COMPOUNDS
FROM
PENTANE
RICHARD L. KENYON AND
GORDON c. INSKEEP
Associate Editors
in collaboration with
LESLIE GILLETTE AND
J. FRANK PRICE
Sharples Chemicals, Inc., Wyandotte, Mich.
Standard Solutions (lower left) Are Used by the Operator in
Control of Amyl Acetate Column at the Sharples Wyandotte Plant
A Staff-latdustruCdlabos tive Renort
T
HE production of synthetic organic chemicals derived from
petroleum sources is one of the largest fields in the chemical
industry today. The mid-continent gas fields are the source of
several raw materials used in the production of many useful products. The pentanes, which are removed from natural gas by
fractionation, are the raw materials from which a large group of
amyl compounds are synthesized by Sharples Chemicals at its
Wyandotte, Mich., plant. The production statistics for amyl
acetate and amyl alcohol from all sources are shown in Table I.
Development of the present industrial process for synthesis of
amyl compounds was stimulated by two related findings in the
early 1920’s. Ayres found that when the hydrolysis of amyl chloride was carried out in the presence of a dispersing agent, such as
sodium oleate, there was a marked reduction in the percentage of
the chloride which was dehydrochlorinated to amylenes ( 4 ) .
There was a corresponding increase in the yield of amyl alcohols.
I n addition, there was developed a vapor-phase method for the
chlorination of hydrocarbons which was more satisfactory with
respect to yield of the desired products and also reduced the
explosion hazard. Several patents were later granted to Ayres
(2,s)for this type chlorination.
(.
(.
(.
SHARPLES HISTORY
The Ayres features were incorporated into. the process by the
Sharples Company and a pilot plant was built in Texas. This
plant was operated only long enough to prove the superiority of
the newly developed techniques. The rising demand for high
boiling lacquer solvents to supply the expanding automobile
industry indicated a need for a full scale industrial plant. Fusel
oil and fusel oil acetates were being demanded by the lacquer industry but could not be obtained in sufficient quantities. Fusel
oil was obtained as a by-product in the ethyl alcohol fermentation.
Kirkpatrick has pointed out the economic aspects considered
in selection of a site for this new plant (9). A survey by the
Sharples Company in 1925 and later an independent but confirmatory investigation by E. B. Badger and Sons recommended
location a t Belle, W. Va. This was near a casing-head gas source
and was near enough to eastern and central United States distribution centers to balance the problems of raw materials and
distribution satisfactorily. Caustic and chlorine were readily
available from the Belle Alkali Company. Ground was broken
for this plant in March 1926 and amyl alcohol was being produced there by December of that year.
December 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
2389
rides the 2-me-2-chlorobutane or the 3-me-2-chlorobutane may
TABLEI. AMYLACETATEAND AMYLAr.coHoL PRODUCTION"
decompose t o form 2-me-2-butene or 3-me-1-butene. These
Am 1 Acetate,
Founds
Year
Amyl Alcohol,
Pounds
olefins can be recycled t o the chlorination step and under the
conditions used, in the vapor phase at high temperature and
under pressure, will chlorinate rather than add chlorine to t h e
double bond
CHa--CH=C(CHs)CHa
+ Cla---t
+ HCI
CH&I-CH=C(CHa)CHa
0
b
U.8. Tariff Commission reports.
Reliable data unavailable.
The hydrolysis was run batchwise at the beginning. The
sodium oleate remained in the reactors; the raw materials were
pumped in, agitated, and distilled off, The operation was converted t o a continuous process in March 1928 with the result
that the yield from the chloride to alcohol rose t o 60% and eventually t o 67%; this was with continuous hydrolysis but batchwise distillation.
The conventional method of esterification was not found satisfactory for the production of amyl acetate. Accordingly,
Sharples set about studying the acetylation of amyl alcohol. By
March 1927 the present method for introduction of the catalyst
and flashing of the alcohol had been developed and was incorporated into a process for the manufacture of the ester.
. The copstruction and operation of the Belle plant has been
discussed previously in the literature (1, 6-7).
A favorable arrangement with the Pennsylvania Salt Company
made a move to Wyandotte, Mich., attractive for the Sharples
organization. Land was available adjacent t o the Penn Salt
plant and contracts for chlorine, caustic, and some utilities were
worked out.
I n the fall of 1932, dismantling of the Belle plant was begun.
Actually, this was a meticulous project. By scheduled shutdown
of t,he various units i t was accomplished with little interruption
of customer's supplies. Each piece of equipment, from large
columns to small sample valves, was oarefully marked and cataloged t o simplify the job of reassembly. The equipment,
housed in pew quarters a t Wyandotte, was back in operation by
March 1933.
Although refinements have been made in the
field of instrumentation and some changes in
materials of construction, the present operation
of the chlorination, hydrolysis, and acetylation
units at Wyandotte is basically the same as at the
original Belle plant.
Additional amyl derivatives of the chloride and
alcohol are now being made at the Wyandotte
plant (8) and are described in this article.
Thus the mixed chlorides will contain all the possible isomers of
normal and isopentane as well as some unsaturated amyl chlorides.
The hydrolysis of the amyl chlorides is carried out in the presence of sodium oleate using aqueous sodium hydroxide. The
sodium oleate may act either to emulsify the amyl chloride in the
aqueous sodium hydroxide solution, or it may react with the amyl
chloride forming amyl oleate which in turn is hydrolyzed by the
aqueous sodium hydroxide. Since amyl oleate has been isolated
from the reaction, it is evident that the hydrolysis proceeds, a t
least partially, in this manner
Na Oleate
+
-+ CbHllOH + NaCl
C6HllC1 + Na Oleate -+- C& Oleate + NaCl
C&l Oleate + NaOH +CsHllOH + Na Oleate
CSHI~CI NaOH
During this hydrolysis, the amyl chlorides are also dehydrochlorinated by the sodium hydroxide solution yielding the various
isomeric pentenes
+
C ~ H ~ I C I NaOH
--+
C6H10
+ NaCl + HzO
The unsaturated amyl chlorides hydrolyze either rapidly or
with difficulty, depending on the position of the chlorine atom
relative to the double bond. The allylic-type amyl chloride
hydrolyzes quite rapidly whereas the vinyl type goes through the
hydrolysis step largely unreacted
CHa(CHa)C=CH-CH2CI
+ NaOH+
CH3(CH3)C=CH-CH20H
+ NaCl
Table I1 gives a typical composition of crude amyl alcohol,
as determined by infrared analysis.
