INDUSTRIAL AND ENGINEERING CHEMISTRY
1998
(24i) Laidler, Keith J., J . P h y s . & CoEloid Chem., 55, 1067-78 (1961). ( 2 5 ) McCabe, Charles L., and Halsey, G. D., Jr., J . Ana. Chem. SOC.,74, 2732-4 (1952). (26i) Perminov, P. S., Orlov, A. 4.,and Frumkin, A. N., Doklady A k a d . Nauk S.S.S.R., 84,749-52 (1952). (27i) Permitina, N. G., and Shlygin, A. I., Zhur. F i z . Khim., 26, 874-7 (1952). (2%) Raik, S. E., Vestnik Moskon. U&., 6, S o . 2, Sei. F k - M a t . i Estestwen. N a u k , No. 1, 67-75 (1951). (29i) Roof, Raymond B., Jr., J . Chem. Phys., 20, 1181-2 (1952). (30i) Schuit, G. C. A., and De Boer, 21'. H., Nature, 168, 1040-1 (1951). (31i) Schuit, G. C. A,, and De Boer, N. H., Rec. trav. chint., 70, 1067-84 (1951). (In English.) (3%) Sokol'skii, D. V., Doklady A k a d . S a u k S.S.S.R., 79, 823-6 (1951). Ibid., 83, 873-5 (1952). (33i) Sokol'skii, D. V., and Popov, 0. S., (34i) Taylor, T. I.,and Dibeler, V. H., J . Phys. & Colloid Chem., 55, 1036-66 (1951). (35i) Turkevich, John, Schissler, Donald O., and Irsa, Peter, Ibid., 1078-84 (1951). ( 3 6 ) Vandael, C., Industrie chim. belge, 17, 581-5 (1952). (375) Voevodskii, V. V., Lavrovskaya, G. K., and Nardaleishvili, R. E., Doklady Akad. Nauk S.S.S.R., 81, 215-18 (1951).
m$
Vol. 45, No. 9
(3%) Wiberg, Egon, and Jahn, Arthur, 2. Naturforsch, 76, 581 (1952). (39i) Winfield, hl. E., A u s t r a l i a n J . Sei. Research, A4, 385-405 (1951). MISCELLANEOUS
Compagnie francaise de raffinage, Franch Patent 973,251 (Feb. 9, 1951). Ibid., 973,624 (Feb. 13, 1951). Dawson, J. K., Ingram, D. W., and Bircumsham, L. L., J . Chem. SOC.,1950, 1421-2. Egerton, -4lfred C., and Warren, D. R., P r o c . Roy. SOC. (London),A204, 465-76 (1951). Kleinert, Th., Monatsh., 83, 623-8 (1952). Mockel, Peter, Chem.-lng.-Tech., 24, 153-4 (1952). Rosenblatt, Edgar F. (to Baker & Co., Inc.), U. 5. Patent 2,582,885 (Jan. 15, 1952). J . Gen. illicrobiol., 6 , 329-35 (1952). Schatz, 8., Vandenheuvel, F. A., Anal. Chem., 24, 847-51 (1952). Wagner, Geo. H., and Erickson, Charles E. (to Union Carbide & Carbon Corp.), U. S. Patent 2,595,620 (May 6 , 1952). Waller, hlilton A I . (to Baker Br Co., Inc.), Ibid., 2,577,720 (Dee. 4 , 1951). Wheeley, Edvard Alfred, and Imperial Chemical Industries Ltd., Brit, Patent 671,421 (AIay 7 , 1962).
NITRATION WILLARD
dec.
CRATER
HERCULES POWDER COMPANY, WILMINGTON, DEL.
O n l y a few articles were published during the past year on nitration processes. The Biazzi continuous nitration unit remains of interest and the first such unit in the United States for the manufacture of nitroglycerin was put in operation this past spring at an explosives factory near Martinsburg, W. V a . Also four such units have been purchased by the Navy for installation. The nitration of amines continues to be interesting, particularly the production of cyclonite and nitroguanidine. Investigations of mechanism and kinetics of nitration reactions remain active.
