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INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 39, No. 9
The results on GR-S (Figure 3) indicated that copper naphthenate caused a serious loss of strength when incorporated into Natural Rubber GR-H. Tensile and tear strengths were materially reduced, and ured 20 hlin. GR-S (Cured 35 Keoprene (Cured 20 “at 300’ F.) Rlin. a t 300° F.) hIin. a t 300’ F.) elongation at break rvas increased. The copper naphthenate had Parts Parts Parts Component by w t . Component by art. Component by w t . a considerable retarding effect on the rate of cure of GR-S. The vulcanized slabs were soft and tacky when i,emoved from the Smokedsheet IO0 0 GR-S, 100.0 Seoprene GN-A 100.0 2.0 Reogen Stearic acid 2.0 XLC magnesia 4.0 mold. Very little resilience, or snap, was observed. This test 3.0 , Stearic acid Zinc oxide 5.0 Stearic acid 0.5 Pine tar 1 0 E P C black 50.0 E P C black 30.0 was made on a GR-S vulcanizate containing 2y0 fungicide. Xeozone U 1.0 Sulfur 2 0 Neoeone D 2.0 5.0 Zinc oxide Altax 0.75 Accelerator 552 0.1 Uther ksts on specimens containing 1 and 0.5y0fungicide indi50.0 E P C black Rarak 1.0 Zinc oxide 5.0 cated a considerably lesser and progressively decreasing effect. 3.0 Sulfur Fungicide 2,0 Fungiride 2 (1 Altax 2.0 1’5-ridyl mercuric stearate had a very slight injurious vffect on Thionex 0.2 Fungicide 2.0 GR-S. Salicylanilide, pentvchlorophenol, and 2,2’-nictthylenetiia(~-clilor~iphenoIj had little or no adverse effect on tho piiysical properties of GR-S. visual evidence of fungus growth vivas observed. Thereforf~,I t Tlie results of tests on Scoprene (Figure 4j iudicatcd that appeared t h a t no fungicide was necessary for the protection uf pyritiyl mercuric stearate, salicylanilide, pentachlorophorlol, and the vulcanizates themselves. 2,2‘-ineth-lrne-bis(i-chlorophenol) caused no measurable loss of teiisili. strength (nithin the limits of ex$drimental e ~ , r o r )aiid , only E F F E C T OF FUNGICIDES x w r y slight reduction of tear strength. Copper ntipht lienate T h e test results suniniarized in Figure 2 shoa that rioiie 01 the raused an appreciable loss of tensile strength after aging, but fungicides tested had any appieciable effect on the unaged n ~ t u ~ a l xpparc~ntlyproduced an increase in the ultimate c~longationand rubber test specimens. However, test specimens containing copI cwiiig sfrerigtli. ;wr naphthenate appeared to age more rapidly in the oxygen bomb test. T h e rubber became much stiffer, as evidenced by t!ie LITERATURE C I T E D sharp decrease in elongation a t break. Tear strength was considerably reduced. Thw it seemed probably that fabrics treated (1) c‘ookc, T. F., aiid Vicklund, R. E., IXD. ENG.Camr., NIL. ED., 18,59-60 (1946). wjth copper naphthenate and having a natural rubber contiiig ( 2 ) Grenthouse. G . -4., and Ames, L. h l . , A1fycologia, 37, KO.1, 138might be expected t o crack when used after lengthy periods o f 55 (1945). storage. Pyridyl mercuric stearate, salicylanilide, pentacliloiophenol, and 2,2’-niethylene-bis(4-chlorophenol)had little or no adverse effect on natural rubber.
TABLE I. COMPOLTDISG FORMULAS
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TESTING OF CRACKING CATALYSTS 31. E. CON” Esso Laboratories, Baton Rouge, La.
T
HE catalyst is one of the paramount factors
.V. .I.
A
fixed Led method for testing craching catal>ats is described, and data are gi’en to iudicate how the test results were applied to show the effect of cataljst qualit? 011jields in fluid ratal>st crac.hing iinits. Craching acti5ity expressed as throughput for a g i \ e n con\erhion ib b e a r with surface area for catal? cts of a gi\en c~hemicalcomposition. Carbon formation i s increased when the catalyst has or acquires dehldrogenatiug properties. i d \ antages and disad\antages of \arious t>f)csof testiiirr uuits are discussed.
in determining the rate of the formation of the various products in a given catalytic process. Furthermore catalysts are notoriously busceptible to changm which mav appear small and are -often difficult to predict, but which have a profound effect on production. These factors are important in catalytic cracking as in other cw!alytic proceaws; hence, early in the developnierit of catalytic cracking it becanic desirable t o devise a small laborator?- scde test t o niea3ure catalyst quality quickly. More important than this was the requirement, for evaluating thc effects of preparatiou variables on catalJ-st quality and evaluatiilg the effects of changes of catalyst quality occurring during use in catalytic criicliing e,quipment. Consequently a test unit of the fixed-bed type was designed, constructed, and operated t o test simultaneously four small samples of catalyst (generally 200 cc.) in four KS,S tubes supported in a n electrically heated aluminum-bronze block. Other such units have since been constructed, and have been employed for investigating a wide variety of reactions and for studying I
G. C. COSNOLLY Esso Laboratories, Elizubeth,
Present address, Esso Laboratories, Elizabeth, N. J.
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tl1roug!1’ the 2- a f l d 100I)arrelr-per-day 1Jilo: plant stages to the u)iniiii:rciaI x:ile plaiits havc bcvii previously tlcscriljed ( 2 , J ) . 1)iii,ing this devolopilli~nt,il l l t l ince tlic coninicrrid j i l m t . ~h:i\.e t i i ~ ~ inn operation, c:ctniyct sariiplcs hrire been rciiiu\-c,il fro111t i i i i ( ’ I II time aiid teetcd in the 200-cc. test unitb in order t u dctcrnii1lc wtalyst qu:ilit,y. The infomiation gained in tliia n.ay !itis h r r o i i i i ful in TIE design and operntion of fluid catalyst equipnir:nt. Tlie siniilaritics and diffcrencc>sbct\rc.iin fiscd-bcd crtLrking (as in the test metliotl) and fluid catalyst crackirig from Tvhich the test sample:: arc talicn were discusscd in a previous paper (5). I n this paper the general methods for espressiiig coriyeraions and yields rvere described and defined, arid the rariables affccting conversion and yields, particularly of carbou, ryere also defined and discussed. The purpose of this paper is t o describe the test apparatus, the test proredure, the pilling and pretreating of the catalyst samplea,
September 1947
and to illustrate the application of the trst data to fluid catalyst operations. EQUIPMENT
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
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PYREX BEADS Figure 1 is a fiow shwr slioning one of four testing GAS METER systems Ivliich are operated in REACTOR TUBE parallel to test four saniples simultaneously. T h e four reactors are heated in a single cor, H20 8 ALCOHOL alnininum-bronze block (about
