Major Technical Issues Facing Synthetic Pipeline Gas - ACS

10 Major Technical Issues Facing Synthetic Pipeline Gas L . E . S W A B B and H. M. S I E G E L Downloaded via UNIV OF CALIFORNIA SANTA BARBARA on July 9, 2018 at 10:08:25 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

Exxon Research and Engineering Company, P.O. Box 101, Florham Park, N J 07932

Exxon has been doing research on coal gasification for over ten years. The early part of this work was aimed at making hydrogen for coal liquefaction, but in more recent years we have been working on synthetic pipeline gas, SNG, and intermediate Btu gas, IBG. In our early work, we identified what we believed to be an improved thermal process for coal gasification. We also began experimenting with catalytic gasification. By 1975, we concluded that the catalytic approach would be more promising on a long-term basis, and we shifted our work from thermal to catalytic gasification. Since mid-1976, the U.S. Department of Energy has been funding a substantial portion of our work on catalytic gasification for SNG. As part of our total gasification program, we have made numerous design and cost studies to evaluate our process ideas as well as process systems being pursued by others. The comments that I will make today are based on the understanding of gasification systems that we have developed from this work. F i g u r e 1 shows what we b e l i e v e are the main t e c h n i c a l i s s u e s f a c i n g s y n t h e t i c p i p e l i n e gas. I w i l l d i s c u s s the f i r s t f i v e of these areas. The l a s t area, on c o m m e r c i a l i z a t i o n , w i l l be covered i n two other papers l a t e r t h i s morning. F i g u r e 2 deals w i t h p o t e n t i a l g a s i f i c a t i o n feedstocks i n the contiguous 48 United S t a t e s . As shown, c o a l , a t about 5000 quads, i s by f a r the l a r g e s t recoverable f o s s i l f u e l . Peat i s next a t about 750 quads, and then o i l shale a t about 500 quads. And f i n a l l y , we have a l s o shown crude o i l a t about 170 quads t o add p e r s p e c t i v e t o the reserve estimates. These e s t i m a t e s , i n c l u d i n g crude o i l , were published by the I n s t i t u t e of Gas Technology (IGT) i n l a t e 1977.

0-8412-0516-7/79/47-110-171$05.00/0 © 1979 American Chemical Society Pelofsky; Coal Conversion Technology ACS Symposium Series; American Chemical Society: Washington, DC, 1979.

172

COAL CONVERSION TECHNOLOGY

o

What f o s s i l f u e l resources appear to be the most promising g a s i f i c a t i o n feedstocks?

ο

How can new g a s i f i c a t i o n processes reduce SNG cost...and how much r e d u c t i o n can be expected?

ο

What a r e the main challenges i n planning the development program f o r a new g a s i f i c a t i o n process?

ο

What i s the outlook f o r the n a t i o n a l R&D e f f o r t on new SNG processes?

ο

What i s the impact of environmental c o n s i d e r a t i o n s ?

ο

What i s the outlook f o r commercialization? Figure 1.

Main technical issues facing synthetic pipeline gas

15

COAL

QUADS (1Q BTU)*

SUBBITUMINOUS BITUMINOUS LIGNITE ANTHRACITE

3,100 1,700 200 100 TOTAL

5,100

PEAT

750

OIL SHALE

500

CRUDE OIL

170

* Two quads/year = one m i l l i o n B/D o i l e q u i v a l e n t Source:

D.V. Punwani, e t a l (IGT), "SNG production from peat, December 1977 11

Figure 2.

Recoverable fossil fuels in contiguous 48 states of the U.S.

Pelofsky; Coal Conversion Technology ACS Symposium Series; American Chemical Society: Washington, DC, 1979.

10.

