I .

QUARTERLY TECHNICAL REPORT January 1,1995 to March 31,1995

1. Project Title

Improvement of Hydrogen Solubility and Entrainment in Hydrocracker Feedstocks U.S. DOE Grant No.: DE-FG22-92MT92020

2. Investigator

Vinayak N. Kabadi, Department of Chemical Engineering, North Carolina A&T State University, Greensboro, NC 2741 1

3. Project Objectives and Scope:

The objective of this project is to determine the conditions for the hydrogen-heavy oil feed preparation so as to optimize the yield of hydrocracking reactions. Proper contacting of hy- drogen with heavy oil on the catalytic bed is necessary to improve the yields of the hydro- cracking reactions. It is most desirable to have the necessary mount of hydrogen available either in the dissolved or in entrained state, so that hydrogen diffusion to the reaction site does not provide rate controlling resistance to the overall rates of hydrocracking reactions. This project proposes to measure solubility and entrainment data for hydrogen in heavy oils at conditions such as in hydrocrackers, and investigate the improvement of these properties by usage of appropriate additives. Specifically, measurements will be carried out at temperatures up to 300 OC and pressures up to 120 atmospheres. Correlations for solubility and entrainment kinetics will be developed from the measured data, and a method for estimating yield of hy- drocracking reactions using these correlations will be suggested. Exxon Research and Engi- neering Company will serve as private sector collaborator providing A&T with test samples and some technical expertise that will assure successful completion of the project.

4. Technical Highlights and Milestones:

Results are presented for solubility of hydrogen in hydrocarbons and in heavy petroleum fractions. Comparison with experimental data shows good agreements. It is also demonstrated that the model is easily applied to compute solubility of hydrogen in heavy petroleum3Factions=, _/ ~

with fair degree of accuracy. Detailed results are presented in the following report. A koup3e *..- * - --, of manuscripts are in preparation to be submitted for publication Copies will be providq up6n --..

-? - -- - . completion.. , VI * y,-- -- ” p i . / 5: r, /.- I_ . / .A sc ‘5 r. --- .. . = + F-. 0 5. . , rL-

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use- fulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any spe- cific commercial product, process, or service by trade name, trademark, manufac- turer, or otherwise docs not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

-- TEST THE CORRELATION FOR HYDROGEN SOLUBlLI7Y HYDROCARBONS

Table 1 presents a comparison of the conelation with data for hydrogen in various binary

solutions. Included in the table are the temperature and pressure ranges, the number of experimental

data points, experimental data source, and the absolute average deviation of the predicted from the

experimental VLE data defined by: -

I (calculated - experimental) I 72

x 100 1 AAD - (%) = NC

i experiment a1

where N is the number of experimental points and i denotes the data point.

The ADD values in Table 1 incicate good agreement for almost all of the systems tested,

except for a few systems, such as hydrogen - 2,2,4trimethylpentane (the deviation of mole fraction of

hydrogen in liquid phase is about 45 %), and hydrogen - m-xylene (the deviation of molefraction of

hydrogen in liquid phase is about 35 %). It is shown that the model we developed in this work gives

us the good results of hydrogen solubilities in pure hydrocarbon solvents over a much wider range of

temperatures and pressures, and provides more generalized method for accurate description of phase

equilibria in both liquid and vapor phase.

TABLE 1

-COMPARISON OF CORRELATED AND EXPERTMENTAL VLE DATA FOR HYDROGEN IN HYDROCARBON SOLVENTS

Systems T, K - ~~

P, atm No.of ADD% ADD% Source Points x2 Y1

-

n-Decane (1) / Hydrogen (2)

462-583 ~~

19-252 26 4.7 1 14.08

n-Hexadecane(1) / 462-664 20-250 29 4.47 7.08 1151 Hydrogen (2)

n-Octane (1) / 463-553 6-136 71 17.10 6.03 ~41 Hydrogen (2)

n-Hexane (1) / 277-477 34-680 96 17.53 32.82 [201 Hydrogen (2)

n-Butane (1) / Hydrogen (2)

328-394 27-165 48 15.15 4.77 1151

i-Butane (1) / 310-394 34-204 18 10.55 34.79 [61 Hydrogen (2)

n-Propane (1) / 223-360 17-273 64 10.99 6.95 P I Hydrogen (2)

