Decomposition Of Cumene Hydroperoxide Research Articles

Understanding of Cumene Oxidation Catalyzed by Metal–Nitrogen–Carbon through Theoretical Simulations and Kinetic Validation

M–N–C materials as catalysts are widely used in hydrocarbon oxidation, the intrinsic role of which has not been well illustrated. 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. The changes of Gibbs free energy (ΔG) for the elementary steps demonstrate that the activation of cumene/O2 molecules and the decomposition of cumene hydroperoxide (CHP) play a significant role in cumene oxidation. The interactions between M–N–C and cumene, O2, and CHP are fully investigated. There are strong interactions between FeNC/CoNC and O2, cumene, and CHP, in which the activation of cumene and O2 and the decomposition of CHP occurred more easily, thereby promoting the catalytic activity. Although the adsorption energy over CuNC (ΔECuNC) for cumene is comparable to ΔECoNC, the O2 molecule is physically adsorbed on CuNC, which leads to a lower activity than those of FeNC and CoNC. Metal tetraphenyl-porphyrins (MTPPs) with the corresponding structure of M–N–C as the catalysts are used to catalyze the oxidation of cumene. A volcanic curve correlation between the average adsorption energy (ΔEav.) and the conversion rate of cumene catalyzed by MTPPs is observed. The kinetic experiments confirmed that CoTPP displays the best catalytic activity, due to the high k80 and low activation energy for the crucial steps of cumene oxidation, which is consistent with the theoretical results.

Experimental and theoretical study on ionic liquid [Bmim]Br-catalyzed decomposition of cumene hydroperoxide into dimethylbenzyl alcohol

The Ionic Liquid 1-butyl-3methyl-imidazolium bromide ([Bmim]Br) was found to be a good catalyst for the decomposition of Cumene Hydroperoxide(CHP) to ɑ,ɑ-Dimethylbenzyl alcohol(CA). The mechanism of [Bmim]Br-catalyzed conversion of CHP to CA has been studied using density functional theory(DFT) calculations. The DFT results showed that the Br anion of [Bmim]Br played a crucial role in the decomposition of CHP to CA. The energy barrier of [Bmim]Br-catalyzed decomposition of CHP is 21.4 kcal/mol. This research provides the feasibility of ionic liquid as catalysts for CHP decomposition to CA.

The Effect of Metals of the 2nd and 12th Groups on the Productivity and Selectivity of Cumene Oxidation—The First Stage of the Technological Chain for the Production of Polymer Composites

The effect of the process temperature and the initial concentration of Mg, Ca, Sr, Ba, Zn, Cd, and Hg 2-ethylhexanoates as catalysts on the productivity and selectivity of the oxidation stage of cumene is studied in the technological chain for the production of polymer composites from cumene; “production of phenol by cumene method (stage 1 is cumene oxidation to cumene hydroperoxide, stage 2 is decomposition of cumene hydroperoxide into phenol and acetone) → production of precursors from phenol → production of polymers from precursors → production of composites from polymers”. A criterion has been introduced that reflects the productivity of cumene oxidation at the moment of reaching the maximum concentration of cumene hydroperoxide, which takes into account the cumene conversion and selectivity achieved in this case in the shortest possible time using the selectivity comparable with the selectivity of a non-catalytic process. It has been shown that the achievement of the maximum value of this criterion, among all the considered catalysts, is ensured by Mg 2-ethylhexanoate at its relatively low initial concentration (1 mmol/L) under conditions of moderately-high process temperatures (393–413 K).

