Combined acid additives and the MC catalyst for the autoxidation of p-xylene to terephthalic acid

Saha, Basudeb; Espenson, James H.

doi:10.1016/j.molcata.2005.06.007

Cited by 21 publications

(6 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the PXOX process is ∼60 years old, it has several areas of concerns without appropriate solutions for them. [11][12][13][14][15][16] Dissolution of compounds involved in the PXOX process in the reaction medium is one of the major issues that are yet to be addressed satisfactorily. The most prominent among these is the understanding of the solubility behavior of the main product (terephthalic acid) and the intermediate (4-carboxybenzaldehyde).…”

Section: Introductionmentioning

confidence: 99%

“…Terephthalic acid is manufactured by the p -xylene oxidation (PXOX) process and finds application as a comonomer in the production of polyesters such as poly(ethylene terephthalate). Although the PXOX process is ∼60 years old, it has several areas of concerns without appropriate solutions for them. − Dissolution of compounds involved in the PXOX process in the reaction medium is one of the major issues that are yet to be addressed satisfactorily. The most prominent among these is the understanding of the solubility behavior of the main product (terephthalic acid) and the intermediate (4-carboxybenzaldehyde) .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Determination of Solubility Parameters for the p-Xylene Oxidation Products

Malpani

Ganeshpure

Munshi

2011

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The Hildebrand solubility parameter (δ), which predicts the miscibility of materials, was determined for the compounds that are involved in the oxidation of p-xylene to terephthalic acid. The δ values were determined from the measured intrinsic viscosity [η] of the compounds. The following compounds (namely, methyl benzoate, p-tolualdehyde, 4-hydroxymethyltoluene, terephthalaldehyde, benzoic acid, p-toluic acid, 4-hydroxymethylbenzoic acid, phthalic acid, trimellitic acid, 4-carboxybenzaldehyde, and isophthalic acid, including p-xylene as the reactant and terephthalic acid as the main product) were studied. The predicted δ values were obtained using the group contribution method, which helped in selecting the solvents to be used for viscosity measurements. Mixtures of solvents were used to obtain δ values for phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid. It was observed that δ is apparently related to the melting points of the compounds. Three-dimensional Hansen solubility parameters were also determined for important p-xylene oxidation products for a better understanding of their solubility behavior.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of Solubility Parameters for the p-Xylene Oxidation Products

Malpani

Ganeshpure

Munshi

2011

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…The oxidation of methylarenes to the corresponding carboxylic acids is of industrial importance because such carbonyl derivatives constitute versatile building blocks in pharmaceutical and polymer industries . A variety of oxometal oxidants such as KMnO 4 , Na 2 Cr 2 O 7 , or CrO 3 in stoichiometric amounts and RuO 4 , Co(OAc) 2 , and more recently Bi salts in catalytic amounts have been employed in such oxidative processes. Among nonoxometal oxidants, HNO 3 is commonly used.…”

mentioning

confidence: 99%

NaIO₄-Mediated Selective Oxidation of Alkylarenes and Benzylic Bromides/Alcohols to Carbonyl Derivatives Using Water as Solvent

2006

View full text Add to dashboard Cite

A new transition-metal-free, sodium metaperiodate (NaIO4)-mediated direct oxidation of methylarenes and benzylic bromides to the corresponding aromatic carboxylic acids is described. Under the same reaction conditions, benzylic alcohols are selectively oxidized to afford the corresponding aldehydes in good yields without undergoing overoxidation. Unprecedentedly, oxidation of benzyl bromide, toluene, or benzyl alcohol with NaIO4 underwent nuclear bromination followed by oxidation to give 4-bromobenzoic acid in 60-79% yields.

show abstract

“…Saha and Espenson 22 proposed that the acid additives to the acetic acid ameliorated significantly the oxidation of alkylaromatics to aromatic carboxylic acids. Phosphotungstic acid as one kind of heteropoly acid holds strong Brönsted acidity.…”

Section: Resultsmentioning

confidence: 99%

Oxidation of 3,7‐dichloro‐8‐(chloromethyl)quinolone to quinclorac by oxygen

Long

Song

Guo

et al. 2022

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND: Quinclorac (3,7-dichloro-8-quinolinecarboxylic acid) is commercially produced from the partial oxidation of 3,7-dichloro-8-(chloromethyl)quinolone by nitric acid in 98% sulfuric acid. Such technology suffers from some shortcomings, such as the discharge of NO x and wastewater, and the formation of nitro compounds. Oxygen is a clean, cheap oxidant. The key to realizing the production of quinclorac by oxidizing 3,7-dichloro-8-(chloromethyl)quinolone with oxygen is the development of an efficient catalyst.RESULTS: The transformation of 3,7-dichloro-8-(chloromethyl)quinolone to quinclorac oxidized by O 2 molecule in acetic acid solution can be accomplished under a homogeneous catalyst system composed of H 3 PMo 12 O 40 /Ce/Co/Br. Experiments show that the optimal catalytic system consists of 0.209 (wt)% phosphomolybdic acid, 0.022 (wt)% Ce(III), 0.027 (wt)% Co(II) and 0.0161 (wt)% Br − . CONCLUSION: Temperature is an important parameter affecting reaction rate. The influence of oxygen concentration in the gas phase on quinclorac yield and 3,7-dichloro-8-(chloromethyl)quinolone conversion is great. The activation energy of this catalytic reaction is 57.6 kJ mol −1 . The reaction orders for oxygen and 3,7-dichloro-8-(chloromethyl)quinolone are 0.26 and 0.93, respectively.

show abstract

Combined acid additives and the MC catalyst for the autoxidation of p-xylene to terephthalic acid

Cited by 21 publications

References 17 publications

Determination of Solubility Parameters for the p-Xylene Oxidation Products

Determination of Solubility Parameters for the p-Xylene Oxidation Products

NaIO₄-Mediated Selective Oxidation of Alkylarenes and Benzylic Bromides/Alcohols to Carbonyl Derivatives Using Water as Solvent

Oxidation of 3,7‐dichloro‐8‐(chloromethyl)quinolone to quinclorac by oxygen

Contact Info

Product

Resources

About

Combined acid additives and the MC catalyst for the autoxidation of p-xylene to terephthalic acid

Cited by 21 publications

References 17 publications

Determination of Solubility Parameters for the p-Xylene Oxidation Products

Determination of Solubility Parameters for the p-Xylene Oxidation Products

NaIO4-Mediated Selective Oxidation of Alkylarenes and Benzylic Bromides/Alcohols to Carbonyl Derivatives Using Water as Solvent

Oxidation of 3,7‐dichloro‐8‐(chloromethyl)quinolone to quinclorac by oxygen

Contact Info

Product

Resources

About

NaIO₄-Mediated Selective Oxidation of Alkylarenes and Benzylic Bromides/Alcohols to Carbonyl Derivatives Using Water as Solvent