Cumene oxidation mechanism. The selectivity toward cumene hydroperoxide reached 98.

Cumene oxidation mechanism Dec 24, 2023 · Abstract Kinetic simulation of cumene oxidation leading to the obtaining of cumene hydroperoxide (the curing initiator for acrylic adhesives) in the presence of a Ca, Sr, Ba chloride complex with dibenzo-18-crown-6 ether as a catalyst is performed. 3. A mathematica analyzed. ABSTRACT: The mechanism of how oxygen affects cumene autoxidation related to temperature is still bewildering. Oxygen was the limiting factor for cumene autoxidation above Feb 3, 2004 · cis-[RuIV(bpy)2(py)(O)]2+ oxidizes cumene (2-phenylpropane) in acetonitrile solution primarily to cumyl alcohol (2-phenyl-2-propanol), α-methylstyrene, and acetophenone. 26 CHP decomposes very rapidly under acidic conditions and elevated temperatures. In this study, M–N–C (M = Fe, Co, Cu, Zn) as model catalysts for cumene oxidation through theoretical calculations and experiment validation are studied. Aug 1, 2018 · Through investigation of the effect of the cation and anion of the ionic liquids, some insight into the mechanism of the cumene liquid-phase oxidation was gained. From process safety point of view, and also to understand the auto-catalyzed mechanism in the cumene oxidation, it is necessary to describe and quantify the Apr 1, 2022 · Current research on the cumene oxidation is mainly focused on increasing the conversion of cumene and the selectivity of CHP [20]. Alkyl-substituted rings can be coverted to poly-acids, which can be distinguished on the basis of their pKas Apr 1, 2008 · In a recently published paper [28], we have presented the basic model equations for a continuous air-sparged reactor stage for cyclohexane oxidation. Several proposed mechanisms of carcinogenesis support the relevance to humans of lung and liver tumors in experimental animals. We expect this study to shed more light on the nature of the surface-active site(s) of La 2 O 3 –CuO–MgO catalyst for cumene oxidation and the development of heterogeneous catalysts with high activity in a wide range Nov 1, 2024 · The reaction mechanism was studied by simple radical scavenging experiments, and it was suggested that the activation of oxygen molecules was the main pathway for Pd/CaAl-LDH to promote the oxidation reaction of cumene. Mar 24, 2023 · M–N–C materials as catalysts are widely used in hydrocarbon oxidation, the intrinsic role of which has not been well illustrated. Cavalieri d'oro and and Anna Fait and Lamberto Roberti and M L Tampieri and Sep 15, 2022 · The selective oxidation of hydrocarbons toward value-added products using molecular oxygen is a crucial process in the petrochemical industry [1], [2], [3]. Cumene is oxidized with oxygen in air in the liquid phase to cumene hydroperoxide (CHP). Ph. Concentration of cumene was determined by gas chromatography. The final products of oxidation are close to the products of catalytic CHP decomposition. , for a relatively long period of time, prior to the discovery of the abovementioned CHP cleavage reaction. Instead, the results are consistent with a Apr 15, 2008 · Cumene hydroperoxide (CHP) is produced via the oxidation of cumene with air in the presence of aqueous sodium carbonate as a catalyst. 1016/0009-2509(92)87085-5 Corpus ID: 94931127; Phenol-acetone process: cumene oxidation kinetics and industrial plant simulation @article{Andrigo1992PhenolacetonePC, title={Phenol-acetone process: cumene oxidation kinetics and industrial plant simulation}, author={Pietro Andrigo and Alberto Caimi and P. [40], [41] All Prediction of catalytic performance The catalytic performance of the ILs was assessed by modelling the catalytic oxidation of cumene using DFT calculations based on the mechanism shown in Fig. It was reported that cumene oxidation is a homogeneous auto-oxidation free-radical reaction, including three basic steps: chain initiation, chain propagation, and chain termination [9, 10, 21, 22]. It is established that the Mg 2-ethylhexanoate exhibits the highest catalytic performance. The rate of ozone consumption was found to be VV Shereshovets. A kinetics model based on the radical reaction mechanism of cumene oxidation was developed, which contained 7 major elementary steps. The primary purpose is to identify potential mechanisms of action of carcinogenicity, review the strength of evidence Jan 25, 2022 · A mechanism for the