3 Catalytic Upgrading of SRC-II Syncrude H A R R Y A. FRUMKIN, RICHARD F. SULLIVAN, and BRUCE E. STANGELAND Chevron Research Company, 576 Standard Avenue, Richmond, CA 94802
Chevron Research Company, under a contract sponsored by the U.S. Department of Energy (DOE), is conducting a program to determine the feasibility and estimate the costs of using modern petroleum processing technology to produce distillate fuels, such as high octane gasoline, jet fuel, and diesel, from a number of synthetic crude feedstocks. Pilot plant tests for the key processing steps are being conducted to the extent needed to make reasonable estimates of commercial plant performance. The first feedstock studied under this contract was Paraho shale o i l . In a series of recent papers (1-4) and a DOE report (5), three basic shale oil processing routes for the production of transportation fuels were studied: hydrotreating followed by hydrocracking, hydrotreating followed by fluid catalytic cracking (FCC), and severe coking followed by hydrotreating. It was concluded that shale oil can be refined to high quality transportation fuels via modern state-of-the-art refining technology and that it can serve as a substitute for crude oil in a refinery equipped with modern hydrotreating facilities. The key to successful shale oil refining is the initial hydrotreating step which removes contaminants (nitrogen, sulfur, oxygen, olefins, and metallic contaminants) and permits the use of conventional conversion and refining processes to make finished products. This chapter reports results of a similar study to determine the feasibility of converting solvent refined coal (SRC) to transportation fuels. The next chapter discusses upgrading of H-Coal process products. The SRC process, in its two forms, is one of the major processes under current study in programs sponsored by the DOE for conversion of coal to either (1) a solid deashed low sulfur product or (2) a low boiling liquid. In the original SRC process (6), now designated as SRC-I, coal is dissolved under moderate hydrogen pressure in an 0097-6156/81/0156-0075$10.00/0 © 1981 American Chemical Society
76
UPGRADING COAL LIQUIDS
i n t e r n a l l y generated heavy aromatic solvent to y i e l d a product from which most of the m i n e r a l matter i s removed by f i l t r a t i o n . Solvent i s recovered f o r reuse by vacuum d i s t i l l a t i o n . The d i s t i l l a t i o n r e s i d u e (known as SRC or SRC-I) i s a s o l i d under ambient c o n d i t i o n s . Research on the upgrading of SRC-I i s reported i n other chapters of t h i s book. In an a l t e r n a t e v e r s i o n of the process ( 7 ) , designated SRC-II, a p o r t i o n of the c o a l s o l u t i o n i s r e c y c l e d as solvent i n place of the d i s t i l l a t e solvent of the SRC-I process. The f i l t r a t i o n step i s e l i m i n a t e d ; and, t y p i c a l l y , the process operates a t a higher pressure, higher temperature, and longer residence time than the SRC-I process. Hydrogen consumption and the conversion of d i s s o l v e d c o a l i s i n c r e a s e d , and the primary product i s a l i q u i d r a t h e r than the s o l i d product of the SRC-I process. The l i q u i d product of the SRC-II process i s the feedstock that i s the subject of the work described i n t h i s chapter. In a previous paper (_8) , we presented r e s u l t s of hydrot r e a t i n g SRC-II process product at s e v e r a l s e v e r i t i e s , and p r e l i m i n a r y cost estimates were given. In the present chapter, previous r e s u l t s are summarized; and r e s u l t s of f u r t h e r downstream processing p i l o t p l a n t s t u d i e s are presented, together w i t h process engineering s t u d i e s and updated cost estimates. More d e t a i l s of t h i s study a r e given i n a DOE r e p o r t . (_9) Feeds The P i t t s b u r g and Midway Coal Mining Company provided the SRC-II process products that were used as feeds i n these s t u d i e s . They were produced i n the F o r t Lewis, Washington, p i l o t plant from a West V i r g i n i a c o a l ( P i t t s b u r g Seam, B l a c k s v i l l e No. 2 Mine of the Consolidated Coal Company). Three f r a c t i o n s of SRC-II were provided. These were reblended i n a r a t i o recommended by the DOE t o c o n s t i t u t e the net whole l i q u i d process product from " t y p i c a l " SRC-II o p e r a t i o n as best could be estimated at the time t h i s p r o j e c t was s t a r t e d ( A p r i l 1978). Table I shows the i n s p e c t i o n s of the r e c o n s t i t u t e d SRC-II process product. C h l o r i d e was not removed from the samples before hydroprocessing. However, i t was shown t h a t water washi n g can remove most of the c h l o r i d e . I t i s our understanding that t h i s would t y p i c a l l y be done at the upstream (SRC) proc e s s i n g f a c i l i t y i n a commercial s i t u a t i o n . P r o c e s s i n g of SRC-II P i l o t plant t e s t s were made to hydrotreat the whole SRC-II process product blends to remove n i t r o g e n , s u l f u r , oxygen, and metals using f i x e d c a t a l y s t beds.
