4 Catalytic Upgrading of Η-Coal Syncrudes DENNIS J. O'REAR, RICHARD F. SULLIVAN, and BRUCE E. STANGELAND Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 9, 2017 | http://pubs.acs.org Publication Date: June 20, 1981 | doi: 10.1021/bk-1981-0156.ch004
Chevron Research Company, 576 Standard Avenue, Richmond, C A 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 refining a number of synthetic crude feedstocks to distillate fuels such as high octane gasoline, jet, and diesel fuels using commercial petroleum processing technology. Pilot plant tests for the key processing steps are being conducted to the extent needed to make reasonable estimates of commercial plant performance. The previous chapter describes results with SRC-II process products. Another route used to liquefy coal is the Η-Coal process, which was developed by Hydrocarbon Research Institute. It differs from the SRC-II process in that a catalyst is employed in the liquefaction step. (1,2) Several recent upgrading studies on this material have again shown the importance of hydrotreating. For example, de Rosset and coworkers (3,4) studied the hydrotreating, hydrocracking, and catalytic reforming of vari ous Η-Coal distillates. They concluded that nitrogen, sulfur, and oxygen can be removed to acceptable levels by conventional hydrotreatment with lower-than-normal space velocities. Cata lytic reforming to high octane gasolines proceeded at mild conditions and high yields. Conser, Garrett, and Weiszmann (5) evaluated several schemes involving hydrotreating, hydrocracking, and FCC for processing Η-Coal liquid to produce gasoline and middle d i s t i l late in various ratios and compared and contrasted results to petroleum refining. They concluded that while the processing schemes are not the same as in a crude oil refinery, upgrading of coal liquids to acceptable end products is certainly tech nically feasible. They observed, however, that the properties 0097-6156/81/0156-0115$07.75/0 © 1981 American Chemical Society Sullivan; Upgrading Coal Liquids ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
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of the products from a c o a l o i l r e f i n e r y can be s i g n i f i c a n t l y d i f f e r e n t from products made i n a crude o i l r e f i n e r y . Typi c a l l y , the products are very aromatic. The No. 2 f u e l o i l would not meet h e a t i n g o i l or d i e s e l t r a n s p o r t a t i o n f u e l gravi t y requirements without f u r t h e r extensive hydrogénation. They suggested that probably the c o a l o i l d i s t i l l a t e can best be blended w i t h Crude O i l No. 2 f u e l o i l stocks a f t e r i t has been hydrotreated or i t can be used d i r e c t l y , p o s s i b l y with m o d i f i e d burner systems. In the cases they s t u d i e d , h y d r o t r e a t i n g f o l lowed by hydrocracking appeared to be more a t t r a c t i v e than h y d r o t r e a t i n g f o l l o w e d by FCC. C a l d w e l l and Eyerman (6) hydrotreated and hydrocracked s e v e r a l c o a l - d e r i v e d d i s t i l l a t e s and naphthas, i n c l u d i n g those from Η-Coal, and evaluated these o i l s as p o t e n t i a l petrochem i c a l feedstocks. High y i e l d s of aromatics were obtained upon reforming. In the present chapter, r e s u l t s are presented from a study of the r e f i n i n g steps needed to produce d i s t i l l a t e f u e l s from Η-Coal l i q u i d s . The approach has been s i m i l a r to that used i n the SRC-II work described i n the previous chapter: analyze the s t a r t i n g m a t e r i a l , choose reasonable processing steps, make appropriate p i l o t plant t e s t s , and analyze the products. Syncrude P r o p e r t i e s Η-Coal naphthas and d i s t i l l a t e s derived from I l l i n o i s No. 6 (Burning Star Mine) and Wyodak c o a l s were s u p p l i e d by Hydrocarbon Research, Inc. The naphthas and d i s t i l l a t e s were blended i n the a p p r o p r i a t e proportions to o b t a i n a whole syn crude derived from each c o a l . P r o p e r t i e s of these syncrudes are shown i n Table I . For comparison, Table I a l s o shows prop e r t i e s of the SRC-II syncrude used i n the study described i n the previous chapter. The SRC-II syncrude was d e r i v e d from a West V i r g i n i a c o a l ( P i t t s b u r g h Seam, B l a c k s v i l l e No. 2 Mine of the c o n s o l i d a t e d Coal Company). The Η-Coal and SRC-II syn crudes are not d i r e c t l y comparable because the c o a l s used to d e r i v e these syncrudes d i f f e r . The important p r o p e r t i e s of these syncrudes i n c l u d e the hydrogen content, b o i l i n g range, and i m p u r i t i e s . Apparently, the type of c o a l g r e a t l y i n f l u e n c e s these p r o p e r t i e s . The Wyodak Η-Coal syncrude i s r i c h e r i n hydrogen and contains fewer heteroatoms than the I l l i n o i s Η-Coal syncrude. In c o n t r a s t , the SRC-II syncrude contains the l e a s t hydrogen and the most
Sullivan; Upgrading Coal Liquids ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
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O'REAR E T AL.
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TABLE I
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PROPERTIES OF WYODAK H-COAL, ILLINOIS H-COAL, AND SRC-II SYNCRUDES
G r a v i t y , °API A n i l i n e P o i n t , °F M o l e c u l a r Weight V i s c o s i t y , cSt At 100°F • Ransbottom Carbon, Wt % Hot Cy I n s o l u b l e s , Wt % ι Ash, ppn j Pour P o i n t , °F 1 Bromine No. ! M a l e i c Diene No., j cg I / g ;
Wyodak H-Coal Syncrude
Illinois H-Coal Syncrude
35.1 100