A
S I N the past years this review covers nitration processes in
their broadest sense-that is, the treatment of organic compounds with nitric acid or its equivalent to give either nitrates or nitro compounds: The data presented cover those articles and patents which have been made available since the previous review.
NITRIC ACID ESTERS Continuous nitration units remain of interest and the first such unit for the manufacture of nitroglycerin in the United States has been placed in operation by the Du Pont Co. in a new explosives factory near Martinsburg, ITr. Va. Thiq is a Biazzi unit einiilar to that described and illustrated in the 1952 review (9). The economies and safety advantages of the Biazzi continuous nitration process over the batch process are discussed in an anonymous article (8) published in Chemical Engineering. According to this article, in addition to the unit installed by Du Pont, the Navy has purchased four such units, two of which are to be installed a t Indian Head, Md., and one to be installed a t Radford, S7a. The nitration of cellulose (cotton linters) with acetyl nitrate and also with mixtures of nitric acid and acetic anhydride was investigated by Chedin and Tribout ('7'). The reaction shows clearly the nonpenetrability of dry fibers by nitrating agents. Preliminary treatment (activation of the cellulose, previous partial nitration) allows the reagent to penetrate into the fibrous structures and to react. This appears to be a continuation of the work previously reported by Chedin and referred to in last vear's review (9).
NITRO COMPOUNDS A study of process variables affecb ing the yield of mononitrobenzenes
has been made by Kobe and Mills (16). The variables investigated include the ratio of sulfuric acid t o benzene; concentration of the sulfuric acid; temperature of nitration; concentration of nitric acid; ratio of nitric acid t o benzene; and time of nitration. According to the data presented, a 98% yield of mononitrobenzene has been attained under the nitrating conditions : sulfuric acid t o benzene, weight ratio 1.2; concentration of sulfuric acid 84.0%; nitric acid to benzene, mole ratio 1.0; temperature 60' C.; and a nitrating time of 40 minutes. Graphs are included showing the effect on yield of changing the variables. Kobe and Pritchett ( 1 6 ) investigated the nitration variables affecting the production of mononitro-o-xylene. The variables studied are the ratio of sulfuric acid to xylene; acid concentrat,ion; temperature; ratio of nitric acid to xylene; and time of nitration, A yield of about 90% mononitro-o-xylenes is reported for the optimum nitrating conditions set up and the mixture cont,ained about 58% 3-nitro- and 42% 4-nitro-o-xylene, The effect of changing the variables on yield is shown graphically. -4 process for the manufacture of tetryl (trinitrophenylmethylnitramine) was patented by Desseigne ( I O ) . The process comprises reacting dinitrochlorobenzene with an amine or a mixture of amines and then nitrating the product to give tet'ryl. French patent 972,694 specifies using dimethylamine or a mixture of methyl- and dimethylamines while 972,695 specifies using a crude ammoniacal solution containing dimethyl- or trimethylamine. Also see Brit'ish patents 655,707 and 655,708. The latter patent was referred t o in last year's review (9). A process for the preparation of 2,6-dinitrophenol is described by Phillips (18). The process compyises the nitration of 3-nitro4-hydroxyphenylarsonic acid t o give 3,5-dinitro-4-hydroxy-
September 1953
INDUSTRIAL AND ENGINEERING CHEMISTRY
phenylarsonic acid and its subsequent de-arsonication by treatment with sodium bisulfite to give 2,6-dinitrophenol.