2,2,4-Trimethyl- 310-423 12-363 31 45.92 8.47 161 pentane (1) / Hydrogen (2)

Benzene (1) / 433-533 13-204 130 5.85 2.43 141 Hydrogen (2)

Cyclohexane (1) / 310-410 Hydrogen (2)

34-544 64 6.29 4.85

Benzene (1) / 298-343 0.13-1.0 57 2.62 2.92 1231 Cyclohexane (2)

Cyclopentane (1) / 323-350 1-00 19 3.16 1.41 [ii, r71, 1211, 1233 Benzene(2) 1281, P51, [261

Tetrafi? (1) / Hydrogen (2)

462-621 20-250 19 12.75 6.59 1303

Benzene (1) / m-Xylene (2)

298-323 0.04-0.30 34 4.15 2.04

Benzene (1) / Propane (2) -

310-344 1.36-23.8 16 8.01 3.24 181

Benzene (1) / 343-393 0.54-2.81 45 0.46 1.04 191, [141, 1261, Toluene (2) [101

-

Benzene (1) / 354-393 1 .oo 8 0.57 0.47 [13], [17] Ethylbenzene (2)

Benzene (1) / 383-488 1.57-16.8 74 11.24 14.52 [31 Heptane (2)

Toluene (1) / 462-575 20-27 1 47 15.61 17.22 [30] Hydrogen (2)

m-Xylene (1) / Hydrogen (2)

462-580 20-25 1 27 35.48 13.82

Cyclohexane (1) / 308 0.07-0.19 17 2.76 1.58 [161 3.4-Dimethylhexane (2)

Cyclohexane (1) / 308 0.07-0.19 17 3.33 1.45 t161 4-Methylheptane (2)

Cyclohexane (1) / 308 0.06-0.18 17 3.81 1.55 c 161 n-Octane (2)

Cyclohexane (1) / n-Hexane (2)

308 0.20-0.30 19 2.22 6.15 [2]

t Cyclohexane (1) / 308-348 0.11-0.82 2,2,4-trimethylpentane (2)

114 2.19 2.24

Cyclohexane (1) / 308-373 0.10-LOO 38 Methylcyclohexane (2)

4.66 4.40 [23], [25]

Cyclohexane (1) / Heptane (2)

313-370 0.13-1.00 38 - 5.10 2.95 151, m31

~~ ~~ ~

Cyclohexane (1) / 283-505 6.8-88.5 Ethane (2)

47 6.02

Cumene (1) / - Hydrogen (2)

333-488 6.8-300

1-Methylnaphtha- 286-346 1.00 lene (1) / Hydrogen (2)

Total 3.276 9.48 8.31

Reference:

1. Aleksander, T.; Djodjevic, B.; et al., Collee. Czech. Chem. Commun., 38, 1295, (1973)

2. Battino, R., J. Phys. Chem., 70(11), 3408, (1966)

3. Bucher K. L.; K. R. Ramasubramanian and M. S. Medani, "Thermodynamic Properties of the Benzene and n-Heptane System at Elevated Temperatures", J. appl. Chem., Land. 13., 1133-1155 (1972)

4. Connoliy J. F., Division of Refining, 45 0, (1965)

5, Crutzen, J.L.; Haese, R.; Sieg, L., 2. Natu@orSChUng., SA, 600, (1950)

6. Dean B. R., and J. W. Tooke, Industial and Engineering Chemistry., 38,2,389, (1946)

7. Friend, J.; Kazuo, A.; Nobuo, S., Ind. Eng. Chem. Fundam., 1(14), 117, (1975)

8. Glanville J. W., B. H. Sage, and W. N. Lacey, I' Volumetric and Phase Behavior of Propane- - Benzene System", Industrial and Engineering Chemistry, 42,3,508-513, (1950).

