Document jpdwqzv6vNEVbRGX4VeoNB22
7PRCTLY c o h f ix e h t ia l STH2L CORPORATION
RESEARCH A1D 3S7ELOH4SST DEPARTMENT PROCESS DESIGN ACTION Baton Rouge, L ouisiana
Problems Associated- w ith Production Volt H e Load A ilyi-
Prepared by:
Reviewed by: Approved by: Pate Issued:
L. R, BrifSS8 M. D. ROO* ? . v. Confield
a . H. Wall October 5> 1953
]^f 0 0 2 0 5 3 4
TABLE OB? CQ%S$t3
soessAS
?age
X
BASIC ...................................................... JLAZAKD3 ................ * * * * 4
***
**
*
** *
General ................ 1-jad A l l y l s ......................................................* *
I4 (
A llyl C t i c r i c l e s ............................. * ' * * ' *
*"]c-rj .Miazixwn C hlorides * * * . * * * * 4 4 *
PROBLEMS 3Y PLAIS .S E A .................. ....
* ***
Alloy . ................................. .... deaction . . . . . . * * * * * *
Lead A lly l R e c o v e r y .........................* * *
*****
******** ***
/Airy! le a d Cleanup .........................................................` ` *
B ie n o ir g .........................* * * * * *
Aikyi C a lo ra s R ecovery * * * * .......................
Lead R e c o v e r y ...................* * * 4 * 4 V * 4 `
```*
a ff lu e n t 'H ea tin g . ............................. Laboratory . * * * ' * * .................
** ** **
t Plant Layout . * ` * * 4 * 4 4 '
m n n HASPatim ..................... . . . .
*
p-ojak car Loading and Drussaiag 0 * * * * * * * * * Shipping * * * * * * * * * * * * * * * * * * * * * * Customer Atorage and Handling * * . * * * * * *
}*,
6 6 11 12 1? 13
13
I** Ik Ik
15
15 15 15
H? 0020535
maauMB a s s o c ia t e d w it h h io k k jt iq h o r VOLATILE LEAD ALKYLS
SlftMAHiT Customer in te r e s t has given impetus t o c o n sid era tio n o f manu
fa c tu re o f mixed le a d a lk y ls (m ixtures o f m ethylated and e th y la te d le a d cocgwunds) and te tr a n e th y l le a d . A ll o f th e se compounds a re more v o l a t i le th an TEL and sa y be r e f e r r e d t o a s v o l a t i le le a d a lk y ls .
Manufacture o f v o l a t i l e le a d a lk y ls i s more hazardous th an manu fa c tu re of TEL because o f t h e i r to x ic i ty and e x ? lo * iv ity . The v o la tile le a d a lk y ls ore as to x ic ao TEL o r maybe more to x ic . 'T he'higher v o l a t i l i t y o f th e s e compound; in cre ase th e p r o b a b ility o f contentn a tio n .
The tem perature re q u ire d t o i n i t i a t e spontaneous therm al decom p o sitio n o f th e pure v o la tile lead alk y ls v a rie s from s lig h tly le s s than fo r TEL to somewhat more th an f o r TEL. However, once i n i t i a t e d , decomposi tio n o f th e v o l a t i le le a d a lk y ls proceeds w ith much more vio len ce th an does decomposition o f TEL.
E x istin g f a c i l i t i e s can be converted to m anufacture o f come o f th e v o l a t i l e le a d a lk y ls . However, sin ce both contam ination and decomposi t io n v io len ce in cre ase as th e percentage o f m ethylated compound;; produced in cre ases, a point would be reached where i t would not be a ttra c tiv e to convert e x is tin g f a c i l i t i e s . Thus development work and new f a c i l i t i e s would be needed f o r production o f TML and probably needed f o r production o f jai-xturas containing a high percentage o f m ethylated compounds.
Studies' w ill be required to determine whether or not gasoline containing the v o la tile lead alkylc can be handled safely by re fin e rs and the public.
KE 0 0 2 0536
IHTROIXJCTIOB
The p o ssib le c o m e rc ia l manufacture o f v o la tile le a d a lk y ls loas become im portant to th e C orporation because o f in creased cuotcazer i n te r e s t.
C alifo rn ia Research recen tly requested tim ing and p ricin g fo r t e s t and commercial Quantities o f tetrazseth y l le a d (THE.). Foreign r e f in e r s have been in te r e s te d in mired lead a lk y ls f o r souse tim e.
