CA1279655C - Process for separating iodine and its compounds from the products obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction - Google Patents
Process for separating iodine and its compounds from the products obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reactionInfo
- Publication number
- CA1279655C CA1279655C CA000516170A CA516170A CA1279655C CA 1279655 C CA1279655 C CA 1279655C CA 000516170 A CA000516170 A CA 000516170A CA 516170 A CA516170 A CA 516170A CA 1279655 C CA1279655 C CA 1279655C
- Authority
- CA
- Canada
- Prior art keywords
- iodine
- carbonylation
- products
- methanol
- compounds
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/487—Separation; Purification; Stabilisation; Use of additives by treatment giving rise to chemical modification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/54—Preparation of carboxylic acid anhydrides
- C07C51/573—Separation; Purification; Stabilisation; Use of additives
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Catalysts (AREA)
Abstract
PROCESS FOR SEPARATING IODINE AND ITS COMPOUNDS FROM
THE PRODUCTS OBTAINED ON SUBJECTION DIMETHYLETHER, METHYL ACETATE OR METHANOL TO A CARBONYLATION REACTION
ABSTRACT OF THE DISCLOSURE
Iodine and its compounds are separated from the carbo-nylation products acetic acid, acetic anhydride or ethylidene diacetate obtained on subjecting dimethyl-ether, methyl acetate or methanol to a carbonylation reaction; the total iodine contaminating the carbonyla-tion products is reduced to less than 20 ppb iodine; to this end, the carbonylation products are treated at 50-200°C with a hydrogen/carbon monoxide-mixture in the presence of at least on noble metal belonging to group VIII of the Periodic System of the elements as a cata-lyst, and separated from the catalyst.
THE PRODUCTS OBTAINED ON SUBJECTION DIMETHYLETHER, METHYL ACETATE OR METHANOL TO A CARBONYLATION REACTION
ABSTRACT OF THE DISCLOSURE
Iodine and its compounds are separated from the carbo-nylation products acetic acid, acetic anhydride or ethylidene diacetate obtained on subjecting dimethyl-ether, methyl acetate or methanol to a carbonylation reaction; the total iodine contaminating the carbonyla-tion products is reduced to less than 20 ppb iodine; to this end, the carbonylation products are treated at 50-200°C with a hydrogen/carbon monoxide-mixture in the presence of at least on noble metal belonging to group VIII of the Periodic System of the elements as a cata-lyst, and separated from the catalyst.
Description
l ~ ~ S ll~ ),2 t i n r~ r (~ t, ~ t:~ .I r) l r) r' r'` '; ':; r ~:~ l' c; c p .l r' ~l ~ i r~ -J
i~J(iirle (Irl(l it~ r~ r?o~ (lr~ Fl(~ r (.~ ylc~ti(1rl pro-d(Jcts a(elic acicl, aceti( al1l1yrlridr- or ethyli(lr?r1e di-acrt,ilte wlli(1l arr oht.lioc(l 011 sllt),jc( l,.in(J dilllethyletller, 1ll(~tl1y1 act~ f~ llllo~ (.1rl)r1lly]~1t:iol-l Ir~ctlor i(l t~lr? I)lr~ rl(r? "r ., t~lt.;)ly~ (?rll~li(lirl(l iorlirle, Irlllr?rr?-in thc tol.)1 iodirlc colltalllinalill(J Ihe r.lrt)ol1y1atio ¦ ~ ~' ( ) ( I l l C ~ ( r ! ( l t() ~ rr)~ ,r, 1l~]l, 2 n ~
iodinr? by trci1tirlg the CaTI)ooy] al ion pr odllcts at tempr~-~at~reci of 50 - 20n~c wit~ r(lrlerl 1(l t~le preserlce Or at least one nnhle metal belon(Jin~1 to clroup VIII oF tl1e F'eriodic System o~' t,lle elrmel-)l,s, ar)d sel)arat.irlg tllen r 1~ 0111 t ~ ) P c ~ t ;l ] ~ r~ t .
A process oF this l<incl has a:LIea(IY her?r) dr?scrit)(?rl io Gern)r1(1 Sp(?ciFicatioo I)E-A-33 31 548 In thir; prr)_ cess-, it hac; llJrnr?(i out ~h.1t 11)( c<ll.)1~tic pelforlnar)re sut)s:i(:les rather ral)i(1ly r.o tl)at it. is in\larial)iy necc?s-sary For the processincl tempcraturc ar)d/or catalyst ctual-1tity to be incrr?asecl so as to acl1ieve a satisfacto-rv iodine separatinrl eFfect. II)(?se a1e sLeps which en-t ail an undesi-rclble forrnat:iol1 of by-l)ro(illctc-i~ e.y.