FUNDAMENTAL CHEMISTRY
The fundamental chemistry related t o these
processes is relatively simple. The chlorination
of pentane is carried out in the vapor phase because higher yields t o the primary chlorides are
obtained. Also, the vapor-phase chlorination affords more control over the formation of dichlorides, The principal reaction i s this chlorination
of pentane proceeds with the formation of amyl
chloride and hydrogen chloride
CdH,z
+ Clr
CsHnCl
+ HCI
During the rectification of the amyl chlo-
Coal Fired Pipe Still Reactor
Surrounding barricade can be blanketed by ateam in emergency
INDUSTRIAL AND ENGINEERING CHEMISTRY
2390
Amyl alcohols are esterified with acetic acid in the presence o&
sulfuric acid catalyst to yield amy1 acetate and also some byproduct pentenes
+ HOAC +CsHii0-4~+ HzO
CsHiiOH
CbHiiOH
+CjHio + Hi0
CALCIUM CHLORIDE
DEHYDRATOR
CH LO R I N E
TO VAPORIZER
r----eA
TRACK "SCALE
LINKED TO WEIGHING BEAM
WHICH ACTUATES ALARM HORN.
Figtin. I .
( liloiiii(.
t
iilo.i<lirig
*I~II;O~I
The pentenes are used in alkylating phenol and naphthalene
to form the corresponding amyl derivatives
Amyl mercaptans are formed through the reaction of sodium
hydrosulfide with amyl chloride in the presence of a mutual solvent
C5HllCl
+ NaSH +CsHllSH + S a C l
Amyl sulfide and amyl disulfide are also formed in this reaction
as by-products
+ HzS
2CsHiiSH + [OI +(CjHii)2S2 + HzO
2CsHiiSH
+(CbHii)2S
Products and Their Uses. The mixture of most of the theoretically possible isomeric chloropentanes of n-pentane and isopentane obtained from the vapor-phase reaction is marketed as
mixed amyl chlorides. It is used in the synthesis of other amyl
compounds and as a solvent in the formulation of synthetic rubber cements. I n some alkylation reactions the primary isomers
are more desirable; for these reactions a fractional distillation is
used to produce mixed primaries which are available at a slightly
higher price.
Dichloropentanes produced are a mixture of about 40% true
amylene dichloride and 60% a mixture of most of the other dichloro derivatives of both normal and isopentane. This product
has found use as a solvent, insecticide, soil fumigant, and oil
additive. It is also used in the formulation of dipping cements
for synthetic rubbers of the Buna N type. Dichloropentanes
are one of the lowest priced chlorinated solvents now commercially
available.
Hydrolysis of the chloride yields the alcohol. Sharples produces commercially only the alcohols containing five carbon
atoms in the molecule. One commercial product is a mixture of
the isomers (IO); i t contains six of the possible seven isomeric
amyl alcohols b u t is predominantly composed of the three primary alcohols. This product is used as a latent solvent in the
formulation of nitrocellulose lacquers and as a solvent for urea-
Vol. 42, No: 12
formaldehyde resins. It has been used successfully as the volatile portion of hydraulic fluids, and recently in antibiotic recovery
as an extractant.
Primary n-amyl alcohol, isobutylcarbinol, sec-butylcarbinol,
diethylcarbinol, and tert-amyl alcohol are separated by the fractional distillation of the crude amyl alcohols. All the isomers are
used in various organic syntheses. Diethylcarbinol is used in
the manufacture of flotation agents for nonferrous ores.
By esterification of amyl alcohol with acetic acid, Sharples produces a mixture of the isomeric amyl acetates (11). Large volumes of acetate are used as a penicillin extractant. It is also used
in nitrocellulose lacquer formulations, and small quantities are
used in the food industry as a flavoring agent.
The amyl chlorides are reacted with sodium hydrosulfide to
give a mixture of amyl mercaptans (13) which is used as a fuel
gas warning agent; one pound per million cubic feet of gas is the
usual concentration.
Amyl meieaptan is a mixture of the various amyl isomers and
can be used as a starting material in the synthesis of organic sulfur compounds.
Amyl sulfide is a yellow liquid having the amyl group present in
its isomeric forms. I t is used in the preparation of sulfones, sulfoxides, and other organic sulfur compounds through addition
reactions.
Although Sharples has been producing amylphenols since the
early 1930's, until just recently the amyl group present was
either wholly or predominantly the tertiary isomer. The commercial scale production of the secondary amylphenols by reaction of the normal pentenes has been initiated by Sharples in the
past 5 years
p-tert-Amylphenol (fd) is used in the preparation of palecolored, light-stable, oil-soluble resins and also as a n intermediate
for pharmaceuticals.
TABLE
11.
Component
2-Me-2-butanol
2-Pentanol
1-Pentanol
3-Me-1-butanol
2-Me-1-butanol
3-Pentanol
3-Me-2-butanol
9-Butanol
2-Me-1-butene-3-01
2-Me-2-butene-1-01
COMPOSITION O F
CRUDEAMYL ALCOHOL
Formula
(CH3)zCOHCHzCHa
CHa(CHz)%CHOHCHs
CHalCHz)aCHzOH
(CHa)&HCHzCHzOH
CHaCH&H(CIla)CH2OH
(CHsCH2)zCHOH
(CRs)&HCHOHCHz
CHGHzCHOHCHa
CHz: C(CHa)CHOH-CHs
CHICH:C(CHJ)CH?OH
Roiling
Point,
C.
101.8
119.3
138.0
132.0
129.5
115.6
112.0
99.5
116.6
139.4
Percentage
6.0
25.1
25.5
11.9
16.8
9.4
2.2
1.2
1.3
0.7
Two isomeric o-amylphenols are produced; in one the amyl
group is predominantly tertiary and in the other predominantly
secondary. Both products can be used as intermediates for the
synthesis of other compounds where specific properties are required. Both are effective antiskinning agents for paints and
varnishes. Diamylphenol is also used for this puipose; the
choice of agent depends on the nature of the other components.
Mono-, di-, and polyamylnaphthalenes also are marketed b v
Sharples (14). These are somewhat viscous liquids resembling
lubricating oil in appearance and are used as plasticizers, heat
transfer media, solvents, and as starting materials in the manufacture of surface-active agents.
