HIGHLY CONCENTRATED HYDROGEN PEROXIDE Physical and Chemical Properties
T h e phj sical properties of 90% hjcirogen peroxide art. summarized. The decomposition of hydrogen peroxide i. discussed with relation to catalysis and stabilizers. \ arious typical reactions of high strength peroxide are outlined. These include applications to organic sjnthesis, bleaching, polymerization, and explosives technologj. The handling of concentrated hydrogen peroxide is disriissed w i t h special reference to possible hazard*.
H
YDIlOGES peroxide entered a new c:ra of usefulness during World War 11. Some of the intesting nerv uses for this
Acids arc', probably, thr o u l j kiion.n illaterials which actually increase the stability of hydrogen peroxide. Exact measuremcnt of the effect of alkali on stability is made difficult by the extreme sensitivity of the solutions t o catalysis. Traces of catalysts added with the alkali are responsible for a large part of the observed effects. Table IV shows the behavior of cerrairi hytirogvn peroxidr snlutiiins upori aildition of sodium tiydrouidc
material have already been described (1. 2, 4, 8). Hydrogen peroxide of high concentration (90%) is noIv conimeri4ally available. T h e purpose of this article is t o dercribe a few of the properties of t h e material. .k few of the physical properties arc conipiled in Table 1. STAB1 L l T Y
HydriJgt,ii peroxide solutions of high purity are w r y stablt.. For example, one commercial 90% product contailis hydrogen peroxide and water and substantially nothing c,ls~. Typical rate of loss figures are noted in Table 11. The decomposition of hydrogen peroxide is a strongly f'xoi 111.rmica reaction (21):
HeO?(gj +Ii,O(g) AH
=
-23 lig.-~al.: A/'
+'
TABLE I. P R ~ P E R ' ToIrE90C;. ~ HTUROGESPERUXIUP. Color Ilensity \-iscosity Freezing point Boiling point Refractive index Dielectric constant
I
2 0 2
Clear, colorless Blight a t room temperature 1.393 a t 18' C. ( 2 2 ) 0.0130 puise at 18' C. ( 8 2 )
Odor
-30 kg.-cA
- 1 1 3 c,>. 123) 140O C with deconipnsitior, 1.3998 n p (2;) S i a t 0' C '91
lri spite of the large driving forre, the rate of deconipositioii is very low in the absence of catalysts. Consideration of the free energy data indicates that no attainable pressure has any illBuenee on the decomposition of hydrogm peroxid(,. For ri.lrctiort 1, ALF?qI
- K7'
111
K
=
-30,000
pel y e a r
per week
(8:iI
': of Original .\ctive 0 Lost .Additiuii, during 24 HI. 31g./L. a t 100' C
HJ-drogen peroxide i6 reiiiarkablc for the number and variety of decomposition catalysts and for the minute quantities required t o give large effect-. Table 111shoxs the effect of' adding certain heavy metals t o a commercial hydrogen peroxide of mildly acid reaction. In all cases the metals were added as solublv salts. Nany, but not all, heavy metals are active decomposition catalysts. T h e presuniption is that, only those metals having more than one valence state, correctly placed as t o redox potential. ran so act. Many ferments and enzymes are able to decompose hydrogen peroxide-e.g., those contained in liver extract, saliva, yeast, etc. These materials are very effective in decomposing dilute h.vdrogen peroxide but are sometimes destroyed by concentrated
Sone Alurninuiii Chromiuni Copper
2
10
1
0.1
0.01
T \ B L EI V ,
Yti 24
EFFIXTO F PLRITY o s ST.IBILITT OF AI,K.LLI>K HYDROGESPEROX[UE
C'onipositiun tic,; cnriiniercial H20z in Water 6$% corn. Hz02 20% com. K a O H 6% com. Hz02 Z0q0 C . P . NaOH 6% corn. HeOz + 20% S a O H specially repurified b y absorption process 6% triple-distd. HzOz in Hz0 6 % triple-distd. ,HzOz 20% NaOH specially repurified as above
+ +
+
1536
'& Of Origins; Active 0 Lost ?.dditioii. during 24 H r . 31g . / i.. a t 1000 c Copper 0.1 85 Iron 1.0 12 Tin 10 2 10 10 Zinc
R a t e of Deconlpn a * Room Temp. 2'Z per year (appmx 7 9 r 0 in 24 hr. in 24 hr. 3% i n 24 h r . 2 % per year 2% i n 24 h r .
