SA00210610B1 - Oxidation of alkyl aromatic compounds to aromatic acids in an aqueous medium - Google Patents

Abstract

Abstract: This invention relates to an improved method for the oxidation of substituted aromatic compounds (eg p xylene) to their corresponding aromatic acids (eg terephthalic acid).The improvement involves performing an oxidation reaction in an aqueous medium, in which the medium contains aqueous containing at least 30% water, preferably up to 30% as a surfactant and preferably a low molecular weight substance containing a hydrophilic (water-loving) terminal group as an associated surfactant The agent is carried out at a pH less than 3.0

Description

Y aromatic acids to alkyl aromatic acids oxidation 3 oxidation in aqueous medium Full description of the alkyl oxidation This invention relates to an improved method for conducting a substitution oxidation reaction to the corresponding acidity In particular, the invention relates to an alkyl aromatic pH under aqueous pH control in an aqueous oxidation phase by conducting an oxidation reaction, where it is preferable that the aqueous medium contain a surface activator, and a substance with a low molecular weight of 0 is preferred that contains Contains a polar terminal group as a conjugate surfactant. The starting material for the formation of an aromatic compound contains a gas or an oxygen gas with an alkyl substituted aromatic oxygen; Preferably 3106) and catalyst in the presence of a catalyst or catalytic system oxygen 0 and those reactions are carried out in a solvent consisting mainly of acids other than Br and Co. benzoic acid or benzoic acid Acetic acid Jia ¢ organic acids are organic, and it may be desirable to use a solvent that is less expensive, less workable, less harmful to the reaction, and more moderate in terms of environmental damage. It is non-aromatic acid, and there are many forming materials the initial phase of the aromatic acid Vo, which leads to difficulties in the diffusion of Alla for solubility in any large range in water; however, the organic phase ALS in the aqueous medium. The poor diffusion of the starting material leads to problems such as low yields, low reaction rates, and formation increased of the by-products » compared to the same reaction taking place in the larger solvent. Previous attempts include substituting water for the Y organic acid solvents used preferably in those reactions; US Patent No. 4,758,704 and v are used at least five percent by weight together with an organic acid (Al) £YVAAY and stating that bromine is required as a solvent. These patents do not use bromine, organic acid, more catalysts with larger quantities of water. The recorded acid yields were low acidic and used US Patent No. 77144?; middle lil] relatively; An expensive aqueous treatment and iodine stimulant 10106 is required. Once again, low yields and large quantities of byproducts are recorded. US Patent No. 4,847,978 states a two-stage process for the oxidation of benzenes in the second stage. bromine is substituted; Where the concentration of bromine is increased 5 Using the second stage of the process to increase productivity and reduce the amount of by-products that are present in another way in the certain reactions that take place in an aqueous medium. We find that sll is highly soluble in AL, non-aromatic preform. This invention seeks to improve the spreadability of hydrophobic starting materials. And it was discovered that the pH is relatively low. It is not done well if the oxidation reaction does not take place when oxidation. It was also discovered that surface activators; Such as organic compounds with a double tendency, such as Vo alpha.-olefin sulfonate acid or stearic acid. It is preferable to use it to improve the spreadability of materials (Sa; sulfonate salt). The hydrophobic beginning. It is believed that surfactants improve the diffusion of a precursor in. Also, it was discovered that the associated surfactant was an aqueous liquid or 1-butanol lanatoib-1 (Jia) included. On a polar organic substance with a low molecular weight of 0 ¢ in combination with a surfactant (benzoic acid or toluic acid) can contribute significantly to the efficiency (effectiveness) of the surfactant in the diffusion process. compounds to oxidation Therefore, this invention relates to a method for oxidation of the corresponding Lag, which includes the diffusion of aromatic acids from their aromatic acids

aromatic substituted in an aqueous medium; The substituted aromatic compound comes into contact with a gas containing oxygen in the presence of a catalyst; Cus the liquid medium includes at least 7700 by weight (depending on the total amount of charge reaction mixture) water and optionally up to .73