The Effect of Ca, Sr, and Ba Chloride Complexes with Dibenzo-18-Crown-6 Ether as Catalysts on the Process Criteria for the Efficiency of Cumene Oxidation (the First Stage in the Chain of Polymer Composite Production)

A study was made on the effect of Ca, Sr, and Ba chloride complexes with dibenzo-18-crown-6 ether as catalysts on the process criteria of the efficiency of industrial cumene oxidation using kinetic modeling. It is the first stage in the process chain of polymer composite production. The kinetic scheme of the process is made of classical reactions of the radical chain mechanism (reactions of initiation, chain propagation, and chain termination), molecular reactions, reactions of formation of intermediate adducts “component of the reaction mixture—catalyst” and their decomposition, as well as reactions that take into account the specifics of the catalyst used: (1) formation of planar catalyst complexes with various substances; (2) formation of acetophenone along the catalytic path; (3) hydration of the intermediate adduct “α-methylstyrene—catalyst” to the required alcohol. It is shown that the kinetic model fully reproduces the experimental time dependencies of the cumene hydroperoxide concentration in the cumene oxidation and cumene hydroperoxide decomposition. Using the kinetic model, computational experiments were carried out, as a result of which the following conclusions were made: (1) among the considered catalysts, the complex of Sr chloride with dibenzo-18-crown-6 ether should be recognized as the best, provided that it is used at temperatures of 393–413 K and an initial concentration < 2 mmol/L; (2) to ensure selectivity comparable to the selectivity of a non-catalytic process, it is necessary to conduct the catalytic process at a lowest possible initial concentration of any of the considered catalysts.

MnO2 nanoparticles supported on CNTs for cumene oxidation: Synergistic effect and kinetic modelling

Synergistic effects between the carbon materials and metal oxides usually are considered as the significant factor in the selective oxidation of hydrocarbons. In current study, MnO2/CNTs catalysts were prepared under mild condition and applied in the cumene oxidation. As high as 73.44% cumene conversion with 59.06% selectivity of 2-phenyl-2-propanol(PP) was obtained over 21.23-MnO2/CNTs, which is much higher than those of CNTs-catalysis and MnO2-catalysis systems. The decomposition of cumene hydroperoxide (CHP), a key step for cumene oxidation, was proved to be facilitated by the interaction between MnO2 nanoparticles and CNTs, which also confirmed from the DFT calculations. These results demonstrated that the synergistic effect between MnO2 nanoparticles and CNTs would greatly enhance the activity and tune the distribution of products selectivity. The kinetic modeling study in this work further revealed that the interactions between MnO2 nanoparticles and CNTs would accelerate all the elementary steps, especially, the homolytic cleavage of CHP. The reaction rate constant (k80 = 9 h−1) for 21.23-MnO2/CNTs is 450-folds of CNTs (k80 = 0.02 h−1). Moreover, the concentration distributions of acetophenone (AP) and PP were well illustrated from the kinetic study.

The influence of Fe(III) acetylacetonate and o-phenanthroline towards improvement of NHPI-catalyzed cumene oxidation

Cumene hydroperoxide (CHP) is the most important product or intermediate in the oxidative processing of cumene. In the present study, cooperative action of NHPI catalyst with Fe(acac)3/Phen additives in oxidation of cumene has been described in terms of oxidation rate and selectivity for products, notably CHP, under variable conditions. The oxidation characteristics were influenced by promoting additives, the main function of which was to generate an active PINO radical. An abundance of the additives might enhance the non-selective conversion of intermediates and decomposition of CHP, which led to a decrease in CHP selectivity. The addition of 0.0003 mol% Fe(acac)3 was sufficient to initiate NHPI catalyzed fast cumene oxidation and very selective CHP production at 50 °°C. Phen showed an impressive multifaceted effect, as the increase in its amount initially lowered the CHP selectivity and then increased to 95% with a large excess of Phen over Fe(acac)3. That was due to the different ability of iron complexes of various compositions to react to NHPI and to CHP. UV-VIZ spectroscopy and DFT calculation was used to elucidate assistance of Phen in reduction of Fe(acac)3 with NHPI and creation of FeII/FeIII –Phen2or3 complexes as reversible single-electron carriers upon catalysis by NHPI. In addition, the selective formation of CHP contributes to the resistance of NHPI to degradation during catalysis.