INDUSTRIAL AND ENGINEERING CHEMISTRY
December 1947
as well as the large part played by the inipuri-
ties in the sodium hydroxide. K i t h the purest alkali th(b contaminants in commercial hydrogen peroxide become of dominating importance. It is notexorthy t h a t the comniercial product contains only traces of catalytic impurities. Alkaline hydrogen peroxide solutions, regardless of the degree of purity, are al\va)-s much less stablr than acid solutions of a comparable degrec of purity. For example, if small amounts of hcavy nietal ions, such as copper, lead, niangan t w , cobalt, are added to slightly acid hydrogen peroxide, the rate of decompositiorl may rise from one or two per cent per year t o a feTv pt’r cent pcr n-eek. T h e same solutions riiadc aikaline will decomposc completely in son1(’ niiriutcxs 111‘ hour!: ST~BILIZ.ATIOV
.Igreat iiiany inaterials have h v r l huglijtLstrct anti tricd as hydrogen prroxide “atabilizcrs.” T h e w materials, except for acids, probably have no inflwricc on the hydrogen peroxide, but o w their acti,)n to remora1 or inactivation of deconiposition rxtalysts. One group of stabilizers seems to owe its action to complex-forming ability, which serves t o roniov(: heavy metal ions frorn solution; in this group may be mentioned the pyrophosphates, fluorides, cyanides, and variou.5 organic substances such as8-1iydroxyquinoline a n d acetanilidr. .lnothcr group of stabilizerk 1irol)ably owes its action to adsorptive powers; such substances as frpshly precipitated aluniiiia and silica, hydrous antimony oxitlr. and hydrous stannic oritiix ar(5 r4ective t o varying d e g r ( w i n increasing the stability of hytlrogeri peroxide solutions. There is n o one best choice. of stabilizer for hydrogen peroxide solutions. The cffcct depends upon the nature of the catalyst, p11 of the solution, temperature, and oth1.r factors. Thus the decomposing action of copper under certain c-ircumstancca is inhihitcd 11101’l? \)y jtaiinic oxide and less by pyrophosphate, whik thc opposite is true for chromium ions. I t follow from these considerations that high purity is the best guarantee of hydrogen peroxide storage stability. Stabilizers are usually necessary in stored hydrogen peroxide only t o make u p for deficiencies in the product or its container. . A possibly more valid reason for using stabilizers is to furnish a degree of protection against accidental contamination of the solution. While some protection can be secured in this way, no additive will prevent rapid decomposition if gross contamination occurs. It has been common conimercia1 practice to ship and store hydrogen peroxide solutions containing appreciable quanti-
>
Reading f r o m top to b o t t o m
New Plant for Manufacture of Concentrated Hydrogen Peroxide Hydrogen Peroxide Tank Farm Nonspilling Vented Drum for Hydrogen Peroxide
Concentrated
Tank Cars for Hydrogen Peroxide
1537
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
1538
iiiorf, -olut)le than water
TABIJ;\-,
OF ~OJ,CBII.ITY O F PEROXIDE ASD \ ~ T I . : R
('0MP.iRISOS
90';
0 . of 90'; H?O? 100 G. Solvent 18 28 28 2.5
hiethyl niethacrylate Allymer CR-39 mononier Dimethyl phthalate Diethyl phthalate Ethyl aretate Aniline
iii
a iiuinber of organic niatibrials;. Tatlle
HYI)RO(:I.:S V list3 ~ h r nun1bc.r , of grams of 00% hydrogen peroxitlib that will
G . < I f HrO 100 G . Sol\-etit 1 0 3.0 1.6
1.0 3 .J 3 .?
a m
ties of stabilizers-for exsmple, phosphates or tin coinpounds 01' both. Prrsent tendency is toward incrc~awdpurity and less stabilizer. SOLUBILITY
Concentrated hydrogen perosidc is roinpletvly iiiisciblt' \vi[ / I such substances as et,hanol, isopropanol, acetone, ethyl Ct.110solve, pyridine, a n d many other materials with which watrr is miscible in all proportions. In addition, hydrogen perosidc is
tlisrolvt. i n 100 grams of a few solvents. The correaporicliny figures for watrr ilro listid for comparison. .ill data arc' f o r room t?n1pc~raturt3. Precautions are ralli~ii fiJr in dealing lvith mlutionx o f (YJIIccntrattd hydrogen peroxide in organic matrrials. Violent r('actions u p o n mixing are csceptional hut haw: been n o t i d in ii Few cabex. Solutions containing alcohol-;, krt ones, sugars, t'tc'. , are rr,lativc.l>-stahlc whc~iiundisturb(d, but aril sut)ji)catt o violiwt detonation under sonit' c.onditiona. BEHAVIOR A S IO?rIZIhG MI.:UIUXI
S i n e t y per cent hydrogen pwoside is reported to have a i h l w tric coilstant, of 97 at 0 " C. 1Iorc dilute solutions of hytlropc~Ii peroside x h o w still higher values, reaching a niasiinunl of 121) for a solution containing 35% by weight HyOn 19). That these solutions are good ionizing niedia has hren tmrnP out by thi. vvork of previous invcstigators (9, 1'7:.
.il.k'r[\'t;
EKPERIXENTAL
REAcTlKT -4liphatic arids (acetic)
OXIOAKT"
SOLVEST
90% Hz0a
. .. .
22-23' C., 1% H ~ S O I Perarid formation catalyst
Aloohols (ethanol)
90% HzO?
. .. .
100 p.p.ni. F e - t catalyst, 40' C.
Acetic acid yield, 50mo of theory approx.
Aldehydes (hexaldehyde)
90% Hz0z
.,
80'C.
Hexanoic acid yield, 70% of theory approx.
Primary amines (ethylamine)
90% HzOz
..
22-23' C .
Vigorous decompn. of peroxide. reaction difficult i o control; no products isolated
60' C . for 10 h r .
Triethylamine oxide yield, 60% isolated product
T e r t . amines 90% HzOz (triethyiamine)
.
.,..
Vol. 39, No. 12
RESULT
COBDITIONS
OROASI(' SCHST.IS
REACTIOS RC OOH H 2 0 2;L' RCOOOH H20 HrOt C'?HrOH & CHJC:OOH
KELIIARXS
-+
Kapldefficient reaction for peracid prepn.
90% HzO2
.
,
TVith & without catalysts (Fe, Va, RIn) a t reflux temp.
No reaction
Alioyclics (cyclohexane)
90% Hz02
,
,
K i t h & without catalysts (Fe, Va) a t reflux
S o reaction
Oleflns (1-pentene)
90% Ha01
..