wt. surfactant; And where the reaction mixture is at pH less than Xoo, and the reaction materials and general conditions that suit this invention (other than the liquid medium) are any of those known in the field (see Jad {Kirk Othmer Encyclopedia of Chemical Technology, 4” Ed, Vol. 18, p. 1006. Accordingly, the environmental material can be any aromatic compound substituted with at least one substituent group capable of being oxidized to a carboxylic acid or a derivative thereof. Those on the alkyl, hydroalkyl, aldehyde, hydroxyalkyl, and carboalkyl groups, which are of particular importance for benzene derivatives substituted with di-alkyl-substituted benzene ¢ such as Meta meta and para-

para-xylene » and dimethyl naphthalene. The catalyst system can be any of those known in the art for use in Veo oxidation reactions of the substituted aromatic compounds. See eg W.L. Partnrtheitmer, Catalysis Today, 23 (1995); US Patent 09177; US Patent No. 1YAAY 01; And the international patent [AA 79778 . Preferred catalysts for IT include manganese and at least one other metal selected from the group consisting of cobalt, nickel, chromium, zirconium 00, hafnium, and cerium. Palladium and mixtures thereof. It is preferable to choose the second metal from the group consisting of cerium, cobalt, hafnium, and zirconium. It is also preferable to add a bromine (All) bromine, which may be bromine, bromide, or bromate; Or hydrobromic acid or

0

bromine substituted organic or a combination thereof) ¢ as the domain is known. The catalyst may be added to the liquid before, after, or together with the substituted aromatic compound. The quantity of the components of the catalyst used is in the range known in the field, and for the purposes of this invention, the concentration of bromine (as bromine or iron) ranges in adjusting the reaction consisting of the total charge in the range from 001 to 0001 ppm w/ Weight ; preferably in the range 000 to 100850 ; Most preferred in the range 0001 to 6 . The ratio of bromine to metals 5 ranges from OA to H; preferably in the range 1 to ; ; and most preferably in the range from 0.9 to ? . range ratio

. to 1; Preferably in the range from f to 159 to the additional metal in the range from Mn

001 The oxygen-containing gas supplied to the reactor can be pure oxygen 07860; air and air rich in oxygen, or a mixture of oxygen with inert gas; It may be added to the reactor by any method known in the art.

The liquid medium includes at least 7700 by weight ele . It has been detected that interaction

1 oxidation; when portioned using only water as Jolin's medium; It does not proceed well (low yield, slow rate and low product purity) when the pH of the reaction medium is greater than 5.0. Therefore; The 17 C of the reaction mixture should be less than VO and preferably less than 7.5; The most preferred is less than 7.0. It is preferable to add acetic acid, methanesulfonic acid, or sulfuric acid.

0 or other acids; into the aqueous medium in sufficient quantities to bring the pH of the reaction mixture to the desired level. It is preferable to add an amount of tonic to the surface; up to 770 by weight depending on the reaction mixture made up of the total charge; also to the reaction mixture. A low molecular weight fraction must also be present that contains a hydrophilic (water-loving) terminal group; or 'concomitant surfactant' to increase the effectiveness of the surfactant

+

The conjugate has a molecular weight of less than 0001. Preferably, the surfactant may be a by-product or an intermediate of the oxidation reaction with a substituted aromatic compound. For example ¢ in the oxidation of xylenes to the corresponding phthalic acids; Favorite co-surfactants © include benzoic acid, toluic acid, and acetic acid. It is preferable that the conjugate surfactant be present in a concentration ranging from 1.1 to 701 by weight depending on the total amount of the reaction charge mixture, including any conjugate surfactant that may be produced in the oxidation reaction. It is worth noting that the accompanying surfactant is on