PRODUCTION OF AMYL COMPOUNDS AT SHARPLES
WYANDOTTE PLANT
Raw Materials. Pentane is received from West Virginia, Oklahoma, and Texas. I t s composition varies, according to specification, from a high n-pentane to a high isopentane content.
Most of the product contains approximately equal proportions of
the straightr and branched-chain isomers.
December 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
2392
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 42, No. 12
The r:hloriniLtioii w r l hydn,l,isis opmatiom are aliowri in
Figure 2.
I'rom the storage tanka, i x n b n o for the: imxx:as is pumped by
positivc pressure p u m p to the dehydrstion tsnk, R 45Wgallon.
uiwight, rertmn skel, <wnc.httrmed tank with a %inch gas iiiduct,ion pipe entering the top ;rod rrrtrliing to within 18 i w h w of
1.hebottom. TI,? iriduition pipe ir blinded on ihe cud and drillwl
with numerous holes. Thv dehydraldon tank is connected
:L
grltVity N o x line and RISU I,y it pressure cqut\iirstioo line to a 300.1gdlon horizontal mnkc-up t m k .
About 3300 gallons u f p w t a i a ~:m punipd to thc daliydn~tii,n
t m k arid hydrogen &lorid* gas, ii by-product of chlorination, is
consturrtly bubbled in through t,hc induction pipi. A s it rism it
absorbs m y moisture premnt iii the pentane and a dilute solut,ion
ui hydrochloric acid colltiats in ttw Irjttom oi tlic tlrnk from which
it is driiint.d to the EWPT >it.rsgular intervals. Tlrc excess hydro-
Tertiary Arnylphenol Unit Shewing Alkylation and
Digestion Autoclaves
Tibe p i t a n t : i8 sliip~wdiri SLiiiidiLid ~ t e e lkink O:LE having 2%
trc,t,tuni v d w . The h y d r u ~ : d m ii s puiriped from this bottom
y i i l v ~by
~ mc:~risuf erplofiion-pruof carrtrifugnl pumps, tlirough a
HcLxilAr muclni how, to &ort~gct m k P to which the kink cars are
d 8 0 r:umected hy intliiris of pwsmm wjudizw linos. Thu tanks
m e 27,000-g:tllon Irorisontttl units of wt:lric,ri construction.
Chlorine is rcaeived from Pc:orisylvmia Salt Msnuiacturing
Company, l o u a t d j u s t itcross the highway, in %ton b n k CBIB.
:I full car, in addition to tlut hcing unloaded, is rnuirittLiued R t
the unloadiug statim. F i g u r ~1 nhow tho stutioii schematically.
The liquid chlorine i s forced out of the CKP by compressed sir and
is transferrod to a st;indb,v, or aiicliov car. In order to minkin
anhydrous eonditiuns, this sir is previously dried by passing it
through calcium chloride traps. The ~ I K ; / I O Pcar i s a lGton tank
which sits on iixlf-track scales (2.4).
A small mercury switch is trLtaehnd to the weighing beam
After the supply car has gone empty and the weight of the anchor
car stnrts to decrease, the bezm drorrs act,uating an electric horn.
Thr operator then knows it is t,ime to change o v v supply cars.
He t.hrows H mtrnuiil swiiah which turns off the born and sels
tire circuit to ~:ont,acl,
again whco tho weight oi the tank starts to
increme. When Ire bears tlie alarm again, he knows that the
anchor ear hxu started t,o fill. Tuniirrg off t,he itlmn automaticslly sets tho circuit for contwting when the weight. sI.iwt?l,o fall;
the cycle is then repeated. In this system t,hc anrbor (I% serves
bs a surge tank between tlie iirromirig chlorine CN.I'Sand the
pmress itself; there arcl no other chlorinc storage iia.ilitiea.
Caustic is also reeeivcd from I'con Salt. It is pumped underground from their plant, as li35y0 solution of sodium hydroxide,
to storage tanka when, i t is diluted wit,b w:itor to s 12% concentration
OtIlL'I important raw ,ni,terinls rccei"c<!by Sharpies nrt: HhOW,,
in Table 111.
December 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
2393
1STEAM
~ U D Ean
m
Figure 3.
.sm€
NEUTRALIZATION
AHD BITCH
MSTILLATION
Flow Sheet for f'roclvetinn of Amyl
Acetate
Ilydmgtw diloriric errtws tlre tmtturrr u i the series of 8ini:h
cella m d is pollcrl upward by the va~uunito be met hy a downward R o n o i water which ubsorlx most a i it. Tho unabmrbod
gas p:uscs to the hottom o i the Ginch cell bank where the process
is rqw:~trd. Tho Rinah d l yields 22" BO. lrvdrocbloric acid,
n h t w w thc Binrh cell giwa i t iiolotion of 18" BB. strength. The
neid str~iiiiw.pafie through il~anot*'rawhich itre of Imrtiruler value
i n t,l,<. r b a r t ~ p wbiw
,
sonw ixmti~rici:ond<mscs in the cold system.
The p n t x w i s held io the &ranter irrrd is fllmhrd off by the hot
acid solul,ion which iu ioormtd. Iluring the absorption p~oct:ssin
118, residual pcntmr in thr: hydrogen chloride stream is
vaporii;t:d by the heat of solution in tht: ~ ~ 4 1und
6 p~sscsout the
top ni i.lrc cells through a brim seruhher and a condenser to a
reeeivcr. Any uneondc!nrrd jxmtstnt?g w s through the compresmr
o n tilt! intiikr aide and is dixh:uged, uodor 60 pounds per square
i i i c h prwsure, through n coodcnwr into u reccivcr. tincondonsitIilw are veut,od off through R VWIYC,
and bhe pntnne is diseharged
to thc mrrkc-up tank by the pransure.
Ttic :icid irom the Ginrh-diamrtm a:ll b m k is fed t ~ storiige
)
by
gravity :LS thr take-off is 8cwral Feet sbovc, thc ground. The
arid imm the longer Bind-diameter (.ell bank discharges to B
blow <:ax*from which it is trmsierred by air prem~ret n ator"be. Ahout 98% of the hydrogcn chloride formed is reclaimed
in this system. A very pun, grade hydrochloric acid is produced
arid ia used ~:aelusivt~ly
in tho food industry.