.
n ' i t h & without catalysts (Fe, Va)
S o reaotioti
Olefins ( 1 -dodecene)
90% HzOi
,
Formic 40' C . , , followed by acid saponification
HzOz ('iHIICHO--+ C ~ H I I C O O H
H102
(CtHsiaS
+( C r H j j 3 S 0
.
.
Product h groscopic, isolation &cult, reaction appearsa t oi tbe quantitative h
.
I
90% H10z
Formic Catalyst, 1% HISO< acid 3 h r . a t 40' C . , foli lowed b y saponification
90% H i 0 1
hromatics (toluene)
90% HzOz
T e + + catalyst strips
..,
.
Acetic acid
+
, .
Phenol
iii
sniall yield
Reflux with & w i t h o u t N o reaction catalysts (Fe, Va) 22-23' C. a n d a t re- S o reaction flux
C,HI
2
0
%(
7,
13)
....
( 5 , 26)
1
OH
+
( J . 5 ) : use o f 30% H?Oz (8;)
dH
HIO~
dl
~
f
Ilihydriixy-texrir ac,id C I H I ; C H = C H ( C H ~ ~ : C O O A Efficient hydroxylaH?02 via RCOOOH tion 99% conversion of dAuble bond C'aHiKHCH(C"2) rCOOH H h
Aromatics (benzene)
.
. ..
1,2-D o d e 1' a n e d i o I CHa(CH2)sCH=CH2 yield, i s c % approx. H2Op via RCOOOH
HO
.
Cbe of dil.
..
. ,
CHIfCHdQ C H C H ~
Monounsatd. acids (oleic)
... .
Tendency towardoveroxidation with CO? evolution; in absence of catalyst, no reaction noted in cold or o n refluxing
r a t e faster t h a n for dil. H?O? Paraffins (n-pentane)
E € ERt. S C F
( 1 0 , 16)
+ CsH6OH re"'
S o reaction in abaence
of Fe", reflux
eren a t
..
, . .
..
.
..
.
..
0 As a general laboratory safety precaution it is rerommended t h a t , i n the extenaion o i a n y reaction of 90% H20r t o new materials, work he initially conducted with approximately 3 ml. of total reactants.
INDUSTRIAL AND ENGINEERING CHEMISTRY
December 1947
The oxygen from decoiiiposition reaction 2 can be utilized for the combustion of fuel and thereby greatly increase the total energy yield per gram of fuel mixture.
In this laboratory i t has been confirmed that many salts have similar conducting powcr in solutions ranging from 0 to 90% hydrogen peroxide. Acids behave differently, however, having a lower equivalent conductance in hydrogen peroxide solution. Figure 1 shows typical data. A dctailed study of thie effect is in progress.
OXIDIZIVG PROPERTIES
Concentrated hydrogen peroxide possesses the same gcnei HI uxidizing action noted for more dilute solutions. However, it is a pomrful oxidizing agent with distinct attributes of its own, indicative of the transition from the properties of an aqueous iolution of hydrogen peroxide to the properties of pure hydiogen perovide containing relativelr small amounts of water. Enhanced solubility in organic media, increased concentration of cffective oxidizing agent, and the relative absence of water lend themselves to increased efficieucy when applied to existing procmses employing hydrogm peroxide, as well as making possible many nen- applications. Hydrogen ion cnnrenti at ion, presence and nature of catalyst, and tmnipcratuie a w important controlling and directing in-
ENERGY CONTENT
Hydrogc,ii peroxide decomposition is an exotherniic rclacation (2'4):
l T , Q (/)
+
+1 1 2 0 ( ( I
.Oz(~l
+ 23,450 ~ a l .
(2)
I-pon complete decomposition, 1 liter of 909% peroxide yields 589 grams of oxygen gas and 801 grams of steam. Under adiabatic conditions the calculated temperature of these products is 750" C., and their calculated volume is about 5000 liters at this temperature and 1 atmosphere pressure. This system has 01)~ i o u possibilities s as a power source.
T.%BI,E VI I~EACTAXT 3-Taphttiol
OXIDAXTO
SOLYEST
90% HlOz inacetic acid
dcetic arid
EXPERIMENTAL COSDITIOSS
40° C., catalyst HzSO4
lY0
1539
(Continued)
HESELT
o-Carborycinnamic acid yield, 7 1 % of theory
(6,1 6 )
..., ~ i RCOOOII a
-COCJIl
C H=CHCOOH
.,
iIydraaobenzene
907% H?Oz
,
.Arobenzene
Q 0 5 Hz0: 90% H2Oz inacetic acid
Acetic acid
dniline
....
QO% Hz02 90.70 H20?
in acetir acid
Benzaldehyde
9OYo HsO? in acetic acid
.\nrhracene
90,% HZOZ
i n acetic acid
,
..
.
.. .
22-23' C
.4zobenzene yield, 100% of theory
22-23' C. Catalyst 1.R HzSO? temp. raised t o 70 C . a f t e r slow addition of oxidant
S o reaction dzoxybenzene yield, 100% of theory
22-23" C
Aniline black products
22-23O C . : oxidant added t o water slurry of aniline containing Na bicarbonate
S3C6 azoxybenzene 15% nitrobenzene
Catalyst 1% Hz304, 22-230 C
Benzoic
Finely divided anthracene dispersed i n water, reaction mixture gradually heated to 50° C .
