Fluid Fuels—The Chemists' Problem P E T E R J. D Y N E
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Department of Energy, Mines and Resources, Ottawa, Ontario
Firstly, consider some generalities of the energy problem. These break into three separate parts: the need to restrict or control the increase in energy consumption, the need to provide energy in new forms as a substitute for fluid fuels and the extent to which other energy sources can provide this replacement. These three aspects are summarised in Figures 1, 2, & 3. Without getting into an argument of how much energy consumption can be controlled or reduced, the diagrams indicate the need for large new sources of energy over the next fifty years, even if energy consumption were to be significantly reduced. These diagrams imply by the choice of a single energy axis that all forms of energy are equivalent where, in practice, they are not. When we supply energy in different forms in our national energy system we have to have new or modified devices to use that energy. For example: - solar heat means houses with new designs and new structures; - methanol as an automobile fuel means different engines and a new fuel distribution system; - electricity for the transportation sector means electric cars and presumably development of batteries. A l l our equipment requiring energy w i l l have to be optimized for a new economic environment where energy or fuel, is not cheap. Sharply increased fuel costs w i l l provide the incentive for more efficient energy using devices which, themselves may be more expensive in terms of capital than today's equipment. In the future then we have to pay as much attention to the energy using technologies as on the energy supply technologies. There appear to be a number of ways in which this energy system can be rebuilt. Energy is not an end in i t s e l f . We are supplying energy for another more general purpose, - to provide society with the necessities and the luxuries of life. The way in which we use energy is determined in part by the sort of social and economic system we want and of course, the other way about; This chapter not subject to U.S. Copyright. Published 1979 American Chemical Society. Tomlinson et al.; Chemistry for Energy ACS Symposium Series; American Chemical Society: Washington, DC, 1979.
CHEMISTRY FOR ENERGY
# 4Γ
Î
NATIONAL ENERGY CONSUMPTION
Figure
1. Schematic
φ
φ
CONSERVATION THRIFT EFFICIENCY
I CURRENT JTREND
TARGET
showing the effect of energy conservation arbitrary "target" for consumption
in reaching an
TODAY'S HYDRO • COAL
Figure
2.
Schematic
showing the need to develop "new" energy sources to meet the "target" energy consumption
Figure 3. Schematic illustrating the theme of the talk. How big can the various supply sectors be and how do they mesh together to provide energy in the re quired form?
Tomlinson et al.; Chemistry for Energy ACS Symposium Series; American Chemical Society: Washington, DC, 1979.
1.
DYNE
Fluid
Fuels—The
Chemists'
Problem
5
how
e n e r g y s y s t e m s m o l d e d o u r s o c i a l and e c o n o m i c s y s t e m s . We w o u l d l i k e t o h a v e c h e a p e n e r g y , o r , a t l e a s t , e n e r g y a s i n e x p e n s i v e a s p o s s i b l e ; we w o u l d l i k e s e c u r e e n e r g y s u p p l i e s ( i n t h e p o l i t i c a l s e n s e ) and we want t o h a v e s u p p l y s y s t e m s w i t h minimum e n v i r o n m e n t a l e f f e c t s . Unfortunately, i t i s often d i f f i c u l t t o g e t a l l t h r e e a t t h e same t i m e . F o r many c o u n t r i e s , t h e c h e a p e s t s u p p l i e s a r e f o r some t i m e l i k e l y t o be i m p o r t e d o i l , these