acetai(lehyde, acetic acid allrJ et)1yli(i(?l1e diacetclte clur-iny the 1-12-treatlllerlt acr?tir.~ anllydride corltal))irlated With iodirle is subjected to. rhe prrC.rrlt inver1tior) now pro-2r~ \/irie'~ ~3 procec;s Wil i cl) ~!I)ab] (?S tl1r (~ t ~I(J(` ~Iss(l-Ciat.e(l IAJith the prO(`I' .'' deS(`l'ih('d ill [.el'l(nll) Spr(`if ica-tion DE-A-33 31 548 to be set aside. Io this er)d, the invention ur1expectedly providl:?s For ~just a minor pro-12~g~55 23343.812 portion of carbon monoxide to be added to the hydrogen/noble metal-reaction system; as the targeted result, the Eormation of by-products e.g. acetaldehyde, acetic acid and ethylidene diacetate is strongly reduced and the efficiency of the catalyst is considerably prolonged. In this process, the iodine - regardless of whether bound or elementary - is readily removed from the carboylation products to be purified.
The invention provides a process for separating iodine and its compounds from the carbonylation products, acetic acid, acetic anhydride or ethylidene diacetate, obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction, wherein the total iodine contaminating the carbonylation products is reduced to a content of less than ppb iodine, which process comprises treating the carbonyl-ation products at a temperature of 50 - 200 C and over a period of 0.2 - 6 hours with a hydrogen/ carbon monoxide mixture in the presence of at least one noble metal belonging to group VIII of the Periodic System of the elements as a catalyst, wherein 0.001 - 1 mol each of hydrogen and carbon monoxide is used per mol carbonylation product, and separating the carbonylation products from the catalyst.
Eurther prefered features of this invention which are substantially the same as those described in German Spec-ification DE-A-33 31 548 provide:
a) for carbonylation products containing less than lO0 ppm total iodine to be used;
b) for the noble metal used to be finely distributed on a carrier;
c) for the corbonylation products to be treated over a period of 0.2 - 6 hours;
~i~796S5 d) .Eor the carhonyl.ation products to be treated under a pressure oE 0.5 - lO bars;
e) for 0.00] - l mass % noble metal, hased on the carbonylation products, to be used as the catalyst.
The fixation of the iodine-containing contaminants should conveniently be e~fected by adding the noble metal, which should preferably be finely distributed on a carrier, ~ .~, ~, lX796~;5 st.clr~l of Ille erll ire r;lrhrlny~ Jrl prr)trsr;. Iodi.rlt.-ror~tairl-irl~i r~ r~ f ixr~ to ~r~ llrl~)lr~ r~t,ll o~ c~lrritl .~re r~ f ~ y s r~ l r ~) ~ r~ d l:) y r f~ lll r) ~/ i r l fl t. ll t~ t~ . rl l y ~; ~ f r o lrl t tl e r~ l)UI i f i('rl produrt hy fill,clirlt~ )el)rll(lillrl on the (luarltity of iodirle fixrci l,o l,llr n()l!:l(? mf-~tcll l,hr lal-l,er is recycled for r r - u s e o r r e p l a r r d l- v f r e ~; h r a t a l v s t. .
Ner(llec;s tr) S.ly, il is alr;o p-)ssit)le lor the nob:le m(?l.al catalyst all(l hyrlTr)(~l(rl/r;,ll)r~l~ mr~r~rlxi-lr-mi~l,llrr le-IU cesiarv l-)r el,imirlat,.i.rl(l I.hr io(lill(-corll;lillirlrl cont,amirlrlrlts to be a~lclr,cl ahea(J nF thc~ last Ol~ nrxt t,o last puri fication stage in wtl:icll the carl)ollyli~lir)rl prorluct, is f'rr,ed ~rom high-l)oiling resirlLIe or low-l)(lilincl f~rlcl,iorls.
ille prr)crss nr t.his in\/rrltirlll pellnils t.he tot,a]. ioclirle cnntrrlt in t.llr treateci cnrl)c)nylrlli(lll pl`O(ilJ(` t t O hr r ecluct?d hrynll(l l,llc~ limit, of rlet,((l,i(ll-l ol' Irss tharl 5 pl)l) (= 5 parls hy wr.?irlht iodine per onc~ 1)ill inn (109) parts hy weight carbl:)rlylatiorl product).
Ihe catalyst preparat..ion does not f'orm pclrt of ttle in-2(1 vellt.io(l. It is howe\/r?r prt.~ferat)lt! lo ar)ply tlle nobl.e rnetalto the crlrrier in the form of' VeTy f`,inely di,vicied an(i cata-lytically act.ive mrlterial by init.ially imprerJnating the carr.ier selected witl- a noble rnr~,al .salt, solution and then treatirlg it, wi.th an amlllc)r)iacal tlydrazi.rle solution. In this Z5 way very finely ciivideci not)le mrtal is appli,ed to the carrier; after wasllinrJ until nel.ltral arld clryillg, the cat.a-.l,yst is ready for ucie. It: is also possible for the noble metal to be set, free hy rerillcillc) treat,l))erlt. wit.h hydrngen at elevated temperature.
