Note: Descriptions are shown in the official language in which they were submitted.
~6~5Z3
The present invention relates to an lmproved proces~
~or the manu~acture Oe he~ameth;srlene diamine and in particular
to an improved process ~or the manu~acture of hexamethylene
diamine from adiponitrile, especialLy adiponitrile obtained
~rom adipic acid a~d ammonia~ using a~ iron catalyst.
Xexamethylene diamine may be used as a detergent,
as a~ emulsi~ying agent or, in particular, as an intermediate
in the manufacture o~ polym~rs~ Hescamethylene diamine may be
obtained by the catalytic hydrogenation of adiponitrile.
There are several methods ~or sgnthe~izing adipo- -
nitrile. In particular, adiponitrile may be obtained by re-
acting adipic acid with ammonia in the presence o~ a deh~dr~tin~;
catalyst, ~or example, b~ the technique~ disclo~ed in U.S.
Patent 2,200,734 of Arnold aMd Lazier which is~ued May 14, 1940
and in U. S~, Patent 2,273,633 of M. L. Ao Fluchaire which isæued
,~ ~ebruary 179 1942. Adiponitrile, e~pecially adiponitrile ob- ~-
4' tained from adipic acid3 contains impurities, some of which
~; , , ,
; ma;y be in the ~orm o~ cyclic alalnes, especially N-heterocyclic
compound~ Examp1es o~ such impurities are 2 methyl~4-amino-5, 6-
trimeth;s~lene pyrimidine, hereina~ter sometimes ra~erred to as
MAi, 2-amino-3,4,5,6-bis(trimeth;ylene)pyridine, herelna~ter
om~times referred to ~s ABP9 and 2-cyclopentyl~ amino-5,6
trimethy1ene pyrimidine, hereina~-ter som0times re~erred to as
rAP~
stated hereinabove hexameth~rlene diami~e may be
~:: form~d by the h;ydrogenation o~ adiponitrile. Ma~y catalysts
have been suggested to assist the h;srdrogenation o~ puri~ied
adiponitrile. Most ~requently, nickel or cobalt or mixtures ~ ;
thereo~,~ usually precip1tated upon a rinely divided carrier, aIld
30 ~ Ra~ey catal~st~ have been used. Iron catalysts made by a
,. .
~: :
~6~
melting technlque and actlvated by means of alkali metals haYe
also be~n suggested~ For example~ the hydrogenation of adipo-
nitrile has been carried ou-t in liquid ammonia in the presence
of hl~hly activated nickel or coba3.t catalysts at temperatures
of between 90C and 150C. If the temperature is raised far
above 150 ~ormation of undesirable hexamethyleneimine is con-
siderably intensi~led. Moreover, t;he effecti~e life of such
; catalysts in the hydrogenation of aldiponitrlle is capable of
significant improvement.
~, 10 An iron catalyst capable of being used for the
hydrogenation of adiponitrile has been described by J0 R. B.
8socock, F. T. Flood and ~. J, Kershaw in Canadian patent
gO7,059 whlch is~ued on Augus~ 8, 1972. An improved process
~, ~or the manu~acture of hexamethylene diamine by the hydrogena~
tion of adiponitrile using such an iron catalyst is described
by B. J. Kershawg ~, G~ Pounder and K. R. Wilklns in Canadlan
~! Patent 915,707 which lssued No~ember 28, 1972. Although the
use of an iron catalyst results in an i~pro~ed proces~ for the
manuf~cture of hexamethylene diamin~ by the hydrogenation of- 20 adiponltrile, especially with respect to the formation of hexa-
meth~l~neimine, the yields obtained and the effecti~c life of
~: ~he catalysk, such use may RlSO re~ult ln the ~ormation of
compounds having an obJectionable odour~ These odoriferous
compounds are belleved to be formed from ~ heterocyclic com~ :~
pounds, especlally that re~erred to hereinabove as MAP, in the
adiponitrils on hydrogenation of the adiponltrile ~o hexamethy-
lene diamlne in the pr~s~nce of an iron catalyst, such com-
pound~ not be~ng :~ormed in signl~cant amounts when the cata-
lyst is, ~or exam~ple~ a cobRlt cataly~tO The amount o~ odor-
i~erous compounds in the hexamethylene diamine may be reduced
by dlstil1ation techniques but such techniques may be inef~i-
cien~ on an industrl~l scale for the removal o~ ~uch compounds~
:
. ~..,.,
1~69L~;:3
l~ere is a need for an improved proce~s ~or the m~nu~acture o~
hexameth~lene diamlne by the hydrogenation of adiponitrile,
using iron catalystg in which the formation of odoriferous com-
~,
pounds is reduceda
A process has now been ~olmd for the manufacture of
~ hexamethylene diamine b~ the hydroge!nation o~ adiponitrile in