Tests have indicated th a t production o f these v o la tile lead alkyls
in more hazardous than, production of SSL, "with TML being an extreme case. There a re many problems involved in coping v i t h th e hazard s. However, i t nay be a ttra c tiv e to solve these problems i f customer in te re s t is su ffic ie n t.
v-dten oodiua-lead a llo y i s re a c te d v i t h e th y l c h lo rid e and methyl
c h lo rid e , a m ixture o f le a d a lk y ls r e s u l ts r a th e r than one compound. These
le a d a lk y ls form a s e r ie s from TEL to TML The follow ing f iv e corgoouads fo ra
th e s e rie s and each would be p resen t in varing fra c tio n s in any mixed lead
alkyl manufactured:
_
1. Tetrametbyl lead 1. Triethylm ethyl lead 5. D iethyldim sthyl le a d
T. E thyltrim athyl le a d 5. Tetram ethyl le a d .
The fractio n , o f each compound p resen t in a mixed lo a d a lk y l i s determined by the ra tio of ethyl chloride to methyl chloride used in the rea ctio n and can be found from the follow ing equation:
where x * th e mole fra c tio n o f eth y l groups in th e alk y l groups p resen t y = th e mole f r a c tio n methyl groupa in th e a lk y l groups p resen t n =* th e number o f compounds in th e s e rie s (5).
D istrib u tio n s calcu lated frcm th is equation are in agreement w ith experimental
re s u lts .
C la s s if ic a tio n o f th e mixed le a d a lk y ls can be mods on th e b a s is of percent o f methyl groups p resen t, since a c e rta in percentage always gives th e same d is tr ib u tio n . An example o f th e method used to designate vario u s mixtures is as follows:
I4A-250 Mixed le a d a lk y l in which 25 mole p e rc en t o f th e a lk y l groups a re methyl and 75 a s le percent o f th e a lk y l
groups ere eth y l.
Thus TEL would be MA-000 and TML would be M&-1000.
Tiro types o f f a c i l i t i e s could b e provided f o r m anufacture o f v o l a t i le lead alkyls:
K0 0020537
1 Converted e x is tin g p la n t 2 . lies* plant*
I t appears probable t h a t conversion o f e x is tin g f a c i l i t i e s night provide an economically a ttr a c tiv e ro u te to manufacture o f mixed lo ad alk y ls containing a small percentage o f methyl groups* I-tbsed a lk y ls up to lik- 500 have been manufactured in conventional SSL-type f a c ilitie s ' Bawever, since -the production problems in c re a se a s th e percentage o f methyl groups in c re ases new f a c i l i t i e s would probably be more a ttr a c tiv e f o r m anufacture o f le a d alk y ls containing high percentages o f methyl groups*
The production r a t e range o f in te r e s t appears t o be 15-25 1M pounds o f le a d a lk y l p e r year* T his amount could b e produced l a a converted Baton Tonga b u ild in g . The P itts b u rg p la n t, f o r example, could a ls o be converted to nixed lead alkyl production*
fUBFQSB
The purpose o f t h i s mernsrandusi i s
.
1. To d e scrib e th e g e a e re l haser&o a sso c ia te d w ith commercial production o f nix ed le a d a lk y ls , end in p a r tic u la r TML.
2. To p o in t out a n tic ip a te d p la n t design problems in th e v ario u s plant areas.
5* To suggest p o ssib le so lu tio n s to th e problems and to suggest needed development work.
4 . To d iscu ss a sso c ia te d f l u i d handling problems.
K 4 0020538
h.
BASIC SEIiCIHQm .
2ML end th mixed le a d a lk y ls caa be formed by re a c tio n o f alkyL chloridec triti oodium-lead o llo y . I t s necessery to use a c a ts ly s t fo r th m ethylation re a c tio n . Alkyl aumiaxm c h lo rld e s a re th t e s t c a ta ly s ts nov kaown.
The re a c tio n to fo lti 2ML i s as follow s:
h MeCl + k lisSb % A 1^C13 . Pblfe4 > ; Pb A IfcCl ITO^TT^OOpsi
To f o ra th e vrarious mixed le a d a lk y ls , methyl c h lo rid e and e th y l c h lo rid e a re fe d in about th e same r a t i o as th e d e sire d r a t i o o f a lk y l groups l a th e product. Thun:
!3eCl 3 St c i - k IfePb .i.cMOl-F25, 020+0 3po?bi + h KaCL
3 I'leCl + BfcCl + h riaFb 1 5 0 % .230 p al m -7 5 0 + 5^ Pb + k IfoCl
These re a c tio n s w hile q u ite sim ila r to. th e p resen t TEL r e a c tio n , nre more hazardous to c a rry out due t o th e p ro p e rtie s o f th e re a c ta n ts and the lead alkyl product.