:3[~ The useful carriers rnr the noble met.al comprise e.ri.
12~5~
5ilit'ic aC.i(J antl alumilllJm nxi(lr?. Tlle p.lrticlr sizr oF the carrier rnay vary within the wide limits oF 0.01 - 10 mm, cleperlding orl whettler the catalyst i9 usetJ e.g as a fixed bed or fluiclized btd cata]yst. Ihe r-,ame is true concerning S its inner surFace area (deterrninecl by the BET-method) which may vary within the range 1 - 700 m /y. The noble metal concentration on the cr-)rrier rnay also vary within wide limits, but should preFerably be within the range 0.5 - 5 mass O. rhe carbonylatiorl product should suitably be sepa-rated from the noble metal catalyst by filtering.
Pure hydrogen and pure carbon monoxide shouldpreferably be used, but hydrogen and carbon monoxide con-tainlng e.g. nitrogen, argon and further inert components can also be employed.
The useFul noble metals include ruthenium, osmium, iridium, preferably however rhodium, palladium, platinum.
It is possible for the present process to be carried out continuously or discontinuously.
The total iodine is determined analytically by an iodine-catalyzed reaction between arsenic and cerium ions with photometric final determination oF cerium.
Example 1 200 9 of a carbonylation product of acetic acid (19.1 mass 0)~ acetic anhydride (80.7 mass O) and ethylidene di-acetate (0.2 mass ~O) contaminated with 2 ppm total iodinewas admixed with 0.15 9 palladium finely distributed on 10 9 SiO2 (particle size = 0.01 - 0.2 mm, BET-surface area =
350 m /9 and contacted with 8 l/h of a mixture of 50 vol.,O
hydrogen and 50 vol.,O carbon monoxide at 120C. After a contact timr--3 of 5 hol.)rs the supply of thr. hydrogen/carbon monoxidc-mixtorr- was arrested the rarbonylclt;ion product was f:iltered and an/llyzed A total lodi.ne vallle of 'less -than 5 ppb corresponding to an i.od:ine separat;i.oll of rnore than 99.8 % was determined. Gas-chromatographic (GC) analysis indicat-ed that the product consisted of 19.15 mass % acetic acid 80.6 mass ~ acetic anhydride and 0.25 mass % ethylidene di-acetate; in other words -the carbonylation product treated as described hereinabove had a composltion which scarcely dif-fered froln tha-t of the untreated product. Only 0.1 % acetic anhydride was found to have been lost.
Example 2 Ihe Pd-cat.llyst usc(J in l-xr)lllplr 1. was hrr)ugtlt into con-tact over a period of 200 hours wit;ll altogetller 8 kg carbony-lati.on prodoct composed of 19.1 mass ~ acetic acid 80.7 mass llo aceti.c anhydride and 0.2 mass ' ethylidene diacetate con-taminated with 2 ppm total iodine and also contacted with 8 l/h of a gas mixture of 50 vol. ' hydrogen and 50 vol. %
carbon monoxide at l20C. The ca:rbonylation product so treated and filtered was analyzed after 10n and 200 hours contact ;:ime respectively. 'I'he total iodine valuesfoulld were in each case less than 5 ppb corresponding to all iodi~ separation of more than 99.8 %. Ihe composition of the product was de-termined gas-chromatographically; it was 19.15 mass % acetic acid 80.6 mass % aceticanhydride and 0.25 ma.ss % ethylldene diacetate which remairlr-d constant over the entire contact period.
Example 3 (comparative Example) 200 9 of a carbonylation mixture of acetic acid (19.1 ~27965S
mass %), acetic anhydride (8r).7 mass ,~) and ethyl:iclerle cli-acetate (().2 mass ~/0) contaminatecl wlth 2 ppm total iodine was admixed with 0.15 9 pa:l:ladium finely clistributed on 10 g SiO2 (particle size = 0.()l - 0.2 mm, BFT-surface area =
350 m7/g), arld corltacterl wi~;h 4 ~/h hytlrogerl at 120"C. After a contact prriorJ of 5 hoors, the sopply of hydrogen was arrested, the carhorly]atlorl product was filtered and ana-lyzed. A tolal ioclirle value nf less thr)ll 5 ppb, correspond-ing to t;he ser)arltinll of n~ore thrlrl ~'3.8 1". iodine, was cle-t;ermirled. Ihe product was analyzrd gas-chromatographically and foond to contain 20.() mass ,~, acetic acid, 77.7 mass ~'~
acetic anhydride and 2.3 mass % ethylidene diacetate, i.e.
less acetic anhydride and more acetic acid and ethylidene diacetate than the untreated product of which the composi-tion was found to have been modified. 3.0 % acetic anhydride was found to have been lost after the contact period.
