An advanced MC-type oxidation process — the role of carbon dioxide

Yoo, Jinsu; Jhung, Sung Hwa; Lee, Ki Hwa; Park, Youn Seok

doi:10.1016/s0926-860x(01)00763-3

Cited by 42 publications

(11 citation statements)

References 5 publications

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“…The use of CO 2 as the inert gas has a beneficial effect by further elevating the yield to 83.3% (entry 6) at the higher cobalt concentration. It is possible that the interaction of CO 2 with O 2 leads to the formation of a catalytically active peroxocarbonate species CO 4 2– , which in turn may accelerate the key free radical propagation step via hydrogen abstraction, as reported in the p -xylene oxidation. , …”

Section: Resultsmentioning

confidence: 99%

“…It is possible that the interaction of CO 2 with O 2 leads to the formation of a catalytically active peroxocarbonate species CO 4 2− , which in turn may accelerate the key free radical propagation step via hydrogen abstraction, as reported in the p-xylene oxidation. 51,52 As a minor component of the MC catalyst, the manganese concentration is maintained at a low level to avoid its precipitation (as MnO 2 ) that might contaminate the solid TPA product. 53 Our previous work showed that Mn is very effective in reducing solvent burning.…”

Section: Benchmark Of Semicontinuous Oxidation At 160 °Cmentioning

confidence: 99%

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Optimization of Co/Mn/Br-Catalyzed Oxidation of 5-Hydroxymethylfurfural to Enhance 2,5-Furandicarboxylic Acid Yield and Minimize Substrate Burning

Zuo

Venkitasubramanian

Busch

et al. 2016

ACS Sustainable Chem. Eng.

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2,5-furandicarboxylic acid (FDCA) is a valuable non-phthalate biomass-based plastic precursor with the potential to replace terephthalic acid (TPA) in a variety of polymer applications. In this work, the Co/Mn/Br catalyzed semi-continuous oxidation of 5hydroxymethylfurfural (HMF) to FDCA has been carried out at temperatures lower than those of the traditional Mid-Century (MC) process. As HMF is more susceptible to side reactions (e.g. the over-oxidation to CO and CO 2 ), lower temperatures compared to the MC process are typically used to prevent substrate burning. However, lower temperatures afford much decreased FDCA yield compared to that of TPA in p-xylene oxidation. Therefore, optimization of other operating variables such as catalyst composition, water concentration in the acetic acid solvent and pressure are essential to maximize FDCA yield. Using such optimization, we show that the FDCA yield can be enhanced to 90% at 1/0.015/0.5 molar ratio of Co, Mn and Br, 7% (v/v) water, 30 bar (CO 2 /O 2 = 1/1, mol/mol) and 180 o C, the highest value reported for HMF oxidation using Co/Mn/Br catalyst. The use of Zr(IV) as co-catalyst facilitates FDCA formation, but only at lower temperatures (120-160 °C) where the FDCA yield is compromised. These findings broaden the scope of the application of the industrial MC catalytic process for FDCA production. use) by 65%. As a result, FDCA has been identified by DOE as one of the top twelve building blocks for the future green chemicals industry. 12, 13 The oxidation of HMF to FDCA was originally carried out in presence of strong oxidants, such as nitric acid or KMnO 4 . 2,14 Apart from environmental concerns, these systems produced only modest FDCA yield owing to substrate destruction under the harsh oxidizing conditions. Alternatively, oxidation with molecular oxygen, a much milder and cleaner oxidant, has been developed, employing noble metals such as platinum, 15-20 gold 21-27 and Pd 28-33 as active catalysts.During the past five years, these heterogeneous catalytic systems have been extensively studied and shown to provide nearly quantitative FDCA yield at relatively mild reaction temperatures (65-130 °C). However, because of its low solubility in the reaction medium, FDCA tends to precipitate out in the course of reaction, which might not only deactivate the catalysts by blocking the active sites but also causes separation problems. For this reason, sodium hydroxide is added in some cases to convert the diacid product into its sodium salt, which, after removal of the catalysts, must be treated with a strong acid for recovery of FDCA. 18,23,24 More recently, several base-free processes have been reported by using hydrotalcite-supported gold nanoparticles, 25 carbon nanotube-supported gold-palladium alloy nanoparticles 34 , covalent triazine supported ruthenium 35 and magnetic Fe 3 O 4 −CoO x 36 as catalysts. Nevertheless, even in these cases, the substrate (HMF) concentration needs to be maintained very low to avoid FDCA precipitation. The potential for practical appl...

