t e r m s b e c a u s e many b u s i n e s s c o n s i d e r a t i o n s are i n v o l v e d . For example, the s t r u c t u r e o f the chemical i n d u s t r y i s such t h a t marketing r e l a t i o n s a r e of great importance. I n a d d i t i o n , l o c a t i o n and d i s t r i b u t i o n c o n s i d e r a t i o n s may b e o f c o n s i d e r a b l e i m p o r tance. A c o m p a n y may a l r e a d y h a v e a w e l l - a m o r t i z e d f a c i l i t y t o manufacture i n d u s t r i a l e t h a n o l from a nonrenewable resource. T h e r e f o r e , the s w i t c h t o a renewable resource would c a r r y a p e n a l t y . Beyond the b u s i ness c o n s i d e r a t i o n s , t h e r e are such c o n s i d e r a t i o n s as m a i n t a i n i n g l e v e l s o f employment a t e s t a b l i s h e d l o c a tions. D e s p i t e noneconomic c o n s i d e r a t i o n s , i t i s i m p o r t a n t t o have the economic c r o s s o v e r p o i n t s i n mind because they are the standards a g a i n s t which modif i e d p o l i c i e s are compared. Construction o f a simple equivalence diagram i s shown i n F i g u r e 3. 4.2 l b o f e t h y l e n e a r e r e q u i r e d per g a l o f ethanol manufactured by petrochemical processes. The c o s t o f e t h y l e n e r e c e n t l y has been a p p r o x i m a t e l y 0.010 t i m e s t h e c o s t o f p e t r o l e u m , when t h e petroleum i s expressed i n d o l l a r s per b b l and ethylene
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
SUCROCHEMISTRY
0.40 0.30 0.20 0.10 0
I 0
1 5
1 10
1 15
1 20
Petroleum Price
Figure 3.
1 25
1 30
p
35
$/Bbl
Manufacturing and marketing costs, including profit, for ethanol
in dollars per l b . Using this r e l a t i o n , the ethanol s e l l i n g p r i c e ( i n c l u d i n g m a r k e t i n g p r o f i t s and c o s t s ) can be p l o t t e d on t h e Y a x i s v e r s u s t h e p e t r o l e u m s e l l i n g p r i c e as on t h e X a x i s (see F i g u r e 3 ) . This s t r a i g h t l i n e c a n be compared w i t h p o s s i b l e f e r m e n t a tion-ethanol selling price. F o r example, adding a 30% m a r k e t i n g c h a r g e t o t h e $1.17 m a n u f a c t u r i n g c o s t i n T a b l e 2, y i e l d s t h e h o r i z o n t a l l i n e a t $ 1 . 5 2 , shown i n F i g u r e 3. The i n t e r c e p t o f t h e p e t r o c h e m i c a l - e t h a nol l i n e with fermentation l i n e occurs a t approximately $19/bbl. T h i s e q u i v a l e n c e p o i n t (A) c a n b e c o m p a r e d w i t h p o i n t B , w h i c h i n d i c a t e s t h a t a t ,the c u r r e n t p e t r o leum s e l l i n g p r i c e o f a p p r o x i m a t e l y $ 1 3 / b b l , t h e c o r r e s ponding ethanol s e l l i n g p r i c e i s $1.15/gal. At the current price of petroleum the manufacturing cost f o r e t h a n o l w o u l d h a v e t o b e 88«? t o a l l o w f o r m a r k e t i n g charges o f 30%. T h i s would c o r r e s p o n d t o a cane j u i c e p r i c e o f 2.5C/lb o f s o l i d s , l e s s than h a l f t h e c u r r e n t cost. n - B u t y l A l c o h o l and Acetone
sis
A c e t o n e i s an i m p o r t a n t i n t e r m e d i a t e i n t h e s y n t h e o f methyl m e t h a c r y l a t e and b i s p h e n o l - A , b o t h o f
Hickson; Sucrochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1977.
25.