9. Griswold, J.; et al., Trans. Am. Inst. Chem. Engrs., 39,223, (1943)

10 Heestjes, P.N., Chem. Proc. Eng., 41,3851, (1960)

11. Herbert, M.S.; Simnick, J.J., Journul of Chemical and Engineering Data, 25,68-70, (1980)

12. Kay W. B., and T. D. Nevens, "Liquid - Vapor Equilibrium Relations in Binary Systems", Ind. Eng. Chem. 56. 108-114, (1965)

13. Kesselman, N.D.; et al. J. Chem. Eng. Data., 13,340, (1968)

14. Kirschbaum, E.; Fertsner, H., Vevahranstechnik, 1, 10, (1930)

15. Lin H. M., and H. M. Sebastian, and K. C. Chao, Journal of Chemical and Engineering Data, 25,252-254,1980.

16. Mairs, T.E.; Swinton, F;L., J. Chem. Thennodynamics, 12,575-580, (1980).

17. Makh, G.M.; Azeroua, Z.N., Zh. Prikl. Khim., 19,585, (1946).

18 Mordechay H., J. Wisniak, and L. Skladman, Journal of Chemical and Engineering Data., 28, 2, 164, (1983)

19. Nichols W. B., H. H. Reamer, and B. H. Sage, AIChEJ., 3,2,262, (1957)

20 Nikia, I.; Kazuo, A.; Nobuo, S., Ind. Eng. Chem. Fundam., 1(14), 117, (1975).

21 Nyers, H.S., Ind. Eng. Chem., 48, 1104, (1956). -

22. Osborne, C.G.; Morcom, K,N., J. Chem. Themo., 13,235, (1981).

23. Ott, J.B.; Mamsh, KN.; Stokes, R.H., J. Chem. Thermo., 12,1139, (1980). - - 24 Penia, M.D.; Chede, D.R., Anales. De. Quimice., 66,721, (1970).

-

25 Richards, AX.; Hargreaves, E., fnd. Eng. Chem., 36,805, (1944).

26. Rosanaff, N.A.; Bacon, C.N., Schulze, J.F.N., J.Am. Chem. Soc., 36, 1999, (1914).

27 Scatochard, G., Mood, S.E.; Mochel, J.M., J. Phys. Chem., 43,119, (1939).

28. Sieg, L., Chem. Ins. Techn. , 22,322, (1950).

29. Simnick J. J., C. C. Lawson, H. M. Lin, and K. C. Chao, A I C E . J., 23,4,469 (1977)

30. Sirnnick J. J., K. Lih., Ind. Eng. Chem. Process Des. Dev., 17,2,204, (1978)

31. Simnick J. J., H. M. Sebastian, €3. M. Lin, and K. C. Chao, Journal of Chemical Thermodynamics 11,531-537, 1979.

32. Sokolov V. I., and A. A, Polyakov, Zhurnal Prikladnoi Khimii, 50,6, 1405, (1977)

33. Trust D. B., and F. Kurata, AIChE J., 17, 1,86, (1971)

TEST - THE MODEL - FOR HYDROGEN SOLUBILITY PETROLEUM FRACTIONS

In this section we disscuss about using the model for prodicting hydrogen solubility in petro-

leum fractions in this work to work on the some specific petroleum fractions, such as 'Coker Go' , 'FCC

Lcgo', and their mixture at the hydrocracking reaction operating conditions. As we discussed before,

hydrogen solubility in different crude oil fractions was predicted using modified UNIFAC group con-

tribution method. A new procedure for characterizing crude oil fractions has been estabilished.

Functional group concentrations were estimated by means of suggested group models with non integer

number n correlated as a function of mid-boiling point of petroleum fractions. The calculated results

for hydrogen solubility in petroleum fractions are presented as follows.

- - -

For 'coker Go' and 'FCC lcgo' cuts, the mid-boiling point and API" gravity of each cut are

shown in Table 1. These data are used to predict PNA and determine the functions1 group concentra-

tions of model structure. The PNA analysis are shown in Table 2, where P, N, AI, A2, A3 are

pseudo-compounds (paraffin, naphthene, one-ring aromatic, two-ring aromatic, and three-ring aro-

matic )

The results for calculated hydrogen solubility in 'Coker Go' and 'FCC Lcgo' are presented in

figure 1 and figure 2 respectively.

Table 1 Physical Propertics of 'Coker Go' and 'Fcc Lcgo'

Fraction Mid B. P. Tb, K

MI0 Gravity

Coker Go 653.15 24.0

Fcc Lcgo 916.50 10.7

Table 2 Paraffins, Naphthenes and Aromatics Percent (PNA) in 'Coker Go' and 'Fcc Lcgo'

Fraction Parafins Naph thenes P % . N % A1 %

Aromatics A2 % A3 %

Coker Go 0.500 0.200 0.100 0.100 0.100 -

FCC Lcgo 0.600 0.160 0.080 0.080 0.080

Figure-1 and fiewe 2 show that the hydrogen solubility increase with &creasing the tempera-

tures and pressures.