Example 4 (comparative Example) The Pd-cata]yst of Examp~e 3 was brougllt into contact over 200 hours with altogether 8 ky of a carbonylation pro-duct containing 19.1 rnass % acetic acid, 80.70 mass %
acetic anhydride and 0.2 mass % ethylidene diacetate, con-taminated with 2 ppm total iodine, and also contacted with 4 l/h hydrogen at 120C. Ihe carbonylation product so treated and filtered was analyzed after 100 and 200 hours contact tirne, respectively. Already after 100 hours, the residual iodine content was reduced to 0.4 ppm only corresponding to an iodine separation of B0 %. To improve the iodine separa-tion, the temperature inside -the reactor was increased to 130C, after 100 hours. This permitted the iodine content in -~Z79~
the reaction prnduct to be reducrrd to 7() ppb, corresponding to an iodine separation of 96.5 %. After a furt;her 100 hours contact time (total contact period = 200 hours), the ex-periment was terminated and the filtered product analyzed.
After that time, it was melely possible to reduce the io dine conterlt fronl 2 ppm to 0.3 !:)prn, corresponding to an indine separat:ion of 85 ~'u. Gas-chrnmatogIapl-lic analysis indicated a distinct change in the composit;ion of the car-bonylation procluct used. It contained 20.5 mass % acetic acid, 76.0 mass % acetic anhydride, 3.5 mass % ethylidene diacetate and 600 ppm acetaldehyde.4.7 %anllydride, based on t;he feed mate~rial, was found to have been lost.
Example 5 200 9 acetic anhydride contaminated with 0.6 ppm to-tal iodine was admixed with 0.15 9 palladiurn ~inely distributed on 10 9 silica gel (particle size = 0.01 - 0.2 mm, BET-surface area = 580 m2/g)and contacted with 10 l/h of a gas mixture of 95 vol.% hydrogen and 5 vol. % carbon monoxide at 100C. After a contact period of 3 hours, the acetic anhydride was separated from the catalyst by filtering and analyzed. An iodine value of less than 5 ppb, corresponding to an iodine separation of more than 99.2 %, was determined.
The acetic anhydride was analyzed gas-chromatographically but could not be found to contain a by-product, such as ethylidene diacetate, for example.
i~J(iirle (Irl(l it~ r~ r?o~ (lr~ Fl(~ r (.~ ylc~ti(1rl pro-d(Jcts a(elic acicl, aceti( al1l1yrlridr- or ethyli(lr?r1e di-acrt,ilte wlli(1l arr oht.lioc(l 011 sllt),jc( l,.in(J dilllethyletller, 1ll(~tl1y1 act~ f~ llllo~ (.1rl)r1lly]~1t:iol-l Ir~ctlor i(l t~lr? I)lr~ rl(r? "r ., t~lt.;)ly~ (?rll~li(lirl(l iorlirle, Irlllr?rr?-in thc tol.)1 iodirlc colltalllinalill(J Ihe r.lrt)ol1y1atio ¦ ~ ~' ( ) ( I l l C ~ ( r ! ( l t() ~ rr)~ ,r, 1l~]l, 2 n ~
iodinr? by trci1tirlg the CaTI)ooy] al ion pr odllcts at tempr~-~at~reci of 50 - 20n~c wit~ r(lrlerl 1(l t~le preserlce Or at least one nnhle metal belon(Jin~1 to clroup VIII oF tl1e F'eriodic System o~' t,lle elrmel-)l,s, ar)d sel)arat.irlg tllen r 1~ 0111 t ~ ) P c ~ t ;l ] ~ r~ t .
A process oF this l<incl has a:LIea(IY her?r) dr?scrit)(?rl io Gern)r1(1 Sp(?ciFicatioo I)E-A-33 31 548 In thir; prr)_ cess-, it hac; llJrnr?(i out ~h.1t 11)( c<ll.)1~tic pelforlnar)re sut)s:i(:les rather ral)i(1ly r.o tl)at it. is in\larial)iy necc?s-sary For the processincl tempcraturc ar)d/or catalyst ctual-1tity to be incrr?asecl so as to acl1ieve a satisfacto-rv iodine separatinrl eFfect. II)(?se a1e sLeps which en-t ail an undesi-rclble forrnat:iol1 of by-l)ro(illctc-i~ e.y.
acetai(lehyde, acetic acid allrJ et)1yli(i(?l1e diacetclte clur-iny the 1-12-treatlllerlt acr?tir.~ anllydride corltal))irlated With iodirle is subjected to. rhe prrC.rrlt inver1tior) now pro-2r~ \/irie'~ ~3 procec;s Wil i cl) ~!I)ab] (?S tl1r (~ t ~I(J(` ~Iss(l-Ciat.e(l IAJith the prO(`I' .'' deS(`l'ih('d ill [.el'l(nll) Spr(`if ica-tion DE-A-33 31 548 to be set aside. Io this er)d, the invention ur1expectedly providl:?s For ~just a minor pro-12~g~55 23343.812 portion of carbon monoxide to be added to the hydrogen/noble metal-reaction system; as the targeted result, the Eormation of by-products e.g. acetaldehyde, acetic acid and ethylidene diacetate is strongly reduced and the efficiency of the catalyst is considerably prolonged. In this process, the iodine - regardless of whether bound or elementary - is readily removed from the carboylation products to be purified.
