Cyclohexanone in the production of caprolactam. Problems and solutions

Martynenko, E. A.; Glazko, I. L.; Levanova, S. V.

doi:10.1007/s11172-016-1616-4

Cited by 14 publications

(10 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cyclohexane and its‐based compounds constitute important precursors and intermediates for the production of fine and bulk chemicals [47] . For example, cyclohexanol and cyclohexanone serve as key starting materials in the polymer industry to prepare caprolactam [48] and adipic acid. These two important products are used for the preparation of nylon polymers [49] .…”

Section: Preparation Of Cyclohexane‐based Products From Lignin‐derivementioning

confidence: 99%

Synthesis of Functional Chemicals from Lignin‐derived Monomers by Selective Organic Transformations

et al. 2020

View full text Add to dashboard Cite

The valorization of lignin and its model compounds represents a key technology applied for the production of lignin-monomers, which constitute as renewable feedstocks and intermediates for the synthesis of value-added chemicals and fuels as well as molecules related to life science applications. Hence, in addition to lignin-depolymerization, the effective utilization of lignin-derived feedstocks such as phenols, ethers, alcohols, ketones and aldehydes is also gaining significant importance. In this regard, number of methodologies has been developed on the utility of these feedstocks for the production of various functional chemicals. In this review, we summarize the valorization of lignin-derived feedstocks by amination, hydrogenation, dehydrogenation oxidation, carbonylation, and trifluoromethylation, hydrolysis reactions for the synthesis of amines, cyclohexanes, cyclohexanols, cyclohexanones, esters, ketones, cyclic ethers, trifluoromethylated compounds and heterocycles as well as pharmaceuticals and biomolecules.

show abstract

Section: Preparation Of Cyclohexane‐based Products From Lignin‐derivementioning

confidence: 99%

Synthesis of Functional Chemicals from Lignin‐derived Monomers by Selective Organic Transformations

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Esters of secondary and primary alcohols are formed as side products of the liquid-phase oxidation of cyclo-hexane, other saturated hydrocarbons, and their oxygencontaining derivatives. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Monocarboxylic, dicarboxylic acids, and ω-hydroxycarboxylic acids, aldehydes, and diols can be obtained by a direct oxidation of esters. 11,16 The use of esters as solvents, softeners, and components of lubricating oils is accompanied by a loss of operational properties due to thermal oxidative destruction of these compounds.…”

Section: Introductionmentioning

confidence: 99%

The specific features of the liquid-phase oxidation of saturated esters. Kinetics, reactivity and mechanisms of formation of destruction products

Perkel

Voronina

2020

Russ Chem Bull

View full text Add to dashboard Cite

Data on kinetics, reactivity, and mechanisms of formation of destruction products of the liquid-phase oxidation of saturated esters by molecular oxygen have been systematized and discussed. The ester group has both an activating and deactivating eff ects on the reactivity of the СН bonds of the alkoxyl (α´-, β´-, γ´-, and δ´-) and acyl (α-, β-, and γ-) groups. The activating eff ect in esters is weaker than in alcohols, ketones, and ethers and extends to the αand α´-CH bonds. The reactivity of the β-, β´-, and γ´-СН bonds is signifi cantly lower than that of the secondary СН bonds of hydrocarbons. Oxidation of the β-СН bonds of the acyl moieties of esters leads to НОО • radical, α,β-epoxy-, α,β-dihydroxy-, and α,β-unsaturated esters, but not to hydroperoxides. Upon the oxidation of esters, the highly active α-carboxyalkylperoxy-, α-acyloxyperoxy-, and НОО • -radicals are formed. The recombination reactions involving these radicals occur both with and without chain termination. The specifi city of the decomposition of ester hydroperoxides are due to intra-and intermolecular interactions of the hydroperoxide groups with the ester groups. Labile peroxide intermediates (α-hydroxyperoxyesters, peroxyesters, and peroxylactones) are formed through the corresponding tetrahedral intermediates and decay predominantly by the non-radical pathway. The recombination of the peroxyl radicals and the decay of labile peroxides result in the parallel accumulation of per oxide and non-peroxide products during the oxidation of esters.

show abstract

“…7,18,19 However, besides CPL, other byproducts are formed in the Beckmann rearrangement process. These byproducts can be attributed to the evolution of the impurities originally present in ONE stream 19−21 as well as those formed from cyclohexanone oxime or CPL through the oximation, 19,20,22 rearrangement, purification, or storage steps. 7,23,24 The quality of the nylon-6 fibers is closely related with the impurities present in CPL.…”

Section: Introductionmentioning

confidence: 99%

“…The type and amount of impurities have marked negative effects on the quality of the nylon-6. 19,22 Quantification and identification of impurities gives valuable information about the quality of CPL, but it is a complex task. The main difficulties are the great variety and low concentration.…”

Section: Introductionmentioning

confidence: 99%

“…After oximation, the Beckmann rearrangement (BR) of cyclohexanone oxime in oleum media produces CPL. ,, However, besides CPL, other byproducts are formed in the Beckmann rearrangement process. These byproducts can be attributed to the evolution of the impurities originally present in ONE stream − as well as those formed from cyclohexanone oxime or CPL through the oximation, ,, rearrangement, purification, or storage steps. ,, …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Linear Amides in Caprolactam from Linear Ketone Impurities in Cyclohexanone Obtained from Cyclohexane: Kinetics and Identification

Lorenzo

Salvador

Del-Arco

et al. 2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Caprolactam obtained after oximation and Beckman Rearrangement of cyclohexanone is the monomer of nylon-6. As the quality of the nylon-6 fibers is affected by the impurities present in ε-caprolactam, the type and amount of impurities in the cyclohexanone production process should be studied. Characterization of the purity of ε-caprolactam is accomplished using different parameters. Among them, volatile bases evaluate the presence of linear amides as impurities. They act like chain terminations and have a strong impact on average molecular weight and the size of nylon fibers. In ε-caprolactam from cyclohexane oxidation, these linear amides are frequently found, and N-pentylacetamide is one of the most abundant. In this work, it has been proposed and proven that ketones or aldehydes, such as n-heptanones, n-octanones, and hexanal present in cyclohexanone from cyclohexane oxidation, are the precursors of the most linear amides found in CPL. Special attention has been paid to the reactivity of 2-heptanone and 3heptanone in the oximation and Beckmann rearrangement steps since they have a boiling point similar to that of cyclohexanone and are difficult to remove by distillation. To do this, oximation (T = 80 °C and pH = 5) and further rearrangement (in sulfuric media at 100 C) of the aforementioned ketones or aldehydes has been carried out. Oximes and amides produced have been identified by using NMR and/or GC/MSD techniques. The kinetic model for oximation of 2-heptanone and 3-heptanone has been obtained at two temperatures (80 and 85 °C) within the pH range 3.5−6, simulating industrial conditions. In addition, the relative rearrangement rates of the linear oximes have been analyzed, showing the reaction rate to N-pentylacetamide for the production of the linear amides.

show abstract

Cyclohexanone in the production of caprolactam. Problems and solutions

Cited by 14 publications

References 21 publications

Synthesis of Functional Chemicals from Lignin‐derived Monomers by Selective Organic Transformations

Synthesis of Functional Chemicals from Lignin‐derived Monomers by Selective Organic Transformations

The specific features of the liquid-phase oxidation of saturated esters. Kinetics, reactivity and mechanisms of formation of destruction products

Linear Amides in Caprolactam from Linear Ketone Impurities in Cyclohexanone Obtained from Cyclohexane: Kinetics and Identification

Contact Info

Product

Resources

About