For the mixture of 'Coker Go' and 'Fcc Lcgo', we use two different PNA analysis methods.

Method 1 is that we use the average mid-boiling point over a wide range of true boiling and API"

gravity to determine the functional group concentration of model compounds, the results are given in

Table 3 and Table 4.

Table 3 Physical Properties of the Mixture of Coker Go and Fcc Lcgo for Method 1

Fraction A P I O Gravity

Coker Go (61.8 %) / Fcc Lcgo (38.2 %)

7 17.59 18.9

Table 4 . Paraffins, Naphethenes, and Aromatics Percent (PNA) in the Mixture Using Method 1

Fraction Paraffins P %

Naphthenes N % Ai %

Aromatics A2 % A3 %

Coker Go (61.8 %) / Fcc Lcgo (38.2 %)

0.5618 0.1753 0.0876 0.0876 0.0877

,

Method 2 is that the wide range of true boiling point is broke into two subfractions, Coker Go

and Fcc Lcgo. For each subfraction, we use its own mid-boiling point and API gravity for PNA

analysis respectively to determine the functional group concentration. The results have been given in

Table 1 and Table 2.

The predicted hydrogen solubility in mixture of Coker Go and Fcc Lcgo using these two

methods are presented in Table 5 as isothermal. - Table 5

The Predicted Results for Hydrogen So!ubiIity in the Mixture Using Two Different Method- -

Temperature Pressure Predicted Hydrogen Solubility P, atm

Method 1 Method 2

500

550

60 70 80 90 100 110 120 130 140 150

60 70 80 90 100 110 120 130 140 150

0.107 0.124 0.140 0.155 0.171 0.186 0.200 0.214 0.228 0.242

0.127 0.146 0.165 0.183 0.20 1 0.218 0.234 0.250 0.266 0.28 1

0.108 0.125 0.141 0.157 0. I72 0.188 0.202 0.217 0.23 1 0.245

0.129 0.148 0.167 0.185 0.203 0.220 0.237 0.253 0.269 0.284

i

600

650 -

700

60 70 80 90 100 110 120 130 140 150

60 70 80 90 100 110 120 130 140 150

60 70 80 90 100 110 120 130 140 150

0.158 0.181 0.203 0.224 0.245 0.265 0.284 0.302 0.320 0.337

0.199 0.227 0.253 0.278 0.302 0.325 0.347 0.368 0.388 0.407

0.252 0.286 0.3 17 0.346 0.374 0.400 0.425 0.448 0.470 0.491

0.160 0.183 0.205 0.226 0.247 0.267 0.286 0.305 0.323 0.340

0.20 1 0.228 0.255 0.280 0.304 0.327 0.349 0.370 0.391 0.410

0.254 0.287 0.318 0.348 0.376 0.402 0.427 0.450

.0.472 0.493

In Table 5, it is shown that there is no significant difference between these two methods for

calculating the hydrogen solubility in crude oil cuts. It can conclude that for a wide range of ture

boiling point, we don’t need to divide a TBP curve into a number of subfractions, using the average

mid-boiling point and MI gravity over a wide range of boiling point for a petroleum fraction will give

us the almost same results.

1

0.50 -..

0.45

0.40

a, u) 2 0.35 a

c a, M 0 0.25 L a h 3: =4-l

0

C 0 + 0 ld k

a, 0

0.20 .H

0.15 4

x -

0.10

0.05

0.00 0

- . I 1 I 1 I I I I I P 7oo.o (K)

n i 7’

/

650.0 (K) -

600.0 (K)

550.0 (K)

500.0 (K)

I I I I I I I I I

20 40 60 80 I00 120

Pressure P (a tm)

140 160 180 200

Figure 1. Calculated Values for Hydrogen Solubility in ’Coker G o ’

0.80

0.75

0.70

0.65

0.60

0.55

0 150

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0.00

0'

'700.0 (K)

650.0 (K)

600.0 (K)

550.0 (K)

500.0 (K)

80 100 120 140 160 780 200 0 20 40 60

Pressure P (atm)

Figure 2. Calculated Values for Hydrogen Solubility in ' FCC LCGO '