LITERATURE I.

2. 3.

CITED

Z. I. Syunyaev and V. D. Voloshin, Khim. Tekhnol. Topl. Masel, No. 7 (1966). R. Z. Magaril, F o r m a t i o n of Carbon in T h e r m a l Conversions of Individual H y d r o c a r b o n s and P e t r o l e u m P r o d u c t s [in R u s s i a n ] , Khimiya, Moscow (1973). A. A. Polyakova, L. O. Kogan, et al., Khim. Tekhnol. Topl. Masel, No. 2 (1976).

PRODUCTION PRESENCE

OF OF

OXIDIZED

FERRIC

ASPHALT

IN T HE

CHLORIDE

UDC 665.637.8:66.094.3.37

N. P. P a z h i t n o v a , R. B. G u n , N. M . S k o p i n a , E. F. K a m i n s k i i , a n d D. V. I v a n y u k o v *

It is known [ 1-5] that the introduction of catalytic additives into a bituminous feedstock during oxidation will a c c e l e r a t e the p r o c e s s of molecular condensation and thus increase the capacity of oxidation taaits quite considerably; the use of these additives will also tend to give higher-quality asphalts. Here we are presenting r e s u l t s f r o m a study of the influence of a catalytic additive, f e r r i c chloride, on the productive capacity of the oxidation p r o c e s s and the s e r v i c e p r o p e r t i e s of the oxidized asphalt. We have investigated a mixed T a t a r r e s i d u u m (reduced crude) having the following p r o p e r t i e s : Density p24~ Viscosity VUs0 [Engler] Sulfur content, wt. % Carbon residue, wt. %

0.9856 47.09 2.07 12.25

This r e s i d u u m and individual groups making up the r e s i d u u m were subjected to oxidation. The s e p a r a t i o n of the r e s i d u u m into individual groups was c a r r i e d out in pilot-plant units of VNII NF JAil-Union S c i e n t i f i c - R e s e a r c h Institute for P e t r o l e u m P r o c e s s i n g ] in a c c o r d a n c e with a p r o c e d u r e that was developed by the institute for h i g h - m o l e c u l a r - w e i g h t products and further developed and extended by Soyuzdornii [State All-Union R a i l r o a d S c i e n t i f i c - R e s e a r c h Institute] in cooperation with the Odessa P e t r o l e u m Refinery in application to bituminous feedstocks and asphalts. The asphaltenes were r e c o v e r e d f r o m the r e s i d u u m by precipitation with 40 volumes of p e t r o l e u m ether from a benzene solution; the malthenes r e m a i n ing in the filtrate were s e p a r a t e d into groups by adsorption c h r o m a t o g r a p h y . The groups r e c o v e r e d in this separation had the p r o p e r t i e s listed in Table 1. The r e s i d u u m and its groups (with the exception of the asphaltenes) were subjected to oxidation in a l a b o r a t o r y batch unit with and without f e r r i c chloride added in amount of 0.5% of the weight of s t a r t i n g m a t e r i al, at a t e m p e r a t u r e of 250~ with an air input rate of 5 liters/(min-kg). This oxidation unit is shown s c h e m a t i c a l l y in Fig. 1. The c h a r g e for oxidation was 50 g. The oxidation periods for the r e s i d u u m with and without additive were selected experimentally so as to give asphalts with R & B softening points no lower than 70~ F o r the straight residuum, 13.50 h of oxidation gave a softening point of 72.5~ with the f e r r i c chloride, 3.75 h gave a softening point of 74.0~ This is to say that the f e r r i c chloride reduced the oxidation time by a factor of 3.6. These data d e m o n s t r a t e an a c c e l e r ation of the condensation reaction, and are in full a g r e e m e n t with conclusions from e a r l i e r studies [ 1 - 5 ] . *Deceased. Gubkin Moscow Institute of the P e t r o c h e m i c a l and Gas Industry (MINKh i GP). T r a n s l a t e d f r o m Khimiya i Tekhnologiya Topliv i Masel, No. 8, pp. 35-38, August, 1977. This material is protected by copyright registered in the name o f Plenum Publistting Corporation, 22 7 West 17th Street, New York, N.Y. 10011. No part o f this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission o f the publisher. A copy o f this article is available from the publisher for $Z50.

