• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.515-521
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• 2004

The catalytic oxidation of volatile organic compounds (methanol. acetaldehyde) has been characterized using the copper phthalocyanine catalyst in a fixed bed flow reactor under atmospheric pressure. The catalytic activity for pretreatment conditions was examined by this reaction system. The catalytic activity was ordered as follows: metal free-PC＜Cu ($\alpha$)-PC＜Cu ($\beta$)-PC The formaldehyde, carbon monoxide as a partial oxidation product of methanol and acetaldehyde over Cu ($\alpha$)-PC catalyst were detected and the conversions of methanol and acetaldehyde were accomplished above 95% over Cu ($\alpha$) -PC, Cu ($\beta$) - PC catalyst at 35$0^{\circ}C$. The pretreated metal free -PC, Cu($\alpha$)-PC, Cu($\beta$)-PC catalysts have been characterised by TGA, EA and XRD analysis. The catalytic activity pretreated with air and $CH_3$OH mixture (P-4) or air only (P-5) was very excellent. XRD and EA results showed that Cu($\alpha$)-PC, Cu($\beta$)-PC were destroyed an(1 new metal oxide such as CuO were formed.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.93-96
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• 2007

Catalytic activities of color and conductive carbon blacks in ethane decomposition for $CO_2-free$ hydrogen production were investigated. The ethane decomposition was carried out in a conventional fixed bed reactor under atmospheric pressure at 973-1173 K for 2 hours. When the decomposition in the presence of carbon black was compared with the non-catalytic thermal decomposition, the former exhibited significantly higher ethane conversion, higher C(s) selectivity and lower ethylene selectivity with small increase of the methane selectivity, which resulted in higher hydrogen yield. This indicates that carbon black is catalytically effective for dehydrogenation of ethane as well as subsequent decomposition of ethylene. All the carbon blacks exhibited stable catalytic activity with time. In durability tests, fluffy N-330 and BP2000 maintained their activities for 36 hours.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2157-2163
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• 2018

Catalytic reactors have been essential for chemical engineering process, and different designs of reactors in multi-scales have been previously studied. Computational fluid dynamics (CFD) utilized in reactor designs have been gaining interest due to its cost-effective advantage in designing the actual reactors before its construction. In this work, butadiene synthesis via oxidative dehydrogenation (ODH) of n-butene using tubular reactor was used as a case study in the CFD model. The effects of coolant and reactor diameter were investigated in assessing the reactor performance. Based on the results of the CFD model, the conversion and selectivity were 86.5% and 59.5% respectively in a fixed bed reactor under adiabatic condition. When coolants were used in a tubular reactor, reactor temperature profiles showed that solar salt had lower temperature gradients inside the reactor than the cooling water. Furthermore, higher conversion (90.9%) and selectivity (90.5%) were observed for solar salt as compared to the cooling water (88.4% for conversion and 86.3% for selectivity). Meanwhile, reducing the reactor diameter resulted in smaller temperature gradients with higher conversion and selectivity.

• Journal of the Korean Institute of Gas
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• v.18 no.4
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• pp.63-67
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• 2014

Fischer-Tropsch synthesis mainly produces a wax which is a viscous liquid for long carbon chain. When a catalytic fixed-bed reactor is used for Fischer-Tropsch synthesis, the wax generated on a catalyst surface can keep adsorbing on the catalyst surface. This liquid hold-up causes significant pressure drop and clogging problems through the reactor. Thus, the model for liquid hold-up is required to design the size of reactor and catalyst particles. In this study, the liquid hold-up model considering structural and operational conditions was proposed based on empirical equations for convective mass transfer between the syngas flow and the wax-adsorbed catalyst. The developed model was validated by comparing with the experimental data from Knochen's work (2010). The influence of reactor length and coross section on the wax hold-up in reactor were analyzed and the optimal reactor size were proposed.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.591-597
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• 2023

Pakistan depends heavily on imports for its fuel requirements. In this experiment, catalytic pyrolysis of a blend of feedstock's consisting of date seed, wheat straw, and corn cob was conducted in a fixed bed reactor to produce oil that can be used as an alternative fuel. The main focus was to emphasize the outcome of important variables on the produced oil. The effects of operating conditions on the yield of bio-oil were studied by changing temperature (350-500 ℃), heating rate (10, 15, 20 ℃/min), and particle size (1, 2, 3 mm). Moreover, ZnO was used as a catalyst in the process. First, the thermal degradation of the feedstock was investigated by TGA and DTG analysis at 10 ℃/min of different particle sizes of 1, 2, and 3mm from a temperature range of 0 to 1000 ℃. The optimum temperature was found to be 450 ℃ for maximum degradation, and the oil yield was indicated to be around 37%. It was deduced from the experiment that the maximum production of bio-oil was 32.21% at a temperature of 450 ℃, a particle size of 1mm, and a heating rate of 15 ℃/min. When using the catalyst under the same operating conditions, the bio-oil production increased to 41.05%. The heating value of the produced oil was 22 MJ/kg compared to low-quality biodiesel oil, which could be used as a fuel.

