Cumene Process Research Articles

One-Step Hydroxylation of Benzene to Phenol Over Layered Double Hydroxides and their Derived Forms

Phenol, an important bulk organic compound, has diverse applications encompassing both industry and society. Commercially, it is produced through energy intensive three-step cumene process operating at relatively low yield with the co-production of acetone. Several attempts were made for producing phenol through challenging one-step direct hydroxylation of benzene using different oxidants like O2, N2O and H2O2. Liquid phase hydroxylation of benzene using H2O2 found to be more attractive due to its low reaction temperature and environmentally friendly nature (as water is only formed as by-product). The hydroxylation reaction occurs through Fenton’s mechanism; however along with phenol several other products are also formed due to higher reactivity of phenol compared to benzene. Our research group has been working on this reaction for nearly a decade using layered double hydroxides (LDHs) and their derived forms as heterogeneous selective oxidation catalyst. Screening of different LDHs having different metal ions in the layers revealed the necessity of copper for hydroxylation in pyridine. Addition of co-bivalent metal ion along with copper was made in an endeavour to improve the activity that revealed the promising results for CuZnAl LDHs. Efforts were then made to shift from pyridine to environmentally benign solvent, water, for this reaction that showed reasonably good yields with very high selectivity of phenol. Addition of small amount of sulfolane as a co-solvent increased the selectivity for phenol further. The reusability difficulty faced while using as-synthesized LDHs was overcome when calcined LDHs were used. Structure–property-activity relationships were deduced to understand the results observed. The present review besides covering our work also provides the state-of-art on this reaction using different oxidants with emphasis on H2O2.

Catalytic hydroxylation of benzene to phenol with hydrogen peroxide using catalysts based on molecular sieves

Phenol is an important intermediate for the production of petrochemicals, agrochemicals and plastics. Most phenol worldwide is produced via the three-step cumene process from benzene. The disadvantages of the cumene process have stimulated the development of alternative routes to decrease energy consumption, increase the yields and avoid the explosive intermediate (cumene hydroperoxide) and the byproduct acetone. The one-step direct hydroxylation of benzene toward phenol has been extensively investigated using various oxidants such as molecular oxygen, nitrous oxide and hydrogen peroxide. But the selective production of phenol with high yields remains a challenge because phenol is more reactive toward oxidation than benzene. It is difficult to achieve high selectivity using molecular oxygen because of the high reaction temperatures and overoxidation which arise from the more active catalysts used for activating oxygen. The application of nitrous oxide is limited by the source, although the phenol selectivity and conversion can be high. Amongst the oxidants, hydrogen peroxide has obvious advantages as water is the only byproduct. In the past several decades, a variety of catalysts have been developed for the direct hydroxylation of benzene with hydrogen peroxide as the oxidant. Catalysts based on molecular sieves show outstanding catalytic performances for the reaction. This perspective article discusses the direct hydroxylation of benzene to phenol using hydrogen peroxide with catalysts based on molecular sieves, including pristine molecular sieve catalysts, transition metals incorporated molecular sieves, transition metal oxides supported on molecular sieves, complexes grafted on molecular sieves, and heteropoly acids supported on molecular sieves.

Economic Plantwide Control of the Cumene Process

Economic plantwide control of the cumene process over a large throughput range (design to maximum achievable throughput) is studied. The process has 12 steady state operating degrees of freedom (DOFs), which are optimized for maximum hourly profit. At maximum throughput, the highest number of constraints (eight) is active leaving four unconstrained degrees of freedom. Reasonable controlled variables (CVs) corresponding to these are chosen with implementation of a constant setpoint policy at lower throughputs providing near optimal operation. For economic plantwide control, the best pairings for tight control of the maximum throughput active constraints and self-optimizing CVs are first implemented followed by inventory control loop pairings using the remaining valves. The resulting control structure consists of long level loops that manipulate the two fresh feeds to maintain the bottom sump level of the first two distillation columns. Simulation results show that the unconventional control structure provides smooth operation over the wide throughput range with tight control of the active constraints and the self-optimizing CVs. Comparison with a conventional plantwide control system (throughput manipulator at fresh propylene feed) shows that the synthesized control structure is simpler in requiring no overrides for handling constraints and achieving superior economic performance.