T h e lxine untxi in t.he pentane serubbw i s a 20% salt solution,
eontiioing a.bout 0.5% sotlimn hydroxide, which is R by-product
of the subsequent hydrolysis o i amyl chloride. From the
srrubber it is discharged to the 8ewcr. The scrubbers are roain
impregnated asbestas ( 6 A ) tanks packed with carbon Kusahig
hgs.
Vents from all aoid tanks, blow cases, snd cars are connected
B water scrubber. The resultant scrubber solution, which is
mildly acid, is run to the sen'er, the eontents of which are alkaline.
to
Deasters in Continuous Alcohol Fractionation
2394
INDUSTRIAL AND ENGINEERING CHEMISTRY
MIXED
PENTENE
CONDENSER
PHENOL
YQRMA!.
PENTENES
WEIGH
TANKS
COLUMN
ALKYL AT I ON
AUTOCLAVE
I
I
c
CONDENSER
-m
I3-6DECANTER
DIAMYLENE
WATER
I
Figure 4.
IDiGESTER
CRUDE
PHENOLS
TO BATCH
DISTILLATION
AMYL
Flow Sheet for Production of
Amylphenols
Hydrolysis. Amyl chloride (a mixture of primary, secondary,
and tertiary chlorides) is transferred by positive displacement
”pumpsfrom storage to weighing tanks. These are steel tanks of
1000-gallon capacity, set on scales. As the chloride still contains
some traces of hydrogen chloride it is passed through a caustic,
scrubber before entering the digester. The scrubber is an unpacked tank. It is partially filled with 12y0 caustic from the
regular supply, and the chloride is pumped into the bottom to
rise through the caustic. The scrubbing solution is checked a t
intervals of approximately 3 hours. When its strength is reduced
to 4% sodium hydroxide, i t is drained-and the solution replenished.
The hydrolysis of amyl chloride i s carried out in a pair of digesters, which are steel reaction vessels without packing or agitation, insulated with 2-inch magnesia blocks. Digester 1 is filled,
a t start-up, with oleic acid, amyl chloride, and enough preheated
12y0 caustjc solution to bring the entire reaction mixture to a
sodium hydroxide concentration of 3%. The mixture flows froin
No. I through a n outlet near the bottom which is controlled by a
gate valve, through a heater, and into the top of digester 2. A
stream is pumped by centrifugal pump from the bottom of KO.
2, through another heater, and enters the top of digester 1.
The digester heaters are made of 2-inch pipe inside 3-inch
pipe and are designed as parallel hairpin turns feeding into common headers. Because of its consistmcy, the reaction mixture is
referred to as the “paste.” The paste flows through the innci
Vol. 42, No. 12
tubc. Feed enters the bottom header and the effluent mixture
comes from the top header. The temperature in the digesters is
regulated by automatic control of the steam pressure in thr
heaters within a range of j=1O C.
Once this start-up has been effected, constant chaiging of amyl
chloride is begun. The chloride enters digester 1 through a
1-inch-diameter pipe, 8 feet long, which is closed a t the end and
perforated with ‘/*-inch holes to fecd a spray of the chloride into
the reaction mixture. There are sufficient holes to be equivalent
to one and a half times the cross-sectional area of the inlet pipe.
Addition of caustic, a t the suction side of the circulatory pump,
is begun at a rate which n-ill maintain a c*oncentrationof sodium
hydroxide of not less than 0.570 in digester 2. The caustic
passes through concentric tube preheaters which are heated b y
the condensate from steam traps.
The feed of both amyl chloride and caustic is regulated by
means of pneumatic controllers ( 4 A ) which control the steam
pressure operating the positive displacement pumps on both feed
lines. The pumps operate with a steam pressure of about 150
pounds per square inch. Pressure in the digesters is limited by
a pressure relief valve which blows into a condenser a t the pressure limit. An alternate valve is maintained for checking puiposes.
Product distills from a take-off line leading from the top of
digester 2 to a shell-and-tube condenser in which cold water
passes through the tubes. The alcohol mixture which contains
amyl alcohol, amyl chloride, amylene, and water flows from the
Londenser through a decanter, where a major portion of the water
is removed and sent to a stripper to recover the alcohol. At t h i s
point the organic portion of the reaction product mixture is only
about 3Oj, soluble in water and separation is relatively easy.
The residue, or bottoms, in the digester consists of a brine
d m o s t saturated &ith sodium chloride and containing about
0.5% sodium hydroxide. This is continuously drawn off thc
bottom of digester 2 through an automatic control valve ( S A )
which is regulated by the specific gravity differential between tho
cffluent brine and the reaction mixture in the digesters. A
check sample is constantly drained near the bottom of digester 2
within sight of the operator. The brine is milky, and the reaction
mixture is dark. Visual indication is thus given if the brine level
falls below the safe point. The brine sample is analyzed regularly by the operator to determine its alkalinity. The rate of
caustic feed is based on the alkalinity of the brine. A very small
make-up of oleic acid is added occasionally.
If all the chloride and alcohol were depleted during the hydrolysis there would remain a sticky mass which could not be
pumped. As a safeguard, a sample is taken from the pump oncr
every 2 hours; i t is acidified and steam distilled to determine the
amount of volatile material present. Another safeguard is a red
light for which electrical contact is maintained by the brine under
pressure. If the paste gets into the pressure tap, the small line
plugs up; this reduces the pressure on the electrical contact :tnd
turns off the light.
The brine, which is drawn from digester 1, is discharged by
digester pressure t o a flash tank on the second floor, wherc thc
small amount of low boiling organic material contained is flashdistilled through a water-cooled condenser to a decanter and
thence to a column. The brine then goes to storage tanks. Some
of it is used to neutralize hydrogen chloride which comes off with
pentane vapors from the hydrochloric acid unit.
The product which distills from the top of digester 2 is pumped
from a receiver to a 26-plate bubble-cap column which is sparged
with steam. This column operates under preksure of 26 pounds
per square inch. The low boiling organic material which is
flashed from the brine also goes to this column. The stream is
introduced just below the middle of the column. Amylene is
taken from the t o p of this column and passes through a shell-andtube condensei. A portion is returned to the column as refluy,
December 1950
INDUSTR,IAL A N D E N G I N E E R I N G C H E M I S T R Y
and the remainder goes to a decanter from which watrr is X C ~ I L rated and the amylene is sent to a receiver tank.