FRUMKIN ET AL.
SRC-II Syncrude
TABLE I PROPERTIES OF SRC-II PROCESS PRODUCT Inspections G r a v i t y , °API A n i l i n e P o i n t , °F S u l f u r , Wt % T o t a l Nitrogen, Wt % Basic Nitrogen, Wt % Oxygen, Wt % Hydrogen, Wt % Hydrogen/Carbon Atom R a t i o C h l o r i d e , ppm Pour P o i n t , °F Ramsbottom Carbon, Wt % Hot Heptane I n s o l u b l e s , Wt % Benzene I n s o l u b l e s , Wt % Ash, Wt % Molecular Weight TBP D i s t i l l a t i o n , °F St/5 10/30 50 70/90 95/99
18.6 Steam reforming feeding gas and naphtha in Cases 3A and 3B, 6A and 6B.
F
Refinery
•
Whole SRC-11 Oil
Refining Units
Sour Water from
Gas
Refinery Gas
Light Ends
Gas to Refinery Fuel
Hydrocracking
H,S
Heavy Naphtha
2
Gas
Figure 7.
Heavy Naphtha
SRC-II Oil
Sulfur Plant
.1
Catalytic Reforming
L
Gas
I
Hydrogen Plant*
Refinery Fuel
Motor Gasoline
Ammonia
Sulfur
Hydrogen to Hydrotreaters
Flow diagram: refining of SRC-II oil by hydrotreating and hydrocracking, case 4
J
To Hydrogen Plant Hydrogen
Light Naphtha
Naphtha Hydrotreating Hydrogen
H,S
H S Recovery
• Steam reforming feeding gas and naphtha in Cases 4A, 4B, and 4D. Partial oxidation feeding SRC-II oil in Case4C.
Hydrogen .
Hydrogen
Whole SRC-II Oil Intermediate Severity Hydrotreating
Recycled Water to Refining Units
Sour Water from Refining Units Waste Water Treating
Gas
Refinery Gas
^a^JoJRe^inery Fuel
r ο g θ
8
g δ ο
C Ο >
00
Hydrotreating
Severity
Moderate
to Refining Units
Recycled Water
Treating
Waste Water
2
HS
ι
Gas
2
H S
Heavy Naphtha
Figure 8.
ι m
Hydrogen
Reforming
Catalytic
Gas
Gas Oil
t 1
Plant
t
To Hydrogen Gas
Sulfur Plant
J
r
Hydrogen to Hydrotreating
and Refinery Fuel
No. 2 Furnace Oil
Motor Gasoline
Ammonia
Sulfur
Gas to Refinery Fuel
Plant*
Hydrogen
Simplifiedflowdiagram: refining of SRC-II oil by moderate severity hydrotreating, case 5
Partial oxidation feeding SRC-II oil in Case 5C.
I
Light Naphtha
Naphtha Hydrotreating
Hydrogen
2
HS
Recovery
* Steam reforming feeding gas and naphtha in Cases 5A, 5B, and 5D.