571

TABLF~ 1. C h a r a c t e r i s t i c s of Groups Refractive index~ Yield, n~ wt. %

Group Oils Paraffinic/naphthenic (PN) Monocyclic aromatic (MGA) .. BicycliC aromatic (BCA)

1,4900

19,90

1,4901--1,5300

13,85

1,5301--1,5900

25,35

Resins

1~.~__ene fBR). Alcohol-benzene (ABR)

Asphaltenes

15,73

11,67

10,80

/

Fig. I. L a b o r a t o r y batch oxidation unit: 1) flowmeter; 2) oxidation tube; 3) e l e c t r i c furnace; 4) c o o l e r ; 5) r e c e i v e r for blowoff; 6) a d s o r b e r ; 7) absorption bottle. These oxidation p e r i o d s , 13.50 and 3.75 h, were also used in oxidation of the individual groups f r o m the r e s i d u u m under analogous conditions, without f e r r i c chloride (13.50 h) and with f e r r i c chloride (3.75 h). The p h y s i c o c h e m i c a l p r o p e r t i e s and group compositions of the original and oxidized samples are shown in Table 2. The m o l e c u l a r weights of the s a m p l e s were d e t e r m i n e d c r y o s c o p i c a l l y . It must be noted that, owing to the difficulty in obtaining repeatable r e s u l t s on these h i g h - m o l e c u l a r - w e i g h t products, the m o l e c u l a r weight d e t e r m i n a t i o n was r e p e a t e d s e v e r a l times on each sample, until a s e r i e s of closely agreeing values was obtained, and these values were then averaged. It can be seen f r o m the data of Table 2 that the oxidized paraffinic/naphthenic h y d r o c a r b o n s of the s a m pie PN-OC have lower density, r e f r a c t i v e index, and m o l e c u l a r weight than do those of sample PN-O. The lower density and r e f r a c t i v e index of the PN-OC indicate a higher degree of paraffinicity of the molecules; this may r e f l e c t r u p t u r e of a naphthene ring. The lower m o l e c u l a r weight of the PN-OC can be explained by simultaneous d e t a c h m e n t of side chains f r o m the r e m a i n i n g r i n g s of the molecuies. The behavior of the MCA group in oxidation with f e r r i c chloride is e x t r e m e l y distinctive. The molecular weight of the MCA-OC sample is lower and the density and r e f r a c t i v e index somewhat higher in c o m p a r i s o n with the MCA-O. In this case we should a s s u m e the o c c u r r e n c e of dealkylation r e a c t i o n s , forming MCA m01ecules with fewer or s h o r t e r side chains, i.e., with a lower molecular weight and higher C:H ratio. Conversion of the BCA group p r o c e e d s analogously; for the BCA-OC sample we observe a still g r e a t e r d e c r e a s e in m o l e c u l a r weight and i n c r e a s e in density in c o m p a r i s o n with the BCA-O sample; this indicates s e v e r e breakoff or shortening of side chains and a considerable i n c r e a s e in the C:H r a t i o in the molecules. It was established by r i n g a n a l y s i s [6] that the percentage of the carbon in side chains also d e c r e a s e s without catalytic additives as we go f r o m the paraffinic/naphthenic h y d r o c a r b o n s to the BCA, as a r e s u l t of oxidation of these groups, and this leads to an i n c r e a s e in the C:H r a t i o in the molecules. When f e r r i c c h l o ride is present, evidently, that same m e c h a n i s m of m o l e c u l a r oxidation not only is retained but is intensified, so that the molecules acquire a g r e a t e r a r o m a t i e i t y and a g r e a t e r capability for t r a n s f o r m a t i o n to the p r i n c i pal end product of condensation, i.e., asphaltenes. 572

TABLE 2. Characteristics of Original and Oxidized Samples

Physicochemical

Group composition,

properties

V,ff. ~

temperature

No.