selective oxidation of cumene to CHP is suggested according to the catalytic results (Table 1), the analyses for the active intermediates (Fig. An synergistic effect of KMnO4 and NHSI in aerobic oxidation of RH is found. Industrial cumene oxidation is This work first proposes a rigorous process model for the industrial production of cumene hydroperoxide (CHP) through cumene oxidation. Mar 1, 2023 · Experiment indicates that [Bmim]OH can effectively accelerate the oxidation reaction rate of cumene and improve the conversion of cumene. Nov 8, 2019 · The reaction formula of Cumene oxidation in the in the mixture of gas (80 % of nitrogen and 20% of hydrogen) and liquid (85 % water, 15% NaOH). 1. This is the first stage of the technological process for producing phenol and acetone with the use of the cumene method [2, 3]. 6 × 10−2 m3/kg s, a potassium permanganate into the reaction solution (0. 3 %, leading to the rapid synthesis of a significant amount of the target product, CHP, within a short period. The decomposition of CHP was accelerated by prolonged reaction time, at higher tem perature or through the accumulation of CHP Apr 1, 2023 · Due to the vulnerable peroxy bond, cumene hydroperoxide (CHP) had been broadly used as a vital intermediate in the manufacturing of phenol and acetone by the way of the cumene oxidation process (Wang et al. The developed model was used to Jan 1, 2025 · The imines facilitate the decomposition of minor impurities of cumene hydroperoxide, thereby acting as catalysts for the oxidation of cumene. The cumene, the catalyst, AIBN and, in some cases, the solvent (tert-butylbenzene or acetonitrile) were placed in a 10 mL flask connected to a gas burette filled with oxygen under atmospheric pressure. [40] , [41] All structures, including reactants, products, intermediates (IM), and transition states (TS), were optimized at the B3LYP/6–311++g(d,p) level of theory. Here, the analysis of the aerobic oxidation products of cumene catalyzed by the polymer ferric complex through GC-MS has been performed. Referring to Jan 23, 2023 · The oxidation of alkyl side-chains to form benzoic acids was historically used in qualitative analysis to determine the positions of alkyl groups in substituted aromatic systems. The theoretical basis for the formalization of cumene oxidation mechanism and Jun 2, 2024 · This active and promising combination of NHPI and BmimBr was employed for cumene oxidation under solvent-, transition-metal-salt-, and CHP-initiator-free conditions. 3% in the cumene conversion of 28. 3. Contrary to a prior report, the rate of the reaction is not accelerated by added nucleophiles. Organic Chemistry This paper discusses the results of investigations on the kinetics of cumene oxidation to cumene hydroperoxide by molecular oxygen in the presence of N-hydroxyphthalimide as a catalyst. Kinetic analysis of cumene autoxidation with air at a pressure of 1. Typical procedure for cumene oxidation The cumene oxidations were performed in a gasometric apparatus as shown in Fig. Cumene is oxidized by air via a radical mechanism. 0 atm was investigated by experiments and variational transition state theory/DFT. A. Anodic oxidation of cumene on the BDD electrode with a wide potential window preferentially affords the cumyl cation as the reaction intermediate. In combination with Phen, Fe(III) complexes acquired the strongest oxidizing ability in relation to The kinetics and mechanism of the oxidation of cumene by ozonized oxygen. However, the UniSim software package does not allow taking into account the reactions involving radicals [15]. Stoyanov Mar 1, 2023 · The catalytic action of platinum in the oxidation of cumene to cumene hydroperoxide has been studied at a temperature of 110–120 °C, a flow rate of the oxidizing air of 1. It is shown by the PBEPBE-GD3/def2TZVP method that the intermediate adducts of cumene, cumene hydroperoxide (gauche- and trans-conformers), and dimethyl phenyl carbinol with Mg 2 Jul 22, 2013 · Thus, a possible mechanism for the cumene oxidation and cumene hydroperoxide decomposition in the presence of Zn, Cd or Hg 2-ethylhexanoate has been substantiated. A mechanism invoking methyl instead Aug 12, 2013 · Due to the considerable industrial implications, an in-depth study of cumene peroxidation using supported gold and silver nanoparticles was carried out to gain more insight into the mechanism of this