1466
INDUSTRIAL AND ENGINEERING CHEMISTRY
Neutralization of the acid groups with alkali destroys the activity of the alumina completely for isomerization. Likewise, the commercial aluminas which contain sodium have not been found active a t the experimental conditions used in this study. P1.olonged heat treatment of the hydrogen fluoride-treated catalyst was found to drive off the hydrogen fluoride and thus reduce the isomerization activity of the catalysts eventually to that of pure alumina. Likewise. loss of water from phosphoric acid polymerization catalyst reduces the activitl- of this catalyst for isomerization, alkylation, and polymerization. Concentration of the surface protons (as xell as temperatures) is important from the standpoint of polymerization of the olefin feed. If the acid groups are numerous the concentration of adsorbed carbonium ions will bc high, and the chances for polymerization are good. This is in partial agreement vl-ith the observation that high boiling material is formed over the acidtreated catalysts, \Thereas essentially only the double bond shift takes place over the neutral alumina. Thus, it is possible to explain the mechanism of isomerization and polymerization of olefin hydrocarbons by aluminas by extending the ideas of the carbonium ion theory of reactions. These same ideas could be extended to the cracking of hydrocarbons by various catalysts such as the well known silicaalumina catalyst and the hydrofluoric acid-treated alumina. T h e latter catalyst has been found to be a potcnt cracking catalyst at. temperatures above 425" C. for paraffin hydrocarbons. The data presented in t.his paper show the acid-treated aluminas to be active for the cracking of olefins at a temperature as l o i r ar: 350' C. SUMMARY
The react,ions of 1-pentene and 2-pentene were studied over a limited range of temperatures and space velocities with the use of three different catalysts. These catalysts were siniilar in that thev contained verv little sodium and were either acidic or
Vol. 39, No. 11
neutral in composition. The pure alumina gel catalyst B showed high activity for double bond shifting at low temperatures and produced little cracking or polymerization. Acid-treated aluminaq were active in skeletal isomerization and gave good yields of branchcd pcntenes even at very high space velocities. Shifting of thc, tloublc bond in the n-pentene molecule appeaxs to be a rapid reaction which is catalyzed by neutral alumina even at loir- temperatures. Skeletal isomerization requires higher temperatures and catalysts of more acid character. Branchedchain olefins may be prepared from either 1-pentene or 2-pcntene, since equilibrium is rapidly established between these straightchain olefins. A reaction mechanism is proposed in which carbonium ions are formed by reaction betveen the olefin and protons on the acidic alumina surface. Tlie distribution of products is explained by the various thermodynamic stabilities of the carbonium ions thus formed. LITERATURE CITED
(1) American Petroleum Institute Project 44. (2) Bloch, B. S., Pines, Herman, and Scherling, Louib J . A m . Chem. Soc., 68,153 (1946). 13) Ewell. R. H.. and Hardv. P. E.. Ibid.. 63.3460 11941). (4) Gorin, M . H., Kuhn, C S., and Miles, C. B., IND. EXG.CWEM., 38, i 9 5 (1946).
(5) Hay, R. G., hfontgorneiy, C. W. and Coull, James, I b i d . , 37, 335 (1945). (6) Heard, Llewellyn, U. S. Patent 2,274,634 (March 3, 1942); Reissue 22,196 (Oct. 6, 1942). (7) LLIcCarthy, W. W., and Turkevich, John, J . Chem. Phys , 12, 405 (1944). (S) Magnolia Petroleum Co., unpublished work. (9) Oblad, 8.G., and Gorin, M. H., IND.ENG. CHEM., 38, 822 (19461. (10) Oblad, A. G., hIarschner, R. F., and Heard, Llemellyn, J Am. Chem Soc.. 62, 2066 (1940). (11) Whitmole, F. C., Ibid., 54, 3274 (1932). RECEIVEDhlav 31. 1946. Presented at the Texas Reeionai RIeetine of the ANERICANC H E ~ I X C SOCIETY, AL .4ustin, Texas, December 8 , 1945.