erase favorite is acid; This helps to reach the desired pH levels. 01 The water percentage preferably ranges from “0” to 748; preferably in the range from “or” to 0. The concentration of surfactant 0 including 0 of any accompanying surfactant depends on the surfactant chosen in particular: Any suitable quantity, up to a concentration of 7700 on a weight basis, can be used for the purposes of this invention.The surfactant is any organic liquid or solid compound, miscible with water in special conditions and in the appropriate concentration range 1 for use.It is preferable that Surfactants include stearic acid, benzenesulfonic acid, and alpha.-olefin sulfonates (Witconate AOS-2027.TM J) or sodium lauryl sulfate. The surfactant initially to the aqueous phase before the introduction of the organic phase; or it may be introduced with the organic phase TY; or both in combination Lee. The surfactant must be added in sufficient quantity to form a dispersion, emulsion, or Micro-emulsion 1 or micro-emulsion of the aromatic compound substituted in the aqueous liquid medium, where the micro-emulsion is a dispersion characterized by very small AAA droplets and a clear, homogeneous appearance. In general, it is preferred to be a surfactant

L is present in an amount ranging from 0.06 to 701 by weight depending on the total amount of the reaction charge mixture. Then the reaction is carried out under conditions dependent on those present in the synthetic oxidation 008 of para-xylene. It may be done in the way of operations (batch)© or in a way similar to operations or continuously. It is preferable that the reaction temperature ranges from 81 to 230 C; and most preferred; I Yoo 220m; And the most preferred is about 711 AD. It is also desirable that the reaction pressure ranges from 01 to YAS bar; most preferred in the range from 15.8 to THT bar; The most preferred is about 71.4 bar. You may see the activities of this invention in the following examples: aud 0 in the following examples; The liquid medium and the substituted aromatic compound were placed; factors; And the upper space of it was cleaned by Titanium Parr of type 1 catalyst in a reactor with a capacity of . rpm 1081 - 17011 and the reactor was stirred at . nitrogen by nitrogen bar on the jogging scale. Then the degree of YY was raised to nitrogen and pressurized with nitrogen for an hour. When the reactor temperature reached 1 C for 715 hours, the temperature of the reactor contents reached 0

STP min at [Nj the following: 771 cc gas to 200 m gas flows / cc of air OY (Standard Conditions of Temperature and Pressure) were used to the upper space and atomized to the liquid phase . A horizontal beam was used in the reactor; Below the STP minute when located in the upper space to the liquid surface level gas directly in order to prevent the entry of gas minute; and then; The flow of 18 continues for oh liquid phase has been stopped. 0 reaction was allowed and completed. TH NMR air and cool the reactor. and the solids were separated; Weighed and analyzed by conducting a similar reaction with and without a surfactant. Comparator (with acetic acid)

A

to show the current status of the field; Two similar comparison experiments were conducted with the use of acetic acid as a liquid medium, and the results were averaged. The following substances were shipped to the reactor in each 576 g acetic acid, 10 g acetic acid and 10 p-xylene water. Experiment: para-xylene 1,719 1053 g: g and +, YAY CO(CH;3CO,); 6H,0 5 pa +, 791 Mn(CH3CO,)6H,0 f rpm; And allow 0601 g. The reaction was carried out at the rate of AO - for a total weight of 0 min. The following average results were obtained: the mass of materials 0 has to be continued for a period of time depending on “terephthalic acid” (7748 gm) for a solid yield of 17,775 terephthalic acid: 1.8 TH NMR; and the analysis shows p-xylene to convert p-xylene 741 and xylene mol xylene 7 ;- carboxybenzaldehyde £,Y (terephthalic acid 7 mol p-toluic acid mol p-toluic acid) 14 g4-carboxybenzaldehyde 1 0 ie 544.7 g ¢ and water 0 1 p-xylene The following materials were shipped to the reactor: para-xylene 0 g; and 17 CO(CH;CO6HL0) 0 g, 74 COBGLOH, 0 g and acetic acid 18.5 and 18.5 g ¢ for a total weight of 187.47 g.The 11m reaction contents amounted to 1.97 MnBr, ironing cycle per minute.The results were obtained approximately 1701.And it was Reaction stirred at 0’ 10 g (yield of 80:1 7 of 1,7 terephthalic acid follows: mass of solids based on xylene; conversion of 0,400 pounds from para-xylene; and 7 terephthalic acid is shown 1 0 mol ¢ terephthalic acid 784 mol terephthalic acid : 111 NMR analyte and 7 mol # para-toluic acid ¢ 4-carboxybenzaldehyde ;- carboxybenzaldehyde (p-toluic acid ~~ 000

