PL102150B1 - A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE - Google Patents
A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE Download PDFInfo
- Publication number
- PL102150B1 PL102150B1 PL19153976A PL19153976A PL102150B1 PL 102150 B1 PL102150 B1 PL 102150B1 PL 19153976 A PL19153976 A PL 19153976A PL 19153976 A PL19153976 A PL 19153976A PL 102150 B1 PL102150 B1 PL 102150B1
- Authority
- PL
- Poland
- Prior art keywords
- oxidation
- amount
- weight
- xylene
- air
- Prior art date
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
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
- C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
Przedmiotem wynalazku jest udoskonalony spo¬ sób utleniania p-ksylenu i p-toluilanu metylu, pod¬ stawowego stadium w procesie wytwarzania diwu- metylotereiflLalanu, który uzyskuje sie przez estry- fikacje meltanoilem mieszaniny aromatycznych kwa¬ sów kariboksyiowych ze stadium ultleniania.The subject of the invention is an improved process process for the oxidation of p-xylene and methyl p-toluate, under the articular stage in the production of methyltereiflLalate, which is obtained by esters- the meltanoyl mixtures of aromatic acidic acid mixtures cariboxia owls with the stage of oxidation.
Podczas utleniania tlenem z powietrza, p-ksyle- nu i zawrotowego p-toluilanu metylu w obecnosci soli organieznych metali o zmiennej wartosciowos- ci glólwnie kobaltu^ manganu i niklu jako katali¬ zatorów uzyskuje sie oprócz aromatycznych zwiaz¬ ków karboksylowych, peiwne ilosci aldehydów aro¬ matycznych i niewielkie iilosci alkoholi i ketonów aromatycznych. Aldehydy, alkohole i ketony aro¬ matyczne ze stadiów esitrytfikacji i oczyszczania sa w czesci zawracane do stadium utleniania i ulega¬ ja utlenianiu do celowych aromatycznych zwiaz¬ ków kairboksyiowych, a w czesci ulegaja przemia¬ nom do zwiazków niecelowych usuwanych razem z odjpadaimi z instalacji. W zwiazku z tym mini¬ malizacja ilosci powstajacych aidehydów, ketonów i alkoholi aromatycznych w osltathilm stadium utle¬ niania jeist waznylm zagadnieniem technicznym.During oxidation with oxygen from the air, p-xyl- nu and vertigo methyl p-toluate in the presence of organic metal salts of variable value and mainly cobalt, manganese and nickel as catalysts blockages are obtained in addition to aromatic compounds carboxylic acid compounds, some amounts of aro aldehydes dull and small amounts of alcohols and ketones aromatic. Aldehydes, alcohols and arom ketones mathematical from the stages of esitrification and purification are partly recycled to the oxidation stage and succumbed to and oxidation to targeted aromatic compounds kairboxi, and partially undergoes transformation nom to unintended removed together with dropouts from the installation. In connection with this mini¬ reduction of the amount of formed aidehydes, ketones and aromatic alcohols in the osltathilm oxidation stage The nanny is an important technical issue.
W znanych procesach wytwarzania dwumetylo- tereftialanu', utlenianie tlenem z powietrza p-ksy¬ lenu i p-toluilanu metylu prowadzone jest pod cisnieniem rzedu 4—7 aitin, w temperaturze 130— —160°C wobec katalizatorów soli organicznych me¬ tali o zmiennej wartosciowosci, przy sttaiym nie- wielkim nadmiarze tlenu w stosunku do reaguja¬ cego p-ksylenu i p-toluilanu metylu.In the known processes for producing dimethyl terephthalate, oxidation with oxygen from air p-xy of flax and methyl p-toluate is carried out under a pressure of the order of 4-7 aitin, at a temperature of 130- -160 ° C in the presence of metal organic salt catalysts variable-value waist, with constant non- a great excess of oxygen in relation to the reaction p-xylene and methyl p-toluate.