The cumene oxidation and cumene hydroperoxide decomposition in the presence of Zn, Cd or Hg 2-ethylhexanoate: Kinetic model and analysis of its sensitivity

A general kinetic model for industrially significant cumene oxidation and cumene hydroperoxide decomposition in the presence of Zn, Cd or Hg 2-ethylhexanoate as catalyst was developed. The model was based on the mass action law, in the form of a stiff system of nonlinear differential equations describing the rates of change in the concentrations of all species in the reaction mixture during the processes. Physically substantiated values of the unknown coefficients of the model (the coefficients of the temperature dependencies of the reaction rate constants) were found as a result of solving the inverse problem. It was done by minimizing the average relative error (using the method of direct search of the zero order) between the data calculated as a result of the numerical solving of the model by the implicit BDF method and the experimental data. The analysis of model sensitivity to changes of its coefficients has been carried out. Through this analysis, the original model is reduced to a simplified form, more convenient for studying the kinetic regularities and the mechanism of the considered chemical processes. The modification of the original model involved in exception from its equations of the terms containing the coefficients that were found as a result of solving the inverse problem, for which change the model is insensitive. A total of 39 terms were excepted out of 179. 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. 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. Computational experiments have shown that the catalytic activity of Zn, Cd and Hg 2-ethylhexanoates in cumene oxidation and cumene hydroperoxide decomposition is caused by formation of intermediate adducts ROOH⋅Cat, which turn to be an additional source of free radicals due to their lower thermal stability compared to the original catalyst and cumene hydroperoxide. This phenomenon can be used for practical purposes to increase the rate of cumene hydroperoxide accumulation during cumene oxidation. The kinetic model presented in the article, can be a starting point (model object) for the development of kinetic models of oxidation processes of other aromatic hydrocarbons, catalyzed by nontransition metals due to the formation of intermediate adducts.

COMPLEX OF NICKEL (II) ION WITH TRYPTOPHAN AS A HOMOGENEOUS CATALYST IN THE DECOMPOSITION REACTION OF CUMENE HYDROPEROXIDE IN AQUEOUS SOLUTION

The formation of Ni2+:Tryptophan (Trp) 1:1 complex, which acts as a model catalyst for decomposition of cumene hydroperoxide (ROOH) in Ni2++Trp+ROOH+H2O system, has been confirmed via kinetic study in aqueous solution at pH>7. The kinetic expression of a single catalytic decomposition reaction of ROOH under the influence of [NiTrp]+ complex was brought out. The temperature dependence of the effective rate constant of ROOH decay (Keff=Kcat[Ni2+]0[Trp]0=const) in the temperature range from 323 to 343 K can be expressed by Arrhenius equation (Eeff is in kJ/mol): Keff=(1.87±0.02)·106exp[–(49.8±0.3)/RT], min –1.

Enhanced Room-Temperature Catalytic Decomposition of Cumene Hydroperoxide into Phenol and Acetone

ABSTRACTPhenol is an important industrial chemical that was manufactured by the Hock process. The sulphuric acid used in the Hock process to break cumene hydroperoxide into phenol and acetone suffers from environmental problems along with low selectivity towards the desired products. There are several solid acid catalysts have been tried in cumene hydroperoxide decomposition into an ecofriendly process. In the present work, an efficient environmentally friendly and economically benefitted zeolite-based catalyst was synthesized and tested for breaking cumene hydroperoxide (CHPO) into phenol and acetone. Beta zeolite and ZSM-5 zeolite were synthesised with nano crystalline geometry by hydrothermal method and tested their efficiency to break CHPO. The morphology and structure of nanocrystalline zeolite materials was investigated by Dynamic Light Scattering (DLS), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) methods. From DLS studies it is documented that the zeolite particle size is tuneable as evidenced from particle size growths with the ageing time under hydrothermal treatment process. XRD analysis confirms the zeolite Beta and ZSM-5. The mean crystal size of Beta and ZSM-5 obtained from SEM analysis are 45 nm and 18.3 nm respectively. The optimization of reaction conditions for CHPO decomposition such as catalyst quantity and initial concentration of CHPO has been done using nanocrystalline Beta catalyst. The optimum catalyst amount and concentration of CHPO are 0.03 g and 15 mmol respectively. The results showed that the nanocrystalline Beta zeolite catalyst exhibits exceptional activity with 100% conversion of CHPO and yielded exclusively phenol and acetone at room temperature. No other by-products are detected. Also, the catalyst is stable and exhibits high product selectivity for phenol and acetone. The nature of the enhanced activity at room temperature for the decomposition of CHPO is suggested that higher accessibility of the active sites that are proposed to be associated with the zeolite with nano configuration with higher surface area and short distances for diffusion inside the channels in the nanocrystalline zeolite particles. The possibility of commercialization of beta zeolite is proved by complete conversion of CHPO with selective formation of phenol and acetone.