Code demity

p~0

I

I 2 3 4 5 6 7 8 9 10 ii 12 13 14 15 16 17 18

PN PN-O PN-OC MCA MCA-O MCA-OC BCA BCA-O 8CA-OC BR BR-O BR-OC ABR ABR-O ABR-OC Resid Resid-O Resid-OC

0,8681 0,9002 0,8874 0,9177 0,9400 0,9428 0,9730 1,0087 1,0165 1,0393 1,0572 1,0673 1,0437 1,0675 1,0666 0,9856 1,0150 1.0124

refractive index

plasticity softeninglFraas interval, oils [~ ~ . ~ point, [breaking ~ =o R&B, ~ p o i n t , ~

{ular Weight

1,4789 1,4817 1,4700 1,5118 1,5239 1,5265 1,5557

29,5 80,0 80,0 50,0 98;5 93,0 35,0 16 24

100,0 56,3 76,7 10010 55,2 86,3 100,0 58,8 82,4

--50 --50 --50 --50 --36,5 --49,0 --33,5 --16,0 --19,0 5-12,5 --38,0 -i.37,0 --19,5 4-33,0

42,0 43,0 30,5 65,5 62,0 66,0

-7-3] ,0

72,5

211

74,0

--17

77,5

91,0

4,5 26,6 -O,4 66,6 43,0 55,4

. asphalr e a m tenes

-43,7 23,7

----

-

-

44,8 13.4

---

40,3 16,8 100,0 85,4 61,8 100,0 68,7 67,7 25,9 28,5 18,5

~,,9 0,8 l~,1 li.8 -31.3 32,0 7,5 28,5 26, l

Note. Suffixes Oand OC indicate samples oxidized without and with addition of catalyst.

TABLE 3. Characteristics of Asphaltenes

iElemental Asphaltenes

2~ o'~ X~

c

n

composition, wt. % ]

~

r

From resid 1238 84.97 8 , 7 7 1 1 , 1 2 3 , 7 4 - - 1,40 9,68 From r e s i d - o 1790 85,03 8,480,61 3,70 - - 2,18] 10,02 From residOC 2950 83.33 8,12 1,08 .l, 17 0,45 2,85 10,26

The lower breaking points of the MCA-OC and BCA-OC in c o m p a r i s o n with the corresponding samples MCA-O and BCA-O can be explained by the lower content of resins, i.e. by suppression of the oxidation r e a c tions [1, 2]. The oxidation of the benzene and alcohol-benzene r e s i n s is accompanied by significant reactions of molecular condensation to form asphaltenes, with a manifest tendency toward acceleration of these reactions when iron chloride is introduced [1, 2]. The final condensation product, asphaltenes, undergoes marked changes when oxidized in the p r e s e n c e of ferric chloride; this statement is supported by the data of Table 3. The elemental composition data indicate that the asphaltenes of the resid-OC sample contain 0.45% iron by weight. The considerably higher molecular weight of these asphaltenes in c o m p a r i s o n with those of the r e s i d - O may indicate both a strong increase in cyclicity of the molecules as a result of condensation reactions, and also the formation of iron c o m p l e x e s with the m o l e c u l e s . This latter view is in accord with the conclusions of earlier investigations [7, 1]. The p r e s e n c e of iron in the asphaltene molecules of the restd-OC is further indicated by the appearance of the asphaltenes. In contrast to the normal asphaltenes with spheroidal black granules, they have the form of dry fibers, r e m i n i s c e n t of s l a t e - c o l o r e d fiberglass. Thus, when ferric chloride is present during the oxidation, molecular reactions of dealkylation and c y clization or condensation are intensified. Further, the ferric chloride promotes reactions of complex f o r m a tion. As a result of the intensification of condensation and complex formation, the production of an asphalt with a given softening point is accelerated. The asphalt samples, r e s i d - O and resid-OC, are practically identical in softening point, with different group compositions.

573

The a s p h a l t obtained with f e r r i c chloride has m o r e oils and l e s s r e s i n s and a s p h a l t e n e s , giving it a higher p e n e t r a t i o n (24) and a lower b r e a k i n g point (-17~ i.e., b e t t e r p l a s t i c i t y . Evidently. the specificity of s t r u c t u r e and high m o l e c u l a r weight of the a s p h a l t e n e s in this asphalt a r e r e s p o n s i b l e for the r e t e n t i o n of the s a m e h a r d n e s s as that of the l e s s plastic a s p h a l t (resid-O). LITERATURE