Another method o f obtaining th e v o l a t i li t y d e sired would be to carbine enough TSL w ith an H& m ixture having 0, h ig h er v o l a t i l i t y than, th a t
d esired to give th e f lu id having th e proper v o l a t i li t y . In ouch a case
p ro p o rtio n a te ly le n s o f th e i n i t i a l Hk m ixture would be re q u ire d .
Cther methods o f m anufacturing le a d a lk y ls are:
1. Mixed le a d a lk y ls by r e d is tr ib u tio n o f TEL and TML w ith suitable catalyst.
2, Pure trim ethylethyl lead , e t c ., by fra c tio n a tio n .
These ro u te s may be so re a tt r a c t iv e th an alkylation alone in some c ase s.
However, th e sp e c ia l problems a sso c ia te d w ith r e d is tr ib u tio n , f r a c tio n a tio n ,
e t c . , a re not considered in t h i s report* Thus i t i s pointed toward th e
manufacture o f more v o l a t i le le a d a lk y l 0 by a lk y la tio n clone.
\
ISAZABD3
:'
General
The coapounds to be worked w ith in a p la n t producing th e mere v o l a t i l e le a d a lk y ls would p re se n t in creased hazards over th o se now experienced
ne 0020539
in TEL f a c i l i t i e s . There would be an in creased hysealc problem because o f t b s r e l a ti v e ly high v o l a t i l i t y o f tb s m a te ria ls handled (Gee F igure l ) and because o f th e ir increased to x ic ity . There would also be an increase in th e explosion hazard. This can be seen in Tabic I where a comparison of th e decomposition ra te s i s made. I t should be noted th a t as th e p e r centage of methyl groups increases, th e ra te o f decomposition also in creases* These general hazards would be aggravated by th e pyrophoric
n a tu re of an a lk y l aluminum c h lo rid e c a ta ly s t.
Lead Alkyls
The hazards involved in m anufacturing and handling le a d a lk y ls are two fo ld . These m ateria ls a re both to x ic and explosive to varying degrees. In mixed lo ad a lk y ls th e r e la tiv e hazard in creases aa th e p er centage of methyl groups increases.
The t o x ic ity o f TEL i s v e il e s ta b lis h e d . I t i s safe to assume t h a t th e t o x ic ity o f mixed a lk y ls End TML i s a t l e a s t as g re a t as th a t o f TEL and pi'obably g r e a te r . Thus th e danger o f exposure t o th e vapors in c re a se s as th e r e l a ti v e v o l a t i l i t y of th e se compounds compared to TEL in c re a s e s. The r e l a ti v e v o l a t i l i t y o f th e s e compounds shows a marked in crease os th e percentage of methyl groups g e ts high. This can be ceen in Figure 1.
Cponfcaaeaus therw el. decom position o f TML occurs a t a such h ig h er
tem perature than t h a t ' re q u ire d f o r TEL w hile bom #'nixed le n d ' a lk y ls re q u ire
a s lig h tly lower tem perature ( Cee Item 7 - , Table I ) . The tem perature r e
q u ired t o ig n ite mixed le a d a lk y ls and TML i s h ig h er in a l l cases th an
th a t f o r TEL (See Item 9, Table I ) . Under unusual co nditions such as sparks in
th e vapor phase and h o t sp o ts g r e a te r th an 200 C (Gee Items 7b, 7c and <3,
Table I ) , th e minimum tem perature o f th e b ulk liq u id req u ire d to i n i t i a t e
decomposition i s l e s s f o r mixed a lk y l le a d s and TML then f o r TEL. Thus
under normal co n d itio n s TML and mixed le a d a lk y ls a re probably not as prone
to decomposition as TEL.
,,
However, a s in d ic a te d by Item 10, Table I , th e r a te o f decomposi t io n o f mixed len d a lk y ls and TML, once i n i t i a t e d , proceeds a t a r a t e which i s much g r e a te r th an t h a t o f TEL. The decom position r a t e and th u s th e d e stru ctiv e power increases as th e percentage o f methyl groups in creases.
B ilu tlo n o f any le a d a lk y l compound has been q u a lita tiv e ly shown to decrease decomposition r a t e . F u rth er experim ental work would be re q u ired to e s ta b lis h more q u a n tita tiv e ly th e e ff e c t o f d ilu tio n on decomposition rate.
Alkyl Chlorides
I n th e forming o f mixed a lk y l le a d compounds, b o th methyl c h lo rid e and e th y l c h lo rid e are used. The to x ic e f f e c t a sso c ia te d w ith th e b rea th in g
K0 0020540
f
6
o f e th y l c h lo rid e vapors i s v e i l known. I t has a n a rc o tic e f f e c t on. th e body which i s u su a lly t r a n s ie n t. I t w i l l give some warning o f " i t a presence "because I t i s i r r i t a t i n g h u t exposure can be to le r a te d to th e p o in t o f unconsciousness.