;~ the pre~ence of an iron catalyst in which the hexamethylene diamine so produced may be substantially ~ree o~ odori:~erous
compo~d~ form~d ~rom N-heterocyclic amines during the hydro ;~
genation o~ adiponitrlle. :
Accordingly~ the pre~ent invention provldes a pro- :
cess for the manu*acture o~ hexamèthylene di~mine comprising
the R teps o~:
`~ (a) treating crude adiponitrile with a solid acidic sorption
agent, thereby reducing the amount o~ N~heterocyclic amines in
ald adiponitrlle, and
.j ,
(b) hydrogenating the adiponitrile BO treated i~ the ~uper-
critical~vapour ph~e to produce h~xamethylene diamine, ~aid
hydrogenation being carried out a~ a temperature wlthin the
20 ~ ~ range 100 to 200C under superatmo~pheric pressure~ in the
prc~ence o~ ammonia a~d a catalyst comprising an iron com-
pound~in granular ~orm ~hich has been activated b~ contact
w~th hydroge~ at ~emperature~ not exceeding 600C, sald iron
compound being:capable ultimately o~ con~ersion into elemental
~ ~ ~ iionO
In a pre~erred embodlm~nt Or the proce~æ of the ~:
preDent lnventlon the adlpo~itrlle trea~ed in step (a) ls sub-
tantiall~ ~re~ o~ ~mmonia.
; In anot~er embodiment the agent in step (a) i8 a weak-
~acld ca~ion exchan~e re~ln and the adiponitrile is treated in
the~prc~ence o*~water.
, ~ ;
~ 3 - .
: ~
:: :
,, . , ," ., ", , ~ , .. ," ., ,~
~)64S;~3
In yet ano~her embodiment the agent in step (a) is a
strong-acid cation exchan~e resin having a macroretlcular ~truc-
ture and -the adiponitrile is treated es~entially in the absence
of waterO
In a further embodiment the~ agent in ætep ta) is
a molecular sieve, boron phosphate or bentonite.
In a particularly preferredL embodiment the crude
adiponitrile i~ treated so that the he~methylene diamine ob-
: tained there~rom contain~ less than 1 part per million o~ 2-
methyl-5,6-trimethylene pyrimidine, hereinafter sometime~ re-
~- ~erred to as MHP.
In the process o~ the pre~ent invention crude adipo-
nltrile is treated prior to hydrogenation to reduce the level
o~ N~heterocyclic amines therein. In particular, the crude
adlponitrile is treated ~o a~ to reduce the level o~ 2-methyl- :
4-amino-5,6-trimethylene pyrimidine (MAP3 ~n the adiponitrile~ -
On hydrog~nation of the ~diponitrile, MAP ~ay be con~erted to
2-methyl-5,6-trimethylene pyrimidine ~M~P) which i~ believed to
be the principal source o~ the ob~ectionable odoux ln the ::
20~ ;hexame~hyIene diamine obta~ned on hydrogen~tion o~ ~diponitrile
w~t:h iron cataly~t~ :
The crude adiponitrile being treated ~o ~ ~.o reduce
the le~eI Or N-heterocyclic amines therein should be essentially
ree o~:a~monia. In the treatment o~ the adiponitrile any
ammonia in the adlpon:Ltril0 may be ~imulta~eou~ly or e~en pre~er~
: ~ :
entially removed ~r~m the adiponitr~le with the N-heterocyclic : :
amines thereby result:~ng ln le~ e~icient removal o~ the N-hetero-
cyclio am~nes and/o:r decrea~ed capacity o~ the agent u~ed ~or the
remo~l of the~-heteroc~clic amlne~
;~ The cru~e adiponitrile is kreated by contacting the
~,
adiponitrile with an agent capa~le of reducing the amount of
N-heterocycllc amines ~n the~adiponltril~, The agent should
. " .. , .. . . , .. ,, , ., .,, . . ~ ,
~4316~L523
be capable o~ being separated ~rom the adiponitrile a~ter trea-t-
menta Suitable agents are ~olid acidic sorption agents, ex-
amples o~ which are described hereinafter. Moreover, the choice
of the agent should be such that, under the treatment conditions,
the agent will ~ail to cause deleterious e~fectæ in the adipo~
nitrile, ~or example~ by the lntroduction o~ signi~icant amountæ
o~ lmpurities, and/or in the hydrogenation of the treated
adiponitrile with iron catal~st~ The procesæ condltlons used
in the treat~ent o~ the adiponitrile, e.gO, temperature, pressure,
will depend on the agent with which the adiponitrile is treated,
as will be understood by those skilled in the ar-t. However,
the adipon~trile should be treated under conditions, e.gO, of
temperature, that prevent significant loss o~ adiponitrile by, ~ -
~ ror exa~ple, degradation o~ hydrolysisO The adiponitrile may
j~ be treated i~ the presence or absence of water, depending on
the agent used in the treatment step.