Y example and acetic acid pylons gm para-xylene 01: The following materials were shipped to the reactor gm and 1 (01:00(653:0) 00 5 ¢ g 4 017 COBr6H,0 1/,1 g and acetic acid

pa 1,14 110: for a total weight of 1/99 gm and 1, “gm (on an active basis) was then added a surfactant of the type Witconate 205-2024. t.m. The pH of the reaction contents was approximately 0. The reaction was stirred at a rate of 1601 rpm. The following results were obtained: mass of solids 9.7 g (yield of 74.5 of ter-phthalic acid based on 0-xylene; shift of 797/8.8 of para-xylene p-xylene; shows 1H NMR : 0 mol 7 of terephthalic acid; 71 mol 7 of 4-carboxybenzaldehyde VY 5 mol of p-toluic acid and 77.5 p-xylene -xylene {and accordingly »the degree of conversion of xylene to oxidation products was greater in the presence of 0 surfactant than in the presence of it Ex. g, water 1468 g, acetic acid pat, + acetic acid, 0.11 g (01:002611:0) and Y,Y'Y Mn(CH3CO,)6H0 g LEA and HBr Aqueous 0.8 g for a total weight of AVA g. Added “0.1 g (on 1 active basis) of surfactant type Witconate 808-2024. t.m. The 711 of the reaction mixture was approximately ¥. The reaction was stirred at a rate of 16010 rpm. The following results were obtained: the mass of the solids is zero g (zero 7 yield of terephthalic acid on the basis of xylene; and zero 7 conversion to para-xylene (p-xylene), for example; 7 The following materials were shipped to the reactor: para- Xylene 100 g, water 146 g, acetic acid 8.06 g acetic acid, 0186 CO(CH;CO2)6H,0 g and Mn(CH3CO,)6H,0 YY 5 g LEA of aqueous HBr 7.7 and methanesulfonic acid 01 ml for a total weight of 1748 gm, and 0.7 gm (on an active basis) of activator was added

11

For surface type Witconate 208-2024. t.m. The pH of the reaction mixture was approximately 1.8.

The reaction was stirred at a rate of 0601 rpm. The following results were obtained: Mass of solids 0.49 g (yield LFV of terephthalic acid based on xylene 0) and conversion 771 of para-xylene 0. Analysis 1111018 shows: 001 mole of acid

0 terephthalic acid. Hence, improved results are obtained at a lower pH and it is worth realizing by the person skilled in the field that the invention is

limited to the valid design or valid methods described above; However, various modifications may be made without departing from the scope and spirit of the invention as set forth throughout the claims

‎Adal.

Claims (1)