Methyl chloride has a sim ila r n arco tic e ffe c t on th e body which i s more pronounced end say r e s u l t in cro a ic a f t e r e f f e c t s . I n co n ce n tra tio n s
which a re h a re fu l i t fa- almost o d o rless and th u s dangerous exposure' nay go unnoticed. Even repeated exposure t o low co n cen tratio n s m y cause damage t o c e r ta in p a r ts o f "the body*-
Both methyl and e th y l c h lo rid e .a re explosive when mixed In th e proper p ro p o rtio n s v ith s i r . However, e th y l c h lo rid e i s considered g re a te r f ir e and explosion h e a rd than is methyl chloride.
Since both methyl and eth y l chloride have been safely handled in numerous p la n ts throughout th e country, i t i s reasonable to assume th a t any new p la n t could do th e same.
Alkyl Mualman Chlorides
when a nixed cUryl o r te tra m e th y l le a d i s formed, a c a ta ly s t i s
req u ired to speed the re a c tio n and a lso to improve th e y ie ld . She most s a tis f a c to r y cojapounda found f o r use as c a ta ly s ts a re methyl and e th y l aluminum eesrrulchloride (ifeaAl^Cls end EtsAl-iTLs), These compounds e x h ib it sim ila r p r o p e r tie s . They flam s in s ta n tly When exposed to a i r . They r e s e t v io le n tly w ith w ater and o th e r l iq u i d s . The codbueion o f th e s e m a te ria ls i s d i f f i c u l t t o extinguish. To d a te no s a tis f a c to r y method has been, found.
SROBLEMS BY FL'lfZ A3SA
A llo y
As now eavSrlaned, th e m&nitfacturing o f sodiua-le& d a llo y w ill be th e same f o r plants producing TEL, mixed a lk y ls o r TML.
Reaction
The problems t h a t would be encountered in o p eratin g a 2'e a c to r for production o f volatile lead alkyls a re as follows:
1 . The reacto r would have t o b e f r e e o f vapor le a k s end v e n tila tio n a i r flow would have t o be high to avoid contam ination. .
2. The operating p ressu re s would peak a t 200-500 p sig (com
pared to a peak o f 9 p sig i n th e TEL re a c tio n ) i n making le a d a lk y ls ranging from Ml-2^0 to THL.
5. The higher o p eratin g p ressu re p lu s th e h ig h er e x p lo s iv ity
of m ethylated leads would r e s u lt in higher peak p ressu res i f th e re a c tio n
gets out of control.
"
K r 0020541
TABLE I
RvyrMc::1 Prcroerties o f Vex'Ions Alkyl LeeA Compositions
Compound
T etraethyl Lead TrietkyUnethyl Lead Diethyldim etiyi Lead fth y ltriin eth y l Lead Tatrcjactiiyl Lead
TEL
100 --
>*
w*
***
Mi-950
31.6 49.2 91.1 b .l OJi
Conec o itio n , fole $ Compound FbEi,71o Ml-500 PbEt^ifep MA-
__
10-0
--
--
6.25 95*00
37.50
95.00 6.25
100 --
O.H
M 21. 1*2. 31.6
1. Molecular weight
2 . M elting p o in t, C 3. B oiling p o in t, C h . D ensity o f liq u id , 20 C
g/H. Ib/gal 5. Vapor p re ssu re , eei Eg 25aC 100C
6 . R elativ e v o l a t i l i t y to TEL 25C
100C 7 . Decomposition temperature fo r th e
Pure L icuida, C. Method o f
in itia tin g th e decomposition- a. Increasing the tesoe ratu re of
the liquid h . Sparking in an a ir - f ille d vapor
space above th e liq u id c. Sparking in a n itro g e n -filled
vapor space above th e liq u id
323.5 0-136 193
1.6598 13.0
0.333 93. k
1.0 1.0
* <*
1.19 Ik.'}
1. 65.3 Jf.9
* ..4
179
2?5-3
MM
MfeM
I . 713O 1.739 1 ^ 0 1^.91
1.16 6.05 51.2 lh2
3.0 15.6 1.0 5.0
295.3
W-M*
160
981.3
ww M
1.7906 1.8 -V .95 15.6
3.96 15.3 108 278
Q.h 39.3 3.8 9.8
190 -- , 165
185 163
195
167WM
175 138 iL l
r*
a
1 ,0 0 0
0
V o latility Relative to
100
mm
10
O
^0 60 80 100 120 Temperature C
ASLE I
R i d i c c i Pronte..'Lie:.; o f Various Alkyl Lead Cbjcpoiu'idc (Coat inued)
Coxapoiuid
8 . Minimum t o p e r a tu r c , C, o f th e liq u i d bulk a t which b ulk decent* position la in itiated by a hot spot.
