October 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
For many years hydrogen peroxide has been produced, stored, and shipped in aluminum alloys (9). Of recent interest is the approval by the Interstate Commerce Commission of extending the range of concentration of hydrogen peroxide which may be shipped in aluminum drums meeting Specification 42-D. The upper concentration limit now set by the Interstate Commerce Commission is 52% hydrogen peroxide. An unusual application of light metals in Europe is a container fabricated from a magnesium-base alloy for the transporting of elemental bromine (32). The use of aluminum alloys for sealed containers replacing tin plate as a material for the packaging of foods has continued to grow since the late war (19-11). The greatest application of aluminum for this purpose has been achieved in Norway (21-24, 27). The wide variety of products now available in aluminum alloy cans (30,34) includes fish products such as sardines, fish fillets, fish balls, fish cakes, crab, shrimp, and anchovies, and, in addition, cheese, condensed milk, carrots, cauliflower, peas, beans, meat cakes, beef, mutton, and liver. In most cases it is advisable a t least to anodize the cans, and for many of these products also to employ an organic coating. This general precaution applies as well to fruits, berries, and jam. Food processing equipment of larger sizes than in the past has recently been fabricated of aluminum alloys: industrial butter churns; large buckets for handling meat and fish products; massive boiling pans; aluminum hand trucks for the conveyance of fruit juices, margarine, butter, cheese, and dough; large milk storage tanks; and shipping and handling containers for flour (14, 16,251, 28). Many producers of maple sugar are now using aluminum tapping pegs and pails, large aluminum storage containers, and evaporators to gather and prepare maple sugar and sirup ( 2 ) . An interesting development in the light metal field has been the use of magnesium-base alloy cooking utensils. Frying pans fabricated from cast magnesium-base alloys and griddles drawn from magnesium-base alloys are now on the market (35, 18). Figure 2 illustrates another application of aluminum which has gained widespread importance in many chemical, petrochemical, and petroleum refining industries. This new application is the use of aluminurn alloy sheet to weatherproof thermal insulation on piping and towers containing hot fluids or gases
(35).
2097
LITERATURE CITED
(1) (2) (3) (4)
Alcan Ingot, 8 , 4 (March 25, 1949). Ibid., p. 7.
Aluminum Research Laboratories, unpublished data. Anrilotte, W. F., “Preparation and Reaction of Acrolein,” U.S.Dept.Commerce, F I A T F i n a l R e p t . 1157 (Jan. 21,1948). (5) Balash, J. P., and Verink, E. D., Jr., Chem. Eng., 55,236 (February 1948). (6) Bludworth, J. E., Petroleum Processing, 4, 377 (April 1949). ENQ.CHEX, 40, (7) Brown, R. H., and Verink, E. D., Jr., IND. 1776 (1948). (8) Chem. Eng., 55, 99 (November 1948). (9) Ibid., p. 105. (10) Ibid., p. 106. (11) Ibid., 56, 92 (January 1949). (12) Chem. Inds., 63,585 (April 1948). (13) Clough, H., “Manufacture of Formaldehyde at I. G. Farbcri.” B I O S Final Rept. 1788, Item 22, British Intelligence Objectives Sub-committee, H M. Stationery Office (hlay 26- 27, 1948). (14) Food Inds., 20, 1281 (1948). (15) G.E. Welding Arc Mag., 3 (February 1949). ENG. CHEiu., 40, 1946 (1948) (16) Kaplan, N., and Andrus, R. J., IND. (17) Lee, J. A., Chem. Eng., 55, 129 (November 1948). (18) Ibid., p. 132. (19) Light Metals, 5, 426 (1942). (20) Ibid., p. 470. (21) Ibid., p. 526. (22) Ibid., 6, 137 (1943). (23) Ibid., p. 250. (24) Ibid., 7, 107 (1944). (25) Ibid., 8, 662 (1945). (26) Ibid., 9, 111 (1946). (27) Ibid., p. 206. (28) Ibid., p. 236. (29) Ibid., 10, 57 (1947). 130) Ibid., 11, 115 (1948). (31) Ihid., pp. 123-4. 132) Ibid.,p. 195. 133) IIcCauhn, L. S., Jr., Oil & Gas J . , 47, 72 (Dec. 23, 1948). (34) l f o d e r n Packaging, 21, 134 (April 1948). (35) Petioleum Processing, 4, 65 (January 1949). (36) Petroleum Refiner, 28, 145 (April 1949). (37) Sands, G. d.,IND.ENG.CHIEM., 40, 1937 (1948). (38) Wood, W. L., “Production of Acetaldehyde, Acetic Acid, Acetic Anhydride, and Acetone from -4cetylene at Bunamerke, Schkopau,” Rind Rept. 75, Item 22, British Intelligence Objectives Sub-committee, London, H.M. Statioriery ~
Offire. R E C E EI D~ J u l y 29, 1949.