Recycling of valuable chemicals through the catalytic decomposition of phenol tar in cumene process

The base catalyst LZ-2, which was the mixture of CaO and Na–NaOH/Al2O3·3H2O, was chosen for the decomposition of phenol tar to generate valuable chemicals. The selectivity of LZ-2 for dimethyl phenyl carbinol, α-methyl styrene dimer and cumenyl phenol was 100%, 100% and 98%, respectively. Under the optimum operating conditions of catalyst 2.5wt%, operating temperature 603.15K and decomposition time 3.5h, decomposition ratios of cumenyl phenol and dimethyl phenyl carbinol were 98.7% and 99.97%, respectively. In addition, the experimental repeatability demonstrated that the total yield of valuable chemicals still reached 90.1% after the catalyst being used five times. Mass and energy balance indicated that the catalytic decomposition was a high potential for the recycling of chemicals from phenol tar.

Intensification of Synthesis of Cumene Hydroperoxide Using Sonochemical Reactors

Intensification of chemical synthesis is a key research area due to the current constraints before the chemical industry due to competition as well as economics and demand for greener routes of processing. The present work illustrates the use of sonochemical reactors for the intensification of synthesis of cumene hydroperoxide from cumene. Air oxidation of cumene in the presence of cupric oxide powder as a catalyst has been investigated using a conventional approach and different sonochemical reactors such as an ultrasonic bath and a probe sonicator. Optimization of different operating parameters such as stirrer speed, temperature, catalyst quantity, air flow rate, and cumene hydroperoxide as an initiator have been investigated using conventional stirring method. The optimum conditions for the air oxidation of the cumene process have been obtained as stirrer speed of 300 rpm, temperature as 110 °C, catalyst quantity of 3 g, and air flow rate as 500 mL/min, and cumene hydroperoxide as an initiator had a very marginal effect. In the case of ultrasound assisted synthesis approach, various parameters studied were pulse of ultrasound, power of ultrasound, and frequency of ultrasound. Enhancement in conversion of cumene and reduction in the reaction time was observed in the presence of ultrasound as compared to silent conditions. The selectivity toward cumene hydroperoxide was marginally affected by the use of ultrasonic conditions. The maximum conversion obtained using ultrasound was 67.1% when 40 kHz frequency of ultrasound horn was used in 4 h, while 50.4% conversion was obtained in 8 h of reaction under otherwise similar operating conditions. The obtained selectivity was always greater than 95% for all conditions considered in the work. The present work has clearly revealed that substantial intensification is obtained for the synthesis of cumene hydroperoxide using ultrasound as compared to the conventional approach.

Mesoporous mordenites obtained by sequential acid and alkaline treatments – Catalysts for cumene production with enhanced accessibility

Two commercially available mordenites, obtained from Zeolyst (Si/Al = 10 at/at) and BASF (Si/Al = 8 at/at), were subjected to post-synthesis treatments. The impact of acid treatment, alkaline treatment (desilication) and a combination of both on porosity, crystallinity and catalysis were studied in detail. It was found that sequential acid and alkaline treatments were most effective to obtain mesoporous mordenite with external surface areas up to 250 m 2 g −1. Electron tomography was used to visualize the mesoporosity of a series of sequential acid- and alkaline-treated mordenite samples. Mesopore formation started close to the external surface area and progressed toward the center of the crystallites for higher porosities. Liquid-phase alkylation of benzene with propylene to cumene was chosen to study the catalytic performance of the enhanced accessibility of various mordenite samples. The activity of the most porous mordenite was found to be close to that of a commercial zeolite beta, while selectivity toward the undesired n-propylbenzene was found to be significantly lower for mordenite (∼70 ppm) than for zeolite beta (∼175 ppm). These catalytic data indicate that the acid- plus alkaline-treated mordenite could be a viable catalyst in the cumene process.