Efficient oxidation of cumene to cumene hydroperoxide with ambient O2 catalyzed by metalloporphyrins

A novel and efficient protocol for oxidation of cumene to cumene hydroperoxide was presented using ambient O2 catalyzed by very simple metalloporphyrins. The selectivity toward cumene hydroperoxide reached 98.3% in the cumene conversion of 28.1% with T(4-COOH)PPCu as a catalyst at 80[Formula: see text]C. The origin of the higher performance of T(4-COOH)PPCu was mainly ascribed to the low catalytic performance of copper(II) in the cumene hydroperoxide decomposition, and the ability of T(4-COOH)PP in stabilizing cumene hydroperoxide through hydrogen-bond interactions between them. Compared with current industrial processes and academic research in oxidation of cumene to cumene hydroperoxide with O2, the main superiorities of this protocol were the high selectivity, high conversion, simple catalysts, solvent-free, additive-free and mild conditions which made this work an appealing reference for the industrial oxidation of cumene to cumene hydroperoxide, as well as the oxidative functionalization of other C-H bonds in various hydrocarbons.

A Review on Selective Production of Acetophenone from Oxidation of Ethylbenzene over Heterogeneous Catalysts in a Decade

The consumption of acetophenone (AP) is increasing worldwide because of its applications in products such as alcohol, aldehydes, resins, esters, fragrances, and pharmaceuticals. AP is manufactured via several methods like decomposition of cumene hydroperoxide, Hock process, and Friedel–Crafts acylation reaction using homogeneous catalysts with solvent and oxidant. However, it causes several environmental problems that deteriorate the production of AP with these methods. Oxidation of ethylbenzene (EB) is one of the promising methods to synthesize AP in liquid and vapor phases reaction using heterogeneous catalysts, which plays a vital role for selective production of AP. In this review, numerous heterogeneous catalysts are discussed including transition metal nanoparticles, transition metal complexes, and metal free catalysts (carbon nanotubes) used in last 10 years for oxidation of EB. Additionally, catalyst activity along with reaction parameters and its effect, mechanisms, and kinetics study are summarized in this article. The future scope of this reaction is also highlighted. Moreover, this work identifies best catalysts for bulk production of AP with high yield to satisfy global requirement.

CATALYTIC ACTIVITY OF THE COBALT(II) ION WITH PHENYLALANINE COMPLEX IN THE DECOMPOSITION REACTION OF CUMENE HYDROPEROXIDE IN AQUEOUS SOLUTION

The formation of Cօ2+ : phenylalanine (Phe) 1:1 complex has been confirmed via kinetic study in aqueous solution at pH>7, which acts as a model catalyst for the decomposition of cumene hydroperoxide (ROOH) in Co2++Phe+ROOH+H2O system. The kinetic expression of a single catalytic decomposition reaction of ROOH under the influence of [CoPhe]+ complex, as well as the Arrhenius equation describing the temperature dependence of the effective constant Keff (=Kcat[Co2+]0[Phe]0) of ROOH decay rate in the temperature range from 323 to 343 K are brought out.