• Journal of Environmental Science International
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• v.15 no.3
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• pp.221-227
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• 2006

Oxidative TCE decomposition over $TiO_2$-supported single and complex metal oxide catalysts has been conducted using a continuous flow type fixed-bed reactor system. Different types of commercial $TiO_2$ were used for obtaining the supported catalysts via an incipient wetness technique. Among a variety of titanias and metal oxides used, a DT51D $TiO_2\;and\;CrO_x$ would be the respective promising support and active ingredient for the oxidative TCE decomposition. The $TiO_2-based\;CrO_x$ catalyst gave a significant dependence of the catalytic activity in TCE oxidation reaction on the metal loadings. The use of high $CrO_x$ contents for preparing $CrO_x/TiO_2$ catalysts might produce $Cr_2O_3$ crystallites on the surface of $TiO_2$, thereby decreasing catalytic performance in the oxidative decomposition at low reaction temperatures. Supported $CrO_x$-based bimetallic oxide systems offered a very useful approach to lower the $CrO_x$ amounts without any loss in their catalytic activity for the catalytic TCE oxidation and to minimize the formation of Cl-containing organic products in the course of the catalytic reaction.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.56-61
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• 2005

Methanol was synthesized by homogeneous and catalytic reactions of partial oxidation of methane. The effect of pressure, temperature and oxygen concentration on methanol synthesis was investigated. The catalyst used was Bi-Cs-Mg-Cu-Mo mixed oxide. The partial oxidation reaction was carried out in a fixed bed reactor at 20${\sim}$46 bar and $450{\sim}480^{\circ}C$ and oxygen concentration of 5.3${\sim}$7.7mol%. The results were compared with results of homogeneous reaction performed at the same conditions. Methane conversions of the homogeneous and catalytic reactions increased with temperature. Methanol selectivity of the homogeneous reaction decreased with increasing temperature. However, the methanol selectivity of catalytic reaction increased with temperature. For both homogeneous and catalytic reactions, the methane conversions were around 5%. This may be due to the low oxygen concentration. Methanol selectivity of the catalytic reaction was higher than that of homogeneous one.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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• pp.663-670
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• 2004

The catalytic oxidation of benzene, toluene and xylene over a spent industrial catalyst (Pd-based) was investigated in a fixed bed flow reactor system. According to the priming condition, the properties of a spent Pd-based catalyst were characterized by XRD(X-ray diffraction). BET(Brunauer-Emmett-Teller) and ICP(Inductively coupled plasma). When air was used as a primer, optimum priming temperature was found to be 200$^{\circ}C$, and the catalytic activity decreased as the priming temperature increased. When a spent Pd-based catalyst primed with air at 200$^{\circ}C$ was re-treated with hydrogen at 200$^{\circ}C$, 300$^{\circ}C$ or 400$^{\circ}C$, respectively, the catalytic activity increased and thermal effect were negligible. $HNO_3$ aqueous solution priming resulted in slight decrease of the catalytic activity, with little effects on $HNO_3$ concentrations. The activity of a spent Pd-based catalyst with respect to VOC molecule was observed to follow sequence: xylene> toluene> benzene. Benzene. toluene and xylene could be removed to almost 100% by a spent Pd-based catalyst primed with hydrogen.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.2
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• pp.38-46
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• 1988

NOx is an important air pollution material which is generated when fossil fuels are burning, NOx removal in flue gas by selective catalytic reduction was studied over various catalysts in a fixed bed continuous flow reactor. The ranges of experimental conditions were at the temperatures between $200^\circ$C and $350^\circ$C, the $NH_3/NOx$ mole ratios between 0.8 and 1.4, oxygen concentrations between 1.5% and 3% and the space velocities between 5, 000 $hr^-1$ and 12, 500 $hr^-1$. The efficiency of NOx removal in the ranges of experimental conditions was highest at the temp. of 300$^\circ$C, oxygen concentration of 2.5-2.6% and $NH_3/NOx$ mole ratios of 1.0-1.2. The catalyst with high activity for NOx removal in flue gas was found to be $MoO_3-V_2O_5/TiO_2$.

• New & Renewable Energy
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• v.5 no.4
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• pp.52-58
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• 2009

Upgrading of pyrolysis wax oil using HZSM-5 catalyst has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation was studied with a function of catalyst amount and reaction temperature. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The catalytic degradation using HZSM-5 catalyst shows the high conversion of pyrolysis wax oil to light hydrocarbons. The liquid product obtained shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Here, the experimental variable such as catalyst amount and reaction temperature was influenced on the product distribution.