a r e not however, n e c e s s a r i l y s e c u r e . The u s e o f c o a l may be p o l i t i c a l l y s e c u r e and r e l a t i v e l y i n e x p e n s i v e b u t n o t e n v i r o n mentally sanitary. S y n t h e t i c f u e l s b a s e d on c o a l may p o s e e n v i r o n m e n t a l p r o b l e m s b e c a u s e o f t h e l a r g e amounts o f c o a l t o be m i n e d and p r o c e s s e d , and may n o t be cheap e i t h e r . Electricity, b e c a u s e i t c a n be g e n e r a t e d i n a v a r i e t y o f ways and i n many places responds w e l l to s e c u r i t y of supply. Environmental e f f e c t s a t t h e p o i n t o f end u s e a r e m i n i m a l . E l e c t r i c i t y and t h e e x t e n t t o w h i c h we b u i l d e l e c t r i c a l e n e r g y e c o n o m i c s i s one o f t h e c e n t r a l q u e s t i o n s i n p l a n n i n g o u r energy f u t u r e . I f y o u l o o k a t t h e ways i n w h i c h we u s e e n e r g y , y o u f i n d t h a t a l m o s t a l l o f them c a n o r c o u l d be done v i a electricity. I n a c o n c e p t u a l s e n s e , one c a n i m a g i n e h y d r o g e n f u e l e d a e r o p l a n e s , the hydrogen b e i n g d e r i v e d from the e l e c t r o l y s i s of water. I t i s i n t e r e s t i n g to note t h a t almost a l l o f t h e f u t u r e and f u t u r i s t i c e n e r g y s o u r c e s , f i s s i o n o r f u s i o n e n e r g y , p h o t o v o l t a i c s , o c e a n t h e r m a l g r a d i e n t s , wave p o w e r , end up by p r o d u c i n g e l e c t r i c i t y . One c a n a r g u e t h e n t h a t we w i l l have to b u i l d e l e c t r i f i e d energy economies. One d i f f i c u l t y w i t h e l e c t r i c i t y i s t h a t , i t c a n n o t be s t o r e d cheaply. I t h a s t o be made when i t ' s u s e d . Electrochemical storage, w h i l e very u s e f u l indeed, i s expensive. A lead acid b a t t e r y c o s t i n g $45 s t o r e s l e s s t h a n 5 c e n t s w o r t h o f e l e c t r i c i t y ! S t o r a g e a s c h e m i c a l e n e r g y i s , by c o n t r a s t , e x t r a o r d i n a r i l y convenient. H e r e 1 kWh t h e r m a l , a s p e t r o l e u m a t $ l / g a l l o n , c o s t s 1.2 c e n t s / k W h ( t h ) ; e n e r g y s t o r a g e b e i n g t h r o w n i n f r e e . T h i s l i t t l e i l l u s t r a t i o n b r i n g s us t o t h e k e y r o l e t h a t c h e m i s t s and c h e m i c a l e n g i n e e r s h a v e . However much e l e c t r i c i t y we may u s e t h e r e w i l l be a g r e a t n e e d f o r f l u i d f u e l s . Chemical e n e r g y s t o r a g e i s t h e b e s t t h i n g we h a v e . W i t h t h e f o s s i l f u e l s we g e t t h e e n e r g y and t h e s t o r a g e t o g e t h e r , a t b a r g a i n p r i c e s . However, o n c e we s t a r t t a l k i n g a b o u t s y n t h e t i c c h e m i c a l f u e l s we h a v e t o : 1) S y n t h e s i s e m a t e r i a l s on a v e r y l a r g e s c a l e ; 2) S u p p l y t h e e n e r g y f o r t h e s y n t h e s i s on t h e same l a r g e scale; 3) Do t h i s i n a s a n i t a r y f a s h i o n ; and 4) Do a l l t h i s " c h e a p l y " . The f o u r t h i t e m i s t h e c a t c h : i n a g e n e r a l s e n s e we p r o b a b l y know how t o do t h e f i r s t t h r e e . The c e n t r a l p r o b l e m i s one o f cost or p r i c e . We h a v e b u i l t an e n e r g y m a c h i n e w h i c h was d e s i g n e d t o p r o d u c e as i f e n e r g y was f r e e ( e n e r g y e v e n a t t o d a y ' s p r i c e s i s s t i l l
Tomlinson et al.; Chemistry for Energy ACS Symposium Series; American Chemical Society: Washington, DC, 1979.