SHEPPARD
A N D LIPINSKY
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which are used i n making p l a s t i c s , and i n the s y n t h e s i s of methyl i s o b u t y l ketone, methyl i s o b u t y l c a r b i n o l and i s o p h o r o n e , whiôh a r e u s e d a s s o l v e n t s . I na d d i t i o n , acetone i s used d i r e c t l y as a s o l v e n t f o r c e l l u l o s e acetate s p i n n i n g and f o r p r o t e c t i v e c o a t i n g s . I n 1975, p r o d u c t i o n o f 796,000 t o n s w a s r e p o r t e d . The m a j o r use o f n - b u t y l a l c o h o l i s a s a s o l v e n t a n d i n t e r m e d i a t e f o r making b u t y l a c e t a t e and g l y c o l e s t e r s f o r s o l v e n t use. I t i s a l s o used i n making c e r t a i n p l a s t i c i z e r s , amine r e s i n s and b u t y l a c r y l a t e a n d m e t h a c r y l a t e r e s ins. P r o d u c t i o n i n 1974 w a s 278,000 t o n s . D u r i n g W o r l d War I , a p r o c e s s f o r f e r m e n t a t i o n o f molasses t o give n-butyl a l c o h o l , acetone, and minor amounts o f e t h y l a l c o h o l was d e v e l o p e d b y Chaim W e i s mann. One l b o f m o l a s s e s i s r e p o r t e d t o y i e l d 0.25 l b b u t y l a l c o h o l a n d 0.10 l b a c e t o n e (5). A s w a s t h e case w i t h e t h y l e n e , cheap n a t u r a l gas l i q u i d s as a f e e d s t o c k l e d t o abandonment o f f e r m e n t a t i o n f o r p r o duction o f these chemicals. A c e t o n e now i s made f r o m p r o p y l e n e b y t w o p r o c e s ses. I n the f i r s t , propylene i s hydrated t o i s o p r o p y l a l c o h o l , which i s then o x i d i z e d t o acetone. I n pract i c e , 1.1 l b p r o p y l e n e y i e l d s 1.2 l b i s o p r o p y l a l c o h o l , which i n t u r n gives 1 l bacetone. M o s t new f a c i l i t i e s use a second p r o c e s s , namely c o p r o d u c t i o n o f a c e t o n e and p h e n o l f r o m c u m e n e , w h i c h i s made f r o m p r o p y l e n e p l u s benzene. B u t y l a l c o h o l c a n b e made f r o m 2 m o l e c u l e s o f ethylene v i a acetaldehyde, a l d o l , and crotonaldehyde. One l b b u t y l a l c o h o l r e q u i r e s 1.1 l b e t h y l e n e . Altern a t i v e l y , propylene c a n r e a c t w i t h carbon monoxide and h y d r o g e n t o g i v e a 4:1 m i x t u r e o f n - b u t y l a l c o h o l and i s o b u t y l a l c o h o l . One l b o f a l c o h o l r e q u i r e s 0.58 lb propylene. For c a l c u l a t i o n purposes, b u t y l a l c o h o l from ethylene and acetone from propylene v i a i s o p r o p y l a l c o h o l are assumed. One l b o f b u t y l a l c o h o l a n d 0.4 l b a c e t o n e f r o m c a n e j u i c e a t 6C/lb o f s o l u b l e f e r m e n t a b l e s g i v e s a combined manufacturing andm a r k e t i n g c o s t and p r o f i t o f 36.6C, a s s u m i n g o p e r a t i n g a n d c a p i t a l c o s t s are twice t h a t f o r ethanol s i n c e the fermentation i s m o r e d i f f i c u l t t o c o n t r o l , a n d t h a t t h e stilläge i s w o r t h h a l f t h e v a l u e o f g r a i n stilläge. There a r e many v i t a m i n s i n t h e stilläge, m a k i n g i t v a l u a b l e f o r non-ruminant feed so t h a t t h i s i s c o n s e r v a t i v e . At current p r i c e s , 1 l b b u t y l a l c o h o l s e l l s f o r 22C a n d 0.4 l b a c e t o n e f o r 6C o r a t o t a l o f 28C. W i t h a c u r r e n t p r i c e o f e t h y l e n e o f 12C a n d p r o p y l e n e a t 8.4
