• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.136.2-136.2
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• 2011

A dynamic simulation study on SCR process in GTL process was carried out in order to find optimum operation conditions for pilot plant operation. Optimum operating conditions for SCR synthesis gas process were determined by changing operation variables such as feed temperature and pressure. It was also assumed that physical properties of reaction medium were governed by RKS (Redlich-Kwong-Soave) equation. The effect of temperature and pressure on synthesis gas process $H_2$/CO ratio were mainly examined. Dynamic simulation results were fed back to feed operation condition for optimizing productivity, especially for appropriate condition to FT (Fischer-Tropsch) synthesis unit.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.826-833
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• 2014

Driven by both environmental and economic reasons, the development of small to medium scale GTL(gas-to-liquid) process for offshore applications and for utilizing other stranded or associated gas has recently been studied increasingly. Microchannel GTL reactors have been prefrered over the conventional GTL reactors for such applications, due to its compactness, and additional advantages of small heat and mass transfer distance desired for high heat transfer performance and reactor conversion. In this work, multi-microchannel reactor was simulated by using commercial CFD code, ANSYS FLUENT, to study the geometric effect of the microchannels on the heat transfer phenomena. A heat generation curve was first calculated by modeling a Fischer-Tropsch reaction in a single-microchannel reactor model using Matlab-ASPEN integration platform. The calculated heat generation curve was implemented to the CFD model. Four design variables based on the microchannel geometry namely coolant channel width, coolant channel height, coolant channel to process channel distance, and coolant channel to coolant channel distance, were selected for calculating three dependent variables namely, heat flux, maximum temperature of coolant channel, and maximum temperature of process channel. The simulation results were visualized to understand the effects of the design variables on the dependent variables. Heat flux and maximum temperature of cooling channel and process channel were found to be increasing when coolant channel width and height were decreased. Coolant channel to process channel distance was found to have no effect on the heat transfer phenomena. Finally, total heat flux was found to be increasing and maximum coolant channel temperature to be decreasing when coolant channel to coolant channel distance was decreased. Using the qualitative trend revealed from the present study, an appropriate process channel and coolant channel geometry along with the distance between the adjacent channels can be recommended for a microchannel reactor that meet a desired reactor performance on heat transfer phenomena and hence reactor conversion of a Fischer-Tropsch microchannel reactor.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.110.1-110.1
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• 2010

A bench scale slurry bubble column reactor (SBCR) with active-Fe based catalyst was developed for the Fischer-Tropsch synthesis (FTS) reaction. Considering the highly exothermic reaction heat generated in the bench scale SBCR, an effective cooling system was devised consisting of a U-type dip tube submerged in the reactor. Also, the physical and chemical properties of the catalyst were controlled so as to achieve high activity for the CO conversion and liquid oil ($C_{5+}$) production. Firstly, the FTS performance of the FeCuK/$SiO_2$ catalyst in the SBCR under reaction conditions of $265^{\circ}C$, 2.5 MPa, and $H_2/CO=1$ was investigated. The CO conversion and liquid oil ($C_{5+}$) productivity in the reaction were 88.6% and 0.226 $g/g_{cat}-h$, respectively, corresponding to a liquid oil ($C_{5+}$) production rate of 0.03 bbl/day. To investigate the FTS reaction behavior in the bench scale SBCR, the effects of the space velocity and superficial velocity of the synthesis gas and reaction temperature were also studied. The liquid oil production rate increased upto 0.057 bbl/day with increasing space velocity from 2.61 to 3.92 $SL/h-g_{Fe}$ and it was confirmed that the SBCR bench system developed in this research precisely simulated the FTS reaction behavior reported in the small scale slurry reactor.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.333-336
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• 2010

Fe/$Al_2O_3$ granules with various compositions were prepared by combining sol-gel with oil drop method for Fishcer-Tropsh reaction to produce light olefin from synthesis gas. The granules was characterized and employed as a catalyst in the reaction. The surface area of granules was decreased with increasing Fe concentration. Especially, granule with 1.5 of Al/Fe ratios showed the highest CO conversion. However, the olefin selectivity was hardly affected by Al/Fe ratio. K concentration of granule gave a significant effect on catalytic performance. Initial CO conversion and olefin selectivity were increased with K concentration. However, the catalyst with higher K concentration was deactivated rapidly.