The invention provides a process for separating iodine and its compounds from the carbonylation products, acetic acid, acetic anhydride or ethylidene diacetate, obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction, wherein the total iodine contaminating the carbonylation products is reduced to a content of less than ppb iodine, which process comprises treating the carbonyl-ation products at a temperature of 50 - 200 C and over a period of 0.2 - 6 hours with a hydrogen/ carbon monoxide mixture in the presence of at least one noble metal belonging to group VIII of the Periodic System of the elements as a catalyst, wherein 0.001 - 1 mol each of hydrogen and carbon monoxide is used per mol carbonylation product, and separating the carbonylation products from the catalyst.
Eurther prefered features of this invention which are substantially the same as those described in German Spec-ification DE-A-33 31 548 provide:
a) for carbonylation products containing less than lO0 ppm total iodine to be used;
b) for the noble metal used to be finely distributed on a carrier;
c) for the corbonylation products to be treated over a period of 0.2 - 6 hours;
~i~796S5 d) .Eor the carhonyl.ation products to be treated under a pressure oE 0.5 - lO bars;
e) for 0.00] - l mass % noble metal, hased on the carbonylation products, to be used as the catalyst.
The fixation of the iodine-containing contaminants should conveniently be e~fected by adding the noble metal, which should preferably be finely distributed on a carrier, ~ .~, ~, lX796~;5 st.clr~l of Ille erll ire r;lrhrlny~ Jrl prr)trsr;. Iodi.rlt.-ror~tairl-irl~i r~ r~ f ixr~ to ~r~ llrl~)lr~ r~t,ll o~ c~lrritl .~re r~ f ~ y s r~ l r ~) ~ r~ d l:) y r f~ lll r) ~/ i r l fl t. ll t~ t~ . rl l y ~; ~ f r o lrl t tl e r~ l)UI i f i('rl produrt hy fill,clirlt~ )el)rll(lillrl on the (luarltity of iodirle fixrci l,o l,llr n()l!:l(? mf-~tcll l,hr lal-l,er is recycled for r r - u s e o r r e p l a r r d l- v f r e ~; h r a t a l v s t. .
Ner(llec;s tr) S.ly, il is alr;o p-)ssit)le lor the nob:le m(?l.al catalyst all(l hyrlTr)(~l(rl/r;,ll)r~l~ mr~r~rlxi-lr-mi~l,llrr le-IU cesiarv l-)r el,imirlat,.i.rl(l I.hr io(lill(-corll;lillirlrl cont,amirlrlrlts to be a~lclr,cl ahea(J nF thc~ last Ol~ nrxt t,o last puri fication stage in wtl:icll the carl)ollyli~lir)rl prorluct, is f'rr,ed ~rom high-l)oiling resirlLIe or low-l)(lilincl f~rlcl,iorls.
ille prr)crss nr t.his in\/rrltirlll pellnils t.he tot,a]. ioclirle cnntrrlt in t.llr treateci cnrl)c)nylrlli(lll pl`O(ilJ(` t t O hr r ecluct?d hrynll(l l,llc~ limit, of rlet,((l,i(ll-l ol' Irss tharl 5 pl)l) (= 5 parls hy wr.?irlht iodine per onc~ 1)ill inn (109) parts hy weight carbl:)rlylatiorl product).
Ihe catalyst preparat..ion does not f'orm pclrt of ttle in-2(1 vellt.io(l. It is howe\/r?r prt.~ferat)lt! lo ar)ply tlle nobl.e rnetalto the crlrrier in the form of' VeTy f`,inely di,vicied an(i cata-lytically act.ive mrlterial by init.ially imprerJnating the carr.ier selected witl- a noble rnr~,al .salt, solution and then treatirlg it, wi.th an amlllc)r)iacal tlydrazi.rle solution. In this Z5 way very finely ciivideci not)le mrtal is appli,ed to the carrier; after wasllinrJ until nel.ltral arld clryillg, the cat.a-.l,yst is ready for ucie. It: is also possible for the noble metal to be set, free hy rerillcillc) treat,l))erlt. wit.h hydrngen at elevated temperature.
:3[~ The useful carriers rnr the noble met.al comprise e.ri.