W trakcie badan utleniania nieoczekiwanie stwierdzono, ze zmienne ilosci dozowanego po¬ wietrza w czasie reakcji korzystnie wplywaja na szybkosc reakcji i sklad uzyskiwanej mieszaniny reakcyjnej.During the oxidation studies, unexpectedly it was found that varying amounts of dosed amount were air during the reaction has a positive effect on reaction rate and composition of the obtained mixture reactionary.
W pierwszej fazie procesu utleniania, kiedy utlenia sie glównie p-iksylen mniejsze ilosci dozo¬ wanego powietrza i nizsza temperatura .powodu¬ ja, ze przy wystarczajacej przemianie p-ksylenu do kwasu p-toluilowego, uzyskuje sie stosunkowo duze ilosci aldehydu p-ltoluilowegO', który w dru¬ giej fazie procesu przy wiekszym nadimfoairze tfe- nu i w wyzszej temperaturze utlenia sie przede wszystkim do kwasu p-toluiiowego, natomiast p- -toludlan metylu utlenia sie do kwasu i aldehydu monometylotereftalowego.In the first phase of the oxidation process, when mainly p-xylene is oxidized in smaller amounts air, and a lower temperature of the cause I, with a sufficient conversion of p-xylene to p-toluic acid, is obtained relatively large amounts of p-toluyl aldehyde, which in turn the first phase of the process with a higher tfe nu and oxidizes mainly at higher temperatures all to p-toluic acid, while p- -methyltoludate is oxidized to the acid and the aldehyde monomethyl terephthalic.
W drugiej fazie utleniania, tj. po 5 lub 6 go¬ dzinie realklcji, ilosc dozowanego powietrza powin¬ na byc tak dobrana, aiby ilosc nieprzereagoiwanego tlenu w odgazach byla 2 do 5 razy wieksza niz w pierwszej fazHe procesu. Wynosi to okolo 2—&I*. wagowych tilenu w odgaziach pozlbawoonych opar wody i p-ksylenu.In the second phase of oxidation, ie after 5 or 6 hours at the time of realklation, the amount of dosed air should be to be chosen so that the amount of unconverted oxygen in the gases was 2 to 5 times greater than in the first phase of the process. This is around 2— & I *. by weight of tylene in the vapor-free gas water and p-xylene.
W trzeciej fazie procesu utleniania nadmiar tle¬ nu powinien byc najwyzszy, aiby aldehyd mono- metylotereftalowy utlenic w pefoi do kwasu mo¬ nometylotereftalowego. Najkorzystniej trzecia faze utleniania prowadzic w mozliwie wysokiej tempe- 102 1503 raturze 156—d..65°C i przy takiej ilosci powietrza, aby ilosc tlenu w cidgazach wynosila okolo 5— —6% wagowych. Górna granica tlenu w odgazach • -- ¦ odBroltcryyy^^Siczfe byc wyzsza, lecz ogranicza sie ja ze wzgi-odaTnl bezpieczenstwo prowadzenia pro¬ cesu. Dobrze jeetl równiez trzecia faze procesu pro- i' ^wadzjic nayferócei co mozna uzyskac przez dodat- | "kowe zaisifeinie rjeaktora w surowce p-ksyleln lub ^-"^'p^clluliIaTn" [metylu, przy wyjisciowyrn stosunku substratów p-ksylenu do p-toluilanu metylu jak io 1:1^4,8. W wyniku reakciji utleniania uzyskuje sie równiez pochodne p-toluilanu. p-ksyliiu, z. któ¬ rych pochodna aldehydowa utileniana dalej przy nadmiarze tlenu i w nizszej temperaturze daje kwas aldehydoitereftalowy, który w stadium estry- 15 fikacji estryfikuje sie do esitru metylowego kwasu aldehydptereifltalowego. Powodaje to duze straty, gdyz ulega on niekorzystnymi w dalszych stadiach procesu wytwarzania dwumeitylotterefltalanu prze¬ mianom i zwieksza obciazenie wezlów estryfikacji, 20 destylacji surowych estrów i krystalizacji.In the third phase of the oxidation process, excess oxygen is present nu should