__
Carbon and Graphite
C. E . FORD, National
-
____
~
_
_
Carbon
C o m p a n y , Inc., Cleveland, Ohio
T
HE developments and applications of carbon, graphite, and impervious carbon and graphite in the chemical industry during the wartime period were summarized in the 1947 review of “Chemical Engineering Materials of Construction” (11). The scope of this article is to supplement the original review with a summary of the contributions to the literature and the more important developments during the past 2 years. Because of the overlapping uses of both the permeable and impervious forms of carbon and graphite the materials will be considered simultaneously. GENERAL PROPERTIES
The latest information on the physical and mechanical properties, chemical resistance, available forms, methods of fabrication, and types of equipment of carbon, graphite, and impervious
carbon and graphite is presented in a 1948 tabulation (15) of numerical data and related individual facts concerning chemical engineering materials of construction. Williams (34) offers a British viewpoint in a brief discussion of the physical and chemical properties of carbon and impervious carbon and graphite and details their use as bearings, brick, pipe and fittings, and similar items. APPLICATIONS
Metal Finishing. The use of impervious graphite heat exchangers as heaters and coolers for pickling, etching, plating, and cleaning solutions is recommended in a recent review (6)of mctal finishing procedures. A survey (6) of three new stainless steel pickling installations on the West Coast states that carbon brick was selected for lining the pickling tanks because it was the mate-
_
2098
INDUSTRIAL AND ENGINEERING CHEMISTRY
Parts of Pilot Plant for Produrtion of Chlorinated Hydrocarbons Karhate equipment in romplete plant includes fractionating column, concentric coolers, pump, valves, and piping
rial most capable of withstanding the nitric-hydrofluoric acid solutions. Details of the installations of impervious graphite plate type heat exchangers used to heat the solutions arc described. Another recent article .(S),*describing a new process for the internal pickling of low carbon steel pipe by continuous flow of pickling solutions through the pipe, stresses the use of carbon anti impervious graphite for handling the caustic soda, hydrofluoric acid, and sulfuric acid solutions employed. Floors and storage tanks are lined with carbon brick. Acid solutions are mol ed through impervious graphite pumps, piping, and heat exchangers. The caustic soda and rinses are heated by the direct introduction of steam through porous carbon diffuser elements. Fischrupp (10,, discussing the electroplating of telephone swit,ching apparatus, mentions the use of impervious graphite immersion type heaters for inhibited hydrochloric acid and the maintenance of constant temperature of nickel-plating solutions by circulating them through heat exchangers of the same material. Phosphoric Acid. The use of a water-cooled graphite combustion chamber followed by a graphite shell-and-tube gas cooler beta-een the combustion chamber and the carbon brick-lined hydrator is reported by Almond and Steinbiss ( 1 ) to produce a more concentrated acid with less operating trouble, less corrosion, and less maintenance. The cooler reduces the amount of n-ater sprayed into the hydrator and permits a reduction in the size of electrostatic precipitator required (50). Gas is discharged from the precipitator to the stack by a fan with a specially constructed carbon housing. Several other similar phosphoric acid systems are in operation and operators report excellent resistance of carbon and graphite to hot phosphorus pentoxide vapors. Corrosion studies (50) on materials for lining and packing towers for production of superphosphoric acid list carbon and graphite as the most suitable of all materials tested. Atwell (9) describes the use of impervious graphite tube evaporators for the concentration of phosphoric acid from 32 to 36% P P O ~ .