CITED

D. A. R o z e n t a l ' , D o c t o r a l D i s s e r t a t i o n , L e n i n g r a d L e n s o v e t Technological Institute (1972). I. N. K u d r y a v t s e v a , C a n d i d a t e ' s D i s s e r t a t i o n , Leningrad L e n s o v e t Technological Institute (1970). D. V . Ivanyukov, l~. F. K a m i n s k i i , et al., in: New D e v e l o p m e n t s in the Production of I m p r o v e d Asphalts [in R u s s i a n ] , TsNIITl~neftekhim, Moscow (1971), pp. 75-79. D. V. Ivanyukov, I~. F. K a m i n s k i i , et al., N e f t e p e r e r a b . Neftekhim., No. 6, 10-12 (1973). R. B. Gun, P e t r o l e u m Asphalts, Khimiya, Moscow (1973). N. P. Pazhitnova, C a n d i d a t e ' s D i s s e r t a t i o n , MINKh i G P ira. Gubkina, Moscow (1970). E. Y. Barth, Pet. R e f i n e r , 36, No. 9, 290 (1957).

1, 2.

3. 4.

5. 6. 7.

OPTIMIZATION ZEOLITIC

OF

COMPOSITION

HYDRODEAROMATIZATION

OF

PALLADINIZED CATALYST

M. V. L a n d a u , V. Y a . K r u g l i k o v , E. D. Radchenko, V. I . N a z a r o v , N. V. G o n c h a r o v a , a n d O. D . K o n o v a l ' c h i k o v

UDC 678.044

In the d e v e l o p m e n t of c o m p l e x multicomponent c a t a l y s t s , a p r o b l e m a r i s e s in the optimization of c a t a l y s t composition. The dependence of c a t a l y s t activity and s e l e c t i v i t y on the contents of individual components, as d e t e r m i n e d with a fixed p r o c e s s of s y n t h e s i s , cannot m e a s u r e the mutual effects of the components. The m a t t e r of s e l e c t i n g f o r m u l a t i o n s to r e a l i z e the m a x i m u m potential of the s y s t e m can be r e s o l v e d r a p i d l y and efficiently by m a t h e m a t i c a l l y designed e x p e r i m e n t s with c o m p u t e r i z e d data workup. This s o r t of p r o b l e m can be s e t up in that stage of c a t a l y s t d e v e l o p m e n t in which the volume of i n f o r m a tion obtained in the p r o c e s s of s c r e e n i n g t e s t s and p h y s i c o c h e m i c a l investigations is sufficient that the influence of unaccounted p a r a m e t e r s can be eliminated. H e r e we a r e p r e s e n t i n g r e s u l t s f r o m studies of f o r m u l a optimization for s u l f u r - r e s i s t a n t zeolitic h y d r o g enation c a t a l y s t s u s e d in h y d r o d e a r o m a t i z a t i o n of s u l f u r - c o n t a i n i n g p e t r o l e u m distillates. S y s t e m a t i c studies to d e t e r m i n e how the zeolite type, modification method, content of hydrogenating m e t al, and method of molding the zeolitic component with binder will influence the c a t a l y s t activity and s e l e c t i v i t y [ 1 - 3 ] , along with studies in the field of s u r f a c e c h e m i s t r y and s t r u c t u r e of m e t a l / z e o l i t e s y s t e m s [ 4 - 6 ] , have shown that effective d e a r o m a t i z a t i o n of s u l f u r - c o n t a i n i n g p e t r o l e u m f e e d s t o c k s can be achieved by the use of palladium s u p p o r t e d on d e a l u m i n i z e d Type Y zeolite in which p a r t of the sodium cations have been r e p l a c e d by polyvalent cations, followed by molding the c a t a l y s t with binder and then caustic t r e a t m e n t of the c a t a l y s t g r a n u l e s to r e g u l a t e the Na~O content. Thus, the c a t a l y s t activity and s e l e c t i v i t y a r e d e t e r m i n e d by four p a r a m e t e r s x l - x 4, the allowable v a r i a tions of which are:

All-Union S c i e n t i f i c - R e s e a r c h Institute for P e t r o l e u m P r o c e s s i n g (VN/.[ NP). T r a n s l a t e d f r o m K h i m i y a i Tekhnologiya Topliv i Masel, No. 8, pp. 38-42, August, 1977. I This material is protected by copyright registered in the n a m e o f Plenum Publishing Corporation, 227 West 17th Street, New York, N.Y. 10011. No part ] o f this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, [ microfilming, recording or otherwise, w i t h o u t w r i t t e n permission o f the publisher. A copy o f this article is available from the publisher for $ 7.50. [

574