Hydrogen
Whole SRC-II Oil
Refining Units
from
Sour Water
Refinery Gas
_N aphtha
_S R£- I K W
100
UPGRADING COAL LIQUIDS
e f f e c t on r e f i n e r y cost of r e l a x i n g the ground r u l e to make only t r a n s p o r t a t i o n f u e l s . The appendix shows y i e l d s and product p r o p e r t i e s from each of the h y d r o t r e a t e r s and hydrocrackers estimated f o r the studies. Stock Balances - Tables XII-XVI show d e t a i l e d stock b a l ances f o r each of the f i v e cases. Y i e l d s are based d i r e c t l y on p i l o t plant r e s u l t s and general petroleum processing c o r r e l a t i o n s where a p p r o p r i a t e . The primary b a s i s i s to make a cons t a n t 50,000 BPCD of d e s i r e d products i n each case. This c a p a c i t y was s e l e c t e d f o r the f i r s t s e r i e s of s t u d i e s because i t matches the maximum f e a s i b l e throughput f o r a s i n g l e SRC-II plant as p r e s e n t l y conceived. The r e f i n e r i e s are stand-alone grass roots f a c i l i t i e s , that i s , complete new i n s t a l l a t i o n s , i n c l u d i n g a l l necessary supporting f a c i l i t i e s , such as u t i l i t y p l a n t s , tankage, and r e q u i r e d environmental c o n t r o l equipment. Another o b j e c t i v e f o r t h i s s e r i e s was to meet r e f i n e r y furnace f u e l and hydrogen p l a n t feed requirements w i t h i n t e r n a l l y s u p p l i e d clean f u e l s , ensuring minimum a i r emissions. B o i l e r p l a n t s , however, were assumed to be c o a l f i r e d i n comp l i a n c e with present DOE r e g u l a t i o n s . Other options f o r f u e l and hydrogen plant feed are examined i n the complete DOE r e p o r t . (9) Estimates of f i n i s h e d g a s o l i n e production were made by using c o r r e l a t i o n s f o r c a t a l y t i c reforming of naphtha and blending of g a s o l i n e components. C o r r e l a t i o n s could be used i n t h i s case because the p r o p e r t i e s of the reformer feeds d i s t i l l e d from the p i l o t plant h y d r o t r e a t e r products were w e l l w i t h i n Chevron's range of experience on petroleum s t o c k s . Gasoline blending o b j e c t i v e s were to make a s i n g l e unleaded pool meeting accepted i n d u s t r y s p e c i f i c a t i o n s f o r q u a l i t y w i t h minimum octane numbers of 93 (Research + Motor)/2. These octane numbers are t y p i c a l of those projected f o r the e a r l y 1980 s. Table XVII l i s t s the r e f i n e r y product i n s p e c t i o n s . Each plan represents a completely f e a s i b l e and reasonably e f f i c i e n t r e f i n i n g arrangement. A more d e t a i l e d o p t i m i z a t i o n of c o n d i t i o n s , cut p o i n t s , and other f a c t o r s , while not w i t h i n the scope of t h i s study, would be c a r r i e d out i n the course of a normal r e f i n e r y design. Cost Estimates - P l a n t investment costs were developed using cost c o r r e l a t i o n s based on a c t u a l plants constructed by Standard O i l Company of C a l i f o r n i a . The important bases f o r these estimates are summarized i n Table X V I I I . Costs f o r the o v e r a l l Case 1 r e f i n e r y are broken down and d e t a i l e d i n Table XIX. Investments are c a t e g o r i z e d as "onplot," those d i r e c t l y concerned w i t h the i n d i v i d u a l r e f i n e r y process p l a n t s , and " o f f p l o t , " f o r a u x i l i a r y or supporting f a c i l i t i e s , such as u t i l i t y p l a n t s , tankage, e t c . The e s t i m a t i n g allowances shown f
Day
+
Sulfide
Day
• I n c l u d i n g 4.6 LV % B u t a n e s Note: P a r e n t h e s e s () D e n o t e
Hydrogen Sulfur Ammonia
Tons P e r C a l e n d a r
a Negative Quantity,
i.e.,
96
29.1
(174.9)
7, 505
Hydrogen, M i l l i o n s o f Standard Cubic Feet Per C a l e n d a r Day
(Loss) (625)
Gain
67,365 (59,860)
Fuel
Liquid