9 . Temperature, C, o f a h o t surface which w ill cause ig n itio n o f a liq u id drop in opea a ir .
10. Maxixs.ua r a te o f decomposition a t temperature T expressed as cubic fe e t o f gas (latta, } / s tilli secondgallon of liq u id T - 190C T * 112cC
11. Lead a lk y l in vapor space above g a so lin e a t l a t a , 25C, s t i l l i grama/cubic foot 1.5 cc TEL/gal orequivalent lead 2.5 cc TEL/gal o r equivalent load 3 cc EL/tjal o r equivalent lo a d
TEL l 80
180
3.7 0
0.7 1.1 I .3
I4/;-?50 --
Coximposition, Mole $ Compound K B tdfe MA-50 PbKt.ri.tep MA-Y
120 -- 100 --
-- l8>
-- 245
--
---- ** **<*
qjhjd ****
M.-* Him
A ll other*load, a llr/lo ; a ;< rjg/cu. f
# Compositions f o r th ese souples only cp ia-asiaete K-y.
10.
Tito general ty p es o f re a c to rs have "been used corsnsrcially o r experim entally fo r th e production o f le a d a lk y ls . They are:
1 . The conventional autoclave where a lk y l c h lo rid e i s fe d to sodlusa-lead alloy
T. r.aurry-type rea cto r here a llo y in fed in to a large excess of alkyl elloride.
' l a th e 1938- I I &9 p e rio d , v o l a t i l e le a d a lk y ls. were su cceecfu lly pxtoduced i n co ay e atio a a l autoclaves at. th e Jackson L ^boratdrlaa. In th e se runs,, i t v as found t h a t re a c tio n mas i s .acre s ta b le th an th e pure le a d a lk y ls , However, th e XK>st v o l a t i le le a d a lk y l m d e vas th e S&~500 m ixture. TML has been Bade in th e 5 -g a llo a autoclave a t Baton Bouge. T his i s a
conventional-type autoclave*
As poin ted out in iha In tro d u c tio n , i t may prove econom ically a ttr e c tiv e to use e x is tin g equipment f o r production o f v o la tile lead a lk y ls , ,'B'* B uilding a t Baton Houcje e s s designed w ith 12 in . d ice lin e s in a n tic ip a tio n o f fu tu re production o f mixed lea d a lk y ls. I t lr recog
n ize d t h a t contam ination and overpressure probleas may l ir a it pise o f e x is tin g equipment t o a lea d a lk y l co a g id sr^ b i^ lea g 'v o la tile ' Wan 'itSC.
Befereoce to Table I a.-.d Figure 1 choirs th a t m ethylated le a d
cc-smundn ax con sid erab ly more v o l a t i le 'th an T8L, This , of c o u r: , means
th a t th e p ro b a b ility o f c o n tm in stlo n o f a i r around th e autoclaves would
he increased. Careful operation wul& be. required to d etect and stop any
leaks th a t occurred. I f i t were necessary to increase building' v e n tila tio n
air flew in d ire c t proportion to th e re la tiv e v o la tility o f the confound
being settle* i t would seem th a t e x is tin g equ ip aeat would be H a l te d to pro
duction o f a compound w ith low i4(L ir a b e r . D efining th e re q u ire d x e n tiia tlo a
a i r flew r a t e find flow p a tte r n in ag<oeasary~kefore l i s t i n g ' eiiigmeab could '
be need fo r production of v o la tile lead -alkyls.
" '' " r~
Hie e x is tin g autoclaves are designed f o r 300 p e l. V o la tile le a d
a lk y ia up t o 1M could bo made in p re se n t auto clav es fresa o p eratin g p ressu re
coarideresfclottB alone. Bowever, th e aaxiggaa p re ssu re th a t would be obtained
la th e re a c to r during u aco atro llo b le rea ctio n o r decociponition nan not been
completely explored fo r v o la tile lead alkyls and especially with respect to
TML.
*'
R eactors f o r making le a d a lk y ls e re p ro te c te d from over}?re:icur
by use o f sa fety d isc s. I f a reactio n g e ts out o f control o r decomposition occurs from a h o t sp o t, th e p ressu re in th e r e a c to r w i l l r io e r a p id ly . The d isc w ill blow. The co n ten ts o f th e re a c to r w ill vent through a Line to th e atmosphere. I t i s l i k e l y th a t th e p ressu re i n 1th e re a c to r w ill continue
to r i c e a f t e r th e d isc has blown. I t i s t h i s aaxj iftaa p re ssu re th a t o u st be used fo r safe reactor selection.