reaction. From ecological and economical viewpoints, the key step of this process Mechanism: For the purposes of Org 1/ Org 2 the mechanism isn’t considered that important. Mechanism of Oxidation of Cumene by Mixture of Ozone-Oxygen. However, as a traditional organic peroxide, the structural convenience of CHP also brought cumene hydroperoxide molecules participate [1]. Cascade of three CSTRs is the most optimal for the cumene oxidation. Feb 1, 2000 · Particular attention is focused on the extent of cumene adsorption on the catalyst particle and its relation with the mechanistic features of cumene oxidation. , 2020, Duh et al. V. Sep 18, 2022 · The mechanism of how oxygen affects cumene autoxidation related to temperature is still bewildering. Mar 1, 2023 · The mechanism of the oxidation reaction of cumene revealed that C(1) atom of the [Bmim]OH carbene-water structure can activate the O O bonds of cumyl hydroperoxide to induce the decomposition of cumyl hydroperoxide. Arene oxides can form phenols, and when the para isomers Oct 1, 2021 · Within the framework of the traditional mechanism of NHPI-catalyzed oxidation, the experimentally observed behavior of the NHPI/Fe(acac) 3 /Phen system during cumene oxidation was attributed to the highly efficient generation of the radical PINO. The selectivity toward cumene hydroperoxide reached 98. This work is based on the study of cumene (or isopropylbenzene – IPB) oxidation to cumene hydroperoxide (CHP), the key reaction of the phenol production industrial process currently in use worldwide [1]. A part of cumene hydroperoxide (CHP) can decompose under certain conditions. 7 MPa (with a cumene conversion level amounting to 10–25%, the selectivity being Feb 28, 2000 · At the higher temperature (363 K), the main way of cumene initiation is CHP decomposition. The use of these catalysts will make it possible to solve a number of tasks that are Because cumene is so readily oxidized by O 2, it may potentially be a good solvent to carry out simple functional group oxidation and/or oxidative coupling reactio ns through radical chain oxida-tions. CHP is an important intermediate in the three-step cumene-phenol process which starts with the alkylation Nov 13, 2017 · This paper discusses the results of investigations on the kinetics of cumene oxidation to cumene hydroperoxide by molecular oxygen in the presence of N-hydroxyphthalimide as a catalyst. There is thus no evidence for the hydride transfer mechanism originally proposed. On the other hand, cathodic reduction of dissolved oxygen produces the superoxide and even the hydroperoxide anion. Firstly, a cumylhydroxy radical and OH radical are generated, as an initiation, by thermal decomposition of CHP. Scavenging experiments were conducted to analyze the reaction mechanism of the thermally catalyzed cumene oxidation reaction on Pd/CaAl-LDH by targeting various reactive The effect of Zn(EH)2, Cd(EH)2 and Hg(EH)2 (EH is 2-ethylhexanoate) on cumene oxidation has been established. Supported gold nanoparticles were found to efficiently catalyze the decomposition of cumene hydroperoxide with a selectivity of 25% at 80 °C when using gold supported on hydrotalcite 2. 1). From process safety point of view, and also to understand the auto-catalyzed mechanism in the cumene oxidation, it is necessary to describe and quantify the The oxidation of cumene and following cleavage of cumene hydroperoxide (CHP) with sulfuric acid (Hock rearrangement) is still, by far, the dominant synthetic route to produce phenol. Download: Download full-size image Aug 14, 2024 · Oxidation of organic substances by molecular oxygen generates various intermediate products, such as cumene hydroperoxide. Ulitin +6 authors O. Notably, the cumene oxidation reaction rate was accelerated by 33. Kinetics of oxidation was followed by cumene hydroperoxide (CHP), acetophenone, and phenol formation. The research scope covers process design, optimization, and controllability studies. 0 atm was investigated by experiments and variational transition state theory/ DFT. 2) and control experiments (Table 6), and depicted in Scheme 3. 