Product Feed
(97.5 F - l C l e a r )
Liquid Liquid
Total Total
Reformate
6
38,370 3,000
5
300-550°F Kerosene 5 5 0 ° F Bottoms
795 1, 380 1,410
(59,860)
High S e v e r i t y Hydrotreating
3, 795 18,615
59,860 1, 870
Refinery Input
C /C Light Gasoline 180-300°F Heavy G a s o l i n e
Fuel O i l
SRC I I O i l * Equivalent Fuel O i l
F u e l Gas, E q u i v a l e n t Isobutane Normal Butane
Whole Coal,
per Calendar
Feeds and P r o d u c t s ,
Barrels
TABLE X I I
Consumption
17.0
(545)
(990)
9,080 (10,070)
8, 940
(10,070)
115 15 10
Catalytic Reforming
157.9
(5,525)
(9,575)
(9,575)
(8,545)
(510) (520)
Hydrogen Manufacture
Processing
(29.1) 26.2
2
H S Recovery and Sulfur Plant
(1,870)
Offplot Boiler Plant
STOCK BALANCE - CASE 1A REFINING S R C - I I O I L BY HIGH SEVERITY HYDROTREATING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE PLUS J E T FUEL DOE CONTRACT E F - 7 6 - C - 0 1 - 2 3 1 5
6,695
(105)
6,800
2, 570 3, 000
910 160 160
Refinery Fuel
14,200
8, 940
3,795
725 740
Motor Gasoline
35,800
35,800
Kerosene Jet Fuel
Products
26.2 96
Byproducts
Feeds and P r o d u c t s ,
(97 F - l C l e a r )
• I n c l u d i n g 4.6 LV % Butanes Note: Parentheses () Denote a N e g a t i v e Q u a n t i t y ,
Hydrogen S u l f i d e Sulfur Ammonia
Tons Per C a l e n d a r Day
i . e . , Consumption
96
28.7
(41.5)
18
140.9
(4,940)
(117.1)
(770)
Hydrogen, M i l l i o n s o f Standard C u b i c F e e t Per Calendar Day
(8,395)
(1,010)
(250)
2,285
4, 590
(530)
(Loss)
(8,395)
11,900
(6,930)
(735) (730)
12,09Q (13,100)
33,025
(13,100)
145 25 20
Hydrogen Manufacture
36,400 (34,115)
Fuel
L i q u i d Gain
T o t a l L i q u i d Product T o t a l L i q u i d Feed
Reformate
H y d r o t r e a t e d Kerosene
(34,115)
3,170
205
Middle Distillate Hydrotreating
Processing Naphtha Hydrotreating and C a t a l y t i c Reforming
63,616 (59,620)
35,075 4, 535
+
300-550°F Kerosene 5 5 0 ° F Bottoms
645 1, 360 1, 360
(59,020)
Intermediate Severity Hydrotreating
3,775 16,860
59,020 1,250
Refinery Input
Cj/Cg L i g h t G a s o l i n e 180-300°F Heavy G a s o l i n e
F u e l Gas, E q u i v a l e n t F u e l O i l Isobutane Normal Butane
Whole SRC I I O i l * Coal, Equivalent Fuel O i l
B a r r e l s per C a l e n d a r Day
TABLE X I I I
(28.7) 26
2
HS Recovery and S u l f u r Plant (1,250)
Offplot Boiler Plant
STOCK BALANCE - CASE 2A REFINING OF SRC-II OIL BY INTERMEDIATE SEVERITY HYDROTREATING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE PLUS JET FUEL DOE CONTRACT EF-76-C-01-2315
6, 490
6,490
960 4, 535
995
Refinery Fuel
16,975
11,900
3,775
650 650
Motor Gasoline
33,025
33,025
Kerosene Jet Fuel
Products
26 96
Byproducts
Refinery Input
59,130 1,890
Feeds and P r o d u c t s ,
Whole SRC I I O i l * Coal, Equivalent Fuel O i l
• I n c l u d i n g 4.6 LV % Butane Note: P a r e n t h e s e s () Denote a N e g a t i v e Q u a n t i t y ,
Hydrogen S u l f i d e Sulfur Ammonia
Tons Per C a l e n d a r Day
i.e.,
96
28.8
(172.7)
Hydrogen, M i l l i o n s o f Standard C u b i c F e e t per C a l e n d a r Day
Consumption
(385) 47.0
(1,470)
(2,570)
(1,640)
1, 905
7,415
(625)
(Loss)
24,660 (27,230)
24,055
(27,230)
60
220 65
260
Catalytic Reforming
4,270 (5,910)
1,910 (1,515) (1,130) (1,800)/1,300 (745)/535 (720)/525
L i g h t Ends Recovery
Processing
27,595 (25,690)
-
(25,690) 3,415
11,665 6,295
310 1, 575 1,130 1, 800 745 720
Fluid Catalytic Cracking
66,545 (59,130)
-
Fuel
L i q u i d Gain
T o t a l L i q u i d Product T o t a l L i q u i d Feed
Reformate
(98.5 F - l C l e a r )
25,690
+
4 0 0 ° F Bottoms FCC C y c l e O i l
6
3, 750 33,560
1, 395
1,365
785
(59,130)
High S e v e r i t y Hydrotreating
C5/C L i g h t G a s o l i n e 180-400°F Heavy G a s o l i n e FCC L i g h t G a s o l i n e FCC Heavy G a s o l i n e
F u e l Gas, E q u i v a l e n t F u e l O i l Propylene Propane Isobutane Butylène Normal Butane
B a r r e l s per C a l e n d a r Day
TABLE XIV
125.7)
(4,400)
(7,560)
(7,560)
(6,330)
(510)
(220) (500)
Hydrogen Mfg.