Anion effect on the cumene hydroperoxide decomposition in the presence of Cu(II) 1,10-phenanthrolinates

Kinetics of the cumene hydroperoxide catalytic decomposition in the presence of Cu(II) salt complexes with 1,10-phenanthroline (Phen) has been investigated in the water: ethanol (1:1) solvent mixture. Catalytic properties of Cu(CH3COO)2 - Phen complex were confirmed: after full hydroperoxide conversion its new portion had been added to the reaction mixture. The hydroperoxide decomposition rate constant observed on the second cycle was the same. The salt anion effect on the complex catalytic activity has been revealed. The rate constant of the cumene hydroperoxide catalytic decomposition increases in the following row of anions: SO42− < Cl− < CH3COO−, the hydroperoxide decomposition in the presence of Cu(II) nitrate in the same experimental conditions was not observed. The effect of the anion nature in the reaction of cumene hydroperoxide catalytic decomposition may be associated with both the structure of the Cu(II) complex with Phen, as well as the structure of the hydroperoxide - catalyst complex. In addition, the double activation effect is observed in the reaction considered. The hydroperoxide molecule is chemically activated by the corresponded Cu(ІІ) salt. The Cu(ІІ) salt reactivity by-turn is activated in the presence of 1,10-phenanthroline and can be regulated by means of variation in corresponded salt anion.

The kinetic modeling of cumene oxidation taking into account oxygen mass transfer

• The rate constants of cumene oxidation reactions at 383 and 393 K were found. • Oxygen dissolution in cumene does not affect the cumene oxidation rate. • Oxygen concentrations were found at which cumene oxidation runs at highest rate. • The oxidation rate is maximum if less than half of the supplied oxygen is consumed. The effect of oxygen volume fraction in the nitrogen–oxygen mixture on the cumene hydroperoxide accumulation rate has been experimentally established in the cumene oxidation. A kinetic model of the cumene oxidation to cumene hydroperoxide has been developed and based on the radical-chain kinetic scheme, given by the reactions of non-radical decomposition of cumene hydroperoxide. As a result of calculating the oxygen mass transfer rate from the nitrogen–oxygen mixture (gas phase) to the reaction mixture (liquid phase), it was shown that the oxygen mass transfer rate does not affect the rate of cumene hydroperoxide accumulation. This fact is confirmed by comparable values of the oxygen amount entering the reactor and the oxygen amount consumed as a result of the reaction. Based on the calculations using kinetic model, it was shown that the cumene oxidation rate is determined by the amount of oxygen supplied to the reactor per unit time, and not by the oxygen volume fraction in the nitrogen–oxygen mixture, on which the driving force of mass transfer depends. In this case, the cumene oxidation runs at a highest rate when the oxygen concentration in the reaction mixture is at least half of the oxygen concentration in reaction mixture, which corresponds to the equilibrium establishment between oxygen concentrations in liquid and gas phases (in the absence of chemical reactions). The concentration limit of this mode was established.

Thermal hazardous evaluation of autocatalytic reaction of cumene hydroperoxide alone and mixed with products under isothermal and non-isothermal conditions

Severe fire and explosions are frequent phenomena during handling of organic peroxides that are promoted supremely by conditions such as chemical impurities and thermal instability. As an initiator in the polymerization process, cumene hydroperoxide (CHP) has wide usage in the chemical process industry. This violently reactive chemical is studied here experimentally using differential scanning calorimeter (DSC), an isothermal mode of operation that can access the thermal hazards in the decomposition of CHP alone and later mixed with products following an autocatalytic reaction scheme. Importantly, DSC-evaluated thermokinetic parameters such as reaction enthalpy (ΔHd), time to maximum rate (TMRiso), and maximum heat flow (Qmax) were estimated to ascertain the degree of thermal hazard under various transportation and storage temperatures. The Heat-Wait-Search mode of accelerating rate calorimeter has been used to investigate decomposition kinetics parameters data under an adiabatic condition. Data such as initial exothermic temperature (T0), self-heating rate (dT/dt), pressure rise rate (dP/dt) and pressure–temperature profiles help to gauge the runaway reaction hazard of CHP alone and then mixed with its products to support the autocatalytic model of exothermic decomposition. The curve fitting data indicated that activation energy had reduced from 245.4 to 236.7 and 242.3 kJ mol−1, when CHP was mixed with acetone or dicumyl peroxide, respectively. The decrease in activation energy for autocatalytic material thermal decomposition reaction is depicted here with various experimental findings and mathematical analysis.

Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal–Organic Frameworks Prepared by a Facile “Green” Aqueous Synthesis

Co–Ni and Mn–Ni bimetallic trimesate MOFs prepared by a fast aqueous synthesis method are excellent and reusable catalysts for the selective aerobic oxidation of cumene to cumene hydroperoxide (CHP). Isolation of Co2+ (or Mn2+) in an inert Ni-BTC framework is a good strategy to optimize CHP selectivity above 90%: since only Co2+ sites catalyze CHP decomposition, a drop of the CHP selectivity is observed as the cobalt content in the bimetallic MOF increases. The statistical probability of having isolated Co2+ sites is calculated as a function of the total cobalt content of the bimetallic compound, assuming homogeneous distribution of Co2+ ions in the Ni-BTC framework and preferential occupation of terminal sites. Thus, in our best sample, with a Co:Ni ratio of 5:95, 73% of the total Co2+ ions are isolated so that CHP decomposition/overoxidation processes at the surface of the catalyst are not likely to occur before CHP desorption. This can explain the excellent CHP selectivity (91%) attained over this mate...

Microchannel process for phenol production via the cleavage of cumene hydroperoxide

Phenol is commercially produced through cumene hydroperoxide (CHP) cleavage in kettle reactor, having the disadvantages of hazard potential, low selectivity, low efficiency and complicated process. In the study, microchannel reactor has been introduced into the decomposition using sulfuric acid as the catalyst. The influences of various reaction conditions, including temperature, the ratio of sulfuric acid/CHP and residence time, on the reaction have been studied. Compared with kettle reactor, the present process can afford almost quantitative yield of phenol with reduced acid amount and shortened reaction time under higher reaction temperature. The microchannel process can also provide higher security of CHP cleavage. The microtechnology probably gives an alternative protocol for the production of phenol through CHP decomposition. In addition, the possible main reaction pathways for the CHP cleavage in microchannel reactor have been discussed according to the obtained results.

Antioxidant properties of amide derivatives of 3,4-dihydropyrimidin-2-one with phenolic substituent in heterocycle

The antioxidant properties of 4-[3,5-di(tert-butyl)-4-hydroxyphenyl]-5-aminocarbonyl-6-methyl-3,4-dihydropyrimidin-2-one were researched by volumetric analysis and decomposition of hydroperoxide. The reactant was obtained by three-component Biginelli condensation using urea, 3,5-di (tert-butyl) -4-hydroxybenzaldehyde and acetoacetic acid amide as reactants. The decomposition of cumene hydroperoxide in dimethylformamide under these conditions is described by a first-order kinetics equation. As the concentration of hydroperoxide increases, the rate of its decomposition decreases, apparently due to the formation of dimethylformamide dimer stabilized by molecules. 4- [3,5-Di (tert-butyl) -4-hydroxyphenyl] -5-aminocarbonyl-6-methyl-3,4-dihydropyrimidin-2-one inhibits the decomposition of hydroperoxide by slowing induced and homolytic cleavage. The inhibitory effect rises with the increase of the concentration of the inhibitor. An equation, which describes the inhibitory action of the analyzed compound on the hydroperoxide decomposition, was proposed, and the coefficients of this equation were calculated. The initiated oxidation of cumene was carried out at a temperature of 343 K in the presence of the initiator azodiisobutyronitrile. The concentration of 4- [3,5-di (tert-butyl) -4-hydroxyphenyl] -5-aminocarbonyl-6-methyl-3,4-dihydropyrimidin-2-one varied from 1,5×10-4 до 5,0×10-3 mol / l. In the concentration interval of the analyzed substance (1,25¸5,0)×10-3 mol / l the duration of the induction period exceeds 60 min. At lower concentrations, a linear change in the duration of the induction period is observed. The inhibitory action of 4- [3,5-di (tert-butyl) -4-hydroxyphenyl] -5-aminocarbonyl-6-methyl-3,4-dihydropyrimidin-2-one is higher than that of ionol. The basic kinetic parameters of the processes of initiated oxidation of cumene and decomposition of cumene hydroperoxide are calculated. Therefore, the analyzed compound has an antioxidant effect both during the decomposition of hydroperoxide and during the initiation of cumene oxidation. The phenolic group and the urea moiety of the dihydropyrimidinone cycle have an inhibitory effect.