11
l a g e n e ra l, tike m x is u a p ressu re t h a t w i l l occur a f t e r Use
ra p tu re i s a function' o f fo u r v a ria b le s : ..............................
'
1 . The preneurs a t which tits d is blows
2 The slo e and shape o f th e vcsxfe l i a s
The r e a c to r fre e volume
k . The emunfc o f le a d e lk y l farming o r decongoalag ( t h i s ia tu r n ia a fu n ctio n o f th e tsaouat of- o?loy fe d t o th e re a c to r)*
Any o r a l l o f th e s e v a ria b le s m y be changed t o allow m anufacture o f v o l a t i le le n d a lk y ls i a e x is tin g ecjuipsenfc. One would c e r ta in ly expect
th e o p tim a case to bo fo r production o f lea d olh y ls tilth m ch lower es-
p lo s iv ity th a n SIL Thun, i f i t ciapears econcsdcedly a tt r a c t iv e to 'a a n u - ' fe a tu r e le a d e lh y ls e o stain lg a high percentage o f THL, m odificatio n o f
th e prenant autoclave design o r development o f a new r e a c to r w ould'be....... ....... indicated
In regard to the overpressure problem, i t should be noted th a t pressure r is e from decos^osition o f lea d alk y ls ia reaction'm ass i s not nearly as rap id aa pressure r is e from docarposition. o f pure lead alk y ls, f a t a from Jackson L ab o rato ries in d ic a te t a c t decomposition o f ik-tOO in re a c tio n mass proceeds o nly f o u r t i a e s a s .fa s t as decomposition o f XBL in -reaction mane. bhereao Thble' I risot-m tS S trp n fe -'''/W500 ec c ^ se s about SO tisses as f a s t a s pure TEL.
A development p ro g rea would be accessary to d e fin e a new re a c to r design* Perhaps a d ilu te d caetera would be th e answer to th e e rp lo s iv ity problem. A fera la b o ra to ry t e s t s have in d ic a te d t h a t hydrocarbons might be ur:cd as d ilu e n ts. E thyl has developmental es^erieace w ith slu rry re a c to rs th a t could be brouglat to bear here*
Lead Alkyl Sacovory
.
The problems .associated w ith a lk y l le a d recovery a re :
l . Contamination o f a i r in th e area
2. Possible overpressure from decceositloa o f lend alk y l,
Cosaae r c io l and experim ental ira it o f th e follow ing ty p e s have been operated fo r lead alkyl recovery:
1 Steam d i s t i l l a t i o n
2 . Water Oisplocisaeat o f le a d alk y l in e x tra c t phase which is le ss dense than water
2 H eaction m a s slu rry in g and le a d extrusion*
She com enta made l a th e B eactor se c tio n on a re s contam ination and ventH a t ion a ir flow are generally applicable to the lead alhyl recovery
section.
I f & hydrocarbon d iluent or a s ta b ilis e r such as naphthalene vere used p ast experience in d icates th a t lead alh y l recovery by steam d in tilla tio n vould be sa fe f o r cocs&ounds up to ISl-500* S his should a ls o be tr u e i'o r ecapounds co n tain in g more methyl groups th an lia-pOO. D iluents p re se n t a t th e
le a d alkyl recovery step vould go through th e rea s iadar o f th e process cad appear ia the product.
Bccovery o f le a d a lk y l by th e re a c tio n mass slu rry in g technique now being developed s ig h t f in d good a p p lic a tio n in a process t o produce th e v o l a t i l e le a d aLkylc. One b ig sdmxfcage- i s t h a t t h i s vould bo a low tem p e ra tu re o p e ra tio n . In th e process a s new designed, th e le a d a liy l vould fo ra a separate phase under a la y e r o f v o te r, r ts b iliz e r s could be added i f necessary.
llhyl. Lend Cleanup
She major prdblesss in clh y l le a d cleanup ere:
1. Contamination o f a ir la th e area from v essels containing
lead alkyls sad frost aeration
.
2. Danger a t overpressure i f pure le a d alk y ls are handled by present procedures.
r Hashing and a e ra tio n o f SSL has been accomplished b atc h v ise and
eontlatvously (a t Houston) fro p o rly designed continuous a eratio n could reduce th e le a d a lk y l hold-up raid th u s adduce tls e*iosioa h asard swh&t.