11 Protectants Substituted to Alkyl Aromatic Compounds Alkyl Aromatic Oxidation Method for Oxidation 1-1: Analogue  Aromatic Acids Include Their Aromatic Acids | alkyl { 1 anhydrous comprising a sufficient quantity of a surfactant to form a dispersant or emulsion. 8 with an alkyl substituted aromatic b) the reaction of the alkyl substituted aromatic compound 05 in the presence of an oxygen catalyst containing gas Oxygen 1 The liquid medium contains greater than Cus; bromine contains a bromine donor 1" thirty percent by weight water depending on the total charge reaction mixture. and where + Foe 27 m for the liquid medium is less than 1 ; where the 1-alkyl aromatic compound is ?- method as in element 1 xylene is alkyl substituted aromatic ~~ ¥ ; where the 1-alkyl-substituted aromatic compound is the same as in the element -* 1.dimethyl naphthalene naphthalene Jie is alkyl substituted aromatic ¥ .7,0 less than pH; where the 1 is the method as in the element + 1 1,0 less than pH ; where the 1 is the method as in element o — 1 the surfactant is a dua compound; Cua The method is as in element + 7 - 1 stearic acid stearic ¥ The method is as in element 6 in which the surface activator is an alpha sulfonate - + 1 alpha olefin sulfonate of olefin ¥ VY method as in the + element; in which the surfactant is 1-sodium lauryl sulfate ¥; in which the surfactant is added in an amount ranging from 1 method as in element 1-01 to 270 by weight depending on the total charge reaction mixture. vee; in which a surfactant is added in an amount sufficient to form, 1 method as in item 11-1 a microemulsion. Y; In which the liquid medium also includes a 1-method molecule as in element 11-1 hydrophilic low molecular weight containing a hydrophilic Y-terminal group (hydrophilic) as an associated surfactant. ¥; In which the accompanying surfactant is statement 17 of the method as in item 1-1 “compound oxidation” about an intermediate or by-product in the oxidation reaction of an aromatic acid to its substituted aromatic acid; landscapes; In them the conjugated surfactant is present in an amount of 11 the way as in element 1-14 by weight depending on the total charge reaction mixture. 701 to 11 range_from ; In it, the associated surface activator is selected from the VY method, as in the element Ye 1 toluic acid and benzoic acid Ac gana the group consisting of “. acetic acid and acetic acid VW to 730 by weight +0; in which the liquid medium includes 1 method as in element 1 -11 1 ela 7 Ihe to 50 includes the liquid medium Led; 11 method as in element 1 ele -117 by weight " no -18# 1 method as in item 1 ; Led includes Mn(IID) catalyst; and an alkaline substance ¥ to bromine and at least one other metal selected from the group v consisting of (000 tar rodt pat le. -14 1) the method as in element VA; in which the bromine donor is bromine is "- elemental bromine". VA; in which the bromine donor is ¥ .bromide salt 1 77”- the method as in element VA; Lend the bromine donor is .hydrobromic acid acid YY The method as in element VA; in which the bromine donor material is bromine-substituted organic 1 40;?- The method as in element VA In which the concentration of bromine in the mixture of total charge varies in the range from 0 to 00001 ppm. Yo oy method as in the element; in which the concentration of bromine in the mixture ranges from 0 total charge in the range 00 to 10085 ppm 0 +7- method as in element Yo ; In them the concentration of bromine in the total charge mixture ranges from 0.001 to fev ppm. 1 7 ?- method as in item VA ; In it, the ratio of bromine to metals ranges from 1061816 in the range from A to 6. YA The method is as in element 717; Led The ratio of bromine to metals ranges ¥ in the range from 1 to 4; 1 to the metalloids bromine; In which the ratio of bromine, YA, varies in the method as in the element -741 to 0,# 0. In the range from 0610185 "metals to Mn metals, the ratio of Leh ; YA in the method varies as in the element -* 0 0.4 to 0.5 other in the range from to metals bromine; in which the percentage of bromine ranges from 00 in the manner as in the element -? 1 1 1 to 1 in The range is from 061816 ¥; in which a step is made in contact with the aromatic compound 1 method as in the element SFY at the degree of oxygen with alkyl substituted aromatic oxygen "2230 to 0880 temperature ranging from ; Where the temperature ranges in the range from FY method as in element -©* 1 to 220 °C., 000 oy; Where the temperature is 215 C. FY The method is as in the element STE; Where the step of contacting the compound 1 method is carried out as in the element -*©*© 0 oxygen with alkyl substituted aromatic oxygen "to 78.5 bar. 01" at a pressure ranging in the range from to 15.8 where the pressure ranges in the range from TO the method as in element SY LYE where the pressure is 71.4 bar. FU method as in element 7 - 1 Veya