Vol. 41, No. 10
Sulfuric Acid. The resistance of carbon, graphite, and impervious carbon and graphite t o the corrosive action of all but the most highly oxidizing concentrations of sulfuric acid solutions and of mixtures of sulfuric acid and other corrosive agents is discussed by Palmquist (85). He states that over four miles of impervious graphite tubes are in use in tube bundle heat exchangcrs as external boilers for the evaporation of ethyl alcohol and ethyl ether from a water solution of sulfuric acid. The successful use of graphite linings, trays, and bubble caps in towers for scrubbing organic rapors containing sulfur dioxide and sulfuric acid mists with dilute caustic solutions is detailed. Fricnd ( 1 2 ) touches on the m e of lead-lined and carbon-lined pipe for the handling of hot 40 to 60% sulfuric acid in the recovery of alkylation acid. Hydrochloric Acid. In a general review of carbon and graphite materials in hydrocliloric acid service Gaylord (14) states that more hydrogen chloride is being absorbed in equipment employing impervious graphite tubes or towers than all other construction materials combined. He also describes a typical system for the production of high purity anhydrous hydrogen chloride from ram wet chlorine-caustic cell gases which employs a vertical water-cooled graphite combustion chamber and an impervious graphite falling film type absorber, stripping tower, reboiler, condenser, and pump. The complete chemical inertness of both the permeable and impervious forms of carbon and graphite to all concentrations of hydrochloric acid is &ressed. I n a discussion of materials of construction for Mannheim hydrochloric acid plants, Armstrong (8) also describes the use of impervious graphite cooler absorbers, stripper towers, reboilers, and condensers, and comments favorably on the ease of maintenance of impervious graphite equipment. The use of impervious graphite water-cooled absorption toners is reported by Oldershaw (24) and co-workers in a paper on the ahsorption and purification of hydrogen chloride from chlorination of hydrocarbons. Maude (200) brings out some of the uses of graphite and impervious graphite in the production of synthetic hydrogen chloride, such as combustion chambers for l\-et gases, gas coolers, and pipe linings. A report ( 1 7 ) on a pilot plant operation of the Deacon process for the oxidation of hydrogen chloride tells of the use of a double pipe impervious graphite cooler for the concentrated hydrochloric acid from the product gas cooler a.nd an impervious graphite tower product gas absorber. Nitric Acid. Carbon is generally preferred to graphite for use in nitric acid solutions. HoJvever, despite the slow progressive attack that may be expected on impervious graphite, a life of several years has been obtained v i t h this type equipment operating in solutions of 10 and 40% nitric acid at 185" and 140" F., respectively (IS). Hydrofluoric Acid and Fluorides. I n a recent report ( 2 ) on materials of construction used for hydrofluoric acid manufacture, weak acid coolers of conventional water-sprayed impervious graphite coils and pumps for acid under SO% concentration are described. Graphite crucibles are operated a t 950" C. in the decomposition of ammonium beryllium fluoride into beryllium fluoride and ammonium fluoride (28). The beryllium producing reaction is also carried out in graphite crucibles. Alcohols. Rcvilock ( 2 7 ) points out the successful use of carbon, graphite, and impervious graphite in ethyl, methyl, isopropyl, butyl, amyl, octyl, and other aliphatic alcohols and emphasizes the resistance of these materials to the more severe corrosive action of the chlorinated derivatives of these alcohols. He d s o reports on an installation of impervious graphite trays and bubble caps for the stripping and scrubbing operations in the concentrated sulfuric acid process for the production of ethyl alcohol from ethylene (7). Fatty Acids. Impervious graphite tube heat exchangers are used for the concentration of lactic acid to L5070strength with no
2099
INDUSTRIAL AND ENGINEERING CHEMISTRY
October 1949
evidence of chemical attack after 4 years of service (66). The condensers on this operation are also impervious graphite tube he:rt exchangers. Impervious graphite pumps and heat exchangers are reported m chemically satisfactory for evaporation of levulinic acid (26). Chlorine, Sulfur Dioxide, and Sodium Chloride. I n a series of reports on the corrosion resistance of carbon and graphite, Werking (31-33) makes the following observations:
1. Carbon. graphite, and impervious graphite are unattacked by dry chlorine, but their behavior in hypochlorous acid is more variable, ranging from no attack to rapid oxidation. 2. An exrelltnt esamp!e of the resistance of carbon and graphite tu sulfur dioxide is their use as elements in wet flue gas scrubbers for 10 years with no corrosion observed. 3. Carbon, graphite, and impervious graphite are not attacked by sodium chloride, either dry or aqueous solutions. Impervious graphite heat exchangers are universally applicable for rooling operations u4ng sea water as the coolant.
22" B6. hydrochloric acid is available as a packaged unit complete with all accessories for automatic operation (4, 22). The absorber, which operates most efficiently on gases of 40 to 100% hydrogen chloride content, is 21.5 feet high and occupies a floor space approximately 3 X 4 feet. Hydrogen Chloride Synthesis. Graphite combustion chambers for the burning of hydrogen and chlorine have been developed in standard sizes ranging from 12 to 33 inches inside diameter and having capacities from 250 to 1660 pounds per hour of chlorine, respectively ( 2 3 ) . The combustion chamber is a vertical graphite tower with external water cooling. An impervious graphite burner nozzle is inserted vertically through the tower bot'tom. The equipment is especially suited for burning wet gases. Heat Exchangers. The 5senson Evaporator Coxnpany has patented a tube anc!iorage consisting of a ring-gasketed joint for mounting impervious graphite tubes in tube sheets of lead, leadcovered stec!, rubber-covered steel, or corrosion resistant alloy (291.