be the highest so that the mono- Oxidize methyl terephthalic acid in pefol to monoacid nomethyl terephthalic. Most preferably the third phase conduct oxidation at the highest possible temperature 102 1503 ratura 156 — d..65 ° C and with such amount of air, so that the amount of oxygen in the gases was about 5— —6% by weight. Oxygen upper limit in the gases • - ¦ fromBroltcryyy ^^ Serpent to be higher, but limited I have the safety of driving a ride cess. He was also good at the third phase of the process and '^ wadzjic nayferócei what can be obtained by addition- | "kowe zaisifeinie rjeaktora in raw p-xyleln or ^ - "^ 'p ^ clluliIaTn" [methyl, at original ratio p-xylene substrates to methyl p-toluate as well as 1: 1 ^ 4.8. As a result of the oxidation reaction it is obtained p-toluate derivatives are also included. p-xyliiu, with rych aldehyde derivative utileniana further at excess oxygen and at lower temperatures gives aldehyde terephthalic acid, which in the ester stage - 15 It is esterified to the acid methyl ester phthalaldehyde. It causes big losses, for it becomes unfavorable in the later stages of the process for the production of dimitylterefltalate values and increases the load on esterification nodes, 20 crude ester distillation and crystallization.
Utlenianie p-ksylenu i p-itoluilanu meltylu tle¬ nem z powietrza pod cisnieniem i w podwyzszo¬ nej temperaturze w obecnosci znanych kataliza¬ torów utleniania prowadzi sie wedlug wynalazku 25 trzyteltojpniowo, w pierwszym stopniu stosuje sie nizsze tem|peraitury rzedu "12BMli50oCi, w drugim stopniu od 14)5 do li60oC, w trzecim stopniu od 155 do 170°C przy dozowaniu takiej ilosci po¬ wietrza, alby w pierwszym stopniu ilosc nieprze- 30 reagowanego tlenu w odgazach nie przekraczala 2,15% wagowych:, najlepiej okolo 1% wagowy, w drugim stopniu ilosc tlenu w odgazach powinna wynosic 2—5% wagowych, a w trzecim stopniu ilosc tlenu w odgazach powinna wynosic co naj- 3© mniej 3% wagowych, najlepiej okolo 6% wago¬ wych.Oxidation of p-xylene and meltyl p-toluoylate from the air under pressure and overhead temperature in the presence of known catalysts Oxidation pathways are carried out according to the invention 25 three steps, the first step is used lower temperature of the order "12BMli50oCi, in the second from 14) 5 to li60oC, to the third degree from 155 to 170 ° C when dosing this amount of water it is ventilated, or in the first degree, the amount does not exceed 30 reacted oxygen in the gases did not exceed 2.15% by weight: preferably about 1% by weight, w second stage, the amount of oxygen in the gases should be 2-5% by weight, and in the third degree the amount of oxygen in the gases should be at least 3 © less 3% by weight, preferably about 6% by weight out.
W wyniku v stosowania utleniania p-ksylenu i p- -toluilanu metylu wedlug wynalazku uzyskuje sie zmniejszenie stoat w procesie wytwarzania dwu- 40 mefcylotereftalanu i przede wszystkim wzrost prze¬ pustowosci wezlów technologicznych utleniania, estryfikacji, destylacji surowych estrów i krysta¬ lizacji dwumetylotereftalaniu.As a result of v using the oxidation of p-xylene and p- methyl toluate according to the invention is obtained reduction of stoats in the production of double-40 mefcyloterephthalate and, above all, the increase in emptiness of oxidation technological nodes, esterification, distillation of crude esters and crystals lysis of dimethyl terephthalate.