• Clean Technology
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• v.30 no.3
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• pp.188-194
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• 2024

This study investigates the impact of reduction temperature on the structure and performance of cobalt-manganese (CM) based catalysts in the direct hydrogenation reaction of carbon dioxide (CO₂). It was observed that at a reduction temperature of 350 ℃, these catalysts could successfully facilitate the conversion of CO₂ into long-chain hydrocarbons. This efficiency is attributed to the optimal conditions provided by the core-shell structure of the catalysts, which effectively catalyzes both the reverse water-gas shift (RWGS) and Fischer-Tropsch (FT) reactions. However, as the reduction temperature increased to 600 ℃, the effectiveness of the reaction process was hindered, and there was a shift in selectivity towards methane. This shift is due to the excessive reduction of the catalyst's outer shell, which reduces the number of RWGS sites and subsequently suppresses the production of CO. These findings highlight the importance of carefully controlling the reduction temperature in the design and optimization of cobalt-based catalysts. Maintaining a balance between the RWGS and FT reactions is crucial. This emphasizes that the reduction temperature is a key factor in efficiently generating long-chain hydrocarbons from CO₂.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.279-287
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• 2009

Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of $C_{5+}$ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.307-310
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• 2010

The research for production of jet fuel from petroleum displacement resources such as bio-mass, coal, natural gas mainly consists of three sub-research areas; the fisrt step is the pretreatment for producing a synthetic gas, and the next step is the Fischer-Trophsh reaction process for making hydrocarbons. The last is the upgrading technology for the hydrocarbons to fit a jet fuel specification via cracking and isomerization reactions. This talk presents reaserch trends and main technologies for production of jet fuel derived from petroleum displacement resources.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.304-310
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• 2010

The FTS(Fischer-Tropsch synthesis) was carried out over precipitated iron-based catalysts with or without $SiO_2$ in a fixed-bed reactor at $250^{\circ}C$ and 1.5 MPa. The catalysts with $SiO_2$ showed much higher catalytic activity for the FTS than those without $SiO_2$, displaying excellent stability during 144 h of reaction. The X-ray diffraction and $N_2$ physisorption revealed that the catalysts with $SiO_2$ showed enhanced dispersion of $Fe_2O_3$ compared with those without $SiO_2$. Also, the results of temperature-programmed reduction by $H_2$ showed that the addition of $SiO_2$ markedly promoted the reduction of $Fe_2O_3$ into $Fe_3O_4$ and FeO at low temperatures below $260^{\circ}C$. In contrast, surface basicity of the catalysts, which was analyzed by temperature-programmed desorption of $CO_2$, decreased as a result of $SiO_2$ addition. We attribute the high and stable performance of the catalysts with $SiO_2$ to the improved dispersion and reducibility by the $SiO_2$ addition.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.617-623
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• 2008

GTL (gas-to-liquid) fuel produced by the Fischer-Tropsch reaction of carbon monoxide (CO) and hydrogen ($H_2$) is expected to be one of the environmental friendly biomass based alternatives and blended to petrodiesel. In this study, the characteristic of the fuel was analyzed by its concentration differences after blending petrodiesel in domestic market with different amounts of GTL fuel which produced from Shell. Gas chromatography shows that GTL fuel consists of longer paraffin chain than common diesel. GTL fuel showed a high flash point, distillation, kinematic viscosity, and derived cetane number. In addition, GTL fuel showed lower lubricity due to low sulfur content.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.74.2-74.2
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• 2011

A simulation study on synthesis gas process in GTL process was carried out in order to find optimum operation conditions for GTL (gas-to-liquid) pilot plant design. Optimum operating conditions for synthesis gas process were determined by changing reaction variables such as feed temperature and pressure. During the simulation, overall synthesis process was assumed to proceed under steady-state conditions. It was also assumed that physical properties of reaction medium were governed by RKS (Redlich-Kwong-Soave) equation. The effect of temperature and pressure on synthesis gas process $H_2$/CO ratio were mainly examined. Simulation results were also compared to experimental results to confirm the reliability of simulation model. Simulation results were reasonably well matched with experimental results.