A eration o f a v o l a t i l e le a d a lk y l, *EIL f a r example, by p resen t p ra c tic e vould involve exhausting th e a i r used fo r aeratio n ' to th e atmos phere. .This might rso u t in dangerous a re a contam ination. I t vould be more d e sira b le t o o p erate in a c lo sed sy a te s. l a ouch a case th e a i r vould b e continuously recy cled v i t h solas oxygen asko-up.
f
SHL i s more s ta b le tow ard o x id atio n th en SSL co th e r e i s no problem of product lo ss daring aeration.
lead.
One vay around th e a e ra tio n problem might b e t o use debism athiaed.
She problems associated w ith sc ra tio n vould have to be solved b e fo re com nercial m anufacture V o ^ d ,''ber'ijn^^'akffiln . "'. ` ' .. ...... ' r
In th e SSL p ro ce ss, se v e ra l tan k s co n tain in g SSL a re employed in clean-up. The e r p lo s iv ity o f m ethylated le a d ccrtcoundc rosy -preclude t h i s p r a c tic e . Again a d ilu e n t may be th e answer.
B lending
The problems encountered in blending v o l a t i le le a d a lk y ls would be sim ilar to those encountered in the cleanup area.
The p a r tic u la r problem which stands out is area contamination, from th e dye chute. This could be prevented by pumping in th e dye in so lu tio n .
Of course, th e composition o f th e v o l a t i le le a d a lk y l blends would have to be established.
.Alkyl Chloride Recovery The p rin c ip a l problem encountered in a lk y l ch lo rid e recovery in a
p la n t making v o la tile le a d a lk y ls would be condensation o f methyl ch lo rid e . vented to the recovery system.
In a ll p rio r experience, excess alkyl chlorides are recovered by v ap o risatio n and subsequent low tem perature condensation. Three vents are now employed:
L 1. A s n if f vent which removes products o f side re a c tio n s and some e th y l ch lo rid e from th e autoclave
2. A primary vent in which unreacted eth y l chloride is vaporised by hot water in the autoclave jacket
j>, A secondary vent in which e th y l c h lo rid e re ta in e d in the re a c tio n mass is vented from th e s te m s t i l l .
Ifethyl ch lo rid e b o ils a t -10F. 'vlien mixed w ith l i g h t hydrocarbons th is presen ts a d if f ic u lt condensation problem. Methyl chloride vented to th e atmosphere would c re ate an are a contamination problem. Adequate re frig e ra tio n and condensers would have to be supplied.
Lead Recovery The follow ing problems would be a sso c ia te d w ith le a d recovery:
1. I f v o l a t i le le a d a lk y ls were m anufactured a t th e Baton Rouge p la n t, th e n ecessity o f occasionally breaking th e long sludge lin e s would create a contamination problem.
2. V entilation of the sludge p it.
KB 0 0 2 0 5 4 8
S ie long -sludge lin e s l a use a t t i e Baton Rouge p la n t re q u ire breaking and cleaning occasionally This could c re a te an a re a contam ination problem An ta^arcr/ed s lu ic in g aethod f o r moving th e sludge from th e s t i l l s to th e sludge p it would he in order.
Use o f a hydrocarbon d ilu e n t i n th e s t i l l s m y h e lp reduce th e lo ad a lk y l in th e sludge. AI30 raore o f th e v o l a t i le le a d aLkyi would he removed in th e sludge d ry er, lim e le s s le a d a lk y l vould he p resen t in th e dry sludge t o cause contasaination o r overpressure in .the fu rn a ces.
I t i s l ik e l y t h a t th e le a d e x tru d e r now being developed would prove a ttra c tiv e fo r lead recovery in a v o la tile lead o llr/ls p lan t, This, o f course, would he th e b e s t seethed o f l e a d sep aratio n i f re a c t Ion m s s slurrying ware used fo r lead alkyl recovery.
A ffluent (Treating
lio unus'oal p ro b lem a re fo reseen in tr e a tin g e f f lu e n t w ater ir o n u v o latile lead alkyls plant.
Safe procedures would have to he worked out fo r handling blender
rnpXes and recovered a lk y l c h lo rid e saE^des f o r a saore v o l a t i l e lo ad ally rl
Lent.
.
P lant Layout
.
To m ajor hazards would guide th e lay o u t c f a new p la n t to produce cha isore v o l a t i l e le a d a lk y ls . Those hazards a re :
Co*n.tsiain atio n o f working ureas w ith orgeno lo a d compounds
2. Danger o f equipment ru p tu re due to overpressure
Perhaps experience w ith p lan ts unking highly to x ic m aterials such
as nerve gas could m used as a' guide t o `the p le a t la y o u t and v e n tila tio n
requirem ent s . The nerve gas p le a t a t Rocky fountain A rsenal hmaployed th e
follow ing:
.