Amyl alcohol, amyl chloride, and water are taken from the
bottom of the first column, wher? the liquid level is maintained
hy liquid-level ( S A ) control traps. The mixture is discharged by
pressure to column 2, a 26-plate column, the stream enaring
about the middle. A sparge ot steam is used to maintain thr
dexired heat. Amyl chloride is taken from the top of the column
through a condenser and partly returned to the column as reflux.
The remaining poition of the stream flows to a decanter whew
water is separated and the amyl chloride flows to receivers; from
here it id returned directly to the digester feed weighing tanks.
The alcohol and water are collected from the bo,ttom of column
2 and passed through a coil-in-shell cooler, thence pumped centrifugally to a decanter. Water goes to the collection tank which
receives all decanter water from this operation, and the amyl
alcohol goes to column 3, which is called the dehydration column.
This c o h m n has a steam heated coil reboiler. All water and a
small amount of alcohol are taken off through the top of tthe
column, through a condenser, and to a decanter. The alcohol
collected from the decanter is returned to the'colunin as reflux.
From the reboiler, a stream of alcohol is taken through a coil
cooler and is centrifugally pumped into 500-gallon receivers.After analysis it is sent to storage.
Alcohol Distillation. After thc crude alcohol is collected in a
storage tank it is rectified. The rectification still consistrj of ti
G000-gallon steel kettle with a 26-plate bubble-cap colhmrt,
There are two of these columns.
About 5500 gallons of alcohol are charged into tho kettle,
which is heated by means of a steam scroll. The distillatr stream
is passed through a decanter until it has become nearly dry. A
distillation rate of about 1200 gallons per hour is then established.
A small stream of alcohol is taken off and the remainder R
i returned as reflux until the stream is thoroughly dry. The take-off
is then increased and the collection of distillate fractions i R begun.
Alcohol specifications are shown in Table IV.
.
Pentane Dehydration Tank, Product Storage Tanks in
Foreground
/
TABLE
IV. AMYLALCOHOL
SPECIFICATIONS
Color
Specific gravit 20/20° C.
Acidity, mg. K%H/g. maxiroilill
Water content
Distillation, C.
Initial, min.
Not more than 5 % below
Not more than 5 0 7 belaw
Not more than 8 5 2 below
Final, max.
95% bdtween
")
PentaEol
No. 27
Water white
0.81-0.82
0.06
None
112.0
118.0
ia5.o
13o.o
140.0
tert-Amyl
Alcohol
Water white
0 81-0.82
0.06
None
2395
Normal
Amyl Alrohol
Water white
0.82
0.06
None
..
...
0 8 . S-'io3.8
The residue, amounting to about 201, of thc total charge, is
redistilled to obtain amyl ether, which is collected over a distillatFn of 165" to 199' c. The remaining residue, which is
principally oleic acid, is discharged as waste products.
Amyl Acetate. A flow shect for the acetylation reaction is
shoivn in Figure 3. Amyl a9etate is prepared in a 4 ~ - g a l I o n
copper reaction kettle to which is attached a bubble-cap copper
column, 4 feet in diameter. Amyl alcohol and glacial acetic acid
(approximately 99%) are added with enough water to give an
acetic acid concentration of approximately 4Q% in the total
mixture. Two per cent, by weight, of concentrated sulfuric
acid is added.
Steam, at 40 to 60 pounds pressure is passed through the heating coil to begin distillation. About 5% acetic acid is initially
carried over in the stream. The entire product is fed back as
reflux until the acetic acid content is 0.5yo or less. The take-off
is then opened to the receivers to give a 3: 1 reflux ratio and the
product is collected in reveivers. The nddition of alcohol is then
1
begun and is continued a t a rate to maintain the liquid volume
of the still. Acetic acid is added to maintain the 40% concent,ration.
The water resulting from the esterification reaction must be
taken off. The distillate from the still passes through a tubeand-shell condenser and into a decanter. One side stream is
taken from the decanter as crude acetate and another as water.
A portion of both the water and the acetate is refluxed to the
column.
The crude acetate is collected in receivers where it is held until
nn analysis has been made. It then flows to the neutralizing
tank where sodium carbonate solution is added to produce neutrality. From the neutralization tank, the product is pumped to
a storage tank which feeds the rectification still. After analytical
checking, the batch is fed to a 6000-gallon carbon steel batch still
with bubble-cap column. The f i s t product from the still is the
amylene produced by decomposition during the process. The
nest product is water which goes to a decanter for separation of
the crude acetate. A cut is then taken which consists of about
23% acetate and the remainder alcohql. This is recycled back'
to acetylation. Anintermediate cut follows. This is about 60%
acetate with alcohol which is returned to the crude neutralizing
tank. The relative volumes of these heads cuts depend on the
ester content of the crude ester charged. The remainder of the
lmtch comes off as amyl acetate product containing about 87 to
SSyoamyl acetate in amyl alcohol. All cuts are collected through
a copper shell-and-tube condenser. There is no residue in the
still. The final product is blended with amyl alcohol to produce a
consistent 86% concentration of acetate.
Water fractions from this distillation are sent to a storage tank.
When a sufficient quantity has accumulated, i t is distilled through
n pot still t o recover the acetate, which then goes to the acetate
rectification still.
Tertiary Amylphenols. The pentenes produced as a by-product in the hydrolysis 6f the amyl chlorides contain all the isomeric
pentenes. The two tertiai y pentenes, %methyl-Zbutene and
Zmethyl-1-butene, are preferentially reacted with phenol to
form the tertiary amyl phenols. This process is shown in Figure
4. Phenol is alkylated with the tertiary pentenes in the presence
2396
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 42, No. 12
December 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
of sulfuric acid. The reaction is carried out at 50' C. in a glasslined reactor ( 8 A ) . The unreacted normal pentenes are removed from the reaction mass by distillation after the addition
of water to inactivate the sulfuric acid. The aqueous layer is
decanted from the alkylate and the latter. is transferred to a digester. After digestion, the crude containing a preponderance
of p-terl-amylphenol is neutralized with dilute caustic solution.
This neutralized crude is then sent t o a batch vacuum still t h a t
separates the isomeric monoamylphenols and the diamylphenol.
The still is equipped with a two-stage steam ejector which provides 29 inches of mercury vacuum.
Secondary Amylphenols. The unreacted normal pentenes
from the terl-amylphenol process are reacted under more drastic
conditioris to form sec-amylphenols. The reaction temperature
is 100' C. and the pressure above 1.50 pounds per square inch.