12~5~
5ilit'ic aC.i(J antl alumilllJm nxi(lr?. Tlle p.lrticlr sizr oF the carrier rnay vary within the wide limits oF 0.01 - 10 mm, cleperlding orl whettler the catalyst i9 usetJ e.g as a fixed bed or fluiclized btd cata]yst. Ihe r-,ame is true concerning S its inner surFace area (deterrninecl by the BET-method) which may vary within the range 1 - 700 m /y. The noble metal concentration on the cr-)rrier rnay also vary within wide limits, but should preFerably be within the range 0.5 - 5 mass O. rhe carbonylatiorl product should suitably be sepa-rated from the noble metal catalyst by filtering.
Pure hydrogen and pure carbon monoxide shouldpreferably be used, but hydrogen and carbon monoxide con-tainlng e.g. nitrogen, argon and further inert components can also be employed.
The useFul noble metals include ruthenium, osmium, iridium, preferably however rhodium, palladium, platinum.
It is possible for the present process to be carried out continuously or discontinuously.
The total iodine is determined analytically by an iodine-catalyzed reaction between arsenic and cerium ions with photometric final determination oF cerium.
Example 1 200 9 of a carbonylation product of acetic acid (19.1 mass 0)~ acetic anhydride (80.7 mass O) and ethylidene di-acetate (0.2 mass ~O) contaminated with 2 ppm total iodinewas admixed with 0.15 9 palladium finely distributed on 10 9 SiO2 (particle size = 0.01 - 0.2 mm, BET-surface area =
350 m /9 and contacted with 8 l/h of a mixture of 50 vol.,O
hydrogen and 50 vol.,O carbon monoxide at 120C. After a contact timr--3 of 5 hol.)rs the supply of thr. hydrogen/carbon monoxidc-mixtorr- was arrested the rarbonylclt;ion product was f:iltered and an/llyzed A total lodi.ne vallle of 'less -than 5 ppb corresponding to an i.od:ine separat;i.oll of rnore than 99.8 % was determined. Gas-chromatographic (GC) analysis indicat-ed that the product consisted of 19.15 mass % acetic acid 80.6 mass ~ acetic anhydride and 0.25 mass % ethylidene di-acetate; in other words -the carbonylation product treated as described hereinabove had a composltion which scarcely dif-fered froln tha-t of the untreated product. Only 0.1 % acetic anhydride was found to have been lost.
Example 2 Ihe Pd-cat.llyst usc(J in l-xr)lllplr 1. was hrr)ugtlt into con-tact over a period of 200 hours wit;ll altogetller 8 kg carbony-lati.on prodoct composed of 19.1 mass ~ acetic acid 80.7 mass llo aceti.c anhydride and 0.2 mass ' ethylidene diacetate con-taminated with 2 ppm total iodine and also contacted with 8 l/h of a gas mixture of 50 vol. ' hydrogen and 50 vol. %
carbon monoxide at l20C. The ca:rbonylation product so treated and filtered was analyzed after 10n and 200 hours contact ;:ime respectively. 'I'he total iodine valuesfoulld were in each case less than 5 ppb corresponding to all iodi~ separation of more than 99.8 %. Ihe composition of the product was de-termined gas-chromatographically; it was 19.15 mass % acetic acid 80.6 mass % aceticanhydride and 0.25 ma.ss % ethylldene diacetate which remairlr-d constant over the entire contact period.
Example 3 (comparative Example) 200 9 of a carbonylation mixture of acetic acid (19.1 ~27965S
mass %), acetic anhydride (8r).7 mass ,~) and ethyl:iclerle cli-acetate (().2 mass ~/0) contaminatecl wlth 2 ppm total iodine was admixed with 0.15 9 pa:l:ladium finely clistributed on 10 g SiO2 (particle size = 0.()l - 0.2 mm, BFT-surface area =
350 m7/g), arld corltacterl wi~;h 4 ~/h hytlrogerl at 120"C. After a contact prriorJ of 5 hoors, the sopply of hydrogen was arrested, the carhorly]atlorl product was filtered and ana-lyzed. A tolal ioclirle value nf less thr)ll 5 ppb, correspond-ing to t;he ser)arltinll of n~ore thrlrl ~'3.8 1". iodine, was cle-t;ermirled. Ihe product was analyzrd gas-chromatographically and foond to contain 20.() mass ,~, acetic acid, 77.7 mass ~'~
acetic anhydride and 2.3 mass % ethylidene diacetate, i.e.
less acetic anhydride and more acetic acid and ethylidene diacetate than the untreated product of which the composi-tion was found to have been modified. 3.0 % acetic anhydride was found to have been lost after the contact period.