NITROAMINES CYCLONITE
c
Factors affecting the nitration of hexamethylenetetramine to give cyclonite continue t o be of interest. Epstein and Winkler (IS) investigated the variables which influence the reactions to form cyclotrimethylenetrinitramine (cyclonite or R D X ) and cyclotetramethylenetetranitramine (HMX) by the nitration of hexamine by the Bachmann process. Variables studied include the effect of dilution of acetic anhydride; the effect of ammonium nitrate on the optimum nitric acid mole ratio; the effect of acetic anhydride on relative yields and initial rates of formation; and the effect of delayed addition of ammonium nitrate on relative yields for the production of cyclonite and HMX. The withholding of the ammonium nitrate from the reaction was found t o have a more deleterious effect on cyclonite production than on HMX production. A mechanism is proposed which attempts in a general way to represent the relation between cyclonite and H M X production in the type of reaction mixtures used. Dunning and coworkers ( 12 ) investigated the heat of nitration of hexamine with nitric acid. By comparison of the rate of heat evolution with the rate of production of cyclonite, their results indicate the presence of an intermediate in the reaction. Nitration with formation of two nitramino groups occurs rapidly and the slow step is the conversion of this intermediate into cyclonite. Graphs showing the effect of various variables on these rates are included. Willson et al. (20) patented a process for the safe crystallization of cyclonite in a granular free-flowing form from nitration mixtures obtained by nitration of hexamine or hexamine dinitrate with strong nitric acid. The process comprises adding the nitration mixture gradually and continuously with stirring to water or t o dilute aqueous nitric acid previously heated to and maintained a t a temperature of between 50" to 90" C. in such proportion that the diluted liquor contains 50 to 70% by weight of nitric acid. During the main dilution, the dilution bath is held between 70" and 75" C. by cooling if necessary. By following this procedure the decomposition of the undesired products is controlled; however, under certain conditions this decomposition may be delayed and the undecomposed material in the mixtures may become undesirably high; hence, in such cases the initial stages of the decomposition may be more vigorous than desired. To overcome this condition a substance such as a metallic nitrite or paraformaldehyde may be added t o the diluting water or acid mixture. An alternate procedure is to heat the dilution medium to a temperature between 75" and 90" C. before the addition of the nitration mixture. This process is adaptable to either batch or continuous operation. To illustrate the process specific examples are given. OTHER N I T R O A M I N E S
9 review by McKay ( 1 7 ) has been made in which he summarizes t o January 1952 the published results on nitroguanidine. The following items are covered by this review: nomenclature, preparation, physical properties, structure, decomposition by acid and heat, hydrazinolysis of nitroguanidines, aminolysis, nitration, hydrolysis, and tables listing nitroguanidine derivatives and their melting points. The bibliography contains 139 references. Work by Simkins and Williams (19)shows t h a t the conversion of guanidine nitrate to nitroguanidine in sulfuric acid-water media is reversible. Equilibrium is approached from either side in 71 t o 83% sulfuric acid and very rapidly in media containing more than 85% sulfuric acid. The process is a nitration and
1999
not a dehydration. Their investigation indicates that the nitronium ion is the effective agent. Desseigne (11) describes a method for the preparation of dinitroxydiethylnitramine (DINA). By this process diethanolamine is converted into &%dinitroxydiethylnitramine by nitration with 97% nitric acid and acetic anhydride in the presence of hydrochloric acid or one of its salts as a catalyst. The nitration product is stabilized by treatment with boiling water, then aqueous precipitation from an acetone solution. Some properties of DINA are listed. Bryson and Garnett (6) report simultaneous sulfonation and nitration of p-naphthalene by the addition of mixed acid to a solution of t l e amine in sulfuric acid a t -25' C., or by the addition of the solution t o mixed acid. The product was a mixture of two isomeric aminonaphthalenesulfonic acids in a ratio of approximately 70:30. The main product was 1-nitro-2-aminonaphthalene-6-sulfonic acid. The authors state this anomalous behavior is not shown by a-naphthylamine.
NITROPARAFFINS A process for the nitration of aliphatic hydrocarbons was patented by Bachman et al. (8). Essentially the process consists of conducting a vapor phase nitration of aliphatic hydrocarbons a t temperatures ranging from 200" to 500" C., with a nitrating agent such as nitric acid in contact with a free halogen or a halogen-containing material and in the presence or absence of molecular oxygen. Any free halogen can be used, but in order of preference, chlorine, bromine, or iodine is employed. The preferred halogen-containing compounds are those which are oxidized by nitric acid to give a free halogen and which give no other substances that are harmful to the reaction. This process is stated to give much higher conversions to nitrohydrocarbons than is attained by other methods. I n general the process is applicable to the nitration of aliphatic hydrocarbons which are gaseous under the temperature conditions used. It may be employed for the nitration of paraffins such as ethane, propane, 1-butane, 2-methyl propane, and pentanes, and also for other saturated or unsaturated hydrocarbons such as the cycloparaffins and olefins, and acetylenes having three or more carbon atoms.