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Section: Resultsmentioning

confidence: 99%

Section: Benchmark Of Semicontinuous Oxidation At 160 °Cmentioning

confidence: 99%

Optimization of Co/Mn/Br-Catalyzed Oxidation of 5-Hydroxymethylfurfural to Enhance 2,5-Furandicarboxylic Acid Yield and Minimize Substrate Burning

Zuo

Venkitasubramanian

Busch

et al. 2016

ACS Sustainable Chem. Eng.

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“…Jhung reported the effects of alkali metals on the liquid-phase oxidation of xylenes. , The reaction rate can be eventually accelerated, even though the rate is decelerated a bit initially, with the addition of a suitable composition of alkali metal. Replacing the acetic acid with water and utilizing carbon dioxide as a co-oxidant was also attempted . For the first time use of guanidine as catalyst additive on the liquid-phase Co−Mn−Br-catalyzed oxidation of p -xylene was studied.…”

Section: Introductionmentioning

confidence: 99%

Effects of Guanidine on the Liquid-Phase Catalytic Oxidation of p-Xylene to Terephthalic Acid

Cheng

Wang

et al. 2005

Ind. Eng. Chem. Res.

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In previous papers Xie, G. Ind. Eng. Chem. Res. 2005, 44 (2), 261-266; 2005, 44 (13), 4518-4522], a lumped kinetic scheme and a fractional kinetic model for the liquid-phase oxidation of p-xylene catalyzed by Co-Mn-Br was proposed and tested and the effect of water on the oxidation reaction kinetics was investigated. In this paper the effect of guanidine catalyst additive on the liquid-phase oxidation of p-xylene to terephthalic acid over Co-Mn-Br catalyst system was studied. Experiments on four levels of guanidine composition were carried out in a semibatch oxidation reactor where the gas and liquid phases were well mixed. The results show that the addition of guanidine apparently accelerates the oxidation of the second methyl group. However, for the oxidation of the first methyl group there is an optimal guanidine composition w 0 . When the composition of guanidine is lower than w 0 , the oxidation rates for the first methyl group increase with the increase of guanidine composition, whereas when the composition of guanidine is higher than w 0 , the oxidation rates decrease with the increase of guanidine composition. Moreover, the addition of guanidine inhibits the side reactions remarkably. A possible mechanism for interpretation of the effect of guanidine on the oxidation of p-xylene to terephthalic acid is presented.

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“…reaction in sub-or supercritical water, 15,16 heterogenization of the catalyst, [17][18][19][20] using carbon dioxide as co-oxidant, or alternative promoters. [21][22][23] However, all efforts did not replace the original AMOCO process. Under optimal conditions, more than 98% of the para-xylene react to the desired product with selectivities around 95% within 8-24h.…”

Section: Xylene Oxidation (Amoco Process)mentioning

confidence: 99%

Development of Bulk Organic Chemical Processes—History, Status, and Opportunities for Academic Research

et al. 2021

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An advanced MC-type oxidation process — the role of carbon dioxide

Cited by 42 publications

References 5 publications

Optimization of Co/Mn/Br-Catalyzed Oxidation of 5-Hydroxymethylfurfural to Enhance 2,5-Furandicarboxylic Acid Yield and Minimize Substrate Burning

Optimization of Co/Mn/Br-Catalyzed Oxidation of 5-Hydroxymethylfurfural to Enhance 2,5-Furandicarboxylic Acid Yield and Minimize Substrate Burning

Effects of Guanidine on the Liquid-Phase Catalytic Oxidation of p-Xylene to Terephthalic Acid

Development of Bulk Organic Chemical Processes—History, Status, and Opportunities for Academic Research

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