Wzrost przepustowosci wymienionych wezlów 48 pozwala na zwiekszenie zdolnosci produkcyjnej instalacji Idiwuimetylotereftalanu o okolo 1 do <10% w zaleznosci old stosowanego dotychczas sposobu utleniania p-kisyienu i p-toluilanu metylu.Increase in the capacity of these nodes 48 allows you to increase the production capacity Idivimethyl terephthalate installations by about 1 to <10% depending on old method used so far oxidation of p-kisyiene and methyl p-toluate.
Przy tradycyjnie prowadzonych procesach utle- TO niania p4ssylenu i p-toluilanu' metylU), to jest przy stosowaniu takiego zasilania powietrzem, ze w od¬ gazach ilosc tlenu wynosi l^i3% wagowych, nie¬ zaleznie od tego w jakim stadium znajduje sie pro¬ ces utleniania ilosci afljdehydóiW, ketonów i alko- 5B holi aromatycznych w tmiieszaninie reakcyjnej z ultlenianiai, a nastepnie po przemiahie w stru¬ mieniu surolwych estrów i surofwym dwulmeltylo- teftraiftalalnie wynosza okolo &—5% walgowych, co przy stosowalnej cyrkulacji strutaiiehi i zachodza- 6° cych przemianach powoduje znaczne zmniejszenie wydajnosci procesu wytwarzania dwumetyloterefta- lanu.With traditionally conducted oxidation processes p-4-p-toluate and methyl p-toluate nanny), i.e. the use of such an air supply that in In the gases, the amount of oxygen is 1-3% by weight, not depending on the stage at which the request is located the process of oxidation of the amount of alcohols, ketones and alcohols aromatic hides in the reaction mixture from the oxidation and then after transformation into a stream change of raw esters and raw dimethyl- teftraiftally amounts to about -5% of valgus, co with an adequate circulation of strutaiiehi and there is - 6 ° transformations causes a significant reduction efficiency of the production process of dimethyl terephthalate Ian.
Przyklad. Do trzech reaktorów ze stali o po¬ jemnosci roboczej 40 m3 kazdy, zaopatrzonych w w l 150 4 plaszcze grzewcze i urzadzenia wewnetrzne do od¬ bioru ciepla reakcji, posiadajacych uklad do za¬ silania i zawrotu odpedzanego z odgazami p-ksy¬ lenu i p-ltoluilanu metylu zawierajacych miesza- nine reakcyjna z normalnej produkcji dozowano w sposób ciagly,' czysty i zawrotowy p-ksylen, za- wroltowy |p-itoiluilan imetylu, roztwór wodny octa¬ nów kolballtu, manganu i niklu w ilosci il3 ton na godzine, przy zachowaniu stosunków wagowych p-ksylenu ido lp-toluilanu metylu na poziomie od¬ powiednio 1 do iT,i2, a stezenie jonów kolballtu,^ manganu i niklu w mieszaninie reakcyjnej wyno¬ silo odpowiednio kobaltu — 0,08% wagowych, manganu — 0,04% wagowych i niklu — 0„.0Q'1I2% wagowych.Example. Up to three steel reactors with approx working capacity of 40 m3 each, provided with l 150 4 heating mantles and interior fittings for odor take the heat of reaction, having a system to start silage and recycle with p-xy gases of lene and methyl p-toluylate containing mixed Reaction nine from normal production was dosed continuously, 'clean and dizzying p-xylene, ethylmethyl p-itoyloylate, aqueous solution of acetate new colballtu, manganese and nickel in the amount of 3 tons per hour, while maintaining the weight ratios p-xylene and to methyl 1p-toluate at the level from 1 to iT, i2, respectively, and the concentration of colballt ions, ^ manganese and nickel in the reaction mixture are cobalt silo - 0.08% by weight, manganese - 0.04% by weight and nickel - 0 ".0Q'1I2%" by weight.