SWABB AND siEGEL

Synthetic Pipeline Gas

173

As you know, most o f the g a s i f i c a t i o n work to date has been on c o a l . Coal i s most abundant, and would a l s o appear to be the most economical feedstock; that i s , to produce the lowest cost SNG. O i l s h a l e s , i n both the western and e a s t e r n United S t a t e s , o f f e r another p o t e n t i a l resource f o r SNG p r o d u c t i o n . IGT has been doing research f o r s e v e r a l years on the h y d r o g a s i f i c a t i o n of o i l s h a l e . They have shown t h a t h i g h recovery o f the organic carbon i n the shale can be obtained as gas and l i q u i d products. From a cost s t a n d p o i n t , the main challenge i s how to minimize and overcome the major cost of mining, c r u s h i n g , f e e d i n g , p r o c e s s i n g , and f i n a l l y d i s c h a r g i n g the very l a r g e shale volumes t h a t must be handled per u n i t o f gas product. The shale volumes are very l a r g e because the shale contains only 10-15% organic m a t e r i a l t o begin w i t h . Turning to peat, peat i s the f i r s t product i n nature's c o a l i f i c a t i o n process. About h a l f o f the t o t a l U.S. peat reserves are i n A l a s k a , and the other h a l f , shown here, i s i n the northern and eastern U.S. G a s i f i c a t i o n research on peat i s r e l a t i v e l y new. O v e r a l l , the m a t e r i a l i s h i g h l y r e a c t i v e and can produce r e s p e c t a b l e y i e l d s of gas and l i q u i d s on a dry peat b a s i s . But t h e r e i n l i e s a key problem—how to get peat on a dry b a s i s . Peat i s about 90% water as mined. The challenge i s how to remove t h i s water without an overwhelming c o s t . I t would appear at t h i s stage that more r e s e a r c h , d e s i g n , and cost s t u d i e s would need t o be made before the p r a c t i c a l i t y and competitiveness of peat g a s i f i c a t i o n can be b e t t e r assessed. And now I would l i k e to move on to the second i s s u e : "How can new g a s i f i c a t i o n processes reduce SNG cost...and how much cost r e d u c t i o n can be expected?" F i g u r e 3 i n t r o d u c e s t h i s i s s u e . Commercially demonstrated g a s i f i c a t i o n technology i s a v a i l a b l e today to produce i n t e r m e d i a t e Btu gas from c o a l . I am r e f e r r i n g to the L u r g i , Koppers-Totzek, and Winkler processes. Each of these processes has the p o t e n t i a l to a l s o produce SNG by the a d d i t i o n of s h i f t and methanation steps downstream of the g a s i f i c a t i o n system. As of 1977, L u r g i and Koppers-Totzek each had about 15 p l a n t s , and Winkler had 3 p l a n t s , o p e r a t i n g i n other c o u n t r i e s to produce low and i n t e r m e d i a t e Btu gases. Over the past seven y e a r s , a number of groups i n the U.S. have announced plans f o r L u r g i c o a l g a s i f i c a t i o n commercial p r o j e c t s to produce SNG. However, none of these p r o j e c t s has reached the c o n s t r u c t i o n stage. The main reasons f o r the delays have i n c l u d e d problems w i t h government approvals and r e g u l a t i o n s . D i f f i c u l t i e s w i t h environmental c l e a r a n c e s , the cost and p r i c i n g