The normal pentntnes containing only traces of isopentenes are
pumped into an autoclave which contains molten phenol and a
catalyst. The r a t , of the pentcne feed is regulated by the pressure
in the wtocIav(*. After the desired degree of alkylation is
reached, the nrutrslised crude is pumped t o intermediate storage
and then to a high temperature vacuum still. This still is provided with the same type two-stage ejector but is operated a t a
kettle temperature in excess of 200" C. A biphenyl ether heat
transfer medium (Id)is circulated in the heating coils. The
ortho-, para-, di-, and poly-ser-amylphenols are separated in this
still.
Amylnaphthalenes. T h r amylnaphthalenes are produced by
alkylating naphthalene with the unreackd normal pentenes from
the amylphenol process and with amyl chloride using aluminum
chloride in the Friedel-Crafts reaction (Figure 5 ) . Mixed amyl
chlorides are mixed with molten naphthalene and the sytem is
dehydrated azeotropically by distilling off a portion of the amyl
chloride. Aluminum chloride is then added to the dry mixture,
and the temperature is increased. When most of the hydrogen
chloride is vented off t h o u g h a scrubber, more aluminum chloride
is added and then normal pentenes are pumped in a t a rate to
maintain the reaction mass a t about 180" C . T h e erude reaction
2397
TABLE
V. MATERIALS
OF CONSTRUCTION
Product. or
Operation
Chlorination
Chlorination
Equipment
Pentane deVenturi
hydrator
mixer
Material
Monel-clad
cone
Cast steel
Remarks
Aqueous HCl present
Anhydrous conditions
Carbon steel
Carbon steel
Anhydrous conditions
Anhydrous conditions
HCI recovery
HCI recovery
HCI recovery
Pentane recovery
Pipe still
Fractioneting
columns
Gas absorbers
Decanters
Blow cases
Scrubbers
Ceramic
Haveg
Rubher-lined
Haveg
Hydrolysis
Digesters
Carbon steel
Alcohol distillation
Esterification
Steel
Copper
Acetic acid present
Steel
Neutral conditions
Glass-lined
Steel
Stainless steel
Phenol present
Crude is neutralized
Product is discolored
by iron
sec-.dimylphenol
Kettles
arid
columns
Kettle
and
column
Kettle
and
column
Reactor
Still
Condenser
and subsequent lines
Autoclave
Aqueous HC1 present
Aqueous HCI present
Aqueous HCI present
Caustic and brine used
to neutralise HC1
Alkaline material a t
high temperatures
Neutral conditions
Nickel-clad
Amylnaphthalenes
Amyl mercaptan
HC1 scrubber
Autoclave
Acidic conditions a t
high tern eratures
A ueous
present
SJfideR and chlorides
present
Chlorination
Chlorination
Eater distillation
terl-Amylphenol
tert-Amylphenol
terl-Amylphenol
Wood
Inconel-clad
HE^
mass is then pumped to a neutralizer where dilute caustic is added
and the aluminum chloride complex is decomposed. The unreacted amyl chloride and pentene are then distilled off. The
aqueous layer is separated from the crude amylnaphthalenes
which are dried in an aerator. The dried crude is filtered and
then fractionated in a high temperature vacuum still. The
mono-, di-, and polyamylnaphthalenes are separated by this
fractionation.
Amyl Mercaptans. The amyl mercaptans are produced by reacting mixed amyl chlorides with an aqueous solution of sodium
hydrosulfide in a mutual solvent, ethanol (Figure 6). Amyl
chloride, aqueous sodium hydrosulfide, and ethanol are charged t o
an autocalve; the total charge is 650 gallons. Thie mixture is
reacted at 140' C. and 325 pounds pressure for 5 hours. The
Weigh Tanks for Amyl Chloride and C a u s t i c F e d to Digesters; Acetylation K e t t l e at R i g h t
--
2398
INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
Vol.. 42, No. 12'
CORROSION
n
HCI VENT
SCRUBBER
In a series of rwctions involving the usc
or formation of such materials as chlorine,
hydrochloric acid, caustic, and brine, tremendous problems of corrosion would be
rxperted. Althdugh these problems w e r ~
NORMAL PENTEN
almost overwhelming during the initial
stages of operation, most of them have been
CONDENSER
satisfactorily workcd out.
WA~ER
Clark (6) pointed out that the dehydration
TO SEWER
o f the pentane was originally attempted in
coke-packed touws. Because of the gradual
disintegration
of the coke and packing of the
WATER a
wetted coke, the towers required frrquent
RECOVEREO
PENTENES
cleaning and replacement of packing. Thc
TANKS
remedy found was the one that is still in usc
CONDEJNSER
today-bubbling anhydrous hydrochloric acid
through the pentane.
By rarefully maintaining anhydrous conditions, it is possihle t o use carbon steel
equipment for the chlorination. A carbon film
forms in the Venturi mixer and undoubtedly
c
serves a s an effective protective coating.
COLUMN
Where the aqueous hydrochloric acid must
be handled, ceramic , resin-impregnated asbestos, and rubber-lined equipment is successfully used. More expensive metals such
as tantalum have been considered, but an
economic balance of their high initial cost
against the replacement costs of the present
materials does not indicate that use of such
metals would be advisable.
Corrosion in the KO. 1 digester is negligible
because the unit is always full of liquid. In
the No. 2 digester, which is operated with a
vapor chamber, the corrosion is evident. The
possibility of using a different type material
for construction of the upper section is being
considered.
The scrubber for vented hydrogen chloride
vapors is a barrel-like structure made entirely
of wood and containing several perforatcd
Figure 5. Flow Sheet for Production of A m y l Naphthalenes
plates.