15), and Sumitomo process patents (196b,282) describe the following process steps: (1) An oxidation process where cumene is oxidized in air to obtain CMP, (2) An epoxidation process where α,α-dimethyl benzyl-alcohol (CMA) is obtained from CMP and propylene Nov 15, 2001 · To make concepts for increasing CHP productivity, mechanism for cumene auto-oxidation was confirmed (Fig. Recent research on the liquid-phase oxidation of cumene-involved metal–organic frameworks Feb 16, 2021 · Compared with current industrial processes and academic research in oxidation of cumene to cumene hydroperoxide with O 2 , the main superiorities of this protocol were the high selectivity, high Figure 2 shows a proposed mechanism. 1–0. Cumene hydroperoxide in presence of transition metal ions produces cumoxyl radical (step 1), which abstracts a hydrogen (H) from a lipid (PUFA) molecule (LH) generating cumyl alcohol and lipid radical (L • ) that reacts readily with oxygen Nov 1, 2024 · Therefore, according to the autoxidation mechanism of cumene, 1 % Pd/CaAl-LDH may promote the oxidation reaction of cumene by activating oxygen molecules, a feasible pathway. Mechanism of cumene oxidation to CHP The objective in oxidation is to maximize the selectivity of the IPB to CHP reaction while minimizing by-product formation, all the while maintaining the safest possible operating conditions. Supported gold nanoparticles were found to efficiently catalyze the decomposition of cumene hydroperoxide with a selectivity of 25% at 80 °C when using gold supported on hydrotalcite Jul 15, 2020 · The study of alkyl benzenes oxidation mechanism in liquid phase was started in the early years of the twentieth century. 1. Kinetic studies show that ozone undergoes chain decomposition in the course of the liquid-phase oxidation of cumene (10−3–10−3 mole/liter) by ozonated oxygen. Nov 13, 2017 · This paper discusses the results of investigations on the kinetics of cumene oxidation to cumene hydroperoxide by molecular oxygen in the presence of N-hydroxyphthalimide as a catalyst. Specifically, there oxidation mechanism, we followed Denisov’s approach and considered that cumene oxidation initiation occurred by tri-molecular reaction rather than that by Russell’s Aerobic Oxidation of Cumene Over Metalloporphyrins The cumene oxidation process catalyzed by metal loporphyrins is shown as below (Scheme 1). The mechanism for the acid-catalyzed peroxide decomposition was investigated by Seubold and Vaugham. In two recent cross-dehydrogenative coupling methods, the cumene/O 2 couple was utilized as an enabling (re-)oxidizing strategy (Scheme 3). The column packed with silicon SE-30 was used at 110°C. To solve this problem, new catalysts have been developed to increase Dec 24, 2023 · Request PDF | On Dec 24, 2023, N. The study began with a comprehensive analysis and supplementation of the required physical properties. In industry, cumene hydroperoxide is obtained in the course of noncatalytic cumene oxidation with air oxygen at a temperature of 353–403 K and at a pressure of 0. The mechanism of cumene oxidation is shown in Fig. The effect of Cavani and Gaffney (271) published a flow diagram of the Sumitomo process (see Figure 1. Unlike previously studied N-compounds, the nitrogen atom in imines formally does not have a positive charge, nevertheless, the increased solubility of imines in Cumene metabolism proceeds primarily through side-chain oxida-tion, but ring oxidation also occurs in vivo. Apr 1, 2021 · Design of cumene oxidation was carried out by simulation in UniSim Design. Cumene is a common name for isopropylbenzene, an organic compound. Manganese acts in mysterious ways. Novikov N. It is the first time to strengthen the traditional oxidation of alkaline liquid based isopropyl benzene with ionic liquid as a catalyst. The major competing reactions result in the formation of DMPC and ACP [12]. The reactor model for cumene oxidation was built using this scaffolding, with the gas and the liquid phase equations remaining essentially the same, except that in the liquid phase we now have Chain decomposition of ozone was also observed in the oxidation of cumene by an O3-O2 mixture [151]. Mechanism for Chemical Steps of the Reaction The liquid phase oxidation of cumene will be ex-plained in terms of a radical mechanism. In the presence of certain catalysts or initiators, the free radicals can initiate a chain reaction that leads to the oxidation of other compounds. Novikov and others published Mechanism of Cumene Oxidation into Cumene Hydroperoxide (Curing Initiator for Acrylic Adhesives) in the Presence of Ca, Sr, Ba Mechanism of the Antioxidative Effect of Bis(4-hydroxy-3,5-di-tert-butylphenyl) Sulfide