Preparation of acid-modified bentonite for selective decomposition of cumene hydroperoxide into phenol and acetone

Phenol is industrially produced by the Hock process, in which cumene hydroperoxide (CHP) is decomposed with sulfuric acid to obtain equimolar amounts of phenol and acetone. Use of the liquid acid requires subsequent neutralization and purification of the phenol at substantial cost, and a waste stream generation that could be avoided if an effective solid acid catalyst could be used. Modified clays exhibit attractive properties as solid acids. Acid treatment produces an increase in surface area and acidity. The present study was undertaken to modify bentonite clay by treatment with hydrochloric acid for the production of phenol and acetone via the decomposition of cumene hydroperoxide. The effects of various parameters such as acid activation, catalyst weight, concentration of CHP, reaction temperature and reusability of catalyst were studied. The results indicate that the acid-modified bentonite catalyst may be used instead of sulfuric acid for selective decomposition of CHP into phenol and acetone.

Design and Control of the Cumene Process

The chemistry of the cumene process features the desired reaction of benzene with propylene to form cumene and the undesirable reaction of cumene with propylene to form p-diisopropylbenzene. Both reactions are irreversible. Since the second has a higher activation energy than the first, low reactor temperatures improve selectivity of cumene. However, low reactor temperatures result in low conversion of propylene for a given reactor size or require a large reactor for a given conversion. In addition, selectivity can be improved by using an excess of benzene to keep cumene and propylene concentrations low, but this increases separation costs. Therefore, the process provides an interesting example of plantwide economic design optimization in which there are many classical engineering trade-offs: reactor size versus temperature, selectivity versus recycle flow rate, and reactor size versus recycle flow rate. Design optimization variables affect both energy costs and capital investment. They also affect the am...

Remarks on studies for direct production of phenol in conventional and membrane reactors

AbstractThe great interest in the oxidation reaction of benzene to phenol is linked to some disadvantages of the cumene process, such as environmental impact, production of an explosive intermediate, a multi‐step process (which involves (1) difficulty to achieve high phenol yield, in relation to the benzene used and (2) high capital investment), and a high acetone production as a co‐product which results in an over supply in the market.In this paper, we discuss various studies concerning a new approach based on a one‐step and acetone‐free method for phenol production. Particular attention is devoted to phenol production processes using various configurations of membrane reactors (MRs) and a photocatalytic membrane reactor (PMR). In particular, the biphasic MR allowed to achieving high selectivity values (97–98%).The described studies have been classified according to oxidant type such as N2O, O2, and H2O2. Each of them shows that direct oxidation of benzene to phenol is a difficult task and further efforts are needed to search and replace the three step traditional process of converting benzene into phenol with a process of direct oxidation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Loss Prevention and Waste Minimization with Cascade-Engineered Green Synthesis of Bisphenol-A from Cumene Hydroperoxide and Phenol using Heteropoly Acid-Supported Clay Catalysts

Bisphenol-A (BPA), an important raw material for the synthesis of epoxy resins and other polymers, is conventionally synthesised by acid-catalysed condensation of phenol and acetone, which produces 28 known byproducts. This leads to heavy costs for purification of the final product and loss of raw material. Phenol itself is almost exclusively manufactured via the three-step Hock process which includes vapour-phase isopropylation of benzene to cumene, autoxidation of cumene to cumene hydroperoxide (CHP), and finally the highly exothermic liquid acid-catalysed cleavage of CHP to acetone and phenol. The second step in the Hock process produces around 35% w/w CHP, which is then concentrated to 80% w/w. There are inherent process hazards involved in the manufacture and/or concentration of CHP, leading to run-away situations and explosions. Cascading these two series reactions in a single pot using the same catalyst fits elegantly into the concept of waste minimization and results in a greener and cleaner environment with added economic incentives. Traditionally, single-pot synthesis overlooks the concepts of atom economy, reaction mass efficiency and the environmental impact factor which are of prime importance to any methodology desiring to be called “green synthesis”. In this work, a novel technique of BPA synthesis from CHP and phenol was engineered in a single pot by using 20% w/w dodecatungstophosphoric acid (DTP) supported on acidic clay (K-10) at 100 °C, wherein CHP produced in cumene itself and was used along with phenol to make BPA. The process is atom economical, producing water as a coproduct. In comparison with the traditional process of making BPA from phenol and acetone, there is 58% enhancement in yield and 33% enhancement in BPA selectivity. There is also a 28% improvement in reaction mass efficiency and 25% reduction in the environmental impact factor. Along with preserving the atom economy, the hazard involved in the concentration and handling of CHP, which has resulted in numerous accidents in process industries, has been eliminated. In the current process CHP produced from cumene by the Hock process is used as such without separation, and this strategy avoids the hazards of concentration and costs of separation. Finally, a comprehensive parametric sensitivity was also done, and a Langmuir−Hinshelwood−Hougen−Watson (LHHW) model was developed to describe the reaction mechanism. The theoretical predictions were found to match the experimental data.