The agPnt is a solid acidic sorption agent. The agent
ls solid aæ with agents in suc~ a state the separation o~ the adipo-
nitrile ~rom the agent is ~acilitated. In addition the agent
should be acidic in nature so as to ef~ect a reduction in the
a~ount o~ N het~ro~yclic amlnes in the adiponitrile~ Fkrthermore,
; the agent should ha~s sor~tion characteristics. Such sorption
char~acteri~tic~ may beg ~or axample, ~bsorption characteristics
~nd/or ion e~chang~ characteri8tics. Example~ o~ suitable agents
are weak-acid cation exchange resins in the h~drogen form~ strong-
acid cation e~change resln~ especially such resin~ havlng a
croret:lcular str~cture, mol~cular Bi~ves~ boron pho~phate and ~:
~: ~:s bentorl~te ,,
In the ~ir~t ~tep o~ the process o~ the present ln-
~: 3o~ v~ntion crude sdiponitr1le i8 treated with the agent. In the
p~oce~s ~he ~diponitrile may b~ treated by contacting the adipo-
itrile a~d ~g~t in a continuou~ proce~s ~r irl a batch proces~,
5 -
5'~
~he ~ormer bein~ pre~erred. Pr~erably the ad~ponitr~le i8
pas~ed throu~h a ~ixed bed o* the agent.
~ hlle the adiponitrile treated ~o as to reduc~ the
amount of N-heterocyclic amines therein i8 described a~ "crude
adiponitrile~" the adiponitrile being treated is preferably
adiponitrile that has be~n subject~3d to partial purification,
e.g., by distillation~
; Techniques f'or the treatInent o~ crude adiponitrlle
90 as to reduce the amount o~ N-heterocyclic aminee ~herein are
known. For example~ the adiponitrile may be kreat~d with a
weak~acid cation exehan8e resin, ln its hydrogen form~ in the
presence of water. The adiponitrlle ~hould be substantially ~:
free of ammonia~ Th~ temperature at which the adiponitrile ls
treated is ln the range from 20C up to the t~mp~rature at which
degradation o~ the weak-acid cation exchange resin becomes ~ig- -
. nlficant. Pre~rred temperatures are in the range 20DC to 140C
!1 and eapecially in ~he range 25C to lOO~C. Pre~r~bly the adipo-
n1trile contain^~ at lea~t 5~ by weight of watgr although the
water con~ent l~ the ~diponitr~le may be varled from about 1
by weight to a ratio of water to adiponitrile o~ about 2:1 on
`~ a w~ight basis3 the upper limit o~ water being determined pri-
marily by pract~cal c~nslderations. The use o~ weak-acid cation
exchan~e re~ins in the treatment o~ ~diponitrile and the regen-
eration of the~e re~in~ i8 described in greater detail in the
copending appllcation ~rial No. 234,3S9 Of B. JD Kershaw filed
on the ~ame day as the present appllcation. A~ stated therein
the clas~ification of ion e~change re~in~ as strong-Qcld or
I weak~acid exchange resin~ i~ di~cussed in "DUO~ITE* Ion-Exchange
M~nual" obta~nable ~rom Diamond Shamrock Chemical Company~
*de~ote~ trade mark
~ 6 -
,~ ,.
.,
~(~6~5;~3
~ e crude adiponitrile may be treated wlth a strongacid cation exchange resin in the presence o~ water. Pre~erably
the adiponitrile is substantially fxee of ammonia. The adipo-
nitrile should contain at least 1% b~ weight of water and prefer-
ably at least 3% by weight of water. me water content may be
as high as 2 parts by weight of water for each part by weight of
adiponitrile, thi~ upper limit being determined primarily by
practical conslderations. The temperature at which the adipo-
nitrile is treated may be in the range ~rom 20 C up to the
temperature at which de~radation o~ the strong-acid cation ex-
change resin become~ æignificant. Pre~erred temperatures are
in the range 20~C to 150C and especially ln the range 20C to
o
100 C. ''
The crude adlponitrile may ~lso be treated with a :: -
strong-acid cation exchange resin having a macroreticular
structure and essentially in the absence o~ water. me adipo-
nitrile should be substantially ~ree o~ ammonia. The temper-
ature at which the adiponitrile is treated i8 ln the range - -
rom 20C up to the temperature at which degradation o~ the
~20 s~rong-acid cation exch~lge res1n becomes signi~ican~, Pre-
erred temperatur s are in the range 20C to 150C and espec-
ially ~n the range 50C to 110C~ me expression "treatment
. ~ ~
o~ ad~ponitrile esse~tlall~ in the abs~nce o~ water" means thetreatm~nt o~ adiponitrile contain~ng less th~n Ool~ water.
; Treatment in the presence o~ water may re~ult ~n the hydrolysis
o~ any 2-cyanocyclope~tylidene~m~ne pre~en~ aæ ~n additional
impurit~ ~ the adiponitrileO Such hydrolysi~ would result in
th~ ~ormation o~ a~onia whlch would be absorbed by the resin
thereby reduc~g the capaci~y o~ the re~in ~or removlng other
~;~3o~ impuritlés. me ~trong-acid ca~ion exchiange re~n~ h~ving
;~acroret~cular structure are capable o~ being used ~n anhydrous
7 -
medlaO Such resin~ are de~cr$bed ln "AMBERL~ST* 15 synthetic
re~in catalysts" obtainable from Rohm and Haas. me use of
strong-acid cation exchange resins having macroreticular struc-
ture in the treatment of adiponitri.le and the regenera~ion o~
the3e re~inq i~ de~cribed in gr~ater detai~ ln Canadian Patent
1,0429465 of B. J. Ker~haw which l~lsued on November 14~ 1978~
Another method for the txeatment of crude adiponitrlle
i~ uslng a molecular sieve sel@ctedl from the group consi~ting
o~ Type X and Type Yg and mlxtures thereof~ a~ the agent and
treating the adiponitrlle in the presence o~ water at a tempera-
; ture ln the range of 25C to 250Co Type Y molecular sieve~ are
preferred. me molecular sleve may ~e in a poly~alent cation
~orm, the ammonia ~orm or the hydrogen form~ although when the ~ :
molecular si~ve i8 in the ammonla ~orm the tempera~ure should
be in the range 100C to 250Co The adiponitrlle may also be
treat~d with the molecular sieves substantially in the ab~ence
o~ water, provlded that th~ temperatur~ i5 in the range 100C
to 250C~ When water is pr~sent, the w~ter cont~nt o~ the
adiponltril* may be as hi~h as a ratiG o* water to adlponitrile
of about 2:1 on R weight basi~9 the upper limit o~ the level o~water belng determin~d prim2rily by practical consid0rations.
I~ the ~d~ponitrlle contaln~ water and, in addition~ contains
2-cya~ocyclope~tylldeneimine a~ an impurity and i~ the tempera-
~: ture i~ at laast 140C the 2-cyanoeyclopentylideneimine ~ay be
hydrolyzed, one product o~ the hydrolysis be~ng Ammonia. It
i5 b~lle~ed tha~ the relative affinlty o~ the m~lecular ~ieve
; ~or N heterocycli,c amin~ over arr~onia increa~es wlth increa~i~g
~: tem~eraturQ and ~bat t~mpQra~ures ~ or ~xample, at least
180C the N-h~terocyclic amines are pre~erentially ~bsorbed by
the molecular sieveg Thus, 1~ de~ired the molecular sleve~
may be used to hydrolyze 2-cyanocyclopentylideneimine~ thereby
: *de~ot~s trade mark
:: ` .
,, ,;""`,~",,";",'.,";~:""~'.','"'''''"'
1~6~S~
reducing tha amount of 2-an~nomethyl cyclopentylamine, the
hydrogenation product of 2-cyanocyclopentylideneimlne~ in the
hexamethyle.ne diamine 3ubsequently produced from the adipo-
nitrile~ as well as reducing the annount o~ N-heterocyclic amines~
The use of molecular sieves ln the treatment of adiponitrile3
the regeneration of these sieve~ and a dlscussion of the atruc-
ture of the sie~es ~s de~cribed in greater detall ln copending
Canadian patent application Serial No. 234,357 o~ B~ ~. Kershaw
~lled on the same day as the present applicationO
A ~urther method ~or the treatment of crude adipo-
nitrile is using boron phosphate and/or bentonite as the agent
and treating the adiponitrile at a temperature ln the range 20C
to 100C and, preferably~ substantiRlly in the absence of ammon~aO ;`
The adiponitrile may be treat~d in the presence or absence of
water. ~owe~er~ it ls preferred to treat the adiponitrile in
the presence of both water and a water soluble acidic compound,
for exampleg acetic acid or pho~phoric acid~ The adlponltrlle
may contain up to two parts, by welght, of water per part of
-
adiponitrile, pre~erably 1 to 10% by weight of water. The u~e
of bentonltc a~d boron phosphate in the treatment of adiponitrile
and the regenerati~n of the bentonite and boron p~osphate i5
deficrib~d in greater detail in Canadian Patent 1,042,464 of
B. J, Ker~haw whlch i~sued on ~ovember 14~ 1978.
After treatment to r~duc~ the level o~ ~heterocyclic
amine~ there~ n the adiponitrile is hydrogenated ln the super-
critlcal v~pour phase to produce hexamethylene diamine~ Th~
hydrogenation is carried out at te~perature~ ln the range 100C
to 200C under supera~mo~pheric pressure~ in the presence of
a~moniR and a catalyst. Th~ catalyst comprlse~ an lron compound
in granular ~orm which has b~en activated by contact wlth hydro-
g~n at temperatures not exceeding 600~C~ the iron co~pound being
_ g _
~6~5;~3
capable ultimatel~ o~ convers-lon into elemental iron~ By "super-
critical vapour pha~e" is meant a condition in whlch the temper-
ature o~ the reactor is above the pseudo-critical temperature
of the reactor ~eed mi~ture.
When the iron catalyst is used in a f'i~ed bed it i8
preferably uæed ~n relatively coar~e granular form, e . g ., a
particle size of from about 0.25 to 0~50 cmO Much flner particle
~izes tending to powdPrs ma~ be used in a fluid bed or in a slurry-
type reactorO
me pre~erred method of activation o~ the iron catalyst
is to treat iron oxide by heating it at about 400C in a ~urnace .:
under a stream of dry hydrogen for 40 to 50 hour~ using a rel
atlvely high ~low rate for th~ ~tream of hydrogenO If activ-
ation is allowed to proceed too long a perlodg sintering of the
catalyst may occurO It is desirable that substantially no
water be prese~t during.the actlvation treatment. The catalyst
prepaxed ln this manner will ~requentl~ show surfare areas of
: up to 30~35 m /g~ me activation of ~ron catalysts is described
in grea~er detail ~n ~he a~orementioned Canadian Patent 907,059
-~20 o~Boocock:et al.
:me hgdrogenation step o~ the proce~ o~ the presert
nvention i~ part~cular~ adapted ~or continuous operation.
;The~temp~ra~ture o~ the hgdrogenation should be regulated with~n
the r~ge o~ ~rom 100;~ to 200C and accuratel~ mainta~ed
durlng the cont~nuou~ react.~on by co~ventional procedure~ such
s ~he regu~ation o~ ~low rate~ and the t~mperature o~ the
reacbant~. Tempera-ture~ o~ 105 C to 165 C e~pecial~y 110 C
to 150 C are pre~erred. The hydrogenation o~ adiponltrile
u~ing an lron catalys~ i~ de~cribed in greater detail in the
a~oremantioned Canadian .Patent 915~707 of Ker~haw et al.
~ ~ ,
The prir~ciple source o~ the ob~ectionable odour is
: balieved ~to be the compound referred to hereinabove as MHPo
~ 645Z3
The ~ormation o~ M~IP in the hydrogenation i~ believed
to be dependen-t on the temperature o~ the hydrogenation reaction7
While lower level~ are formed at lower temperatures such lower
temperatures may not be practical ~or other reasons, ~or example~
rate o~ hydrogenation o~ adiponitrile and increas0d capital
cost~ ~or the equipment due to the re!quirement that the hydro-
genation be carried out ~t higher pre~ssure in order to operate
in the super~critical vapour phaseO Because MHP may be readlly
detected by smell it is pre~erred that the hexamethylene diamine
~ormed on hydrogen~tion o~ adiponitrile conta~n less than l ppm
0~ MHPo ' '
The proce~s o~ the present invention i~ partlcularly
useful ~or the manufacture o~ hex~methylene diamine ~rom adipo-
nitrile that has been obtainecl f'rom adlpic acid ~nd ammonia.
.
: The present invention ls illustrated by the ~ollowing
~ examplesO
,~ E ~ ~PLE I
7 A sa~ple of lO0 ml of crude adiponitrile~ hexeinafter
,~
referred to a~ adiponltrile ~l~ was heated to 100Co 1 g of
20~ ~AMBERLYST 15~cation exchange re6~n3 a strong-ac~d cation exchange
resln o~ macroreticular structure, was added to the adiponitrile
and the mixture' wa~ stirred ~or 2 hours at 100Co The cation ..
excha~ge-re~in wae ~lltered o~f and the ~iltrate o~ puri~ied ~ '~
~:; adlponitril~, referred to hereina.~ter a~ adipo~trile ~2 wa~
analyzed using ga~ chro~atographic techniques.
e re~ult~ o~ the analysi~ are ~iven in Table Io
~: :
: EXAMPLE II '"
h ~ample o~ lO0 ml o~ adipo~itrile ~l was heated to
~ 9~5 CO 2 g o~ SK~500* (pol~valent cation ~orm)~ a Type Y molec- :' :
'~30 ~ ular ~ieve obtalnab:Le from the Linde Divl~ion of Union Carbide ':
: ~ ,
Corpor~tio~, were aaded to the adipon~trile and the re~ultant
' *denote~ trade mark
..
~: . : : , - . ..... . . ...... .. ...
.: i. . . .
~ii4~Z3
mixture was stirred ~or 2 hours at 95 C. The molecular sieve
was .~iltered o~ and the ~iltra-te of` purified adiponitrile,
re~erred to hereina~ter as adiponitrile ~3, was analyzed b~
gas chromatographic technlque~.
The results of the analysi~ are given in Table I~
EXAMEIE III
A sample o~ 100 ml of adiponitrile ~1 was mixed
with 6 ml of water and 1 g o~ DOWE~' 50W-X8~ a strong-aGid
cation exch~nge re in obtainable from the Dow Chemical Company.
The mix-ture wa~ stirred ~or one hour at ambient temperature
and then ~iltered. The ~lltrate o~ adiponitxile wa~ partially
dehydrated by heating to 160 C under reduced pre~ure (12 mm
Hg). me dPhydrated adiponitrile, hereina~ter re~erred to as
adiponitrile ~4, wa~ analyzed u~ing gas chromatographic tech-
: niquesO
,~ The results o~ the analysi~ ~re given in Table I.
EX~MPLE IV ~ .
A sample o~ 100 ml of adiponltrile ~1 was mlxed
w~th 6 ml o~ water ~nd 2 g o~DUOLITE* CC-3~ ~ weak-acid
~20 ~ cation exchange resin obtainable ~rom Diamond Shamxock Chem- ..
lcal CompanyO The mixture wa~ stirred ~or one hour at ambient
temperature and then ~ilteredO me ~iltrate o~ adiponitrile
was~paxti~11y dehydrated by heating to 160 C under roduced
pre~sure (lZ mm Hg). The dehydrated adiponitrlle, here~na~ter
re~err~d to a~ adiponitrile ~5, was analyzed u~lng gas chromato~
: ~ gr&phic technique~
The re~ult~ o~ the anal~ are giver1 irl Table I~
~,~
EXAMPLE V
28 g o~ -8+14 me~h sample o~ a naturall~ occurr~ng ~.
30~ iron o~ide~a203) containl~g a ~ew percent o~ ~llica and oth~r
tr~ce imp~rities wa~:activ~ted by heating in a 6txeam o~ hudrogen
*denot~s trade~mark
12 -
..