6
CHEMISTRY FOR
ENERGY
e x t r e m e l y c h e a p ) . W h i l e we h a v e become a c c u s t o m e d t o s i g n i f i c a n t i n c r e a s e s i n e n e r g y c o s t s we s t i l l h a v e t o f a c e t h e s i t u a t i o n t h a t t h e y w i l l be s i g n i f i c a n t l y h i g h e r i n t h e f u t u r e . W h i l e we may c o n t e m p l a t e an i n c r e a s e i n e n e r g y c o s t by a f a c t o r o f s a y , two o r t h r e e , w i t h o u t h a v i n g a m a j o r e f f e c t on t h e way we do t h i n g s , an i n c r e a s e o f a f a c t o r o f t e n w o u l d make a v e r y s i g n i f i cant d i f f e r e n c e . L e t me g i v e y o u some numbers w h i c h i l l u s t r a t e how " c h e a p " we h a v e t o be. As a s t a n d a r d , l e t us t a k e t o d a y ' s " e x p e n s i v e " e n e r g y ; a t a r s a n d s p l a n t c o s t i n g s a y two b i l l i o n d o l l a r s . This p r o d u c e s 100,000 b a r r e l s / d a y . T h i s two b i l l i o n c a p i t a l w o r k s o u t t o $12.00 f o r lkWh/day. T h a t d o e s n ' t sound v e r y much! Indeed, it isn't! To p u t t h i s i n a n o t h e r c o n t e x t , I am g o i n g t o u s e t h i s e x a m p l e t o show how t h i s i d e a o f c o s t p r o v i d e s a s t i m u l u s f o r p r a c t i c a l ideas. There i s today r i g h t l y a very great d e a l of i n t e r e s t i n s t o r i n g and c o n v e r t i n g s o l a r e n e r g y . How much c a n we a f f o r d f o r s o l a r d e v i c e s ? The a v e r a g e s o l a r f l u x i s a b o u t lkWh/day/m so t h a t f o r a s o l a r c o n v e r s i o n d e v i c e a t 10£)% e f f i c i e n c y we w o u l d l i k e t o h a v e s o m e t h i n g c o s t i n g , s a y $12/m o r i n t h e o r d e r o f $ 1 . 0 0 / s q u a r e f o o t t o be c o m p e t i t i v e w i t h t a r sands, e t c . I n c a s e you d o n ' t know i t , a thermopane window i s l i k e l y t o c o s t f i v e o r t e n t i m e s t h a t a l r e a d y ! This, o f c o u r s e , i s an u n f a i r and o v e r s i m p l i f i e d c o m p a r i s o n : i t ignores a l l s o r t s o f t h i n g s l i k e o p e r a t i n g and t r a n s m i s s i o n c o s t s . But e v e n i f we a l l o w t h e s o l a r c o n v e r s i o n d e v i c e t o be t e n t i m e s a s e x p e n s i v e ( s a y $100/m ) t h a t w o u l d s t i l l be a c h e a p p i e c e o f hardware! T h i s example b r i n g s out i m m e d i a t e l y the p o t e n t i a l of n a t u r a l photosynthetic processes. P l a n t s do t h i s p h o t o c h e m i c a l c o n v e r s i o n for a l i v i n g ! F o r them, a l l t h e r e s e a r c h and d e v e l o p m e n t on c o m p l e x p h o t o c a t a l y t i c p r o c e s s e s has b e e n done and t h e y h a v e b e e n h i g h l y o p t i m i z e d ; the energy c o l l e c t o r s , the l e a v e s , a s e l f e v e n t i n g membrane, a r e a l m o s t f r e e ! As a c o n s e q u e n c e , f o r t h e c o n v e r s i o n of s o l a r energy to a c h e m i c a l l y s t o r e d energy, n a t u r a l p h o t o s y n t h e t i c p r o c e s s e s w i l l be v e r y h a r d t o b e a t . They d o n ' t , o f c o u r s e , g i v e us a f l u i d d i r e c t l y : we h a v e t o do s o m e t h i n g w i t h t h e c e l l u l o s e t o make i t i n t o a more u s a b l e f o r m , b u t t h a t may be a l o t e a s i e r t h a n t r y i n g t o r e p r o d u c e t h e p h o t o s y n t h e t i c step. H a v i n g s a i d t h a t I w o u l d n ' t want t o d i s c o u r a g e f u n d a m e n t a l w o r k i n p h o t o c a t a l y t i c r e a c t i o n s , i t i s much t o o e a r l y t o a s s e s s t h e t r u e t e c h n i c a l i m p l i c a t i o n s o f s u c h w o r k and we h a v e l i t t l e i d e a o f where i t c a n l e a d . We c a n o n l y s a y t h a t i t i s w o r k i n g i n the r i g h t s o r t of area. Besides the q u e s t i o n of c o s t there i s the q u e s t i o n of s c a l e . I n mass t e r m s o u r p r e s e n t o i l c o n s u m p t i o n , 2 m i l l i o n b a r r e l s / d a y , amounts t o a b o u t 300,000 t o n s / d a y . ( L i t t l e wonder t h a t , on a t o n / m i l e b a s i s , o i l and gas t r a n s p o r t i s t h e l a r g e s t s i n g l e commodity b e i n g moved a r o u n d ) . When you s t a r t t a l k i n g o f s y n t h e t i c f u e l s ( o r of s e m i s y n t h e t i c f u e l s l i k e o i l from t a r sands
Tomlinson et al.; Chemistry for Energy ACS Symposium Series; American Chemical Society: Washington, DC, 1979.