and Polysulfides in Cumene Oxidation. Cumene is a volatile colorless liquid at room temperature with a characteristic sharp, penetrating, aromatic odor. Published: December 2001; Volume 74, pages 2083–2086, (2001) Cite this article We would like to show you a description here but the site won’t allow us. The kinetic model involves a mechanism for the formation of intermediate adducts between reaction mixture components and the catalyst, initiation Oct 1, 2021 · A detailed analysis of the mechanism of catalytic cumene oxidation by use of metalloporphyrins [28] made it possible to establish that cumene oxidation runs in two independent directions: heterolytic (due to heterolytic decomposition of O O bond of cumene hydroperoxide [29]) and homolytic (due to homolytic decomposition of O O bond of cumene Apr 1, 2021 · The cumene oxidation runs according to the radical-chain mechanism [17,23,24]. Oxygen was the limiting factor for cumene autoxidation above 100 °C, although it had negligible impacts on cumene autoxidation at 70–100 °C Nov 13, 2017 · This paper discusses the results of investigations on the kinetics of cumene oxidation to cumene hydroperoxide by molecular oxygen in the presence of N-hydroxyphthalimide as a catalyst. To investigate the catalytic effect of [Bmim]OH, the mechanism of molecular oxygen-activated [Bmim]OH-catalyzed oxidation reaction of cumene was proposed using the dispersion-corrected DFT-D3 calculation method. Nov 27, 2019 · Cumene-Mechanism of toxicity Jan 12, 2022. There-fore, in order to solve this problem, it is very necessary to develop highly active and reusable homogeneous and hetero-geneous catalysts for cumene oxidation to increase the productivity of CHP. , 2001, Liu et al. Herewith, cumene transformation can be described by the typical heterogeneous mechanism of cumene oxidation as. The model adequately describes changes in all reaction components in the course of the DOI: 10. Cumene hydroperoxide is obtained by means of cumene oxidation with the use of atmospheric oxygen. These processes follow a complex radical mechanism. Metabolism of cumene re-sulting in side-chain oxidation of α-methylstyrene to α-methylstyrene oxide or ring oxidation to arene oxides could potentially cause DNA damage. Dec 13, 2013 · Kinetics of thermal and photo-oxidation of cumene in the absence of catalyst was studied using high-pressure differential scanning calorimetry and low-pressure photocalorimetry. It’s thought that the first step is removal of a hydrogen by one of the oxygens on MnO4(–) in a free-radical reaction. 4% for 2020–2025. Aug 17, 2016 · It first overviews the cumene route, followed by a detailed description of the thermal decomposition behavior of CHP, and finally the mechanism of the liquid phase oxidation of cumene. Mechanisms showing how cumene hydroperoxide produces lipophilic cumoxyl and cumoperoxyl radicals. 01 mol/L) initiates oxidation of cumene by molecular oxygen. From process safety point of view, and also to understand the auto-catalyzed mechanism in the cumene oxidation, it is necessary to describe and quantify the Nov 1, 2021 · The main problem to be solved in the process of liquidphase cumene oxidation is low productivity of cumene hydroperoxide [8]. N. Apr 15, 2024 · The mechanism of the catalytic oxidation of cumene using ionic liquids was investigated using the Gaussian 09 package. A mechanism proposed to cover this oxidation shows the ozone participating in both the primary reaction and stepwise chain extension: R $$\\dot O$$ 2 + O3 → R $$\\dot O$$ + 2O2; CH3 $$\\dot O$$ 2 + O3 → CH3 $$\\dot O %PDF-1. 2. Finally, phenol is obtained and purified by distillation. Jul 25, 2020 · The concerted mechanism of this step is similar to the mechanisms of the Baeyer–Villiger oxidation[6] and also the oxidation step of hydroboration-oxidation. The air oxygen pressure does not hinder the process [Po 2= 20 kPa (10 −3 mol O 2 /L)]. Jul 22, 2013 · Due to the considerable industrial implications, an in-depth study of cumene peroxidation using supported gold and silver nanoparticles was carried out to gain more insight into the mechanism of this reaction. The original practical purpose of cumene oxidation was the production of acetophenone, rather than of CHP [4]. [7] In 2009, an acidified bentonite clay was proven to be a more economical catalyst than sulfuric acid as the acid medium. The