Corrosive conditions in the preparation of
phenol derivatives arc met by the use of glasslined equipment and nickel-clad autoclaves. Stainless steel
crude mixture in the autoclave is discharged to a batch still
where the hydrogen sulfide and a portion of the pentenes are disequipment is used €or handling distilled amylphenols because
tilled off. The hydrogen sulfide is absorbed in two caustic scrubiron would cause discoloration of the product.
bers forming sodium hydrosulfide which is used in subsequent
Some of the important pieces of cquipment along with the innbatches. The crude amyl mercaptans are steam distilled in this
terials of construction arc listed in Tahlc V.
still separating them from the amyl sulfides and disulfides. The
SAFETY
residue in the still is separated into two layers; the lower aqueous
layer is disposed of with no subsequent treatment and the upper
With' large quantities of flammablc, volatile, and skin-corrosive
sulfide layer is sent to storage. The crude amyl mercaptans arc
materials as well as toxic gases to contend with, attention t o
sent to a second still where the last traces of hydrogen sulfide and
safety is particularly important. Safety systems and devices
pentenes are removed. The charge is then aeeotropicab dried
designed specifically for the process are found throughout thc
and the amyl mercaptans are separated from ethanol,. amyl
plant.
chloride, amyl alcohol, and amyl sulfides.
Fire prevcntion and fire fighting are planned in great detail.
Control of odor is the biggest problem in this process. All
All persons entering the plant are required to surrender matches
vents from the scrubbers and tanks are connected to a header
and smoking is not tolerated in any of the danger areas. Nonwhich leads to a flare. This flare handles all hydrogen sulfide
sparking shoes are worn by all operators in the fire hazardous
areas; toe or heel plates are expressly prohibited.
and amyl mercaptan vapors. Aqueous discharges are chlorinEmergency steam hoses are located a t convenient points
ated before dropping t o the sewer. Chlorination converts the
throughout the plant. Ininiediatcly on spillage of any flammable
odorous mercaptans and sulfides to sulfoxides and sulfones.
material, the area is blanketed with steam to prevent fire while
The blending room, where open streams of mercaptans are presthe material is being cleaned up. Instructions are issued to all
ent, is ventilated b y an exhaust blower which discharges through
opwators pointing out the danger of throwing any clcctrical
a n activated charcoal tower. By constant vigilance, escaping
switch in a n explosive atniospherc.
odors from this process are kept to a minimum.
FII
I
I
-
1
December 1950
INDUSTRIAL A N D ENGINEERING CHEMISTRY
The pentane dehydration tank and the make-up tank are situated adjacent to each other in an area surrounded by a Transite
wall. The door to the area is kept closed a t all times, except
when an operator is inside. The entire area can be flooded with
live steam in event of a fire. The shed around the c o a l - h d pipe
still can also be flooded with steam in an emergency. Valves on
the steam lines to these zones are located away from potential fire
areas.
Wherever necessary, all vents carrying flammable vapors are
run to the outside of the buildings and are protected with flame
arrestors.
All motdrs and other electrical equipment are of explosionproof design when installed in any area where flammable vapors
might be encountered.
The two-story buildiiig housing the digesters and the alcohol
rectification units is equipped with one indoor and three. outdoor
slide poles for rapid exit. I n addition, the second floor is connected by a walkway to an adjacent building.
A specially engineered 'fie alarm system (6A) is installed
throughout the plant with boxes located a t strategic points.
Employees are instructed to turn in as an alarm any emergency
which could lead to a fire.
Each storage tank for holding pentane received by tank car is
surrounded by a dike about 3 feet high. A fire fighting system,
controlled at a central station, is piped t o each of these dikes.
In the control house there is a mixing chamber which is connected with a feed line from the plant water system; foam generating chemicals are available and can be added to the water a t
this point.
Operators who would be able to leave their production units in
an emergency are designated as members of the plant fire squad;
squad members participate in special training drills.
2399
At the first sound of the fire alarm, the plant water pressure is
immediately increbsed by the powerhouse. When the squad
member assigned to the foam generation unit is notified of a fire
in one of the dike areas, he opens the valve which feeds the dike
in t h a t area and dumps into the mixing chamber a 5-gallon can of
foam generating chemical. Several dikes in the adjacent areas
are also flooded with foam. The entire dike system is outlined
in colors on the wall of the fire control house with each dike area
painted a different color and the valve which feeds that dike area
painted the same color.
It is important in the Venturi mixing chamber, where pentane
and chlorine are combined under pressure, t h a t the pressures of
the two components are maintained in the proper relationship.
T o prevent. the entrance of chlorine into the pentane system, an
indicator light device is attached to the pentane feed chamber.
When the pressure is maintained at the proper level a green light
burns, an excessive pressure rise lights an amber light, And a red
light indicates a drop in the pentane pressure.
Respirators with cartridges for chlorine or hydrogen chloride
vapors are provided .at convenient points. Operators are required to wear a respirator when changing chlorine supply cars,
and gas masks with chlorine canisters are available in case of any
major leaks.
I n the derivatives processes, phenol, caustic, acetic and sulfuric
acids, as well as the various amyl compounds must be handled
safely. Rubber gloves and goggles are required attire when oper-,
ators are exposed to any of these skin-corrosive chemicals.
CONTROL
Two separate control groups are maintained a t the Wyandotte
plant. The regular control laboratory checks all raw materials
as well as some of the materials in process and finished products.
'I'
WATER
AMYLENE
AMYL CHLORIDE
AMYL MERCAPTAN
SERIES
w
2400
INDUSTRIAL AND ENGINEERING CHEMISTRY
The shipping control group checks all materials prior to shipping.
Although much of the routine process control testing is done by
the plant operators, there are analysts in the laboratory for each
shift.
Raw Materials. The boiling range is checked on samples from
each car of mixed pentanes received. Initial boiling point mu'st
not be below 27' C. and 95% of the sample must boil in the range
of 28" to 39' C.; final boiling point must not be above 40' C.
Infrared absorption analyses are made on every car for company
reference and for billing purposes.
UPPER
L I M I T : * I I I *C.
SPECIFICATION
t
IO8
0
0
-
0
3
ECONOMICS
0
I
2
4
8
AM
Figure 7.
1
2
TIME
4
8
PM
1
by specific gravity measurement each time one is full. If the
specifications are not, met, the product is returned to the column.
At other points in the process a statistical study of the necessary sampIing frequency has been made. I n several cases i t was
found that many more samples were being taken than were
actually necessary to keep the operation running within the control limits.
Customer Complaints. All complaints from customers are
reported to the control group by any employee who receives or
hears of them. Investigation is made immediately to assign
causes and make corrections. Record cards are kept on each
product showing complaints per lo00 shipments. By means of
control charts whose limits have been determined by statistical
study, the quality of the production and shipping techniques can
be determined at a glance.
Complaint causes are also bioken down as to department, or
operation; this breakdown includes such classifications as procedure, operation, handling, carrier, and vendor. These data
are also subject to careful statistical study and are available to
top management in the form of regular reports.