担持Ｒｅ触媒を用いたベンゼンと酸素からのフェノールの直接合成反応

Phenol is one of the most important chemicals in industry and it is produced from cumene process from benzene. Direct phenol synthesis from benzene and O2 is an alternative way to produce phenol efficiently. We have succeeded in preparing a HZSM-5-zeolite-supported Re catalyst, which was highly active and selective for direct phenol synthesis from benzene and O2 (steady-state reaction: 5.8% benzene conversion and 88% phenol selectivity, pulse reaction: 9.9% benzene conversion and 94% phenol selectivity) in the presence of NH3. The formation of active Re clusters, their structural change, and the role of NH3 which are relevant to the selective benzene oxidation were investigated.

Studies towards the catalytic anti-Markovnikov functionalisation of alkenes

In 1986 Jensen and Trogler reported that a biphasic system containing the mononuclear complex trans-[(Me3P)2PtHCl] and NaOH catalysed the anti-Markovnikov hydration of 1-hexene to 1-hexanol. The unusual method of preparation could also give rise to dinuclear complexes with bridging hydride ligands. We have tested some dinuclear complexes for catalytic activity and discovered that on heating these yield trinuclear complexes. Using the independently prepared trinuclear complex [(dppe)3Pt3H3]+, we found that it acted as a catalyst for the reaction between 1-octene and methanol to give 1-methoxyoctane, although the results were somewhat erratic. A cause of the erratic behaviour was found to be the presence of varying amounts of hydroperoxide impurities, which underwent a Hock rearrangement in acidic conditions.

The cumene process for phenol-acetone production

The history of designing and the evolution of the process for the joint production of phenol and acetone, which is now the basic industrial method for the manufacture of these products, the state of the art and parameters of its key steps in industrial facilities among world manufacturers of phenol are presented. Special attention is given to the consideration of ways of improving the characteristics of the process and its environmental safety on the basis of the recent advances in science and to methods for the solution of scientific and practical questions of the reconstruction and renovation of out-of-date industrial phenol manufacturing facilities.

Unexpected Formation of Etheno-2‘-Deoxyguanosine Adducts from 5(S)-Hydroperoxyeicosatetraenoic Acid: Evidence for a Bis-Hydroperoxide Intermediate

Analysis of products from the reaction between 5(S)-hydroperoxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid and 2'-deoxyguanosine in the presence of FeII, FeIII, or vitamin C by liquid chromatography/atmospheric pressure chemical ionization/mass spectrometry revealed the presence of four DNA adducts. Surprisingly, adducts I and II had mass spectral characteristics identical to those for 1,N2-etheno-2'-deoxyguanosine and heptanone-1,N2-etheno-2'-deoxyguanosine. These adducts have previously been shown to arise from the homolytic decomposition of 13(S)-hydroperoxy-9,11-(Z,E)-octadecadienoic acid. It appears that under the reaction conditions, 5(S)-hydroperoxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid was subjected to a previously unknown peroxidation reaction to give a bis-hydroperoxide intermediate that underwent a Hock rearrangement to produce 3(Z)-nonenal from the omega-terminus. The 3(Z)-nonenal was then converted to 4-hydroperoxy-2-nonenal, a precursor to the formation of 4-oxo-2-nonenal. 4-Oxo-2-nonenal forms heptanone-1,N2-etheno-adducts with 2'-deoxyguanosine, whereas 4-hydroperoxy-2-nonenal forms 1,N2-etheno-2'-deoxyguanosine. Two novel carboxylate adducts were also identified. The structure of the more abundant adduct (III) was characterized as its methyl ester derivative by NMR spectroscopy as 3-(2'-deoxy-beta-D-erythropentafuranosyl)imidazo-7-(5' '-carboxypenta-2' '-one)-9-oxo[1,2-alpha]purine (5-carboxy-2-pentanone-1,N2-etheno-2'-deoxyguanosine). This etheno adduct was formed by the reaction of 2'-deoxyguanosine with 5,8-dioxo-6(E)-octenoic acid. The bifunctional electrophile is proposed to arise from the alpha-terminus during the Hock rearrangement of bis-hydroperoxide derived from 5(S)-hydroperoxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid. 5-Carboxy-2-pentanone-1,N2-etheno-2'-deoxyguanosine may serve as a biomarker of 5-lipoxygenase-mediated oxidative stress. The less abundant carboxylate adduct IV arose from a quite different pathway and was tentatively characterized as 6-carboxy-3-hydroxy-1-hexene-1,N2-etheno-2'-deoxyguanosine.

Dioxododecenoic Acid: A Lipid Hydroperoxide-Derived Bifunctional Electrophile Responsible for Etheno DNA Adduct Formation

It has been proposed that 13(S)-hydroperoxy-9Z,11E-octadecadienoic acid [13(S)-HPODE]-mediated formation of 4-oxo-2(E)-nonenal and 4-hydroxy-2(E)-nonenal arises from a Hock rearrangement. This suggested that a 4-oxo-2(E)-nonenal-related molecule, 9,12-dioxo-10(E)-dodecenoic acid (DODE), could also result from the intermediate formation of 9-hydroperoxy-12-oxo-10(E)-dodecenoic acid. A recent report has described the formation of DODE-derived etheno adducts when 13(S)-HPODE was allowed to decompose in the presence of 2'-deoxynucleosides or DNA. However, the regioselectivity of lipid hydroperoxide-derived DODE addition to 2'-deoxyguanosine (dGuo) or other 2'-deoxynucleosides was not determined. The structure of carboxynonanone-etheno-dGuo formed from vitamin C-mediated 13(S)-HPODE decomposition has now been established by a combination of 1H and 13C NMR spectroscopy studies of its bis-methylated derivative. The site of dGuo methylation was first established as being at N-5 rather than at O-9 from NMR analysis of a methyl derivative of the model compound, heptanone-etheno-dGuo. (1)H,(13)C 2D heteronuclear multiple bond correlations were then used to establish unequivocally that the bis-methyl derivative of carboxynonanone-etheno-dGuo was 3-(2'-deoxy-beta-d-erythropentafuranosyl)imidazo-7-(9' '-carboxymethylnona-2' '-one)-9-oxo-5-N-methyl[1,2-a]purine rather than its 6-(9' '-carboxymethylnona-2"-one)-9-oxo-5-N-methyl[1,2-a]purine regioisomer. Therefore, etheno adduct formation occurred by initial nucleophilic attack of the exocyclic N(2) amino group of dGuo at the C-12 aldehyde of DODE to form an unstable carbinolamine intermediate. This was followed by intramolecular Michael addition of the pyrimidine N1 of dGuo to C-11 of the resulting alpha,beta-unsaturated ketone. Subsequent dehydration gave 3-(2'-deoxy-beta-d-erythropentafuranosyl)imidazo-7-(9' '-carboxynona-2' '-one)-9-oxo-[1,2-a]purine (carboxynonanone-etheno-dGuo). An efficient synthesis of DODE was developed starting from readily available 1,8-octanediol using a furan homologation procedure. This synthetic method allowed multigram quantities of DODE to be readily prepared. Synthetic DODE when reacted with dGuo gave carboxynonanone-etheno-dGuo that was identical with that derived from vitamin C-mediated 13(S)-HPODE decomposition in the presence of dGuo.

Selective decomposition of cumene hydroperoxide into phenol and acetone by a novel cesium substituted heteropolyacid on clay

Phenol is industrially produced by the Hock process starting from benzene and propylene to yield cumene, which is subsequently oxidized with oxygen to generate cumene hydroperoxide (CHP) which is then decomposed with sulfuric acid to obtain equimolar phenol and acetone. Both phenol and acetone are important bulk chemicals having separate as well as interrelated markets. The last step of the Hock process is polluting and results in loss of selectivity leading to formation of by-products beside the desired products phenol and acetone. The current work reports the decomposition of CHP by using K-10 clay supported catalysts such as 20% (w/w) dodecatungstophosphoric acid (DTP)/K-10, 20% (w/w) Cs 2.5H 0.5PW 12O 40/K-10, 20% (w/w) ZnCl 2/K-10 and K-10, and also sulfated zirconia at 40 °C. For the first time, the synthesis of Cs 2.5H 0.5PW 12O 40 supported on K-10 clay has been reported with complete intact Keggin anion structure. This catalyst has been found to exhibit excellent activity for decomposition of cumene hydroperoxide exclusively into phenol and acetone. Various kinetic parameters were studied over 20% Cs 2.5H 0.5PW 12O 40/K-10. The reaction follows the first order kinetics. The catalyst is stable and reusable giving 100% conversion with exclusive selectivity to 100% phenol and acetone during all the runs.

Structural characterization of plasmenylcholine photooxidation products.

Oxidative damage to plasmenyl-type lipids contributes to decreased membrane barrier function, loss of membrane structure and formation of nonlamellar defects in membrane bilayers. Previous results from this laboratory have shown that membrane-soluble sensitizers (e.g. zinc phthalocyanine and bacteriochlorophyll a) mediate the photooxidation of palmitoyl plasmenylcholine (1-O-alk-1'-Z-enyl-2-palmitoyl-sn-glycero-3-phosphocholine; PPlsC) vesicles with the subsequent creation of lamellar defect structures, vesicle contents leakage and membrane-membrane fusion. Because plasmalogen lipids are significant components of sarcoplasma and myelin membranes, we sought to characterize the products of their photooxidation. This study focuses on the photooxidation of PPlsC vesicles in the presence of the water-soluble sensitizer, aluminum phthalocyanine tetrasulfonate (AlPcS4(4-)). Attack of photogenerated singlet oxygen on the 1-O-alkenyl ether linkage of PPlsC lipids was expected to generate dioxetane- and ene-type photoproducts. The products formed during continuous aerobic irradiation (28 mW/cm2, (610 nm) of PPlsC vesicles in the presence of AlPcS4(4-) were separated via reverse-phase high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) or evaporative light-scattering detection (ELSD). Photooxidized dipalmitoyl-phosphatidylcholine-cholesterol vesicles (control) were used to optimize the HPLC-ECD conditions, using 7 alpha-hydroperoxy-cholesterol as standard. HPLC-ECD was found to be most sensitive for PPlsC hydroperoxides, whereas HPLC-ELSD was more sensitive for nonhydroperoxide photoproducts. The three major photoproducts formed during vesicle irradiation were isolated via preparative HPLC and then characterized by 1H-nuclear magnetic resonance and mass spectrometry. 1-Formyl-2-palmitoyl-sn-glycero-3-phosphocholine and 1-hydroxy-2-palmitoyl-sn-glycero-3-phosphocholine were identified as dioxetane cleavage products that coeluted at approximately 3 min. The second fraction (retention time [RT] = 48 min) was identified as a PPlsC allylic hydroperoxide. The third photoproduct, eluting at RT = 64 min, is tentatively identified as an oxidation product arising from allylic hydroperoxide degradation via Hock rearrangement or free radical decomposition.

Formation of Phenol from Benzene Catalyzed by Polymer-Bound break Vanadyl Acetylacetonate

Industrially, phenol is produced by a multistep cumene process and it is desired to develop its direct synthesis from benzene where the oxidation occurs either by H{sub 2}O{sub 2} or by molecular oxygen. In the past, the latter using H{sub 2}O{sub 2} as oxidant has been catalyzed using several transition metal complexes and transition metal salts but is mostly carried out in molar ratios and the metal cannot be recycled. Recently, titanium silicalite has been reported to be an effective hydroxylation catalyst for benzene as well as phenol. Previously, vanadium complex with picolinic acid ligand has been shown to hydroxylate benzene in moderate yield. However, this complex is unstable and cannot be stored as it decomposes in air at room temperature. In view of this, the authors wished to develop other vanadium complexes which are stable. Here, the authors report on a polymer-supported VO(acac){sub 2} (acac, acetylacetonate) catalyst which is useful in the direct synthesis of phenol from benzene in acetic acid medium using H{sub 2}O{sub 2} as the oxidant. 16 refs., 1 fig.

97/00686 Desalting phenol tar from cumene process by washing with water

97/00686 Desalting phenol tar from cumene process by washing with water

The kinetics and thermodynamics of the phenol from cumene process: A physical chemistry experiment

The kinetics and thermodynamics of the phenol from cumene process: A physical chemistry experiment