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measurement of the excess of a standardized Grignard solution, gave data for estimating groups which react with the Grignard reagent but do not liberate methane (IO). As applied to the analyses of complex mixtures such as an oxidation product of a higher hydrocarbon, the method was unsatisfactory. Hydrogenation of the oxidation products under hydrogen pressures of approximately 2000 pounds per square inch, using a copper chromite catalyst ( I ) , gave materials which reacted normally with the Grignard reagent. Data for these hydrogenated samples follow:
of a sooty carbonaceous suspension and was very low in part,iwl
oxidation products, acids, esters, and alcohols. ACKNOWLEDGMENT L
The authors wish t,o acknowledge the financial aid of thc Purdue Research Foundation. The assistance of W. E. Fish ana G. A. Hawkins in the design, const,ruction, and hydraulic tbstinp of the apparat>usis greatly apprcxsiated. LITERATURE CITED
Active Hydrogen, Mole/1000 Grains Sample 1 Sample 2 Average
Run No. 3 5 6
0.706 0.762 0.203 0.610
10
0.610 0.901
7 9
0.635
11
0.617 0.697
0.662
0.730
0.195
0.199
0.605 0.580
0.608
0.595
0.901 0.648
0.901
0,642
Complete analyses for functional groups were made on certain of the hydrogenated oxidation products, and the results are expressed as moles per kg. These data, along with the solubilities in concentrated sulfuric acid on a weight basis, allow calculation of the average molecular weight. The average molecular ~vt7ight~ of alcohols in the hydrogenated oxidation products follow: % b y Wt. Run No.
Voles per lie.
Sol. in
Coned. HzSOI
Temp. of Oxbd;t,ion.
Exposure Time, Nin.
~ 1 0 1 Wt. . of Oxygen
Com-
poundr-
We mere unsuccessful in carrying out a smooth oxidation of hexadecane a t 300” C. with air a t 2000 pounds per square inch gage. The react’ion under these conditions was characterized by minor explosions evidenced by ‘‘knocks” and oscillation of the pressure gage indicator. The product containpd large amounts
VOl. 37, No. 5
(1) Adkins, Homer, “Reactions of Hydrogen”, Univ. Wiu. Prech. 1937. (2) -4ssaf, A . G., and Gladding, E. K., IND.ENC.CHE 11, 164 (1939). ( 3 ) Assoc. of Official Agr. Chern., Methods of Analysis. 5 t h ed.. 1940. (4) Bittler, W.P., and James, .J. 8., Chsm. & M e t . Eny., 35, 1 % (1928). (5) Burwell, A . W., ISD.Ex(;.CHIQM., 26, 204 (1934). (6) Egloff. Gustav, Schaad, R. E., and Lowry. C. D . , I h i d . , 21, 7% (1929). (7) Ellis, Carleton, “Chemistry of Petroleum Derivatives”. \‘(>I, 1 and 11, New York, Reinhold Pub. Corp., 1937. (8) Hellt,haler, Theodor, 8,nd Peter, Erich, U. S.Patent 1.947.R)iW (1934). (9) Hentrich, Lainau, and Kaiser, f h i d . , 2,128,903 (1938). (10) Kohler, E. P., Stone, J. F., and Fuson, R. C., J . Am. C h e r r i Soc., 49, 3181 (1927). (11) Larsen, R. C., Thorpe. H. b;., and Armfield, F. A., I N D . bixcl CHEM.,34, 183 (1942). (12) Lecky, H. S., IND. ENG.Cfimr., AXIL. ED.,12, 544 (1940). (13) Luther and Dietrich, German Patent 564,208 (1929). (14) Niederl, J. B., and Niederl, Victor, “Organic Quaiitit,ati\ 1 Microanalysis”, h-ew York, John W i l e y & Sons,1938. (15) Pope, J. C., Dykstra, F. J., and Edgar, Graham, J . A m . (.‘hen*. SOC.,51, 1875, 2203 (1929). (16) Schaal, E., Brit. Patent 12.806 (Sept. 25, 1884); J . S O C . C h , u i n Ind., 4, 679 (1885). (17) WiBaevich, P. ,J., and Frolich. P. K., IND.EXG.CHB:M..26. 267 (1934). THISarticle contains material from t h e doctoral thesis of J. W. C h u r c h i l l
ROSIN ESTER DEVEL Richard
P. Carter
HERCULES POWDER COMPANY, WlLMlNGTON 99,DEL.