174


of the gas, and f i n a n c i n g arrangements. The technology has not been a l i m i t i n g f a c t o r , and new technology now under development w i l l not overcome these b a r r i e r s . And now, l e t ' s t u r n t o the new technology, summarized i n F i g u r e 4. The new c o a l g a s i f i c a t i o n processes now being developed f o r SNG have two main o b j e c t i v e s : (1) t o reduce c o s t , and (2) t o process a wider range of c o a l types and c o a l p a r t i c l e s i z e s . Regarding cost r e d u c t i o n , we have l i s t e d on the s l i d e the process improvement goals t h a t we b e l i e v e a r e l i k e l y t o be the most f r u i t f u l i n a c h i e v i n g lower SNG c o s t s i n new or improved processes. The f i r s t goal i s t o reduce the r e q u i r e d heat input t o the g a s i f i e r . This can be done by producing more methane d i r e c t l y i n the g a s i f i e r and l e s s methane by downstream methanation. Lower g a s i f i c a t i o n temperatures would a l s o h e l p . The next g o a l i s t o accomplish the heat i n p u t without u s i n g pure oxygen. Two p o s s i b i l i t i e s f o r a c h i e v i n g t h i s i n c l u d e the c i r c u l a t i o n of hot s o l i d s and the a d d i t i o n of a separate h e a t - l i b e r a t i n g chemical r e a c t i o n t o the g a s i f i e r . I w i l l come back t o these f i r s t two goals l a t e r on. A d d i t i o n a l goals a r e to reduce equipment m u l t i p l i c i t y ; reduce the number, complexity, and s i z e of i n d i v i d u a l process s t e p s ; improve heat recovery and u t i l i z a t i o n ; and f i n a l l y , t o improve the o p e r a b i l i t y and r e l i a b i l i t y of the o v e r a l l p l a n t system. The c h a l l e n g e i n developing lower cost SNG g a s i f i c a t i o n processes i s : (1) t o combine as many of these items as p o s s i b l e i n t o each new process; and (2) t o accomplish t h i s without adding so much a d d i t i o n a l cost i n other p a r t s of the processes so as to wipe out the savings. I n t r y i n g t o achieve these improvements, a wide v a r i e t y of t e c h n i c a l approaches and process v a r i a t i o n s have been or a r e being pursued by d i f f e r e n t groups, and these a r e l i s t e d i n F i g u r e 5. The r e a c t o r types i n c l u d e moving beds; f l u i d s o l i d s systems w i t h s i n g l e or m u l t i p l e stages; r e a c t o r s w i t h ash agglomerating, ash s l a g g i n g , or d r y ash removal f e a t u r e s ; and molten s a l t or molten i r o n baths. Some systems a l s o use c a t a l y s t or dolomite a d d i t i o n . The methods f o r heat input i n c l u d e oxygen i n j e c t i o n d i r e c t l y i n t o the g a s i f i c a t i o n bed, a i r combustion outs i d e the g a s i f i c a t i o n bed, e l e c t r i c heat, and the r e c i r c u l a t i o n of hot steams o f gas or s o l i d s . G a s i f i e r pressures range from atmospheric t o about 1500 p s i , and g a s i f i e r temperatures range from about 1300 to 3000 F. A l t o g e t h e r , many combinations of g a s i f i e r types and o p e r a t i n g c o n d i t i o n s have been o r a r e being pursued.


swABB AND siEGEL


ο

Commercially demonstrated technology i s a v a i l a b l e L u r g i , Koppers-Totzek, W i n k l e r

ο

Groups i n U.S. have announced plans f o r L u r g i SNG p r o j e c t s , but none have reached c o n s t r u c t i o n , the problems have been -

ο

Government approvals and r e g u l a t i o n s Environmental clearances cost and p r i c i n g of gas F i n a n c i n g arrangements

New technology w i l l not overcome these b a r r i e r s Figure 3.

Gasification technology

Two main o b j e c t i v e s — Reduce c o s t ; Process a wider range of c o a l types and p a r t i c l e s i z e s Process improvement goals t o achieve lower c o s t s - Reduce heat input to g a s i f i e r (produce more methane d i r e c t l y i n g a s i f i e r , reduce temperature) - Accomplish heat i n p u t without pure oxygen - Reduce equipment m u l t i p l i c i t y - Reduce number, c o m p l e x i t y , & s i z e of process steps - Improve heat recovery & u t i l i z a t i o n - Improve o p e r a b i l i t y & r e l i a b i l i t y of o v e r a l l system Figure 4.