Anthraquinone yield, 70% of theory
...
....
....
+
acid
,...
..........
....
..
( 15 )
..
yield,
I
.
.
.
.
( 11 )
100% of theory
0
1540
INDUSTRIAL AND ENGINEERING CHEMISTRY -1
t o cwnipletion as shown. T h r figures in ‘I’able VI1 indicatc the possibility t h a t useful explosivtxs may be eompountietl with eonceiitratcd hydrogen ptsroxide. HLEACHISG XGEST. Concent rated hydrogen peroxide, ber.ausc of increased solubility and higher effective oxidizing eonrentration at the inttsrface, S ~ O W promise for the bleaching of oils, fats, and ivaxcb. ExprrimtLnts have shown that Y O g hyrlroyc~ii perositir addtfitl to Imswax yields a superior hleach to that obtaintd when thv sanie riumbrr of equivalrsrits of 3OC4 pertixide iy employrd. Similarly, excellent results have heen obtaintd in the blcaching of soluble atid insoluble roninierc.ia1 sorbitail esters of the Span anti Twwn typt.. Discolored concentrattd acids can readily hi: h l t v w l i t ~ ( l with ! J O S hydrogen peroxide. In this way sulfuric acid arid glacial acetic acid have been hleached t o a co1orlt:ss produrt. Bleaching with concentrated hydrogen p ~ ~ r o x i dsuggessts itself i i ~ n step t~ in thi. rwovrry of spent arirls.
t/ t‘
“a L\\
400 $,,
4
300
A -NITRIC
a
-
Vol. 39, No. 12
ACID
SULFURIC ACID S -4CETIC 4CID
POLYMEKIZATIOY HEACTION
s
Hydrogen peroxide is a c~otiiniu~i catalyst in etnulriuii pilyrric,rization of vinyl type compounds-for example, R u m S, styrene, and niethyl methacrylate. I n bulk polymerization of L L-_._ 20 40 60 80 IOi vinj-l type compounds, unr is limited to a monomer-siilut,li, ratalyst and thus aqueous hydrogen peroxidr (307, concentration) PERCENT YY@QOI;CN PF”nyIpE i> iiot applicable. Hitherto the bulk of such cataly Figure 1. Effect of Salts arid Acids 011 < : O I I t he organic. peroxides--Le., benzoyl peroxide. durtance of Hydrogen Peroxide Solutions C’unrcsritrated hydrogen peroxitie (‘3OT0)is a n effect ivc: c.atalysi for t h e bulk polymerization of niany vinyl type substaricc3 (styrene, rnrthyl methacrylatr,!. Solubility tables stlow that Huriic,t.> iu hydrogeii pt.ruxide react iuuh. L3j. proper clioic~t~ ,if ! ) O r ( , liydrogi~nperoxide is surprisingly soluble in many inononicrs solve~it,it is possible to modify the oxidizing action of (cniiccii(methyl iritbthacrylate, allymer). Furthermore, although the trated hydrogen pcroside. Thus, with alipha wluliility in compounds such as styrene is limited it is in tht. reactions characteristic ?E the perarids are obtainetl. raiigi’ of catalytic concentrations. Accordingly, it is not surO X I D A K T IS O R G A X I C SYSTHESIY. T a h k 1 pi,isirig t h a t hulk polymerization can be effected with coiiwna study of the general class reactions of con trut c,tl li)-drogen peroxide (goyo) in contrast t o the ~ ~ ~ p t ~ i ~ i i ~ r i c * c ~ pcrosicli. with represcntative organic sul~star of functioning in acid, alkaline, or rieutral solutiorir, a i ~ ~ N* ~ 1 wit 1 ti i i i n w dilute hydrogen peroxide (30%). Ilitcrntlj-, Delrnonte ( l a ) compared SOG$ hydrogen pi.ro.de bcinp applicable t o nonaqueous media by itself or througli iiicBrt with a number of commonly used organic peroxides and found svlvcnts. .Is a n oxidixing agent, hydrogen pcrosid(1 is rh:ir:tc!IO?, hydrogen peroxide to be the most rapid-acting catalyst terized by the distinct advantage of producing only n-atchr 8 s ii for polyester castings. Concentratcd hydrogen pt’roside (‘30%) reaction by-product. This is of great significance in t h i s n i a i ~ i i 1ias I i w n succcssfully applied in thip laboratory t o the curing of Facture of dyestuff’s, pharmaceuticals, and food cheniicals \VIII,IY~ ilartiullg polymerized polysulfides tJf the Thiokol typcj, which are inetallic inipurites resulting from oxidizing agczrits :LI’O c l t ‘ t c , r l i l impregnating rind i.aiilkirig compn~itions. tlclctcrious t o the final product. K i t h aliphatic aititis as s o l v ~ ~ ~ ~ t , . .i i ~ i ~ t ’ t iii important rcactioiis rharacteristic of the peracids c m be olJt:tillct(l becauae o f I lie high i’ntc. of formaiiori of peracids with rolli r A z.mns centratcd h y t h g e i i p,c$roxidt). .iccc~rdiiigly,use of convvrit rat ( , , I ( ~ o i ~ c c ~ n t r a tliydrugeii ed peroxide has obtained a soinowhat hydrogen pcrcixidt~suggests i t self for increased reaction c.fficit,ili.y tbuaggt*ratcd i,eputation for being hazardous. Like any material ~ i n arc’t ic. nheri~voroxitiatioris have berri c o n i m o n l ~conducted ~ i high i eiitlrgy content, it requires intelligcxnt care in handling, acid nitdiuni Ivitli 111orc dilute Iiydrogc.ii peroxide (i.ib., X I r ; ) , such as i i d u c t ioii of substitutcd quinories (3) froin lic~rizc~iic tlrit givc.ti this care it can tx used in mfvty. Toxmi~Y. Hydrogen prJroxide solutions and vapors art! a n d naphthaloiic derivativcw and quinolinii. acid Froni quiiioiitrntosic. Both ar(’ irritating, however. T h e vapor causes t is thtl rt~pnrtc~il oYidatioii of rarotc’iic’ t o ilisromfort of the eyt’s and nose. The liquid a t moderate eonvitamin A ~ 1 ~ 9 ) . cc~ntrationcauses Xvhitening of the skin and a more or less severe CoarwscsT OF Exkbi,ubi\,w Exp1usir.c. i*oriip,)sitioriscan stiiiging sensatioii. In most cases the