PROCESS EQUIPMENT DEVELOPRIEXT
Filters. The satisfactory use of porous carbon tubes in hdams filters for the removal of phosphate rock dust, fine Florida sand, and calcium sulfate from molten sulfur is reported by Lee (19). The filter shell is steam-jacketed and the tubes are cleaned by backx-ashing with steam. Jet Pumps. Jackson ( I S ) , in discussing the selection and use of vjectors, describes the construction of carbon ejectors enclosed in metal casings. The carbon parts are used as a core and an external sleeve of cast iron is cast around the unit. I n larger sizes, 1 he esternal casing is usually made of cast lead. Richelsen (28) has tahulated the critical criteria of construction materials for iet p u n i y Inipervious carbon and graphite materials are rated as good to excellent on such properties as resistance to t Lernia! shock, rehistance to erosion, machinability to close toki anws, flexibility of design, corrosion resistance, and comparat iT,e price practicality. Textile Machinery. The use of impervious graphite in the fabrication of those parts of textile machinery subjected to corrosive action is increasing. Impervious graphite is light weight, easily machined to intricate shapes, dimensionally stable under wide temperature changes, and resistant to chemical attack. Sulfuric Acid Dilution. h system for the efficient production of cool, dilute sulfuric acid from the required quantities of commercia! strength acid and diluting water has been developed ($1). An impervious graphite mixing fitting of simple design for mixing the acid and water is connected to an impervious graphite cascade type cooler which removes the heat of dilution. The reactants arc contained in a closed system and no dilute acid pump is required. The equipment is adaptable to fully automatic control. Hydrochloric Acid Absorption. An impervious graphite fallingfilmytype absorber for producing 2.5 to 16 tons per day of 20" to
LITERATURE CITED
(1) Almond, 1,. H., and Steinbiss, 13. K., Clirni. Eng., 55 ( I O ) , 105
(1948). ( 2 ) Anon., Chem. Eng., 55 ( l l ) , 104 (1948). (3) Anon., Iron Steel Engr., 25,102 (1948). (4) dnon., Rayon Textile X o n t h l y , 30 (3), 98 (1949). ( 5 ) Anon., Steel, 122 (23), 106 (1948). ( 6 ) Anon., Ibid., 123 (51, 101 (1948). (7) .4ries, R. S., Petroleum Refiner, 27 (4), 124 (1915j. (8) Arrnstrong. W.F., Chem. Eng., 54 ( S ) , 96 (1947).
(9) (10) (11) (12)
Atwell, James, IXD.EXG.CHEM.,41,1323 (1949). Fischrupp. C. R., Steel, 124 (la), 102 (1949). Ford, C. E., ISD. Esa. CHEJI.,39, 1202 (1947). Friend, W.Z., CorTosion, 4 (3), 101 (1945). (13) Gaylord, W. M., Chem. Eng., 55 (3), 225 (1948). (14) Ibid., 56 (l),231 (1949). ENG.CHEM.,40, 1821 (1948). (15) IND. (16) Jackson, D. H., Chem. Eng. Progress, 44 ( 5 ) , 347 (1948). (17) Johnstone, H. F., Ibid., (Y), p. 657. (18) Kjellgren, B. R., J . Electrochem. SOC.,93,122 (1948). (19) Lee, J. A . , Chem. Eng., 55 (4), 119 (1948). (20) Maude, A. H., Chem. Eng. Progress, 44 (3), 179 (194s). (21) National Carbon Co., Inc., New York, N. Y.,Tech. Bull. M8806-A. (22) Ibid., M-9600. (23) Ibid., M-9602. (24) Oldershaw, C. F., Sirnenson, L., Brow!. T., and Radcliffe, F., Chem. Eng. Progress, 43 (7), 371 (1!:47). ( 2 5 ) Palmquist, W.W., Chem. Eng., 55 (6), 226 (1948). (26) Ibid., 56 (4),217 (1949). (27) Revilock, J. F., Ibid., 55 (101,236 (1948). (28) Richelsen, Mark, I b i d . , ( R ) , p. 114. CHEM.,41 ( 5 ) , 14.4 (1949). (29) Swenson Evaporator Co.. ISD.LXG. (30) Tennessee Valley Authority, Chemical Engineering Report KO. 2 (1948). (31) Werking, L. C., C h r m . Eng., 54 (2), 226 (1948). (32) Ibid., 54 (9). 222 (1947). (33) Ibid., ( l l ) , p. 217. (34) Williams, A. E., Chpm. Age, 58,234 (1948). RECEIVED J u l y 14, 1949
RING GASKETS
/
TUBE SHEET
-
TUBE (METAL OR CARBON ) COURTESY SWENSON EVAPORATOR COMPANY
Carbon-Tube Heat Exchangers
