• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.543-549
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• 1997

The direct reaction of carbon dioxide($CO_2$) with butane($C_4H_{10}$) to obtain synthesis gas and hydrocarbon compounds have been studied on nickel loaded catalysts. In the reaction of $CO_2$ with $C_4H_{10}$, Ni loaded catalysts showed similar activity with Pt catalyst and Coke deposition on the catalyst was severe by dehydrogenation of butane. The main products were carbon monoxide and hydrogen, when alumina and Y type zeolite were used as a support. Instead, a great deal of aromatic hydrocarbons were obtained on the Ni loaded ZSM-5 catalyst. The conversion of $CO_2$ increased with the increasing molar ratio of $CO_2$/$C_4H_{10}$ on Ni/ZSM-5, Ni/NaY and Ni/alumina catalyst, but the conversion decreased again from the ratio of 2. The value of $CO_2$ conversion was the highest at the 5wt% of Ni loading on ZSM-5 catalyst. A part of cokes deposited on the catalysts diminished when only $CO_2$ gas or water steam flowed into the reactor. The coke deposited on the catalysts was very reactive and it may be an important intermediate for the carbon dioxide reforming reaction.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.239-251
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• 2024

In this study, a hydrogen fuel cell process based on methanol was developed to reduce greenhouse gas emissions. In Case1, the methanol fuel engine system was designed to investigate the emission of exhaust gas when methanol was supplied as fuel instead of gasoline to the engine. In Case2, a hydrogen fuel cell system was designed by adding a methanol reforming system to Case1. This hybrid system produced gray hydrogen and combined the output of the engine and fuel cell to drive the ship. However, gray hydrogen emits carbon in the process of producing hydrogen. To address this problem, a carbon capture and utilization (CCU) system was added to Case3. The CO2 of the flue gas discharged from Case2 was synthesized with gray hydrogen to produce blue methanol. The results of the case studies revealed that the optimal operating conditions were 220 ℃, 500 kPa, SCR = 1.0, and flow ratio = 0.7. The system of Case3 reduced carbon emissions by 42% compared with that Case1. Thus, the hybrid system of Case3 could considerably reduce the ship's CO2 emissions.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.423-429
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• 2009

The purpose of this study is to investigate the optimal condition for the hydrogen-rich gas production and the CO removal by reforming of gliding arc plasma reforming system using biogas. The parametric screening studies were carried out according to changes of steam feed amount, catalyst bed temperature in water gas reactor and catalyst bed temperature, input air flow rate in preferential oxidation reactor. The standard condition is as follows. The steam/carbon ratio, catalyst bed temperature, total gas flow rate, input electric power and biogas composition rate ($CH_4$ : $CO_2$) were fixed 3, $700^{\circ}C$, 16 L/min, 2.4 kW and 6 : 4, respectively. The results are as follow, HTS optimum operating conditions were S/C ratio of 3 and reactor temperature of $500^{\circ}C$. LTS were S/C ratio of 2.9 and temperature of $300^{\circ}C$. Also, PROX I optimum conditions were input air flow rate of 300 mL/min and reactor temperature of $190^{\circ}C$. PROX II were 200 mL/min and $190^{\circ}C$ respectively. After having passed through each reactor, the results were as follows: 55% of $H_{2}$ yield, 0% of CO selectivity, 99% of $CH_4$ conversion rate, 27% of $CO_2$ conversion rate, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.54-61
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• 2008

Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increases the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.888-888
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• 2009

A simulation study on SCR (Steam Carbon dioxide Reforming) process in gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) process was carried out in order to find optimum reaction conditions for GTL (gas-to-liquid) process reaction. Optimum SCR operating conditions for synthesis gas to FT (Fischer-Tropsch) 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. SCR process was considered as reaction models for synthesis gas in GTL proess. The effect of temperature and pressure on SCR process $H_2$/CO ratio and the effect of reaction pressure on SCR reaction 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.

• Journal of the Korean Applied Science and Technology
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• v.15 no.1
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• pp.79-90
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• 1998

One of the objectives of this study were to develop a process for manufacturing activated carbons from agricultural by-products(rice shells and saw dust) and another is to measure the iodine number, ash content and removal ratio of COD. The other is to compare those values with those of commercialized activated carbons. Agricultural by-products based activated carbons were manufactured through the steam-reaction method. A rotary kiln type furnace was used for both carbonization and activation. The optimum operating temperatures for carbonization and activation were $650^{\circ}C$ and $900^{\circ}C$, respectively. For the activated carbons produced under these conditions, the iodine number was 1,127mg/g. Especially, removal efficiency of COD was 61.5% for 40mg/L of wastewater and 30% for 150mg/L of SLS(Sodium Lauryl Sulfate).

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.813-818
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• 2008

Various additives were added in small amounts on Ni/YSZ anode of SOFC (solid oxide fuel cell) in order to improve reactivity and to inhibit deactivation due to coke deposition during methane reforming using a low mole ratio steam ($H_2O/CH_4=1.5$) at $800^{\circ}C$. Ni/YSZ catalysts added with various perovskites did not show any improvement but exhibited a gradual decrease in the methane conversion. K-doped Ni/YSZ showed a steady increase and maintenance of the conversion up to 42 hours, after which there was an abrupt deactivation of catalyst owing to potassium loss by volatilization. Addition of 5% of $K_2Ti_2O_5$ on Ni/YSZ showed a stable maintenance of the conversion without K loss, and was able to prevent coke formation during a long time operation. Deactivation of catalyst during the reaction was mainly caused by the accumulation of graphidic carbon on the catalyst surface.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.1-8
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• 2023

Research, such as developing alternative energy in the transportation field, including aviation, is being actively conducted to solve the issue of current climate change. Interest in ammonia fuel as a carbon free energy (CFE) source is increasing due to the ease of liquefaction and transportation and similarity in energy density to that of methanol. However, explosiveness and toxicity of ammonia make it difficult to handle. Therefore, in this study, stable ammonia production was attempted using relatively easy-to-handle urea water solution (UWS). High temperature steam was used to promote the hydrolysis of ammonia. In order to determine the causes for ammonia production below the theoretical equivalent ratio, it was suggested that there were not enough collisions to promote the hydrolysis based on the kinetic theory of gases. The hydrolysis of unreacted isocyanic acid (HNCO) was tested according to the change in water supply. As a result, an increased amount of ammonia produced was confirmed. The increased amount of ammonia produced in a certain section was dependent on the steam temperature and the flow rate of water supplied.

• Journal of the Korean Applied Science and Technology
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• v.21 no.3
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• pp.225-230
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• 2004

Synthesis gas is a high valued compound as a basic chemicals at various chemical processes. Synthesis gas is mainly produced commercially by a steam reforming process. However, the process is highly endothermic so that the process is very energy-consuming process. Thus, this study was carried out to produce synthesis gas by the partial oxidation of methane to decrease the energy cost. The effects of reaction temperature and flow rate of reactants on the methane conversion, product selectivity, product ratio, and carbon deposition were investigated with 13wt% Ni/MgO catalyst in a fluidized bed reactor. With the fluidized bed reactor, $CH_4$ conversion was 91%, and Hz and CO selectivities were both 98% at 850$^{\circ}C$ and total flow rate of 100 mL/min. These values were higher than those of fixed bed reactor. From this result, we found that with the use of the fluidized bed reactor it was possible to avoid the disadvantage of fixed bed reactor (explosion) and increase the productivity of synthesis gas.

• Journal of Hydrogen and New Energy
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• v.25 no.2
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• pp.105-113
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• 2014

Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).