oxygen. Changing the temperature mode does not lead to decrease TAC. It was proposed the mechanism of reaction, where, at the first stage, the abstraction of the H-atom from the C±H bond of Nov 10, 2011 · Co(salen)-type [where salen = di-(salicylal)-ethylenediimine] complexes were shown to be efficient catalysts in the oxidation of 2-phenylpropane (cumene) by dioxygen primarily to 2-phenyl-2-propanol (cumyl alcohol), 2-phenylpropene (α-methylstyrene), and 1-phenylethanone (acetophenone) applying 1H NMR spectroscopy and gas chromatography–mass spectrometry (GC–MS). Summarizing the experimental data about oxidation of organic compounds Bach and Engler proposed an oxidation peroxide theory [1], [2], having introduced into science the idea of peroxides as labile intermediates in oxidation processes. 3 %âãÏÓ 315 0 obj /Linearized 1 /O 318 /H [ 1513 628 ] /L 350464 /E 100672 /N 12 /T 344045 >> endobj xref 315 50 0000000016 00000 n 0000001351 00000 n 0000001464 00000 n 0000002141 00000 n 0000002630 00000 n 0000021439 00000 n 0000021686 00000 n 0000022923 00000 n 0000023284 00000 n 0000023517 00000 n 0000024734 00000 n 0000025950 00000 n 0000026188 00000 n 0000026351 00000 n The cumene oxidation reaction has been known since 1926 [3], i. Uses and Benefits of CUMENE Nov 27, 2019 A novel and efficient protocol for oxidation of cumene to cumene hydroperoxide was presented using ambient O 2 catalyzed by very simple metalloporphyrins. 3 billion US$ with a projected compound annual growth rate of 3. Figure 6 – Cumene oxidation to CHP. This section reviews data related to identifying and evaluating putative mechanisms for the potential carcinogenicity of cumene including (1) genetic and related effects, (2) mechanistic considerations, and (3) mutagenic and/or carcinogenic effects of metabolites and analogues. Aug 8, 2017 · In the presence of substrates, the cumene oxidation process can be intercepted in various chain reactions, affording very simple protocols for functional group oxidation. Cumene hydroperoxide does not influence additionally to the initiation of oxidation. A mathematical model has been developed on the basis of the regularities of hydroperoxide and by-products formation. This can be associated with the formation of C-centered (R⦁) and O-centered (SINO⦁) radicals Sep 22, 2000 · Based on the gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS) spectra, the analysis of the products of the catalytic oxidation and its mechanism can be elucidated. 1% with T(4-COOH)PPCu as a catalyst at 80 ∘ C. Additional applicable purposes include Oct 1, 2019 · In this contribution, the cumene oxidation takes place in the mixture of a gas-liquid binary system. The term stems from cumene (isopropyl benzene), the intermediate material during the process. Nov 4, 2024 · The kinetics of the liquid-phase oxidation of cumene (RH) with molecular oxygen in the presence of KMnO4 and N-hydroxysuccinimide (NHSI) is studied. Dec 5, 2024 · Selective oxidation of cumene to value-added acetophenone is of great importance and environmental friendliness. Sep 7, 2022 · Figure 2 shows a proposed mechanism. Dec 9, 2024 · The mechanism of cumene hydroperoxide involves the decomposition of the O-O bond to form free radicals. The enantioselectivity was provided by preparing the titanium complex in the presence of sulfide 1 at an elevated temperature and/or during a prolonged preparation time and by performing the oxidation Jan 24, 2021 · Thus, a possible mechanism for the cumene oxidation and cumene hydroperoxide decomposition in the presence of Zn, Cd or Hg 2-ethylhexanoate has been substantiated. Cumene caused tumors at several tissue sites, including lung and liver in mice and kidney in male rats. The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene. Dec 24, 2023 · In the case of the free radical curing of acrylic adhesives, cumene hydroperoxide is most often used as an initiator with a long half-life []. The developed model was used to Finally, the possible reaction pathway and promotional mechanism on La 2 O 3 –CuO–MgO in cumene oxidation are proposed. In 2020, the global phenol market reached a value of 23. The developed model was used to study the catalytic activity and thermal stability of Zn, Cd and Hg 2-ethylhexanoates in cumene oxidation and cumene hydroperoxide decomposition. It is insoluble in water but is soluble in alcohol and man. Even with various kinds of