T
HE Synthetics Department of this company has specialized in the developmiout of modified and unmodified esters of rosin, and in four plants it manufactures sonw fifty different materials. Most of these esters are made in the same type of equipment, a high-t,emperature reaction vessel. The maximum reaction temperaturris usually about 300” C., which can be obtained by using a direct-fired or jacketed kettle, or a coil-containing vessel circulating hot, oil or employing Dowtherm vapor heating. Different products require different amounts of agitation-mild, violent, or’ none a t all; some are made under’pressure and others under vacuum. Some modifying agents are very volatile liquids, others are fusible solids. The resin pilot plan1 , therefore, must be flexible in order to duplicate plant conditions and to study V W I X tions in process and product. LABORATORY REACTORS
Figure I. One-Gallon Stainless Steel Resin Reactor
A new rosin ester or modification is first investigated in the laboratory. The nwt step frequently is the preparation of the ester in a one-gallon stainless steel, or other metal, reactor (Figure 1). This is the first approach t o pilot plant work, and here ic chosen the metal of construction for larger pilot, and final plant reaction vessels. Stii ring and rate of heating can be varied a t will. The reactor is heated by an air b a t ) ) in a n insulated container with a standard electrical ring heater at, the bottom. Thi, take-off condenser, as shown, can be made into a reflux condenser merely by putting ib stopper in the take-off outlet. Few engineering data can be had from a rosin esterification in the laboratory, b11r
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A
permanent setup is maintained b y Hercules for pilot plant development of new products derived through rosin esterification. The reactor capacity for this work ranges from 1 to 400 gallons. The unit process of a rosin esterification can be closely followed at eech stage b y a method of plotting whereby a straight line represents accurately the progress of the reaction in laboratory, pilot plant, and commercial plant operations. The development of a rosin ester to a full-size plant process by these means is achieved in the shortest possible time and with maximum control.
much useful basic information 011 the rcaction and the product will have been gained. The reaction rates at different temperatures can be determined under the most ideal conditions. S M A L L PILOT P L A N T SCALE
A number of small pilot plant reaction vessels are available for the next step. The materials of construction are varied, consisting of stainless steel, aluminum, nickel, and glass-lined steel: capacities are about 25 t o 50 gallons. These reactors approach in size the smaller commercial units, and from their operation engineering data can be obtained. Two of these reactors are shown in Figure 2. This equipment is flexible in respect to typev a i d speeds of stirring. The pressure in the reactors can be either subor superatmospheric; inert gas can be applied to blanket the reaction mixture, or a n inert gas sparge ran be employed.
Figure 2.
Small Pilot Plant Reactors
At this stage of the development a given rosin esterification is studied critically to determine the proper operating conditions for duplicating or improving upon the previously made laboratory product. It frequently happens, for instance, t h a t in going up from laboratory-size equipment the color of the resin improves, primarily because of decreased ratio of surface t o volume. The rate of up-heat and the proper temperature a t which modifying agents should be added t o rosin esters are important and are determined txs carefully as possible on equipment of this size. Heating by either electricity or circulating oil is automatically controlled. A portion of the control panel can be seen in the rear of the reactors of Figure 2. Any given heating rate, therefore, can be followed, and desired reaction temperatures can be closely duplicated. The reaction 'rate is studied, and if it is not up to the value which wm predicted in the laboratory, conditions are investigated t o effect ?n improvement. After t h e new rosin ester has been made in the small pilot plant vessel, samples of the product may be sent t o the trade for evaluation and recommendations, or may be tested for further uses b y Hercules exclusively. If reports from this work are promising, the development is carried to the next step. L A R G E PILOT PLANT SCALE
Figure 3.
General V i e w of Large Scale Pilot Plant
The next stage involves the preparation of the resin in 400-gallon r e a c t o r s . O n e of t h e u n i t s c a n be seen in the background
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