stinging subsides quickly formed by dissolving crrtain coiribustible niatwiak i i i coiim~ri-. aiid t IIC skin gradually returns to normal without any damage. tratrd hydrogcn peroxide. Such niixturtys may l)c, quit 1, stiiblt, t Iighly roncentrated hydrogen peroxide can cause blistering if in storage hut d e t o i i ~ t t *violc~rrtly untkr. the. prOIJ(’Y stiiiiulrl.;. T h e range of materials and concentratiuris over which this t+Tt,(*i is observed is discusscd in t h i s wctioii o n Hazards. Sonit, 01’ the d a t a on explosives compounded with glycerol and ti! di’ogcxil E:xrr,osrv~:i v r m 1 \ H r . i c VII. (,’o>w.kRIsos O F PXROXIDE peroxide are outlined iii Table VI1 as typical of the performanw ?;ITKOGLYCEROL t,obe expected from such conipopitions. The data arts for. inixtiirca.* Glycerol + Sitro!loot HAh“ qlycerol made up with 9OY0 hydrogcn pei,oxidc~arid glywrol t o sat i 4 y t 1 1 t h Liiiiiact seiiairivity (droll w t . t e s t ) , kg.-cru 15 2 equation:
-
SODIUM
ACETATE
-
0
1115
, I
C’sHsOi
+ 7 H,( +3C’OZ + ).:
I I I[:U
T h e maximum power and sensitivity occur i i c w t h t . stoiriiiometric composition, even though the ac,tiial iwctirin does n n t eo
Total energy released, kg.-cal./grarn Total gas vol. released, liter/gram r)etonation rate, meters/sec. a
Stuirhiometric mixture.
1.6
1.0 6.500
1.6
0.7
anon
December 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY
left 011 skin surfaces for any length of time. Contact Ivith the material should be avoided, but immediate flushing with water will preverit any reaction in case accidental contact occurs. FIRE. Hydrogen ptlroxidi, of high roncentration can must= fire upon contavt with combustible calculation^ show that hydrogen material. peroxide of 65'; concentration releases jUst enough enrrgy upon complete decomposition tfJ evaporate all the water present and formed. Consequently, decomposition of weaker hydrogen peroxide solutions would not he expected to Icad t o spontaneous ignition oi inflammablc materials. On the other hand, hydrogen prroxide solutions stronger than about) 657' can release enough enrrgy to heat the, decomposition product. to high temperature-i.e., 750 C. in thc, case of 90c;, hydrogen peroxide. Ignition of ncarhy inflanimablr material is then to be expccted. .ictual expctriments have been carried out which Weter coilfirm the above line of reasoning. Tt i i difficult t o c'ause fire3 viith €107~ hydrogen pr:roxid(, Figure 2. except under conditions favorablcb to evaporatiori, when i t may he assumed that the concentration exceeded 655; ht:fore ignition oec'urred. On the other hand, firrs can be started a t will by dampening combustihlr niatcrials with hydrogen peroxidc stronger than about 7Oc;, provided that the proper catalyst is present. In the absenctz of catalysts -i,ci., clean cotton or \vood-evt:n 90% hydrogel] peroxide causes no vigorous reaction. hlost wooden flooring, straiv, rags, clothing, etc., contain enough catalytic material t o cause rapid ignition upon addition of 90c; hydrogen peroxide. Proper precautions should be taken with this fact in mind. Storage areas for concentrated solutions should be of fireproof construction, and provision should be made for the flushing and draining of spillage. Workmen should be provided with rubber aprons, boots, and gloves resistant to hydrogen peroxide; the lhroseal type is suitable. In rase of spillage or any other emergency with concentratcd hydrogen peroxide, water is the btist remedy. If used in tiine i t will prevent any vigorous reaction, and it is also the Iwst ['stinguishing agent for fires resulting from spillage. EXPLOSIOX. Apparently it is impossible to obtain a p1,;ipagating detonation in pure 90% hydrogen peroxide. The matcrial has been subjected t o mechanical impact in drop weight testers, to rifle and machine gun fire, and to a variety of tests with blasting caps with and xithout booster charges. I n no case has a propagating &.tonation been observed. Similar tests by other workers have tended to confirm these results (4). Catalytic decomposition of hydrogen peroxide in a closed contaiiier may cause pressure rupture of the vessel. Containers for hydrogen peroxide should always be vented in order to obviatc this possibility. I n case concentrated hydrogen peroxide becomes badly contaniiiiated, the decomposition may become self-accelerating because of heating of the solution. This process goes slowly at first but can rise to a climax capable of rupturing the containing vessel in spite of the vent. Forewarning of this unconinion eventuality is given by a more or less protracted period during which a steady temperature rise occurs. The rate of temperature rise is a function of the degree of contamination. Unless heating can be arrested, contaminated peroxide should be flushed promptly to drain with adequate diluting water. I t is desirable to provide thermometers on large storage vessels for concentrated hydrogen peroxide to provide forewarning of any possible difficulties. Mercury thermometers are not t o be used in direct contact with strong hydrogen peroxide because of t,he vigorous decomposing action of this metal. (This caution applies, of course, to all measuring devices utilizing mercury.)