MECHANISM AND KINETICS The exchange of oxygen atoms between nitric acid and water was followed by using O1*.Bunton, Halvei, et al. (6), determined at low acid concentrations that the reaction is highly dependent upon nitrous acid, but at higher concentrations a reaction is observed in the absence of nitrous acid. The reaction rate increases rapidly with increasing nitric acid concentration. The nitration kinetics of a number of aromatic compounds (secondary amines, substituted phenols, etc.) were examined in aqueous nitric acid. B y comparison of these rates with those of oxygen exchange, a reactivity sequence for the aromatic compounds and the water molecule is deduced. Bachman, Addison, et al. ( I ) , published a series of articles on the general mechanism of vapor phase nitration. The effect of oxygen, nitrogen dioxide, halogens, and combinations thereof and their role in promoting the nitration of aliphatic hydrocarbons are discussed. There is evidence that vapor phase nitration is a free radical process. If so, an essential reaction in such a nitration process is the formation of free alkyl radicals a t a n optimum rate, so they react immediately with the active nitrating radical and maintain the proper radical balance. The following nitration reactions were investigated: (1) effect of oxygen on the vapor phase nitration of butane; ( 2 ) effect of oxygen on the vapor phase nitration of propane with nitrogen dioxide; (3) effect of bromine on the vapor phase nitration of propane; and (4)effect of chlorine on vapor phase nitration with nitric acid.
2000
INDUSTRIAL AND ENGINEERING CHEMISTRY
The role of nitrous acid in organic chemistry is presented by Ingold (14). Catalyzed nitration, diazotization, halogenation, etc., are discussed kinetically, including reaction order, rate, and mechanism. By their investigation, Blackall and Hughes ( 3 ) have shown that the formation of nitramines from secondary amines and the formation of alkyl nitrates from alcohols by the action of nitric acid involve attacks by the nitronium ion on the nitrogen or oxygen atom. The oxygen nitration of glycerol and of cellulose was shown indirectly to involve attack on oxygen by the nitronium ion. T h e rate and order of reactions of the nitration of aromatic compounds are discussed. Bonner, Bowyer, and Williams ( 4 )have investigated the rates of nitration of the trimethylphenylammonium ion in 100 to 82% sulfuric acid solutions. The velocity coefficient for nitration has a maximum value in 90.40% sulfuric acid, and the variation in 90 t o 82% sulfuric acid can be correlated with the carbinol acidity function or directly with results for the extent of ionization of 4,4',4"-trinitrotriphenylcarbinol in the same medium range. The correlation suggests that the diminution in the extent of ionization of nitric acid to the nitronium ion is the major factor which causes a 200-fold diminution of the nitration velocity coefficient in this medium range.
Yol. 45, No. 9
LITERATURE CITED (1) Baohman, G. B., Addison, L. RI., et al., J. Org. Chem., 17, 90613,914-27,928-34, 942-54 (1952). (2) Bachman, G. B., and Hewett, J. V. (to Purdue Research Foundation), U. S. Patent 2,597,698 (May 20, 1952). (3) Blackall, E. L., and Hughes, E. D., Nature, 170,972-3 (1952). (4) Bonner, T. G., Bonyer, F., and Williams, G., J . Chem. SOC., 1952,3274-SO. (5) Bryson, A., and Garnett, J. L., Nature, 171, 41 (1953). (6) Bunton, C. A., Halvei, E. A,, et al., J . Chewa. Soc., 1952, 491316,1417-24. (7) Chedin, J., and Tribout, A,, Mhm. services chim. &tat ( P a r i s ) , 36, SO. 1,31-42 (1951). (8) Chem. Eng., 60,No.3,130 (1953). (9) Crater, W.deC., IND. ENG.CHEW,44, 2039-43 (1952). (10) Desseigne, G. (to fitat Francais), French Patents 972,694 and 972,695 (February 1951). (11) Desseigne, G., Mdm. poudres, 32, 117-20 (1950). (12) Dunning, ITr. J., Millard, B., and Nutt, C. W., J . Chem. Soc., 1952,1264-9. (13) Epstein, S., and Winkler, C. A,, C a n . J. Chena., 30, 734 (1952). (14) Ingold, C . K., Bull. soc. chim. France, 1952, 667-71. (15) Kobe, K. A , and Mills, J. J., IND. ENG.CHEX, 45, 287 (1953). (16) Kobe, K. A., and Pritchett, P. W., Ibid., 44, 1398-401 (1952). (17) McKay, A. F., Chem. Revs., 51, 301-46 (1952). (18) Phillips, M. A , , Chemistry & I n d u s t r y , 1952, 714-15. (19) Simkins, R. J. J., and WXliams, G., J. Chem. SOC.,1952, 3086-94. (20) Willson, F. G., Forster, A., and Roberts, E., Brit. Patent 658,978 (Oct. 17, 1951).