Example 4 (comparative Example) The Pd-cata]yst of Examp~e 3 was brougllt into contact over 200 hours with altogether 8 ky of a carbonylation pro-duct containing 19.1 rnass % acetic acid, 80.70 mass %
acetic anhydride and 0.2 mass % ethylidene diacetate, con-taminated with 2 ppm total iodine, and also contacted with 4 l/h hydrogen at 120C. Ihe carbonylation product so treated and filtered was analyzed after 100 and 200 hours contact tirne, respectively. Already after 100 hours, the residual iodine content was reduced to 0.4 ppm only corresponding to an iodine separation of B0 %. To improve the iodine separa-tion, the temperature inside -the reactor was increased to 130C, after 100 hours. This permitted the iodine content in -~Z79~
the reaction prnduct to be reducrrd to 7() ppb, corresponding to an iodine separation of 96.5 %. After a furt;her 100 hours contact time (total contact period = 200 hours), the ex-periment was terminated and the filtered product analyzed.
After that time, it was melely possible to reduce the io dine conterlt fronl 2 ppm to 0.3 !:)prn, corresponding to an indine separat:ion of 85 ~'u. Gas-chrnmatogIapl-lic analysis indicated a distinct change in the composit;ion of the car-bonylation procluct used. It contained 20.5 mass % acetic acid, 76.0 mass % acetic anhydride, 3.5 mass % ethylidene diacetate and 600 ppm acetaldehyde.4.7 %anllydride, based on t;he feed mate~rial, was found to have been lost.
Example 5 200 9 acetic anhydride contaminated with 0.6 ppm to-tal iodine was admixed with 0.15 9 palladiurn ~inely distributed on 10 9 silica gel (particle size = 0.01 - 0.2 mm, BET-surface area = 580 m2/g)and contacted with 10 l/h of a gas mixture of 95 vol.% hydrogen and 5 vol. % carbon monoxide at 100C. After a contact period of 3 hours, the acetic anhydride was separated from the catalyst by filtering and analyzed. An iodine value of less than 5 ppb, corresponding to an iodine separation of more than 99.2 %, was determined.
The acetic anhydride was analyzed gas-chromatographically but could not be found to contain a by-product, such as ethylidene diacetate, for example.
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for separating iodine and its compounds from the carbonylation products, acetic acid, acetic anhydride or ethylidene diacetate, obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction, wherein the total iodine contaminating the carbonylation products is reduced to a content of less than 20 ppb iodine, which process comprises treating the carbonylation products at a temperature of 50-200°C and over a period of 0.2-6 hours with a hydrogen/carbon monoxide mixture in the presence of at least one noble metal belonging to group VIII of the Periodic System of the elements as a catalyst, wherein 0.001-1 mol each of hydrogen and carbon monoxide is used per mol carbonylation product, and separating the carbonylation products from the catalyst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3534070.3 | 1985-09-25 | ||
| DE19853534070 DE3534070A1 (en) | 1985-09-25 | 1985-09-25 | METHOD FOR SEPARATING IODINE AND ITS COMPOUNDS FROM CARBONYLATION PRODUCTS OBTAINED FROM CARBONYLATING DIMETHYL ETHER, METHYL ACETATE OR METHANOL |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1279655C true CA1279655C (en) | 1991-01-29 |
Family
ID=6281824
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000516170A Expired - Fee Related CA1279655C (en) | 1985-09-25 | 1986-08-18 | Process for separating iodine and its compounds from the products obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0217182B1 (en) |
| JP (1) | JPH0825929B2 (en) |
| AT (1) | ATE34734T1 (en) |
| AU (1) | AU585647B2 (en) |
| BR (1) | BR8604600A (en) |
| CA (1) | CA1279655C (en) |
| DE (2) | DE3534070A1 (en) |
| MX (1) | MX168436B (en) |
| ZA (1) | ZA867301B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3331548A1 (en) * | 1983-09-01 | 1985-03-21 | Hoechst Ag, 6230 Frankfurt | METHOD FOR SEPARATING IODINE AND ITS COMPOUNDS FROM CARBONYLATION PRODUCTS OBTAINED FROM CARBONYLATING DIMETHYL ETHER, METHYL ACETATE OR METHANOL |
| DE3612504A1 (en) * | 1985-09-30 | 1987-04-09 | Hoechst Ag | METHOD FOR SEPARATING IODINE AND ITS COMPOUNDS FROM CARBONYLATING PRODUCTS CONTAINING CARBBONYLATION OF DIMETHYL ETHER, METHYL ACETATE OR METHANOL |
| JP2600676B2 (en) * | 1987-05-19 | 1997-04-16 | ブラザー工業株式会社 | Thermal printer |