New or improved coal gasification processes for SNG


176


And now I would l i k e to comment on how much cost r e d u c t i o n can we r e a l l y expect from a l l of t h i s work. F i g u r e 6 shows a breakdown of investment by p l a n t s e c t i o n f o r a t y p i c a l L u r g i SNG p l a n t . The i n f o r m a t i o n i s about three years o l d from the open l i t e r a t u r e . As shown, the g a s i f i c a t i o n s e c t i o n accounts f o r only about 20% of the t o t a l p l a n t investment. Other process s e c t i o n s , i n c l u d i n g s h i f t , methanation, and other process gas account f o r another 30%, making a t o t a l of 50% f o r the process s e c t i o n s . The u t i l i t i e s add up to 33%, i n c l u d i n g 11% f o r the oxygen p l a n t alone. What t h i s means i s that any cost r e d u c t i o n i n the g a s i f i c a t i o n s e c t i o n alone cannot have a major impact on the o v e r a l l gas c o s t . For example, a o n e - t h i r d r e d u c t i o n i n the g a s i f i c a t i o n s e c t i o n investment would reduce the t o t a l investment by about 7%, o n e - t h i r d of 20, and t h i s corresponds to a r e d u c t i o n i n gas cost of only about 3-4%. Therefore, any improvements i n the g a s i f i c a t i o n s e c t i o n should be aimed at reducing c o s t s i n the other p l a n t s e c t i o n s as w e l l . This c o n c l u s i o n was the b a s i s f o r my e a r l i e r d e s c r i p t i o n of process improvement g o a l s . As you may r e c a l l , I h i g h l i g h t e d a number of items that could have t h e i r main impact o u t s i d e of the g a s i f i c a t i o n s e c t i o n . One of these was to accomplish the heat input without pure oxygen which would e l i m i n a t e the oxygen p l a n t . Another item was to produce more methane d i r e c t l y i n the g a s i f i e r which would reduce the s i z e , or change the nature, of the downstream process s e c t i o n s . From the work that we have done, we have drawn c e r t a i n conclusions about the p o t e n t i a l f o r cost r e d u c t i o n . These are o u t l i n e d i n F i g u r e 7. For the new thermal processes that have been s t u d i e d the most i n recent y e a r s , we f i n d i t d i f f i c u l t to see how the f i r s t commercial p l a n t s can provide much more than about 10% r e d u c t i o n i n SNG cost over e x i s t i n g technology. As a mature i n d u s t r y i s developed, and a d d i t i o n a l p l a n t s are b u i l t f o r the i n d i v i d u a l new processes, an a d d i t i o n a l 10-15% cost r e d u c t i o n might be achieved f o r the r e a l l y good new processes. This a d d i t i o n a l r e d u c t i o n would r e q u i r e that f u r t h e r improvements be developed from the commercial p l a n t o p e r a t i n g experience and from c o n t i n u i n g R&D. A l t o g e t h e r these are c e r t a i n l y worthwhile cost r e d u c t i o n s , but they should not g r e a t l y a f f e c t the o v e r a l l economics of p l a n t s b u i l t e a r l i e r using e x i s t i n g technology, such as L u r g i . The e a r l i e r p l a n t s should be able to continue o p e r a t i n g v i a b l y f o r normal p r o j e c t l i v e s . For c a t a l y t i c g a s i f i c a t i o n , we b e l i e v e that the p o t e n t i a l f o r cost r e d u c t i o n i s g r e a t e r . For example, f o r the SNG process t h a t we are now developing w i t h DOE f o r bituminous c o a l , and f o r a pioneer p l a n t , we estimate a p o t e n t i a l r e d u c t i o n i n gas cost over e x i s t i n g technology of about two times our estimated reduct i o n f o r the thermal processes. In t h i s regard, we have not had the o p p o r t u n i t y to evaluate other newer processes that i n v o l v e



SWABB A N D siEGEL

REACTORS ο ο ο ο ο ο

Moving Beds F l u i d S o l i d s — s i n g l e o r m u l t i p l e stages Ash Agglomerating/slagging/dry ash removal Molten s a l t o r molten i r o n baths Catalyst addition Dolomite a d d i t i o n

HEAT INPUT ο ο ο

Oxygen o r a i r i n j e c t i o n i n t o g a s i f i e r A i r combustion o u t s i d e g a s i f i e r E l e c t r i c Heat

ο

R e c i r c u l a t i o n of hot g a s / s o l i d s

PRESSURES — ATMOSPHERIC TO 1500 p s i TEMPERATURES —

1300 t o 3000°F

Figure 5.

Variety of technical approaches

COAL HANDLING

% 8 20

GASIFICATION SHIFT & METHANATION

9

BY-PRODUCT RECOVERY GAS PURIFICATION SULFUR PLANT

7 11 3

OXYGEN PLANT STEAM & POWER WATER SITE, BUILDINGS, ETC.

PROCESS SECTIONS, 50%

UTILITIES, 33% 9 100

Figure 6.