Antioxidant properties of derivatives of 3,4-dihydropyrimidin-2-one with sterically hindered phenolic substituent in heterocycle

In the processes of free-radical oxidation of organic compounds, the inhibitory action of the inhibitor is mainly due to either the breakdown of the reaction chains on its molecules, or the slowdown of the decomposition of intermediate hydroperoxides, or both at the same time. We analysed the inhibitory properties of 4-[3,5-di(tert-butyl)-4-hydroxyphenyl]-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-one (I) and 4-[4-methoxyphenyl]-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-one (II) gasometry and hydroperoxide decomposition methods. These compounds were obtained by the three-component Biginelli reaction. The decomposition of cumene hydroperoxide in dimethylformamide under these conditions is described by a first-order kinetics equation. The first compound significantly inhibits the decomposition of hydroperoxide. The dependence of the effective rate constant of the decomposition of cumene hydroperoxide on the first concentration is described by the equation: . The second compound also slows the decomposition of hydroperoxide, but much less than the first compound. Therefore, both the phenolic moiety and the urea moiety of the dihydropyrimidinone cycle take part in slowing the cumene hydroperoxide decomposition. Initiated oxidation of cumene happened at 343 K with the presence of the initiator azodiisobutyronitrile. The concentration of the first compound varied from 1,5·10-4 to 2,5·10-3 mol/l. With a concentration of the first compound 1,25·10-3 and 2,5·10-3 mol/l, the duration of the induction period exceeds 80 min. In the concentration range (1,5÷6,3)·10-4 mol/l the linear change in the duration of the induction period is observed. 4-[3,5-Di(tert-butyl)-4-hydroxyphenyl]-5-aminocarbonyl-6-methyl-3,4-dihydropyrimidin-2-one is a more effective inhibitor than the ionol due to the urea moiety of the dihydropyrimidinone cycle. Confirmation is the notable antioxidant activity of the second compound. In conclusion, 4- [3,5-di (tert-butyl)-4-hydroxyphenyl]-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-one is a bifunctional inhibitor.

Numerical simulation and experimental study of thermal decomposition of cumene hydroperoxide in closed pressure vessel

Cumene hydroperoxide (CHP) is prone to thermal decomposition in chemical industry, but there are few reports on the related phenomena in the reactor when decomposition occurs. In order to reveal the complex phenomena of fluid-solid coupled heat transfer, two-phase flow and multi-phase chemical reaction in the CHP decomposition, computational fluid dynamics (CFD) approach was applied to simulate the decomposition of CHP with different mass in a closed pressure vessel. Based on a known reaction scheme and the kinetics evaluated from differential scanning calorimeter (DSC) results, a comprehensive CFD model of CHP decomposition was created. As a result, detailed information on the reaction course was obtained, and distribution of temperature, pressure, reaction rate, and flow velocity in the vessel were also investigated. Finally, closed pressure vessel tests (CPVT) were conducted to verify the validity of the CFD model. This work is conducive to deeply understand the thermal decomposition and reactive hazards assessment of CHP.