1 . Three continuous processing tra in s each in separate concrete
bays th a t are six sto ries high
-
2 . Bays sep arated by h a llo where personnel tra v e le d
3. A ll operations conducted by remote control fro a a control ' rocaa on th e f i r s t f lo o r
h. V e n tilatio n a i r c atere d h a lls , flowed to bays and was eoiiausted through scrubbers imdergrcnmd
5. A ir fe rn -o v e r every minute
.
S is danger o f equipment rupture could be g re a tly ralainloed by
c a re fu l vent l i n e s iz in g , In th e esse o f TKL, however, i t n ig h t be p r a c t i
c a lly impossible to e lse vents due to th e high ra te o f decomposition. I f th is proves to be the ease, blow-out v a ils v a lid have to he provided.
H im ) HAaOUBO
The handling o f nixed a lk y l le a d flui&e. v i l l p re se n t p ro b lem
sim ila r to th o se encountered w ith SSL b u t g r e a tly m agnified by t h e i r in creased v o la tility and e x p lo s lb ility . Major considerations in f lu id handling
ore tank car loading and drum iag, s h illin g , and customer storage end handling.
T:vak Car Loading and Srtsaptiag "
lih ila methods o f loading tank c a rs o r drum ing nixed elk y l flu id s
v i l l be sim ila r to those used v i t h TEL, extreme care v i l l be re q u ire d t o
p rev en t even, th e m o t minor le a k s and s p i l l s . She hygenic danger in c re a se s
a t l e a s t as f a s t as th e r e l a ti v e v o l a t i l i t y o f th e compound being loaded.
C'ire -.rill a lso be re q u ire d to prevent ig n itio n o f th e m t e r i s l from sparks
and other sources.
.
.
D istrib u tio n problems on f lu id containing d ilu e n t would have to be reconciled before process design bases could be fira ly s e t,
5Skj shipping o f mixed a lk y l lead, f lu id s w i l l f a l l under th e ju r is d ic tio n o f th e I n t e r s t a te Coerasrce' Coowtceioa. A thorough in v e s tig a tio n v i l l have to bo made to c!etenaine th e re g u la tio n s which v i l l a ffe c t' th e shipping Inaannch a s th e f l u i d v i l l probably b e d ila te d t o th e p o in t where i t i s no c o re dangerous th a n I33L, no changes in ta n k c a r design should bo in q u ire d .
Customer storage cad Handling
Customers purchasing th ese high v o l a t i li t y mixed a lk y l le a d flu id s w i n be re q u ire d to use considerably nor c au tio n in s to rin g and bundling the. I t i s probable th a t special storage f a c ilitie s and tra n sfe rrin g m thods beyond those already supplied v i l l so t be required.
Continued e e ^ ia sis on th e custom er's m in ta in ia g safe handling pro cedures v i l l bo re q u ire d . Ho should f u l l y understand and a p p re c ia te th e danger# involved in th e use o f th e s e ecsqpauada and t o tail n ecessary p re cautions to protect h is personnel against possible exposure.
The use o f g a so lin e co n tain in g mixed lo a d a lk y ls o r SiL by th e p u b lic m ist be considered. As i n th e case o f TEL th e ab so rp tio n o f th e more v o l a t i le le a d a lk y ls through th e sk in from handling lead ed g a so lin e v i l l be o f no p r a c tic a l consequence. However, th e in cre ased v o l a t i l i t y o f th e se mixed lo a d a lk y ls and Q34L in c re a se th e danger o f exposure from v ap o rised m aterial.
tfJE* 0 0 2 0 5 5 0
A shown i a Table X, Xtea 11* TML la TO tim es as v o l a t i le a s m * . Thus g roat? d ilu tio n o f gaoolXae v a lo rs c o n tain in g th e -S3. i s re p a ire d . to rv ie e s ta tio n pei'scBaael t o u t ! probably experience th e g r e a te s t e n s u r e . Gasoline leaks which to ta l ly evaporate over sh o rt periods of t i a a rsresent a statins? caa ta ad n a tlo a p rd b le a Tor o i l a lk y l le a d ccasgounds incladJiss TEL* A study would b e re q u ire d t o deterralne the- oerioasnees o f
th e T reb les r e la tiv o t o th e e x is tin g exposure t o TEL.
D lctributloa; P r. B, A* iiehoe Dtr. P. A. SfcKisa Mr. H* K. S cales - Hr. v . G. L ovell 24p. H. H. Viali Mr. P* S. K e ia r
KH 0 0 2 0 5 5 2