(28.8) 25.9
2
HS Recovery and Sulfur Plant
STOCK BALANCE - CASE 3A REFINING SRC-II OIL BY HIGH SEVERITY HYDROTREATING AND FLUID CATALYTIC CRACKING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE DOE CONTRACT EF-76-Ç-01-2315
(1,890)
Offplot Boiler Plant
6,680
6,680
3,415
3,265
Refinery Fuel
50,000
24,055
11,665 6,295
3,750
2,230 535 1,470
Motor Gasoline
Products
25.9 96
Byproducts
6
+
Sulfide
• I n c l u d i n g 4.6 LV % Butanes. Note: Parentheses () Denote a Negative
Hydrogen Sulfur Ammonia
Day
Quantity,
(52.5)
i . e . , Consumption
92
27.7
(142.0)
Tons Per C a l e n d a r
(570) 49.0
145. 5
(5,015)
(9,190)
(2,795) (1,880)
6,965
6,195 (230)
(9,910)
31,060
(4,325)
(3,325) (1,546)
31,720 (34,515)
(32,625)
38,615
(34,515)
475 100 85
Hydrogen Manufacture
39,590 (32,625)
10,795 21,755
3,700 17,085
Processing Naphtha Hydrotreating and C a t a l y t i c Reforming
62,715 (56,520)
470 5,235 1,335
Hydrocracking
675 1, 320 1, 320
(56,520)
Intermediate Severity Hydrotreating
Hydrogen, M i l l i o n s o f Standard c u b i c F e e t Per Calendar Day
(Loss)
56,520 1,110
Refinery Input
Fuel
L i q u i d Gain
T o t a l L i q u i d Product T o t a l L i q u i d Feed
(96 F - l C l e a r )
Bottoms
Reformate
300°F
5
C /C Light Gasoline 180-300°F Heavy G a s o l i n e
F u e l Gas, E q u i v a l e n t F u e l O i l Isobutane Normal Butane
Whole SRC I I O i l * Coal, Equivalent Fuel O i l
Day
Products,
B a r r e l s per C a l e n d a r
Feeds and
TABLE XV
?
(27.7) 25
HS Recovery and Sulfur Plant
STOCK BALANCE - CASE 4A REFINING OF SRC-II OIL BY INTERMEDIATE SEVERITY HYDROTREATING AND SINGLE-STAGE ISOCRACKING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE DOE CONTRACT EF-76-C-01-2315
(1,110)
Offplot Boiler Plant
7,695
7,695
5,990
1,620 85
Refinery Fuel
50,000
31,060
14,494
3,245 1,200
Motor Gasoline
Products
25 92
Byproducts
p e r C a l e n d a r Day
Feed O i l
+
Note:
4.6 LV % B u t a n e s
Sulfide
P a r e n t h e s e s () D e n o t e
•Including
Hydrogen Sulfur Ammonia
T o n s P e r C a l e n d a r Day
a Negative Quantity,
17.0
84.1
(2,945)
(5,125)
(930) (740)
(5,125)
(4,605)
(260) (260)
11,870 (10,800)
11,590
(12,800)
215 35 30
Hydrogen Manufacture
Processing Naphtha Hydrotreating and C a t a l y t i c Reforming
i . e . , Consumption
88
26.7
(101.1)
3,085
Hydrogen, M i l l i o n s o f Standard Cubic Feet Per C a l e n d a r Day
(Loss)
60,285 (57,200)
36,585
3,165 17,405
490 1, 320 1, 320
(57,200)
Moderate Severity Hydrotreating
Fuel
Gain
Liquid
Product Feed
56,200 8C0
Refinery Input
(410)
Liquid Liquid
Total Total
(96.5 F - l C l e a r )
Bottoms
Reformate
300°F
6
Cs/C Light Gasoline 1 8 0 - 3 0 0 ° F Heavy G a s o l i n e
F u e l Gas, E q u i v a l e n t Isobutane Normal Butane
W h o l e SRC I I O i l * Coal, Equivalent Fuel O i l
Barrels
Feeds and P r o d u c t s
TABLE XVI
(26.7) 24 .0
2
H S Recovery and Sulfur Plant
(860)
Offplot Boiler Plant
4,095
(145)
4,230
3,090
705 220 215
Refinery Fuel
STOCK BALANCE - CASE 5A REFINING S R C - I I O I L BY MODERATE SEVERITY HYDROTREATING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE PLUS NUMBER TWO HEATING O I L DOE CONTRACT E F - 7 6 - Ç - 0 1 - 2 3 1 5
16,505
11,590
3,165
875 875
Motor Gasoline
33,495
33,495
Number Two Oil
Products
24.0 88
Byproducts
106
UPGRADING COAL LIQUIDS
REFINERY PRODUCT INSPECTIONS REFINING OF SRC-II OIL DOE CONTRACT EF-76-C-01-2315
Case
I n s p e c t i o n s of Motor
1978 Specifications
1
2
3
4
5
D 323 D 484 D 1266
Negative 0.0 3 Max
10 Negat i v *