Do reaktora pierwszego oprócz dozowanych re¬ agentów i katalizatora wprowadzono powietrze w ilosci '4,13 ton na godzine. Temlperaiture w pierw¬ szym reaktorze utrzymywano na Ipoziomie 140°C, przy cisnieniu €1,6 altn. W gaizach odlotowych ilosc tlenu wynosila 1,4% wagowych, a mieszanina re¬ akcyjna zawierala okolo 1,11% wagowych aldehy¬ dów aromatycznych.To the first reactor, in addition to the dosed re the agents and catalyst were introduced into the air quantity: 4.13 tons per hour. Temlperaiture in the first the first reactor was kept at I at 140 ° C, at a pressure of € 1.6 altn. Quantity in outlets of oxygen was 1.4% by weight and the mixture re the share contained about 1.11% by weight of aldehyde aromatic desserts.
Do drugiego reaktora oprócz mieszaniny z pierw¬ szego reaktora dozowano powietrze Iw ilosci 4,4 to¬ ny na godziine. Temlperaiture w drugim reaktorze utrzymywano na poziomie 115l5°C przy cisnieniu ,8 £ilttn. iZ&wartoIsc tlenu w odgazach z drugiego realkJtbra wynosila' 41% wagowych.To the second reactor, in addition to the mixture with the first In the first reactor, 4.4 tons of air were dosed ny for an hour. Temlperaiture in the second reactor was kept at 115-15 ° C under pressure £ 8 ilttn. and the value of oxygen in the gases from the second realkJtbra was 41% by weight.
Do trizeciago reaktora dozowano mieszanine z drugiego reaktora i okolo 0,15 tony na godzine zawrotowego p-ksylenu i 0,!5 Itony na godzine za- wrotowego p-itoluilanu imetylu oraz powietrze w ilosci 4,i6 Itony na godzine. W trzeeilm reaktorze utrzymywano temiperatuire na ipoziomie li©2^C, przy cisnieniu 5 atn. Ilosc tlenu w oidigazach z ostatniego reaktora wynosila 5,5% wagowych, a miiels.zairi.ina reakcyjna zawierala ponizej 0j5% wagowych zwiazków aromatycznych zawieraja¬ cych grupy aldehydowe. Selektywnosc (procesu utleniania liczona jako ilosc . powstajacych moli reagentów zwiazków celowych do przereagowa- nych moli reagentów wynosila 90,6% molowych.The mixture was dosed into the trizeciago reactor from the second reactor and about 0.15 tons per hour of dizzying p-xylene and 0.5 Itons per hour per- portal imethyl p-itolate and air in quantities 4, i6 Itony per hour. In the third reactor the temperature was maintained at li © 2 ° C, at a pressure of 5 atm. The amount of oxygen in oidigases z of the last reactor was 5.5 wt%, and the miiels.zairi. the reaction contained less than 0j5% aromatic compounds by weight contain aldehyde groups. Selectivity (of the oxidation counted as an amount. emerging moles target compound reagents to be reacted The total mole of the reactants was 90.6 mole%.
W omawianym ukladzie trzech reaktorów przy¬ stosowanych do utleniania w sposób ciagly prze¬ prowadzono identyczna próbe z tymj, ze ilosci po- wieitrza i temperatury stosowano jak ponizej: pierwszy reaktor: temperatura ¦— il45°C Cisnienie — 6,!5 altn ilosc dozowanego powietrza — 4^,5 tony na godzi¬ ne ilosc tlenu w odgazach — 1,7% wagowych drugi reaktor; temperatura — HI50°C cisnienie — '3,5 atn: ilosc dozowanego powietrza — 3,5 tony na godzi¬ ne ilosc tlenu w odgazach — 2J2% wagowych trzeci reaktor: temperatura — 160°C cishieniie — 5 altn ilosc dozowanego powietrza — 3,3 tony na godzi¬ ne ilosc tlenu w odgazach — 2,j5% wagowych102 150 6 W mieszaninie reakcyjnej z trzeciego stopnia sumaryczna zawartosc zwiazków aromatycznych z grupami aldehydowymi wynosila 2>$P/o wago¬ wych, a selektywnosc 96,01% molowych.In the discussed system of three reactors, used for the oxidation in a continuous manner an identical test was carried out except that the amounts wind and temperature were used as below: first reactor: temperature ¦— il45 ° C Pressure - 6,! 5 altn amount of dosed air - 4, 5 tons per hour ne the amount of oxygen in the gases - 1.7% by weight second reactor; temperature - HI50 ° C pressure - '3.5 atm: amount of dosed air - 3.5 tons per hour ne the amount of oxygen in the gases - 2J2% by weight third reactor: temperature - 160 ° C cishieniie - 5 altn amount of dosed air - 3.3 tons per hour ne the amount of oxygen in the gases - 2, j5% by weight 102 150 6 In the third stage reaction mixture total content of aromatic compounds with aldehyde groups was 2% percent by weight and a selectivity of 96.01 mol%.