~ C!1645;~;~
(16 l/hr.) and nitrogen (2.5 l/hr~) at a temperature o~ 300-350C
until essentially all o~ the iron oxide has been converted to
elemental lron.
2 g o~ adiponitrile, 1 g o~ the activated iron catalyst
and 20 g o~ anhydrou~ ammonia were added to a stainle~s steel
autoclave having a capacity of 100 ml. The autoclave was then
pressurized to about 90 kg/cm with ~drogen~ The autoclave
wais then hea~ed to 180 C and mainta~led at 180 C ~or 30 mlnute6.
The autoclave waA continuou~l~ agitated during thi~ period at
elevated t~mperature~ A~ter coollng the product obtained wa~
di~solved in a minimum ~mo,unt o~ water and analyzed ~or MHP
; using ga~ chromatbgraphic techni~uei~0 Further experimental
deta~ls and the result6 obt~lned are glven in Table II.
TABLE I .
,......................................................................... .
Adiponltrile ~ 1 2 3 4 5
Impuritles* (ppm)
CPI 1750 428 1580 1090 1910
Succinimlde 796 731 377 825 901
MAP:: 258 ~5 65
~BP 1040 75 325 10 160 ~:
C~A 917 13~0 692 960 9
VAP ~ ~ : 76 51 0 35
ater ~ 600 800 900 200 100 ::
CPI~ 2-cyanocyclop~ntylldeneimine
MAP~=~2~-methyl-4~amino-5,6~trimethylen~ pyrimldine
ABP~= 2-~mino-3~4,5,6~bls(trlmeth~1ene)~yridine
C~A = ~ ~cyano~aleramide ..
VAP~ cyclopent~1~4-amlno-5,6-trlm~thylene ~yrimidine
,
.,~" . ............................... . .
,
~BLE II
Run No. 1 2 3 4 5 6 7
Adiponitrile ~ 1 1 1 2 3 4 5
Autoclave Pre~sure
(kg/cm~) 224249 214 226 240 ~29 238
MHP* (ppm) 11 11 10 0 1 0 0
Odour** yes yes yel3 no ye~ no no
*MHP = 2-meth~1-5,6-trimeth~lene pyr:imidine
** objectionable odour as detected by at least 3 out o~ 4 people
. 10EXA~PLE VI
Adiponitrile #1, ammonia and hydrogen ~ere ~ed to a
continuous reactor that was 2~5 cm ~n diameter and 35 cm in
length and which contain an activated ~used iron oxide con-
taining 3% o~ alumlnaO The hexamethylene diamine obtained wa~
analyzed using gas chromatographic technlques. Further experi-
mental det~ils ~nd the reæul-tæ obtain~d are given in Table III.
- :
~:As a comp~rison the iron cat~lyst was replaced with : ::
,:~a cobalt~cataly~t o~ the type dè~cribed aæ cobalt cataly~t (X)
n the ~orementloned Canadian P~tent 915,707~ ~xperimental :~
det&ils and the result~ obtained are given in Table IIIo
The results show that under ~lmilar conditions the
hydrogenatlon o~ adiponltrile using ~n iron cat~lyst resultæ
in~the~ormatlon o~ th~ ~dorous compound MHP ~rea~ wlth a
coba1t~cat~lyst~MHP is not ~ormedO Such cobalt c~talyst~ have ~;
: b~en used industriall~ ~or the hydrogenatlon o~ ~diponitrlleO
, ~ . .
~14 - .
""'~
,~ ~ " . ., i
~6~ 3
TABLE III
Run No. 1 2 3 4
Catal~st Fe Fe Co Co
: Adlponitrile tg/hr.) 399 47() 448 484
Ammonia (g/hr.) 1780 2200 1800 2080
Hydrogen (l/min.) 27.4 391,2 36.8 37-8
Reactor Temperature (C)
Inlet 110 104 88 95
Outlet 155 141~ 132 13Ç
Hexamethylene Dlamine,
yield (~) g7.0 97~8 96.8 96.6
MEIP in Xexam~thylene
Diamine (ppm) l9 ll O O
No-te: Adiponitrile ~1 had not been treated so as to reduce -the
:: amount of N-heterocyclic amines therein~
~: ,
:~ :
. ~ :
.
: , ~
:~; : :~.: : .:,. .. . . . . .