Breakdown of investment for typical Lurgi SNG plant


178


very short r e a c t i o n times achieved through the use of rocket technology. Therefore, I cannot comment on t h e i r p o t e n t i a l f o r reducing SNG c o s t . I w i l l come back to these processes l a t e r on. So f a r , I have t a l k e d mainly about cost r e d u c t i o n but what i s the cost of SNG produced from coal? F i g u r e 8 show a summary. There i s c e r t a i n l y a wide range of views and numbers t h a t have been p u b l i s h e d . Depending on the bases and the accounting methods used, SNG c o s t s ranging from $3 to $7/MBTU, i n 1978 d o l l a r s , have been quoted. The upper h a l f of the range $5-7, i s , i n our o p i n i o n , probably more r e a l i s t i c , p a r t i c u l a r l y when feeding h i g h e r - c o s t , deep-mined c o a l s . In t h i s regard, i n d u s t r y and government have had a t r a c k record of g e n e r a l l y u n d e r - p r e d i c t i n g s y n t h e t i c f u e l s c o s t s . Some of the f a c t o r s c o n t r i b u t i n g to t h i s i n c l u d e the f o l l o w i n g : o p t i m i s t i c process p r e d i c t i o n s based on l i m i t e d data; incomplete development of a l l process f e a t u r e s ; l i m i t e d depth of engineering d e s i g n ; weak d e f i n i t i o n of support and o f f s i t e f a c i l i t i e s ; weak p r o j e c t d e f i n i t i o n ; and, f i n a l l y , the inexperience of many of the study groups i n p r e p a r i n g cost estimates f o r very l a r g e and very complex p r o j e c t s . A l t o g e t h e r , i t i s very d i f f i c u l t to a r r i v e a t r e a l i s t i c cost estimates f o r a complex new technology. In t h i s r e g a r d , even the f i r s t commercial a p p l i c a t i o n of a new process can have s u b s t a n t i a l t e c h n i c a l and cost u n c e r t a i n t i e s i f the development program has not been c a r e f u l l y planned and conducted. This i s o u t l i n e d i n F i g u r e 9. One of the main challenges i n p l a n n i n g the development program i s , f i r s t , to determine whether a l a r g e p i l o t p l a n t i s needed, and then, i f i t i s , to e s t a b l i s h the proper design and s i z e f o r t h i s p i l o t p l a n t . The main purpose of a l a r g e p i l o t p l a n t i s to provide the engineering scaleup data that cannot be obtained i n s m a l l e r equipment and which are necessary before a commercial p l a n t could be designed w i t h normal t e c h n i c a l r i s k . This development approach, i f p r o p e r l y c a r r i e d out, can e l i m i n a t e the t e c h n i c a l need f o r what i s c a l l e d a demonstration p l a n t which i s a p l a n t i n t e r mediate i n s i z e between the l a r g e p i l o t p l a n t and the commercial plant. E s t a b l i s h i n g the proper design and s i z e f o r the l a r g e p i l o t p l a n t i s easy t o say but d i f f i c u l t to do. I t i s d i f f i c u l t because i t r e q u i r e s the developer to prepare a p r o j e c t e d commercial design f i r s t , and then to work backwards to determine the proper l a r g e p i l o t p l a n t design. This i s done by c a r e f u l engineering a n a l y s i s of each s e c t i o n of the p r o j e c t e d commercial design to determine two t h i n g s : (1) what scaleup data w i l l be needed to prepare the d e f i n i t i v e commercial design; and (2) what i s the minimum s i z e p i l o t p l a n t and the proper design of t h i s p l a n t that can provide these data w i t h a reasonable o p e r a t i n g program.


SWABB AND

ο

siEGEL

For new years

Synthetic Pipeline

thermal processes s t u d i e d the most i n recent

-

F i r s t commercial p l a n t s , about 10% r e d u c t i o n

-

Subsequent commercial p l a n t s , an a d d i t i o n a l 10-15% r e d u c t i o n f o r some processes

ο

Should not g r e a t l y a f f e c t economics of p l a n t s b u i l t e a r l i e r using e x i s t i n g technology

ο

For c a t a l y t i c g a s i f i c a t i o n -

P o t e n t i a l f o r cost r e d u c t i o n i s g r e a t e r Figure 7.

ο

179

Gas

SNG cost reduction

Wide range of views and numbers have been published -

$3 to $7/MBTU (1978 D o l l a r s )

ο

Upper h a l f of range probably more r e a l i s t i c , p a r t i c u l a r l y when feeding h i g h e r - c o s t , deep-mined c o a l s

ο

Industry and government have g e n e r a l l y underpredicted synthetic f u e l s costs -

O p t i m i s t i c process p r e d i c t i o n s

-

Incomplete development of process

-

L i m i t e d depth of engineering

-

Weak d e f i n i t i o n of support & o f f s i t e s

-

Weak p r o j e c t d e f i n i t i o n

-

Inexperience i n cost e s t i m a t i n g of l a r g e and complex p r o j e c t s Figure 8.

features

design facilities

Cost of SNG from coal


180


I f t h i s a n a l y s i s i s not made before the l a r g e p i l o t p l a n t i s designed, then the p i l o t p l a n t can e a s i l y become an unfocused and drawn-out " t r i a l - a n d - e r r o r " o p e r a t i o n that w i l l not provide the necessary scaleup data. I n such a case, the subsequent commercial p l a n t , or demonstration p l a n t , i f i t i s ever b u i l t , would i t s e l f become a very l a r g e p i l o t p l a n t i n many r e s p e c t s . U n f o r t u n a t e l y , t h i s can l e a d to e x c e s s i v e down times, f i x u p c o s t s , o p e r a t i n g f a i l u r e s , and other d i f f i c u l t s i t u a t i o n s i n the commercial or demo p l a n t . The o v e r a l l r e s u l t can be a very u n s a t i s f a c t o r y and perhaps a d i s a s t r o u s p r o j e c t . This i s why we b e l i e v e so s t r o n g l y i n proper planning and conduct of the o v e r a l l development program, i n c l u d i n g the l a r g e p i l o t phase. And now I would l i k e to comment on the N a t i o n a l R&D e f f o r t on producing SNG from c o a l . F i g u r e 10 shows a summary. There i s a growing a p p r e c i a t i o n that the true cost of producing SNG from c o a l w i l l be h i g h . There i s a l s o u n c e r t a i n t y about the impact of the r e c e n t l y passed n a t u r a l gas act on n a t u r a l gas supply. And as A r t mentioned e a r l i e r today, a d d i t i o n a l n a t u r a l gas may become a v a i l a b l e from unconventional sources, such as t i g h t formations and geopressured a q u i f e r s , and the Department of Energy i s funding R&D work i n these areas. Regarding new SNG processes, DOE has been c o n s i d e r i n g which demonstration p l a n t p r o j e c t to fund: the s l a g g i n g L u r g i , COED/COGAS, both, or n e i t h e r . DOE has a l s o awarded a c o n t r a c t to procon to prepare designs f o r a conceptual Hygas process. This may or may not i n f l u e n c e t h e i r c o n s i d e r a t i o n s on the L u r g i and COED/COGAS p l a n t s . I'm sure t h a t we w i l l hear more about t h i s l a t e r today. Regarding DOE's l a r g e p i l o t p l a n t s , the synthane p l a n t was r e c e n t l y shut down. The Hygas p l a n t , as we understand i t , i s scheduled to operate through June, 1979 to provide backup f o r Procon's design work. Bigas w i l l operate through September, 1979 and p o s s i b l y beyond. DOE i s a l s o funding research on newer g a s i f i c a t i o n processes, sometimes c a l l e d " t h i r d g e n e r a t i o n " processes. One of these i s Exxon's C a t a l y t i c Coal G a s i f i c a t i o n , or CCG, process. I n CCG, we use a potassium c a t a l y s t i n a f l u i d bed g a s i f i e r . The c a t a l y s t allows us to operate at lower temperatures and to produce a h i g h y i e l d of methane d i r e c t l y i n the g a s i f i c a t i o n r e a c t o r . The methane product i s then separated c r y o g e n i c a l l y from a r e c y c l e stream of CO and which i s returned to the g a s i f i c a t i o n r e a c t o r to help produce more methane and to provide heat i n p u t . The other two processes, by R o c k w e l l / C i t i e s S e r v i c e and B e l l Aerospace, are based on Rocket Tehcnology, They both u t i l i z e h i g h mass f l u x r e a c t o r s i n which f i n e l y powdered c o a l i s r a p i d l y f i x e d w i t h h i g h v e l o c i t y , hot gas. The mixture i s then q u i c k l y quenched to g i v e very short r e a c t i o n times. The Rockwell Process


SWABB AND siEGEL

ο


One of the main challenges i s t o . . . -

Determine i f a l a r g e p i l o t p l a n t i s needed I f so, e s t a b l i s h proper design and s i z e

ο

Main purpose o f l a r g e p i l o t p l a n t i s t o provide engineering scaleup data f o r commercial design

ο

Must do a commercial design f i r s t and then work backwards t o proper l a r g e p i l o t p l a n t design Requires c a r e f u l engineering

ο

analysis

I f t h i s i s not done p r o p e r l y

-

The l a r g e p i l o t p l a n t could be i n e f f e c t i v e The subsequent commercial or demonstration p l a n t could have major problems Figure 9.

Planning the development program

ο

Growing a p p r e c i a t i o n of true cost of SNG

ο

U n c e r t a i n t y of impact of n a t u r a l gas a c t on supply

ο

DOE i f funding R&D on unconventional sources

ο

Demonstration p l a n t

competition

Slagging L u r g i and COED/COGAS ο

DOE's l a r g e p i l o t p l a n t s Synthane shut down Hygas o p e r a t i o n scheduled through June 1979 Bigas o p e r a t i o n scheduled through September 1979

ο

DOE a l s o funding newer processes

-

Exxon c a t a l y t i c c o a l g a s i f i c a t i o n (CCG) Rockwell C i t i e s Service B e l l Aerospace Figure 10.

National R6-D effort on SNG from coal


182


r e a c t s the c o a l w i t h hydrogen aiming a t SNG. The B e l l Aerospace Process r e a c t s the c o a l w i t h oxygen o r a i r aiming a t medium o r low Btu gas. 1

A l t o g e t h e r , i t would appear that DOE s o v e r a l l commitment t o g a s i f i c a t i o n R&D has not decreased, although the N a t i o n a l record of success f o r developing lower cost SNG processes has not been p a r t i c u l a r l y outstanding. And now the l a s t area on which I would l i k e t o comment i s environmental c o n s i d e r a t i o n s . A summary appears i n Figure 11. The environmental aspects of c o a l g a s i f i c a t i o n p l a n t s could become a major i s s u e , both t e c h n i c a l l y and p o l i t i c a l l y . Technically, the environmental requirements and water a v a i l a b i l i t y and consump t i o n could p l a y major r o l e s i n determining where SNG p l a n t s w i l l be l o c a t e d and what the gas cost w i l l be. The technology i s now a v a i l a b l e f o r c l e a n i n g up gas and water e f f l u e n t streams, f o r c o n t r o l l i n g p a r t i c u l a t e emissions, and f o r minimizing water consumption. For reasonable requirements i n these areas, the t o t a l cost i n an SNG p l a n t f o r gas, water and p a r t i c u l a t e cleanup would be roughly 15-20% o f the t o t a l p l a n t investment. This i s c l e a r l y a major c o s t , but a t t h i s l e v e l i t would not be an overwhelming c o s t . However, the cost would increase very r a p i d l y i f " c l i n i c a l p u r i t y " were t o be u n n e c e s s a r i l y imposed on SNG p l a n t s , and the cost would indeed become over whelming. This i s a key area, and we hope that reason and good judgment, r a t h e r than emotion and u n j u s t i f i e d i m p o s i t i o n , w i l l prevail. ο

Environmental aspects could become a major i s s u e

ο

Environmental and water c o n s i d e r a t i o n s could play major r o l e s i n determining p l a n t l o c a t i o n s and costs

ο

Technology i s now a v a i l a b l e f o r c l e a n i n g up gas and water e f f l u e n t s , c o n t r o l l i n g p a r t i c u l a t e s , and minimizing water consumption Cost i s 15-20% of t o t a l p l a n t investment Cost would i n c r e a s e very r a p i d l y i f " c l i n i c a l p u r i t y " were u n n e c e s s a r i l y imposed

ο

H o p e f u l l y , reason and good judgment w i l l p r e v a i l Figure 11.

RECEIVED May

Environmental considerations

21, 1979.


Major Technical Issues Facing Synthetic Pipeline Gas - ACS

Recommend Documents