Identyczne próby przeprowadzone w sposób periodyczny przy programowanej temperaturze i podobnej ilosci doizowanego powietrza dawaly Iten sann wynik tzn. przy wiejksizylm nadmiarze powie¬ trza w drugiej i trzeciej fazie procesu uzyskiwa¬ no mjieszanine reakcyjna, o niskiej zawartosci zwiazków zawierajacych grupy aldehydowe., a przy tradycyjnej ilosci powietaza dozowanego w kon¬ cowej faizie procesu luzyisMlwano wieksza zawar¬ tosc zwiazków zawierajacych griujpy aldehydowe. !Identical trials carried out in a manner periodic at programmed temperature Iten gave a similar amount of dosed air sann result, ie in the case of a rural excess of speech in the second and third phases of the process are obtained no reaction mixture, low in content compounds containing aldehyde groups., and at traditional amount of air dosed in the end During the entire phase of the Luzyis Milwano process, more number of compounds containing aldehyde griujpy. !
Claims (2)
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL19153976A PL102150B1 (en) | 1976-07-29 | 1976-07-29 | A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE |
| DE19772733917 DE2733917B2 (en) | 1976-07-29 | 1977-07-27 | Process for the oxidation of p-xylene and p-methyl toluylate or a recycled p-toluyl ester fraction |
| RO7791202A RO74142A (en) | 1976-07-29 | 1977-07-27 | PROCEDURE FOR OXIDATION OF PARA-XILENE AND MILITARY PARALLEL |
| CS504077A CS193491B2 (en) | 1976-07-29 | 1977-07-29 | Method for the catalitic oxidation of p-xylene and methylester of p-toluic acid |
| SU772505753A SU706021A3 (en) | 1976-07-29 | 1977-07-29 | Method of preparing dimethylterephthalate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL19153976A PL102150B1 (en) | 1976-07-29 | 1976-07-29 | A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| PL191539A1 PL191539A1 (en) | 1978-02-13 |
| PL102150B1 true PL102150B1 (en) | 1979-03-31 |
Family
ID=19978029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PL19153976A PL102150B1 (en) | 1976-07-29 | 1976-07-29 | A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE |
Country Status (5)
| Country | Link |
|---|---|
| CS (1) | CS193491B2 (en) |
| DE (1) | DE2733917B2 (en) |
| PL (1) | PL102150B1 (en) |
| RO (1) | RO74142A (en) |
| SU (1) | SU706021A3 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5555138A (en) * | 1978-10-19 | 1980-04-22 | Mitsubishi Chem Ind Ltd | Preparation of highly pure terephthalic acid |
| US20070208194A1 (en) | 2006-03-01 | 2007-09-06 | Woodruff Thomas E | Oxidation system with sidedraw secondary reactor |
| US7772424B2 (en) | 2006-03-01 | 2010-08-10 | Eastman Chemical Company | Polycarboxylic acid production system employing enhanced evaporative concentration downstream of oxidative digestion |
| US7501537B2 (en) | 2006-03-01 | 2009-03-10 | Eastman Chemical Company | Polycarboxylic acid production system employing oxidative digestion with reduced or eliminated upstream liquor exchange |
| US7326807B2 (en) | 2006-03-01 | 2008-02-05 | Eastman Chemical Company | Polycarboxylic acid production system with enhanced heating for oxidative digestion |
| US7420082B2 (en) | 2006-03-01 | 2008-09-02 | Eastman Chemical Company | Polycarboxylic acid production system employing hot liquor removal downstream of oxidative digestion |