90% If202
1541
6 ml. ethanol, 4 ml. Wyo H20,
Sppeararice of Lead Pipes after Blasting Cap Tests with Various Ifixtures
dubstauces especially easy to oxidize, or dkaline in nature, or containing heavy metals, may react violently upon mixing u i t h concentrated hydrogen peroxide; therefore propc'r care should be used in making such experiments. On the other hand, niany oxidizable materials show no particuhr evidence of reaction on mixing with hydrogen peroxide o€ m y concentration. Such behavior has been noted with sugars, starch, cellulose, petroleum products, alcohols, and many other materials. In cases where the mutual solubility is very low (i.e., kerosene), the mixtures are not considered particular1.v hazardous. However, if the oxidizable material becomes well dispersed, especially if it dissolves in hydrogen peroxide, then a n explosion hazard oxists. Such mixtures are ordinarily quite stable when uudisturbed, but may be detonated by mechanical shock, heating, or the impact of a blasting cap. h number of such solutions have been investigated with a view to determining the range of explosive compositions. Various procedures have been employed, such as mechanical drop-weight tests, rifle bullet impact studies, and blasting cap test. Since the latter provides the most severe impact, a standardizrd procedure has been adopted on this basis. The test is carried out as follows: The desired quantities of "fuel" and hydrogen peroxide are measured into separate containers and then mixed behind a suitable barricade. The resulting mixture (usually about 10 ml.), in a 15 X 150 mni. Pyrex test tube, is placed in a 7-inch section of Bjd-inch lead pipe having l!a-inch \Tall thickness. This pipe is supported upright on a I-inch steel plate. -4fuse-ignited No. 6 blasting cap is lowered into the test, tube and supported in such a way that the shell of the cap is about half immersed. The cap is then set off. The effect can be judged by the sound and appearance of the lead pipe. The pipe is only bulged when the test tube contains water. If the lead pipe is broken into fragments, it is considered that detonation has occurred. Figure 2 shows the appearance of the pipes after some typical trials. This test, like any other for the purpose, is arbitrary to a certain degree. The impact sensitivity of liquids is particularly dependent on the degree of confinement, and widely varying results can be obtained by changing this factor. The test as described is a severe one. Mixtures not detonated by this procedure can be considered immune to detonation under any circumstances likely t o arise in practice. Figures 3, 4, and 5 show the range (in per cent by weight) of explosive compositions found in this fashion for solutions of
Vol. 39, No. 12
INDUSTRIAL AND ENGINEERING CHEMISTRY
1542
100% \ACETONE
/'* f
100% GLYCEROL
-
I
/
/
/
/
>
!-
- *-EXPLOSION NO EXPLOSION 0.-
X
/ IC
* * "
DETONABLE
. COMPOSITIONS --. -_ I
- - _---
I
100% HYDROGEN PEROXIDE
Figure 3,
-
i
~
4
s
-
STOICHIOMETRIC P_ROPORTIONS
- , --
,
~
-ILb
100% WATER
Range of Explosile Compositions for icetonePeroxide-Water Mixtures
CzHsO
+ 8H?Oi
-+
K O ? f 11H~0
4
.'..> STOICHIOMETRICI, PROPORTIONS
_-_ ? \
\
i
" i - i i - l
-. .'. -A , Y
\
Y
Figure 1. Karipe of Explosi\e Conipositions for GI>c-erolPerokide-Water 3Iiutureq
C ;.F€,O,
+ 7RiOj
+
3COz
T
11H2U
STORAGE AND HASDLING
&%OL
X-- EXPLOSION
DETONABLE COMPOSITIONS
100% HYDROGEN PEROXIDE
Ioos,
WATER
Figure 5 . Range of Explosile Compositions for EthairolPeroxide-Tlr'ater 5lixtures
CzH50H
100% HYDROGEN,? PEROXIDE
\
/=
--EXPLOSION NO EXPLOSION
+ 6HzOe-,2 C 0 2 1.9H20
hydrogen peroxide and three typical iuels (ethanol, glycerol, a n d acetone). It is indicated t h a t the diagrams for other fuel mixtures are similar. I n addition to these three systems esploratory tests have been carried out with a number of other soluble combustible materials. Particular attention has been devoted t o determining the maximum amount of 90mo hydrogen peroxide which is permissible in various solvents nithout entering t h e explosive range. The following materials have been tested: Acetone, acetic acid, acetic anhydride, aniline, carbitol, dioxane, ethanol, ethyl acetate, ethyl Cellosolve, ethylene glycol, glycerol, isopropanol, methanol, methyl methacrylate, and quinoline. Detonations have been observed only when the 90Cc hydrogel1 peroxide formed over 30y0 by volume of the final mixture (more than 3 ml. of 90% peroxide in 10 ml. total). Most soluble fuel mixtures containing 4 ml. of 90yc hydrogen peroside (in 10 ml. total) are detonable in the lead pipe test. Hydrogen perosidc ( 9 0 ~ 0 with ) addition of several per cent of a soluble fuel is usually detonable. In case i t is desirable to niake up hydrogen peroside-fuel solutions which fall within the explosive range, it is advisable to take extensive precautions. Some mixtures may be detonated rather easily-for instance, by dropping the container-and the explosion may sometimes be comparable with that of a torr('sponding quantity of nitroglycerol.
IIydrogcn prroxide of high coricentration can tir handled ari(1 stored nithout hazard. Special methods are rcquirod in c o i l formance with the properties of this material. COSTAISERS.For long term storage of !)Oyohydrogen p i osidcx, containers are best made from high purity (99.67; I aluminum. In contact with 90yo hydrogen peroxide of high purity, this material is unexcelled for r 'tance to attack and lac-li of decomposing action. hluminuni containers should bt, cleantd and pickled before being filled with hydrogen peroxidis. Suitahlv cleaning can be obtained \vith a dilute sodium hydroxidts solution. .\fter this solution is drained, the contairier should lies rinsed and then treated with acid. Several hours of contact witti high purity 10% sulfuric acid is suitable. The acid should bts flushetl out with distilled water. ; i subsequent ririse with hydrogi3ri p r o s i d e may be desirable. I n any event, the C O I I taint,r usually improves with use; that is, fillings after thr iirst are sometThat more stable than the first. It is best t o refill empty hydrogen peroxide coiitaiiicrs without rinaing, unless contamination is known to h a w occurred or i-; suspected. I n such cases the cleaning arid pickling shnuld l i f . repeated. Contai~iersof chemirally reaistant glass are suitatile for with conrcntrated hydrogen peroxide bcpusr. of theair lack 01' attack and lack of effect o n the product. Sniall samples of 90' 1iydrogt.n peroxidc arc regularly shipped in glass bottles providrtl m-ith a protectiw o u t d e metal container. Cil not advisable for use with 9OC> iiydrogclri Iwrouid(~Iwc-auso 111' the hazard from breakage. Coated arid lined cyuipiiient is ge~iorally not acceptabl(3 fur hydrogen peroxide storage bccause of the cleletcrious cffcct small flaws in the coating. 1inpc:rfections arc likely t o gro\v rapidly because deroniposition on the backing furnishes a largt, amount of gas which tends to lift, the coating. In special illstances, flexible containers of t h e pol!-vinyl chloritk t y ~ > (hay(. ' bcen uwd t o hold hydrogen peroxide. .I11 containers for concentrated hydrogvn prroxide s h u l d 1 ) ~ . ventccl. Care should be taken to keep thc vvntirig arrangemerit in working order t o prevent the possibility of pressuris rupturi, due to unforeseen decomposition of the contents. I t is csseiititil to havc the vent designed and arranged so as t o minimize t h ( L possibility of introducing dust and dirt, or other contaminants. PC-VPS I S D PIPISG. For D O ~ . hydrogen peroxide pumps a11r1 piping can be made from aluminum. Porcelain and glass pipiiix and fittings are satisfactory and stainless steel pumps rarl tx, used. Flanged joints are preferred, vith polyvinyl chloriilv C J ~
December 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY
similar gaskets. It is important t o avoid the use of serewed fittings with "pipe dope" of coiiveritional tl-pes becausr red lead and the like are active decomposition catal?-sts for hydrogen pcrosidi,. The grcatt'st care should he taken to escludc fittings o f iron, brass, c o p p ~ rIIonel, , etc. The piping srhcnie should hc arranged so that material oiicc vitlidrawn from the storage tank canriot find its way in again. This bars the use of the conventional measuring tank setup with ~>verAoivback t o storage. Storage spacri for concentratd hyilrogcn peroxido should be of fireproof construction and have :idequate drains and flushing facilities to take varc 01 atiy a?ciclcrital spillages. ACKNOWLEDGMEXT
The authors n-ish to express thanks t o the Buffalo I.;lect~.oCheniical Company, Inc., for permission t o print thib paper and t o H. 0. Kauffmann, research director, for his helpful ativict. t hrouph tho courpc of this work. LITERATURE CITED
E/&neer, p. 46 (Jan. 19, 1945). .YeLcstceek, p. 46 (Jan. 28. 1946). ( 8 ) Arnold, K. T. (to Vnir. of Minn,), t-.S. Patent 2,373,003 (April 3, 1945). ( 4 ) Bellinger, F.. e1 a l . . 1x1.E x ; . C'HCX. 38, 160-9, 310-20. 627-30
(1946). 31 Boehtne ~ ~ e t t c h e ~ i i i e - G e ~ e I l ~111. ~ , l h. ~ a fH.. t F r e n c h Patent 795.391 (1936).
1543
( 6 ) Boeseken, J . and Yon Ronigifeldt, 31. L., Rec. trau. c h h . , 54, 313-16 (1935). 1 7 ) Bruson, H., and hIcCleary, It. (to Rohm & Hans Co.:, C . S.