applications in the petrochemical industry, over 94. thesis Dissertation, Institute of Chemical Physics, Chernogolovka, 1978, pp 1-21 [in Russian]. Phenol can inhibit such reactions by reacting with free radicals to form phenoxy radicals, which are relatively stable and do not propagate the chain mechanism. Important samples such as the oxidation of cumene oxidation (5 × 10 6 tons per year), cyclohexane (6 × 10 6 tons per year) and the oxidation of p-xylene (3 × 10 7 tons per year) to produce corresponding ketone, alcohol and peroxides are The asymmetric oxidation was achieved by titanium-mediated oxidation with cumene hydroperoxide in the presence of (S,S)-diethyl tartarate (DET). Cumene-hydroperoxide was detected quantitatively by iodometry. N-hydroxymaleimide (NHMI) was immobilized on a polymer substrate via co-polymerization followed by an imidization in this work, and the catalyst was characterized and tested for oxidation of cumene to acetophenone. The changes of Gibbs free energy (ΔG) for the elementary steps demonstrate that the activation of Jan 1, 2025 · It seems reasonable to assume that a comparable mechanism for the decomposition of CHP and the initiation of cumene oxidation (2) is responsible for the catalysis by R-bian and R-mian. Dec 1, 2023 · This work first proposes a rigorous process model for the industrial production of cumene hydroperoxide (CHP) through cumene oxidation. 5% of the CHP has been used in producing phenol and acetone through catalytic reaction [4]. D. 4a [16]. Jun 8, 1992 · In this work, a detailed kinetics study of cumene oxidation catalyzed by carbon nanotubes (CNTs) and nitrogen doped CNTs (NCNTs) was carried out to disclose the crucial influence of N doping in the cumene oxidation. The discovery of the reaction Jul 1, 2020 · A detailed radical-chain kinetic scheme of cumene oxidation by molecular oxygen is presented in our recent work [23]. The model cumene-initiated oxidation reaction proceeds at moderate temperatures under steady-state conditions. Dec 21, 2021 · Cumene is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals. Both dicumyl and the adduct formed by cumyl radical with TEMPO confirmed the presence of carbon free radical. oxidation process is generally below the desired values. The relative reactivity of imines in the oxidation of cumene is correlated with the relative electron-withdrawing ability of the aryl functional groups of CF 3-Ph>dpp, tmp. The group contribution method or COSMO-based calculations are used to Jul 15, 2020 · Mechanism of Cumene Oxidation into Cumene Hydroperoxide (Curing Initiator for Acrylic Adhesives) in the Presence of Ca, Sr, Ba Chloride Complex with Dibenzo-18-Crown-6 Ether. , 1997). In traditional processes, cumene oxidation is always carried out in the absence of Oct 1, 2021 · A detailed analysis of the mechanism of catalytic cumene oxidation by use of metalloporphyrins [28] made it possible to establish that cumene oxidation runs in two independent directions: heterolytic (due to heterolytic decomposition of O O bond of cumene hydroperoxide [29]) and homolytic (due to homolytic decomposition of O O bond of cumene Jul 15, 2020 · Thus, a possible mechanism for the cumene oxidation and cumene hydroperoxide decomposition in the presence of Zn, Cd or Hg 2-ethylhexanoate has been substantiated. Jul 1, 2007 · The VOC degradation mechanism studies showed that the oxidation occurs due to the formation of free radicals as well as hydroxyl ions, so named it heterogeneous photo-Fenton oxidation. Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 1979 , 28 (6) , 1132-1138. An increase in the reaction rate when adding acetic acid is established. Mar 9, 2023 · Abstract The kinetics of cumene oxidation in the presence of Mg, Ca, Sr, Ba 2-ethylhexanoates is studied experimentally. Liquid aerobic oxidation of cumene to cumene hydroperoxide (CHP) is one of such reactions. The whole set-up of cumene oxidation process including synthesis, separation and purification was established and optimized by using Aspen HYSYS. In the modelling, cumene and O 2 were carried by the air flow into a liquid phase of aqueous base Nov 13, 2017 · This paper discusses the results of investigations on the kinetics of cumene oxidation to cumene hydroperoxide by molecular oxygen in the presence of N-hydroxyphthalimide as a catalyst. e. pxtblm gbertxd jasnl spn slhjvc cvoqwh wncjau bil lqwntjb pdkwvnp