| US7816556B2 (en) | 2006-03-01 | 2010-10-19 | Eastman Chemical Company | Polycarboxylic acid production system employing enhanced multistage oxidative digestion |
| US7393973B2 (en) | 2006-03-01 | 2008-07-01 | Eastman Chemical Company | Polycarboxylic acid production system with enhanced residence time distribution for oxidative digestion |
-
1976
- 1976-07-29 PL PL19153976A patent/PL102150B1/en unknown
-
1977
- 1977-07-27 RO RO7791202A patent/RO74142A/en unknown
- 1977-07-27 DE DE19772733917 patent/DE2733917B2/en not_active Withdrawn
- 1977-07-29 SU SU772505753A patent/SU706021A3/en active
- 1977-07-29 CS CS504077A patent/CS193491B2/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2733917A1 (en) | 1978-02-02 |
| SU706021A3 (en) | 1979-12-25 |
| CS193491B2 (en) | 1979-10-31 |
| DE2733917B2 (en) | 1980-09-25 |
| PL191539A1 (en) | 1978-02-13 |
| RO74142A (en) | 1981-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| BRPI0608504A2 (en) | aromatic carboxylic acid production and energy recovery process and equipment | |
| BRPI0711297A2 (en) | catalytic compositions and solutions, aromatic charge conversion process, terephthalic, isophthalic and 2,6-naphthalene dicarboxylic or 2,7-naphthalene dicarboxylic acids and terephthalic acid compositions | |
| KR101741279B1 (en) | Method for producing bioresourced acrylic acid from glycerol | |
| TW201219368A (en) | Solid terephthalic acid composition | |
| PL102150B1 (en) | A METHOD OXIDIZING P-XYLENE AND METHYL P-TOLUYLATE | |
| CA2315151A1 (en) | Method to produce aromatic carboxylic acids | |
| WO2006127299A1 (en) | Method for deriving methalnol from waste generated methane and structured product formulated therefrom | |
| CN107311868A (en) | A kind of method for preparing p-tert-butyl benzoic acid methyl esters | |
| BRPI0811905B1 (en) | Process for the continuous preparation of methyl mercaptan from compounds containing carbon and hydrogen | |
| CN102753512A (en) | Improved method for synthesizing acrolein from glycerol | |
| BR112016001127B1 (en) | process for the production of methyl methacrylate | |
| EP0046397B1 (en) | Process for producing trimellitic acid or pyromellitic acid | |
| Gao et al. | Thermodynamic analysis of ethanol synthesis from hydration of ethylene coupled with a sequential reaction | |
| EP0872470A3 (en) | Process for producing 2,6-naphthalenedicarboxyl acid | |
| CN104707646A (en) | Catalyst for toluene preparation through oxidative dehydrogenation of dimethyl ether, preparation method and applications thereof | |
| CN104220409B (en) | Method for producing acrolein and/or acrylic acid from glycerol | |
| PL125337B1 (en) | Method of manufacture and repeated use of catalyst of oxidation in dmt process using witten method | |
| BR112016001424B1 (en) | lead-free catalyst | |
| CN114763320B (en) | N (N) 2 Method for preparing glyoxalic acid by oxidizing glyoxal with O | |
| JP6883696B1 (en) | Method for producing secondary alcohol | |
| CN101636375A (en) | The environmentally benign and simplified method for preparing aromatic dicarboxylic acid | |
| US4537978A (en) | Process for the production of trimellitic anhydride | |
| CN106946697A (en) | A kind of method for synthesizing trioctyl trimellitate (TOTM) | |
| CN105153421A (en) | Method for preparing tetramethyl-1-piperidine-N-oxyl free radical polymer | |
| US7709681B2 (en) | Process for the production of trimellitic acid |