Selenium Dioxide as a Lubricant
Additive RAY E. HEIKS i N D FRASK C. CROXTOS Battelle .llemoricd I n s t i t u t e , Columbus, Ohio Seleniuiii dioxide, although \+ell hnown as an oxidizing agent, has been shown to retard the oxidation of drjiiig oils. With se\eral typical alcohols to increase its solubilit?, selenium diotide was found to act as an antiotidant for lubricating oils. This paper describes the results of a number of bench and engine tests which indicate that the effecti?eness of selenium dioxide is comparable with that of certain commercial antioxidantticking; for ring filling, per rc.rit C J f the oil ring filled with sludge: and heard 0. ing loss, the milligram loss suffered by the bearing during the run. At the end of t h e test the used oil was analyzed for pr'r cent viscositv incwasc, neutralization number, Conradson cart)ori residue, and naphtha insolubles. CHETROLET 6 6 2 , i 3 - HESGISE ~ ~ ~ OILST-~BILITY TEST. An oil containing selenium dioxide \vas tmted according t o the standard Chcvrolet engiric oil stability test operating under the following conditions: speed, 3150 r.p.m. (about 60 m.p.h.i; load, 30 hp. (road load); ivater temperature, 200" F. : oil temperature, 280" F. : duration of tmt, 66*/3 hours (no oil change,, about 4000 miles. At the end of the test the properties of the crankcasr oil were determined and the engine condition noted. The nil analy-
T.4BLE I. ~ ~ S D E R J l - O ooXIDAT1OS D TESTSO F SELENIUM DIOXII)E-2-ETHYLHEXYI. ALCOHOL I S PESSSYI.V.iNIA 1o\Ir B.4sE OIL
(Tests r u n i n laboratory 1)
S e , c;
Sludge, ZIg./lO G Oil
Viscosity Increase,
or
I
j
Xeutraliastion S o
I
Conradson Carbon,
IEARING CORR.
I
I
Figure 1
Bearing Corrosion, Mg. Loss
v--
I
~
70
1470
INDUSTRIAL AND
ENGINEBRING CHEMISTRY
TABLE 11. UKDERWOOD OXIDATIOX TESTSWITH VARIOES ALCOHOLS AS SOLVENTS FOR SELESIUSI DIOXIDE
111. USDERWOOD OXIDATION TESTSO F OIL BLEND’S CONTAISISGSELENIUM DIOXIDE-BENZYL ALCOHOLASD
T.4BLE
TRIPHEKYLPHOSPHITE
(Base oil, Pennsylvania 10W: tests r u n in laboratory A) Sludge, Viscosity Conradson Bearing &Ig./lO G. Increase, SeutraliCarbon, Corrosion, % ’ zation S o . % M g . Loss .llcohol Oil
Se,
70
Selenium Content of 0.07% Base oil Lauryl % E t hylhexyl n-Octyl J I e t h y l amyl Benzyl
231 5.8 6.6 1.9 2.0 0.4
Butoxyethyl Amyl %-Butyl Bensyl Isobutyl 2-Ethylhexyl
0.6 4.0 2.4 1.2 1.7 2.0
320 88.3 63.9 15,8 43.1 24.3
l5,OO 6.60 6.20 4.30 2.95 1.44
3.33 1.55 1.17 1.02 0.82 0.50
116.2 222.0 109.6 44,s 140.0 35.8
1.14 1.10 0.87 0.57 0.50 0.36
7.0 14.8 8.1 39.7 7.4 28.0
0.27 0.58 0.18 0.30 0.16
17.9 0.0
0.00 0.10 0.10 0.10 0.10 0.00 0.07 0.10 0.15
Selenium Content of 0.1070 64.0 61.0 40.0 30.7 28.4 22.0
3.60 3.80 2.30 2.04 1.70 2.50
+
0.8 1.4 1.2 1.2 1.8
15.7 11.3 8.3 21.6 7.2
0.90 0.58 0.48 1.10 0.41
(Base oil, Pennsylvania 1OW; tests run i n l a b o r a t o r y A) Triphenyi- Sludge, Viscosity Conradson Bearing phosphite, hIg./lO G. Increase, NeutraliCarbon, Corrosion, 70 Oil 70 zation No. 70 hIg. Loss 231 0.00 320 15.00 3.33 116.2 30.7 0.00 1.2 2.04 0.57 39.7 19.1 0.07 0.40 2.7 1.48 11.1 17.5 1.8 1 51 0.41 0.10 8.1 0.15 15.6 0.42 1.9 1.18 5.3 264 264 3.24 0.07 12 20 (3.1 0.07 3.0 10.5 2.92 0.73 10.5 19.1 0.07 2.7 0.40 1 48 11.1 1.8 7.2 0.16 0.07 0 41 5.4
--
DISCUSSIOK OF RESULTS
UNDERWOOD OXIDATIOSTESTS. The results obtained using the Underwood oxidation test are shown in Figures 2-5. Table I and Figure 2 show that 0.10 to 0.2070 selenium as selenium dioxide-2-ethylhexyl alcohol imparts powerful oxidation resistance to the motor oil. Comparative tests using different alcohols as the solvent for selenium dioxide are summarized in Table I1 and Figures 3 and 4. These data show that all the selenuim dioxide-alcohol solutions substantially increase the oxidation resistance of the base oil. At a concentration of 0.077, selenium, benzyl alcohol appears to be superior t o the other alcohols tested a t the same concentration. Similar comparisons a t a selenium content of 0 . 1 0 5 are summarized in Table 11 and are shown in Figure 4. At this higher concentration the differences between the various alcohols are not so marked. Butoxyethyl, n-butyl, and isobutyl are superior to benzyl alcohol as regards bearing corrosion.
Selenium Content of 0.15%
2-E thylhexyl n-Butyl Isobutyl Benzyl Benzyl 0.075 triDhenvlphbsphcte
Vol. 39, No. 11
0.0
24.0
5,4
truck nhich used S.A.E. 20 oil and ran for 6000 miles, chariying oils every 2000 miles. The properties of the drain oil wete determined after each change and the average of the three values recorded. The second field test n-as run in a 1934 Oldsniobile coiivcrtible coup6 immediately after the engine v,as overhauled. The oil x a s used for 2300 miles of driving without change or additions over a period of 3 months. The drain oil x a s then analyzed.
LEGEND .----VARIATIONS OF % Se ( A S S e O e B E N Z Y L ALCOHOL) I N PRESENCE OF 0.07% TRIPHENYLPHOSPHITE
0-
VARIATIONS OF % TRIPHENYLPHOSPHITE IN PRESENCE OF 0 . 1 0 S e ( A S S e 0 2 -
B E N Z Y L ALCOHOL)
, ,
W
I
3
D W m
CONRADSON CARBON RESIDUE
$
.z I.
\
z
0
m
, ,
?,
a
z
0 0. 0
3
*%
5
.OO
$ 0 2 .04 .06
-08 .IO
% ADDITIVE
.I2
.I4
.
I
.OO .02
I
.04 .06 .08
I
-10
% ADDITIVE
.I2
.I4
.
.02
I .04 .OS
I
.08 .IO
-...’.
I -12
.I4
.I6
% ADDITIVE
Figure 5. Ten-Hour Underwood Oxidation Tests with Combination of Selenium Dioxide-Benzyl Alcohol and Triphenylphosphite i n Pennsylvania lOW Base Oil
INDUSTRIAL AND ENGINEERING CHEMISTRY
November 1947
1471
The selenium dioxide-benzyl alcohol solution allowed rather high bearing cor' rosion. However, it is much less than the (Tests r u n a t Battelle Memorial I n s t i t u t e ) bearing corrosion of Pennsylvania 1011: Sludge, Viscosity base oil without additive. A survey by hfl./lO 121. Oil Acid No Increase :@eF&s:, Varnish Rating Georgi ( 5 ) shoved that there was no apEe, % 24 hr.b 4 8 h r . 72 h r 24 hr 48hr 72 h r . 48Hr. 24 hr. 4 8 h r . 72 hr parent correlation between the UnderSelenium Dioxide-Benzyl Alcohol Additive wood copper-lead bearing corrosion data 0 1 . 9 5 4.39 5.12 11.69 17.12 26.26 953 ;,5 E.0 and full scale Chevrolet engine results 00 .. 01 50 0 80 3 31 .. 37 05 42 .. 86 05 5 .. 73 73 1 7.62 431 using six reference oils ranging from very 0 .. 6 46 .. 8 8 96 11 0 12.88 185 6 2.0 2 0.50 4.19 8.20 10.70 0 15 1.50 2 . 0 5 221 6.5 5.5 5 stable to very unstable oils. I t has been 5.5 5.-5 10.80 143 10 0.25 0.00 1.05 1.90 1.93 6.69 found that the addition of small amounts Selenium Dioxide-Butyl Alcohol Additive of triphenylphosphite to the base oil 0.05 0.73 3.40 4.00 4.94 13.17 16.42 334 5.5 3 3 in conjunction with the selenium di3.85 5.41 13.98 14.33 373 6 4 3 0.78 3.30 0.10 oxide-benzyl alcohol substantially re1.96 8.77 11.82 188 10 5.5 5.5 0.00 1 , 5 0 2.53 0.15 0.25 0.00 0.60 2.05 0.63 3.55 12.20 165 10 10 10 duces the bearing corrosion and still maintains satisfactory values for the Viscosity increase not determined a t 24 and i2 hours of testing. h Testing time. other deterioration properties. The results of adding varying amounts of triphenylphosSTIRRISG OXID.4TION TESTS O F SELESIUM DIOXIDE-ALCOHOL IT TABLEI-. ISDI.AXA PESSSYLV.4SI.I 1olv O I L .IT 0.15% SELESIUlf COXTEST phite t'o an oil containing (Tests r u n a t Battelle Meinorial I n s t i t u t e ) 0.107, selenium as selenium Sludge, Viscosity Increase dioxide-benzyl alcohol are sumA I I . / l O MI. Oil .kcid No. Increase a t loODF., (7c Varnish Rating marized in Table I11 and Fig24 hr. 48 hr. 72 hr. 24 hr. 48 hr. 72 h r . Alcohol 24 hr.0 48 h r . 72 h r . 24 hr. 48 h r . 72 hr. 5 . These data indicate ure 2.46 6.35 4 1 . 6 109 225 10 9.5 9.5 0.00 0 . 5 3 1 35 0.29 Methyl Ethyl 0 . 0 0 0 . 9 5 1.70 1.10 5.15 7.74 5 6 . 6 140 271 10 that as little as 0.07% tri0 00 0 . 8 3 1 58 1.22 Propyl 5 1 . 4 145 245 10 6 64 5.67 Isopropyl 0 00 0 . 5 5 1 18 0.29 3.35 5,r2 35 1 102 233 10 9 ?,$ phenylphosphite. in conjuncButyl 0.00 1 50 2 5 3 1.96 8.77 11.80 188 10 5 , s 3.0 tion with 0.10'7, selenium as 5.10 7.75 5 i : 4 196 0 . 1 5 1 . 0 0 2.8.5 1.53 id0 10 9 8 Isobutyl 1',06 4 . 9 2 7.17 61.6 163 303 9.5 5.5 Amyl 0.30 1.15 1.93 4.5 selenium dioxide-benzyl alco4 3 3 9 7 . 4 2 . 7 8 5 . 1 7 212 10 8 7 . 5 0 . 0 5 0 . 5 0 1 . 3 5 0 . 7 5 Isoamyl 1.92 5.40 8.31 5 3 . 5 175 327 10 6 Methyl amyl 0 . 2 5 0.83 2 . 1 5 J hol reduces the bearing corro9.11 7 8 . 2 252 550 8 6.5 5 388 5.76 2-Ethylhexyl 0.58 1.50 2.98 10 sion to a satisfactory value. 5.92 8 6 . 6 1'27 10 0.61 3 33 36.2 10 Cndecyl 0 00 0 25 1 . 1 0 6.29 9.40 8 9 . 5 209 0.60 1.73 2.60 2.49 Tetradecyl 409 8 4 ~ ~ 111b andl ~i~~~~ ~ j Lauryl 0 . 1 0 0 . 9 0 2 00 2 05 4.57 7.15 5 3 . 6 177 351 10 ? , ? ?3 , 5 , Benzyl 0.50 1.50 2.05 4.19 8.20 10.70 . . 221 .., 6.5 a.o 0 summarize the results of addBase oil 1.95 4.39 5.12 11.69 17.12 26.26 , . 953 ... 8 4 5.0 of seing varying amounts Commercialoil.4 0.10 0.95 2.80 1 . 3 2 4 05 1 2 . 3 1 2 7 . 9 165 Solid 10 10 10 Pennsylvania l O K 0.80 3 . 5 5 6 . 5 0 5.50 1 5 . 3 9 2 0 . 8 5 .. 452 . ,, 1 1 1 lenium as selenium dioxidebase oil + 1% benzyl alcohol t o an oil coninhibitor A taining 0.07m0 triphefylphos0 Testing time. phite. These data indicate that a combination consisting EXGIUE T E ~ TOFS SELESIV\I-COST%ISISG TABLE VI. LAVSOK of 0.15% selenium as selenium PEXSSYLV.ASI.4 S.A.E. 30 OILS dioxide-benzyl alcohol and 0.07y0 triphenylphosphite imparts (Tests r u n in l a b o r a t o r y B ; used oil analysis) desirable resistance to deterioration t o the motor oil. Viscosity S e u - Conrad- S a p h t h a Se, T e s t , Increase, traliza- son Car- Insol., Table I1 summarizes the results obtained for a comparison of Additive % Hr. CC tion No. bon, % (70 benzyl alcohol, 2-ethylhesyl alcohol, n-butyl alcohol, and iso-
TABLEIV. INDIANA STIRRING OWDC TI ON TESTS OF SELENIUM DIOXIDE-BENZYL ALCOHOL ASD SELEKIUM DIOXIDE-BUTYL .kLCOHOL IK PENXSYLVANIA 1oiv O I L
0
g:! ;:p
S o n e (untreated oil) SeOz-benzyl alcohol SeOz-benzyl alcohol + 0 . 0 7 5 triphenylphosphite O.Oi%triphenylphosphite lco commercial inhibitor E PeOl-benzyl alcohol SeOz-2-ethylhexyl alcoho i
0:65 0.05
90 150 150
54,2 78.0 25.5
3.00 0.82 0.38
1.76 1.66
0.58
0.030 0.010 0,011
,.
150
49.5
2.55
1.29
0,090
, ,
150
39.5
0.38
1.30
0.108
0.10 0 10
120 90
65.5 45.3
0.95 0.46
1.65 1.11
0.050 0.002
TABLE YII.
ESGISETESTSO F SELENIUM-CONTAINING PESSSYLVASIA S.A.E. 30 OILS
L.4L-SON
(Tests r u n in l a b o r a t o r y B ; engine condition) Se,
Test,
None (untreated oil)
..
SeOa-benzyl alcohol
0.05
30 90 30 90 150 30 90 150
%
Additive
VIII. 66*/3-Hon~CHEVROLET ESGIKEOIL STABILITY TESTo s SELENIUM-CONTAINISG PENXSYLVAXIA S.A.E. 20 OIL
TABLE
(Tests r u n i n l a b o r a t o r y A) Composition of Oil Blends Pennsylvania S.A.E. 20 containing 0.15% Se as SeOzPennsylvania benzyl alcohbl & S.A.E. 20, 0.07% triphenylno additive phosphite Used oil analysis Viscosity a t 210' F. Keutralization N o . X a p b t h a insolubles, mg./lO g. Chloroform insolubles, mg./lO g. Conradson carbon, % Engine condition, grams loss Bearing corrosion T o p ring wear M i d ring wear Oil ring wear
+
SeOz-benzyl alcohol 0.07% triphenylphosphite 0.07% triphenylphosphite 1 R commercial inhibitor B
164 3.17 480 74.3 4.72 5 . 7 1 6 a t 38 hr. 0.064 0.024 0.400
70.2 1.15 37.2 2.50 2.78
,
1.684 0.068 0.046 0.091
SeOz-benzyl alcohol
SeO~-2-ethylhexyl alcohol
0.05
.. .. 0.10
0.10
Hr.
30 90 150 30 90 150
30
60 90 * 120 30 60 90
Pi-ton Skirt C
c
D
D D B/C BlC D B
C
D B
C D+
C
D D
C
C C
D
Bearing Rings Ring Loss, Stuck Filling Mg. 0 0 115 0 25 562 0 22 0 10 78 0 0 95 109 0 0 2 0 10 18 1 15 44 0 0 6 0 1; 15 0 o 193 0 0 6 0 0 27 0 0 99 0 0 10 0 5 20 1 25 44 1 60 118 0 0 1 0 45 14 0 60 20
INDUSTRIAL AND ENGINEERING CHEMISTRY
1472
T . ~ B L1s. E 36-HocR
CHEVROLET E N G I N E 011. S T I B I L I T Y TESTS O S ~ E I . F ~ S I ~ ~ \ l - ~ ' O S TOIbS .iISl~~
s -1.E 20 0Containing 1 5 7 Ye as SeO?-Benzyl .1lc. Lt 0.07% Triphenylphosphite''
1'2 ~~
1.sed Oil . i n a l p i s Viscosity increase a t 100' F., %
Neutralization S o .
Hours of Test
Pa. L L E . 20 Containing P a . S,.i.E, 20, 1.25% ConiNo Addn. niercial 111.$gent0 hibitor BIZ
~
0
18' i
. .
33.4
l3fi
16.4
8
0.02 0.21 0 28 0.33 0.43
... ... ...
... ..
16 24 36
7.3
0 :i
...
0 2 2 2 1
02 99 38 17 34
0 50 0 21 0 82 1 85 1 13
+
... ... ...
0
8 1G 24 36
Xlidcontinent Y.A.E. l,O, S o Additlveb
Ilidcontinent S.A.E. 10 0.15% Se as YeOr-Benzyl .1lc.b , .
..
. .
...
Vol. 39, NO. 11 hutyl alcohol at a concc'1:tration of 0,15rc selenium 4. selenium dioside-alcohol solutions. Thcse data indicate that butyl alcohol and imbutyl alcohol are as satisfartorv as the combination of selenium dioxide-benzyl alcohol and triphenylphosphite oii the basis of performance in the Underwood oxidation tt%ter. 1~111.is.4
STIRRISGOXIII.\-
TEST. Table I V arid .. 0 S a p h t h a insolubles, c7 6 summarize the r(-Figure .. ... 8 0.58 16 d t s obtained using this test 24 procedure when variou> 0'87 36 amountr of scllenium as sit... 0 Chloroforrii insolubles, C'r 8 lchniuni dioxide-benzyl alcohol 0 ' 43 0:i 2 0: 46 16 ... and selenuim dioxide-butyl 24 ... 0.48 0:88 0'80 36 alcohol are added to a 0.30 0.20 0.36 0 Conradson carbon, R Pennsylvania 10K base oil. ... 8 ,.. ... 0.96 2:31 1.05 16 These data show that selenuim ... ... ... 24 ... ... 1.76 2:75 2:i2 dioxide inhibits the osidatiori 36 0.718 0 160 of the base oil to a considrr0.224 2.57 (18hr.) 0.30 36 Bearing corrosion, grams loss able extent and that approsiinately 0.15 to 0.20C;, selenium a Test r u n in laboratory A . b Test r u n i p l a b o r a t o r y C . is t,he optimum quantity. Numerous other alcohols were used as the solvent for