0
102
1
2
Vol. 42, No. 12
4
8
AM
Sample Control Chart
It is extremely important that the water content of the chlorine
be controlled; specifications require this to be less than O . O l ~ o .
Samples from each car are analyzed by a gravimetric absorption
technique.
Freezing point determinations are used to check the purity of
the incoming phenol, naphthalene, and acetic acid. Caustic
samples are titrated for sodium hydroxide content and the iodine
number is run on samples of oleic acid. However, neither specification is critical.
Process Materials. As far &s is practical, all control testing is
done in the plant at the site of the operation and by the operator.
Laboratory equipment used in the plant has been modified and
standard solutions adjusted so that the plant techniques and calculations are relatively simple.
Control of the fractionating towers after the chlorination reaction offers a good example of the type process control encountered
in the plant. The final vapor temperature of the first column is
maintained at approximately 40 " C. Special control is exercised
in column No. 3 to keep the final boiling point of the distillate lo~v
enough to prevent distillation of dichlorides. Control charts
have been set u p plotting the fina1,boiling point against time; a
sample chart is shown in Figure 7 . The control limits have been
determined by a statistical analysis of data from several years of
operation. Although the upper specification limit is 111" C.,
the control limit is 105" C. A sample of the distill&te is taken
every 4 hours. When the boiling point goes out of control, samples are taken as often as every half hour until changes in feed,
reflux, or take-off correct the situation.
T o make certain that all monochlorides are being distilled off,
a sample is also taken from the bottom of the No. 3 column every
2 hours. Initial boiling point of this sample must be above
135' C.
The amyl chloride in the receivers from column 4 is analyzed
The operation of the chlorination, hydrolysis, and esterification
units on a 7-day continuous schedule requires a total of 28 men,
rach norking an average of 42 hours pel week. For the production of amylphenols, mercaptans, and naphthalenes an additional
28 operators are required.
Four shift superintendents working under an operations
manager provide night and week-end supervision for the plant.
The entire plant is divided into three areas, each with its own day
supervisor. These area supervisors work only days but are on
24-hour emergency call. The shift superintendents are selected
on the basis of their previous operating and supervisory experience; all have worked as operators themselves.
The cost distribution in the production of the chloride, alcohol,
and acetate is presented in Table VI. The value of the by-products is treated as a credit to the cost of raw materials, and starting
materials which are produced a t the plant are charged a t factory
cost.
TABLE
VI.
a
COSTDISTRIBUTION
(Cents per dollar of total cost)
Cost
Amyl
Amyl
chloride
alcohol
Raw material cost less
by-product credit
67
7SQ
Direct labor and suudiea
20
12
Indirect labor and- Supplies
13
10
Includes starting amyl compound at factory colt.
Amyl
acetate
91a
4
5
The direct labor and supplies include utility costs, operating
labor, maintenance labor and materials, and miscellaneous process
supplies. Charges for indirect labor and supplies cover such
things as materials handling, control, shipping, and billing.
Utility requirements for an average day of opelation are summarized in Table VII.
An indication of the amount of recycled material as well as the
total raw material requirements is given in Table VIII.
TABLE
VII. UTILITIES IiEQGIREhIEXTS
(Per day of operation)
Amyl
Amyl
Alcohol
Chloride
Steam, thous. lb.
Water, thous. gal.
Electricity, kw.-hr.
Coal, tons
450
1000
700
3.8
440
700
45
, . .
4myl
Acetate
11s
540
130
...
L l l t i . H * T l l H E CII'EU
0 )A ~ I C Bii., I<.. I X D .l i x a . CMBM..
21, H!)Y
904 (1929).
(2) Ayrex, IC. E.. 1'. S. Pateiit 1,717,136
(1929).
ll,i,l,, l,U31,474 and 1,835,202 (1931).
(4) .AYlPS, I<. 13.. and 11aillrata,I. I:. I%..
IBid., 1,691,424 5 6 (1928j.
( 5 ) 130hnll. t i . .k,,Rt$,mr 'val,L7<il( h a o i 7 n r .
M / Y . . 11, 438-43 (1982).
( t i ! ('lark. L. H..
Ciism. and Mcd I l u g . , 38,
206~1 0 (1931).
( 7 ) ('lark. 1.. II., IN". END.(~IM.,
22, 43'3
43 (1930).
(kjH,,,it.
1'.
Ibid., 35, 1 0 1 R 5 2
(1943).
(5)) Kiikpat,riok. Y. D., Chcm. a d M e t .
En@.,34, 276 9 (1Y2i).
i l o j Sharpies ('hemicais. Inc.. l ~ t i i l ~ d r l p l i i a .
.i,tbetio Ormriic Chemicals,"
1 5 l i i ~ &p.
. i. 1947.
i l l ) rbia., p. 15.
(12) !bid., I). 47.
(13) Zbid., P. 51.
(14) Zbid.. P. 95.
I:j)
x.,
Hatch Still for A lenhol Distillation
rHwxssmC: EVuri'miwr
TABLE
VIII. HAW hIATERIAL ~tEQUrREMEsTs
!Fur 10.000 wunds of nroduot)
(1Aj Uow Clieniieui Co., Midland, hlich.. heat traaafer inedium,
Donthorn,.
(ZAj Fairbanks. Morse R; C u . , Chiexgo. Ill., reilroad track ecalou.
(3A) Fisher Goveinor <'<>.,hlaralridltown. Iowa. liquid-level contiellers and traps.
(4A) Foxhro &., Y,,x'boro, Mass.. liguid-feed controllera.
(SA) (:anicwcll C"., Newton 1:pper Palls. Muss.. fire alarm aystpnis.
(IiA) Hnvey Corp., IVcst Newwk, Del., wid-resistant chemicd
eqiiipn*ont..
(i.4) Iron I,.iiemsn Mfg. Co.. I'mtland, Ore., w t o m a t i c coal
burlrels.
( S A ) I'fnudler Go.. Koohenter. N. Y., glass-lined equipnrcnt.
(9.4) Thcrmnl Syndioato. Ltd.. Now Yoik.'N. Y., Bull., 4. Vitvcoail
pas absorber..
(10.2) \Vallaoe and Tierrwi, Newark. N. J.. high-cawaoity chlorine
flowmeter.
i i a c w r r i i Ootobei 23. 1950