| DE3823645C1 (en) * | 1988-07-13 | 1989-11-30 | Hoechst Ag | |
| DE69116879T2 (en) * | 1990-08-15 | 1996-06-20 | Eastman Chem Co | METHOD AND PURIFICATION OF ACETIC ACID ANHYDRIDE AND ACETIC ACID |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4102922A (en) * | 1974-12-30 | 1978-07-25 | Monsanto Company | Purification of carbonylation products |
| DE3329781A1 (en) * | 1983-08-18 | 1985-02-28 | Hoechst Ag, 6230 Frankfurt | METHOD FOR SEPARATING IODINE AND ITS COMPOUNDS FROM CARBONYLATION PRODUCTS OBTAINED FROM CARBONYLATING DIMETHYL ETHER, METHYL ACETATE OR METHANOL |
| DE3331548A1 (en) * | 1983-09-01 | 1985-03-21 | Hoechst Ag, 6230 Frankfurt | METHOD FOR SEPARATING IODINE AND ITS COMPOUNDS FROM CARBONYLATION PRODUCTS OBTAINED FROM CARBONYLATING DIMETHYL ETHER, METHYL ACETATE OR METHANOL |
-
1985
- 1985-09-25 DE DE19853534070 patent/DE3534070A1/en not_active Withdrawn
-
1986
- 1986-08-18 CA CA000516170A patent/CA1279655C/en not_active Expired - Fee Related
- 1986-09-08 EP EP86112430A patent/EP0217182B1/en not_active Expired
- 1986-09-08 AT AT86112430T patent/ATE34734T1/en not_active IP Right Cessation
- 1986-09-08 DE DE8686112430T patent/DE3660252D1/en not_active Expired
- 1986-09-24 AU AU63118/86A patent/AU585647B2/en not_active Ceased
- 1986-09-24 BR BR8604600A patent/BR8604600A/en not_active IP Right Cessation
- 1986-09-25 ZA ZA867301A patent/ZA867301B/en unknown
- 1986-09-25 JP JP61225064A patent/JPH0825929B2/en not_active Expired - Lifetime
- 1986-09-25 MX MX003841A patent/MX168436B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU585647B2 (en) | 1989-06-22 |
| DE3660252D1 (en) | 1988-07-07 |
| EP0217182B1 (en) | 1988-06-01 |
| JPS6272636A (en) | 1987-04-03 |
| ATE34734T1 (en) | 1988-06-15 |
| MX168436B (en) | 1993-05-25 |
| AU6311886A (en) | 1987-03-26 |
| EP0217182A1 (en) | 1987-04-08 |
| DE3534070A1 (en) | 1987-04-02 |
| JPH0825929B2 (en) | 1996-03-13 |
| ZA867301B (en) | 1987-06-24 |
| BR8604600A (en) | 1987-05-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0003858B1 (en) | A process for selectively removing minor amounts of beta-chloroacroleins and 5,6-epoxyhexene-1 from epichlorohydrin | |
| CA2119609A1 (en) | Process for the recovery of a carbonylation product | |
| Merzouk et al. | On the use of silylated nucleophiles in the palladium catalysed deprotection of allylic carboxylates and carbamates. | |
| CA1279655C (en) | Process for separating iodine and its compounds from the products obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction | |
| US3442958A (en) | Purification of phenol | |
| EP0634395A1 (en) | Purification of 2-methylglutaronitrile or adiponitrile | |
| US4902829A (en) | Process for the adsorptive separation of hydroxy paraffinic dicarboxylic acids from olefinic dicarboxylic acids | |
| US3736236A (en) | Method of separating vinyl acetate from liquid mixtures by extractive distillation with a glycol | |
| KR20070053745A (en) | Separation of 6-aminocapronitrile and hexamethylenediamine from a mixture comprising hexamethylenediamine, 6-aminocapronitrile and tetrahydroazepine | |
| US4455446A (en) | Method of removal of COS from propylene | |
| US5316627A (en) | Process for producing odorless dimethyl ether | |
| MXPA96002849A (en) | Procedure to separate trioxano from a mezclaacu | |
| EP0641778A1 (en) | Process for purification of epsilon-caprolactam | |
| US3591463A (en) | Separation of chloroform and/or ethyl acetate and/or methylethyl ketone from vinyl acetate by extractive distillation | |
| RU94034114A (en) | Method for production of oxo-products | |
| JP3001020B2 (en) | Acetonitrile purification method | |
| US3878058A (en) | Recovery of alkylvinylether by extractive distillation of a feed containing only trace amounts of water | |
| JPS6058211B2 (en) | Purification method of β-phenylethyl alcohol | |
| EP0314434A1 (en) | Rhodium recovery from hydroformylation reaction product | |
| US4792420A (en) | Purification of carboxylic acid anhydrides | |
| EP0097891B1 (en) | A method for refining crude aldehyde products | |
| US3125608A (en) | Purification of vinyl chloride | |
| US3335547A (en) | Process for the purification of ethylene oxide | |
| US4650615A (en) | Purification of carboxylic acid anhydrides contaminated with halogen or halides | |
| US3399968A (en) | Process for the purification of aqueous solutions of hydrogen peeroxide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |