• Clean Technology
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• v.19 no.4
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• pp.416-422
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• 2013

In environmental friendly aspects, the synthesis of glycerol carbonate from glycerol using carbon monoxide and oxygen gases which were produced in petrochemical plants was studied. The oxidative carbonylation of glycerol under batch reaction system was performed on parameter conditions such as effect of various metals (Cu, Pd, Fe, Sn, Zn, Cr), oxidizing agents, mole ratio of carbon monoxide to oxygen, catalyst amount, solvent types, reaction temperature and time and dehydrating agents. In particular copper chloride catalysts showed the excellent activities, and the glycerol carbonate yields over CuCl and $CuCl_2$ catalysts were the maximum of 44% and 64%, respectively at the following reaction conditions: solvent as nitrobenzene, mole ratio of 1:3:0.15 (glycerol:carbon monoxide:catalyst), mole ratio of 2:1 (carbon monoxide:oxygen), the total pressure of 30 bar at 413 K for 4 hr. It was found that reactivity were significantly different depending on the oxidation number of Cu catalysts, and oxygen plays an important role as oxidizing agents in producing H2O during oxidation reaction after carbonylation of glycerol.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.903-909
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• 1993

Reaction mechanism of palladium(0, II)-phosphines complexes catalyzed cyclocarbonylation for unsaturated carboxylic acid such as crotonic acid, methacrylic acid and 3-butenoic acid has been investigated by product analysis, molecular mechanics and extended Huckel molecular orbital method. Reaction of 3-butenoic acid with palladium(0, II)-phosphines catalyst gives palladium containing cycloester through intermediate palladium-olefin ${\pi}$ -complex in the catalytic carbonylation. Palladium(0, II)-phosphines complexes catalyze the cyclocarbonylation of 3-butenoic acid to give 3-methylsuccinic anhydride and glutaric anhydride. But ${\pi}$ -complexes with palladium(0, II)-phosphines and unsaturated carboxylic acids such as crotonic acid and methacrylic acid are not effective the catalytic cyclocarbonylation.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.710-716
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• 1992

Ethylphenyl carbarmate(EPC) was synthesized by oxidative CO carbonylation of aniline in the presence of transition metal catalysts and alkali metal halide cocatalysts at $120^{\circ}C$ under the pressure of 79atm. Oxygen gas was used for oxidizing agent. Kinetics of the reaction was studied and activation energies with different catalysts were estimated. About 100% conversion to EPC and 95% selectivity was obtained in 5 hour reaction. 5% Pd/C was more effective than 5% Rh/C. Effectiveness of cocatalysts was in the order of KI>KBr>KCl. As the temperature increased from $75^{\circ}C$ to $120^{\circ}C$, the conversion rate increased. The reaction was apparent first order and the activation energies with 5% Pd/C and 5% Rh/C were 5.647 and 5.780 kcal/mol, respectively.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.119-124
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• 2018

The production of methyl N-phenyl carbamate by an oxidative carbonylation method of aniline and methanol is of great interest as an environmentally friendly process that can replace the monomer production process of a polymer produce using conventional phosgene. In this study, heterogeneous catalysts were prepared by using Y-zeolite, $SiO_2$, $Al_2O_3$ as support, and oxidative carbonylation continuous operation from aniline and methanol was attempted using the prepared heterogeneous catalyst. Batch reactor was used to determine the support, and various reaction conditions such as reaction temperature, reaction pressure, and effect of promoter were established using palladium catalyst. A reaction kinetics study was conducted under optimum reaction conditions. The basic data for carbamate process development were obtained by performing continuous operation for a long time under established reaction condition.

• Clean Technology
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• v.14 no.3
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• pp.160-165
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• 2008

The synthesis of dimethyl carbonate (DMC) with Cu catalysts was investigated in a semi-batch high-pressure reactor. DMC was synthesized via the direct oxidative carbonylation of carbon monoxide with oxygen in methanol. The corrosion rate was evaluated fie the weight change for SUS test pieces which had been added into the reactor. In order to reduce the corrosion rate without significantly losing DMC yield, various additives such as amines, olefins, and other metal salts were used. When 1-methylimidazole was used as an additive, 18.6% of DMC yield could be obtained without corrosion. If the amount of 1-methylimidazole was decreased, a high DMC yield (33.2%) could be obtained with a low corrosion rate (0.5%).

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.530-534
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• 2011

The synthesis of dimethyl carbonate by liquid phase oxidative carbonylation of methanol was studied under batch reaction system. Reaction factors such as effect on various metals, anion containing in copper catalyst, temperature, carbon monoxide and oxygen molar ratio and copper content were investigated. In particular $CuCl_2{\cdot}2H_2O$ showed the excellent of the methanol conversion 65.2%, DMC selectivity 96.6% reaction condition under 1.0 g, $150^{\circ}C$, MeOH/CO/$O_2$=0.2/0.215/0.05 (molar ratio). $CuCl_2$ led to corrosion of the reactor. Thus, a new catalyst system using supports was investigated to resolve these corrosion problem. Influence on various supports were examined and copper catalyst supported on zeolite Y showed the most excellent activity on the formation of dimethyl carbonate. The amount of Fe dissolved during the reaction using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometer) was compared with catalysts, calcined Cu/zeolite Y showed the lower value below 5% than $CuCl_2-2H_2O$.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.213-219
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• 2003

The photochemical transformation of carbon monoxide in aqueous solution has been investigated at $25{\pm}0.1^{\circ}C$using ZnO as a photocatalyst. After irradiation of 253.7 nm UV light in the solution, carboxylation and carbonylation processes were carried out, and the formation of formic acid, oxalic acid, glyoxylic acid, formaldehyde and glyoxal was observed. The formation of the products depended on the pH values in the solution. The yield of formaldehyde and glyoxal increased in acidic solution whereas it decreased in basic solution. When the pH values in the solution increased above 11.5, the yield of formic acid increased rapidly. The initial quantum yields of the products were determined and the probable mechanisms for the reactions were presented on the basis of the products analysis.

• Clean Technology
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• v.12 no.2
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• pp.87-94
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• 2006

The reduction of $SO_2$ to elemental sulfur by CO over a series of iron niobate with nominal Nb/Fe atomic ratios of 1/0, 10/1, 5/1, 1/1, 1/5, 1/10 and 0/1 was studied with a flow fixed-bed reactor. Strong synergistic phenomena in catalytic activity and selectivity were observed for the iron niobate catalysts, and the best catalytic performance was observed for the catalyst with Fe/Nb atomic ratio of 1/1. The active phase of the activated iron niobate catalysts was identified to be $FeS_2$ using XRD and XPS. Selective reduction of $SO_2$ by CO was followed by the COS intermediate mechanism.

• Clean Technology
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• v.22 no.3
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• pp.196-202
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• 2016

In this study, ceria- based catalysts were prepared for dimethyl carbonate (DMC) synthesis and reaction conditions were evaluated for finding the optimal reaction route. In order to find optimal catalysts for DMC synthesis, calcination temperature and Cu(II) impregnation amount were evaluated. The oxidative carbonylation using methanol, carbon monoxide and oxygen and the direct synthesis using methanol and carbon dioxide were introduced for producing DMC. Following the law of Le Chatelier, the dehydration reaction was applied for enhancing the reactivity (methanol conversion) as removing water during the reaction. 2-cyanopyridine, as a chemical dehydration agent, was used. In the case of the oxidative carbonylation, methanol conversion rate increased from 15.1% to 38.7% and the DMC selectivity increased from 0% to 98.8%. In the case of the direct synthesis, methanol conversion rate increased from 1.0% to 77.8% and the DMC selectivity increased from 41.2% to 100.0%.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.433-438
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• 2021

Polyethylene is widely used as an agricultural film, but eco-friendly technology is lacking for its decomposition. Thus, recently, much attention has been paid to develop a technology for biological polyethylene decomposition. It has been expected that several oxidation steps will be required in the biological degradation of polyethylene. First, secondary alcohol is formed on the polyethylene chain, and then the alcohol is oxidized to a carbonyl group. In the subsequent process, the carbonyl group is converted to an ester by Baeyer-Villiger monooxygenase (BVMO), and this ester bond is expected to be cleaved by lipase and esterase in the final step. In this work, we reviewed BVMO as one of the promising enzymes for polyethylene decomposition, in terms of its reaction mechanism, classification, and engineering. In addition, we also give a brief perspective on polyethylene decomposition using BVMO.