1.
DYNE
Fluid
Fuels—The
Chemists'
7
Problem
o r m e t h a n o l f r o m wood) one c a n see m a j o r l o g i s t i c a l p r o b l e m s i n j u s t h a n d l i n g and p r o c e s s i n g t h a t amount o f ' s t u f f everyday. One c o u l d c o n c l u d e , t h a t s y n t h e t i c f u e l s w i l l h a v e t o be r e s t r i c t e d i n u s e t o t h e t r a n s p o r t a t i o n s e c t o r where t h e y a r e u n i q u e l y v a l u a b l e and t h a t o t h e r e n e r g y s o u r c e s h a v e t o do everything else. The amount o f ' s t u f f t o be h a n d l e d l e a d s t o t h e two m a i n p r o b l e m s i n any l a r g e s c a l e p r o d u c t i o n o f s y n t h e t i c f u e l s , f i r s t t h e s i z e and h e n c e t h e c o s t o f t h e e q u i p m e n t and s e c o n d , t h e e n v i r o n m e n t a l p r o b l e m s a s s o c i a t e d w i t h t h e mass f l o w s . The s c a l e o f t h e o p e r a t i o n i t s e l f l e a d s t o t h e n e e d f o r l a r g e c a p i t a l investments. C h e m i c a l r e a c t o r s and p l a n t s a r e b i g and h e n c e e x p e n s i v e b e c a u s e amongst o t h e r t h i n g s t h e r e a c t i o n s d o n ' t go f a s t enough. I f t h e r e a c t i o n s c o u l d be s p e e d e d up t h e n t h e s i z e o f t h e p l a n t c o u l d be r e d u c e d . C a t a l y s t s and c a t a l y s i s a r e t h e r e f o r e a key a r e a of fundamental c h e m i s t r y f o r the energy field. T h e s e l a r g e mass f l o w s a r e , t h e m s e l v e s , t h e s o u r c e o f e n v i r o n mental problems. To d e s c r i b e the p l a n t s i m p l y i n terms of i t s p r o d u c t i o n c a p a c i t y o f 300,000 t o n s / d a y i s an o v e r s i m p l i f i c a tion. I n any s u c h p r o c e s s t h e r e w i l l be o t h e r p r o c e s s f l o w s w h i c h , i n some i n s t a n c e s may amount t o much more t h a n t h e s i m p l e product flow. The amounts o f t r a c e m a t e r i a l s , e v e n a t a few p.p.m. i n c o n c e n t r a t i o n , w h i c h c a n a c c u m u l a t e o r w h i c h may h a v e t o be r e l e a s e d amount, i n t i m e s o f months o r y e a r s , t o l a r g e quantities. We a r e c o n c e r n e d a b o u t t h e p o t e n t i a l e n v i r o n m e n t a l e f f e c t s of these t r a c e m a t e r i a l s . I n s p i t e of t h i s c o n c e r n , h o w e v e r , we h a v e l i t t l e h a r d k n o w l e d g e o f t h e s e e f f e c t s , i n p a r t b e c a u s e we know so l i t t l e a b o u t t h e c h e m i s t r y o f s m a l l amounts o f t r a c e e l e m e n t s and compounds i n l a r g e amounts o f w a t e r o r a i r . I f we t h e n a r e g o i n g t o come t o r a t i o n a l t e r m s w i t h t h e e n v i r o n ment, k n o w i n g what c a n be s a f e l y r e l e a s e d and what c a n n o t , we h a v e t o know a l o t more a b o u t c h e m i s t r y o r t r a c e c o n c e n t r a t i o n s . I n b r i e f t h e n my k e y s t o n e message f o r c h e m i s t s and c h e m i c a l e n g i n e e r s i n the energy b u s i n e s s : they have the key problem w h i c h nobody e l s e w i l l t a c k l e , m a k i n g s y n t h e t i c f u e l s a t a p r i c e we c a n pay and w i t h p r o p e r u n d e r s t a n d i n g o f e n v i r o n m e n t a l problems. 1
1
RECEIVED September 2 5 , 1 9 7 8 .
Tomlinson et al.; Chemistry for Energy ACS Symposium Series; American Chemical Society: Washington, DC, 1979.