Patent 2.220,835 ( N o r . 5, 1940). R . .1.,Chem. I n d s . , 58, 957-61 (1945). (9) Cuthbertson, -1.C., and Maass, O., J . Am. Chem. Soc., 52, 48999 (1930). (10) D'Ans, J., and Fie?, \I-,, Z . anorg. Chem., 84, 145-64 (1913). (11) D'Anu. J.,and Kneip. -1.. Ber., 48, 1136-46 (1915). (12) Delnionte. J., M o d e r n Piasfics, 24, No. 6, 123 (1947). (13, Dunstau, IT, It., and Gouldiilg, E., J . Cht,m. Soc., 75, 1004 11 (1S99I . , 14) Gigucre. P. -I., ( ' a n . J . Rrscarch, 21B, 156-62 (1943). i 151 Greenapan, E'. P., ISD.ESG. CHmf., 39, 847-8 (1947). (16) Greeni;pan. F. P.. J . A m . Chem. Soc., 68, 907 (1946). (171 Hatcher. TI-. 13.. and Powell, E. C., Can. J . Research, 7, 270 4'2 (1932). (1s) Hamkinson. A. T., and Elsto~l.-1.(to I)u Punt Co.), 1.. S. Patent 2,371,691 (Slarch 20, 1945). t 19 I €€unt,er,K. F.. and Williams, K. E., J . Chtm. Soc.. 1945, 55-4 (i. ( 2 0 ) Joyner. R . .%., Z . ajtorg. Chem., 77, 103-15 (1912). 1.21) Lewis. G. N., and Randall, &ferle, "Thermodynamic..," 1-t (-11. 11. 496, K e a York, 1IrGraw-Hill Book Co., 1923. (221 X1aa.s. 0 . . and Hatchei. JT. H., J . A m . Chem. Soc., 42, 254s-69 (1920). (23) Maass, 0.. and Herzberg, 0 . IT., Ibid., 42, 2569-70 (1920). (24) Matheson, G. L., and Maass, O., Ibid., 51, 674-87 (1929). ( 2 5 ) Swern. D.,Billen. G.. Fitidley. T., and Scanlan, J.. Ibicl., 67, 17861789 (1945). ( 2 6 ) Swem, D., Billen, G . . atid Scadan, J., I b i d . , 68, 1504-7 (1946, [(Si ('ooley,
KErmnu February 6 , 1947.
China's Motor Fuels from Tung Oil U
CHI-d-CHU CHANG .\ND SHES-WU 5 - 4 3 . Chinu I epetoble Oil Craching the soap of iegetable oils thermally or cracking a Fegetable oil itself thermallj or catalj tically decomposes the fattj acids into hydrocarbons. Subsequent cracking of these hjdrocarbons i s somew hat similar to petroleum vrarkinp. During the war industrial batch-crackinp processes were deweloped in China to produce motor fuelfrom yegetable oils. Tung oil, which could not be exported during the blockade, serbed as the main raw material. The ayerage coniniercial >ield of crude oil wac 7 0 7 ~by yolume of the original tung oil, the gaqolinr cwitent i n rriide oil being 2557~I>> Iolunie.
T
HE n.ealth of vegetable oils iri China has inspired it.5 acieti-
t o become pioneers in exploiting this unique renewable n w u r c e as raw materials of motor fuels nhich may be designated ti?. the newly coined terms "veg-gasoline'! and "veg-Diesel" oil. I Ioit-taver,the niaiiufacturing of motor fuels by cracking vegctahh. oils {vas dictated ilntirely by exigencies of the situatiori brought alwut hy thi. war. It was a hasti]>- developed enterp~isewhich I(5i't much t o be desired. The prescnt paper deals mainly with i t a technical aspects and the LIRV of tung oil in this intluati.y is I ~:wticularlyemphasized. t ists
E X P E R I J I E N T h L DATA
I'rior t o its investigation in China, the crackirig of vegetahh. oil.. had becnstudicd by Robayashi (e),Saito ( I I ) , Llaihle (9, 201, \\.;ttc>rnian and P t q u i t i ( I d ) , Haga ( 4 ) , and Egloff and 3Iorrel
Corporutiort, Shanghai, Chino
131. Chiriese scientists began t o take up t h e work at aniurli later date, shortly before going into war, and nat'urally pursucvl it with great interest. S o r m a l st'eps for the systematic developriicnt of p. novel industrial process ordinsrily extend over many months or even years, but such a. period was too long to be prartical under the emergency conditions of war. Actually the preaa w e of time forced the hasty installation of cracking plants, built on the basis of laboratory d a t a of a rather fragmentary nature. .bong the laboratories undertaking this investigation may b(! mentioned the Research Laboratory of Applied Chemistry at S a n k a i University, t h e Sin Yuan Fuel Laboratory of t h r National Geological Survey oi China, t h e Laboratories of t h c S a t iorial Bureau of Industrial Research (X.B.1 .R), t h e Laboratory ( i f the Tung Li Oil Works: and t h e Research Laboratories of the China Vegetable Oil ('orporation. The results are rarely Ilublished. Of the p u h l i s h d pageis, a digest has bec.11 111adi' available by Koo ( 7 ) . Experi~nentalnicthodb adopted for the preparation of crudc I)il may be roughly classified as : (1) destructive distillatio~iof H wyetable oil and thc siniultaneous or subsequent, cracking of its V W ~ O (2) ~ Sliquid-phase ; cracking of a vegetable oil with or without ueing catalysts; and (3) pyrolysis of the soap of vcgctable oils, DESTRUCTIVEDISTILL-%TION F O L L O W E D B Y VAPOR-PHASE CR.ICKISG. Table I gives the distillation range according to .l.S.T.LI. procedure of the crude oils resulting from the cracking IJ~'rapeseed and tung oils hy subjecting these oils to destructive distillation and passing the vapors a t a n optimum rate through a steel reaction tube mairitained at 400" to 460" C. From