OXIDATION BZ
L. F, MAREK
ARTHUR D. LITTLE, INC., CAMBRIDGE, MASS.
During the past year, commercialization of the process for the manufacture of phenol and acetone by breakdown of cumene hydroperoxide has been achieved and further progress has been made toward more widespread use of this process for production of these important organic chemicals. Major commitments for plants have been made and plans for commercialization announced for processes of ammonia synthesis based on partial combustion of natural gas by oxygen obtained From liquid air Fractionation. Little has been reported on the commercial production of acetylene from hydrocarbons by partial combustion. Considerable work has been done relating to mechanism of combustion studies and to the burning of fuels in Diesel and spark ignition engines. More results have been reported concerning the role of oxidation in the deterioration of rubber, elastomers, and surface coatings, and in the degradation of lubricating and similar oils. Use of ozone in commercial synthesis OF organic products has been reported.
EVELOPMENT of processes, on a commercial scale, for the conversion of hydrocarbons to useful organic compounds has received widespread attention in the field of oxidation.
LOW MOLECULAR WEIGHT HYDROCARBONS The direct oxidation of natural gas is being commercially practiced by several companies t o produce alcohols, aldehydes. acids, and derivatives (37, 133, 136, 188). Acetic acid and anhydride are major products a t Celanese Corp. of America's new plant a t Pampa, Tex. (Figure 1); other chemicals from the direct oxygen oxidation of n-butane are methanol, acetone, and acetaldehyde. It is claimed that aqueous formaldehyde obtained by the vaporphase partial oxidation of hydrocarbons behaves differently from methanol-derived formaldehyde in reacting rvith acetaldehyde to form pentaerythritol, in that much smaller proportions of the diand polypentaerythritols are formed (160). The mzthod of performing the pentaerythritol reaction is described Acetylene from hydrocarbons continues to be of int-rest and a recently published joint study gives a detailed process description and economic analysis of the Wulff regenerated cracking process ( 9 ) . Other processes have been mentioned ( 6 6 ) .
Slow, noninflammatory oxidation of methane by nitrous oxide results in formation of carbon monoxide, carbon dioxide, and water vapor as main products of a two-stage reaction (161). A reaction mechanism for the process is discussed. Reaction between acetylene and nitrogen dioxide and the catalytic action of nitrogen dioxide on acetylene oxidation have been studied (174). The major product is glyoxal, 32% of the reacted acetylene going t o form this product. Further studies are under way in an attempt t o gain further insight into the mechanism of the reaction. A noncatalytic, flame process for the synthesis of hydrogen cyanide from methane and ammonia has been claimed to result in satisfactory yields and to avoid the catalyst problems associated with current methods used commercially ( 1 8 s ) . Examples show that ammonia conversions to hydrogen cyanide of up t o 91 % have been obtained. The technique for producing synthesis gas mixtures of hydrogen and carbon monoxide by the incomplete combustion of natural gas with oxygen, which received so much attention a few years ago in connection with modified Fischer-Tropsch syntheses, has again come to the fore and is now ~vellon the way to major industrial importance (43, 137, 166). Plants based on processes developed jointly by Texaco Development Co. and Hydrocarbon Research, Inc., are now in process of erection or design and will furnish synthesis gas for use in the manufacture of ammonia and urea. Companies reported to be proceeding with such plants include W. R. Grace & Co., Spencer Chemical Co., and John Deere Co. The oxygen unit for the W. R. Grace & Co. ammonia-
