• New & Renewable Energy
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• v.3 no.4
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• pp.77-89
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• 2007

폐기물의 플라즈마를 이용한 열분해-가스화-용융 처리공정은 청정연료 형태로 정화된 합성가스를 얻을 수 있고, 이 합성가스를 WGS 반응과 PSA 공법을 이용하면 고순도 수소로의 전환 및 회수가 가능하다. (주)애드플라텍에서는 자체 보유하고 있는 3톤/일급 플라즈마 폐기물 처리설비와 수소 정제/회수시스템을 연계하여, 페기물로부터 고순도 수소 생산($20Nm^3/h$이상)을 위한 플라즈마 폐기물 처리 추소 생산 통합시스템 개발을 진행하고 있다. 합성가스 내 질소 농도를 낮추기 위해 산소를 매질로 하는 100kw급 산소 플라즈마 토치를 제작하였다. 수소 정제/회수 시스템은 폐기물의 플라즈마 처리 후의 합성가스 생성량과 조성의 변화에 대응할 수 있도록 하였으며, WGS 반응기로 들어가는 합성가스를 가스 컴프레서를 통하여 최대 10기압으로 승압시키고, 고농도 일산화탄소의 효과적인 제거 및 열 회수 극대화가 이루어질 수 있는 최적의 가스처리 시스템으로 구현되도록 하였다. 설치 완료된 WGS 반응기의 성능시험을 플라즈마 처리설비와 연계하여 수행하였다. 합성가스 내 각각 34%와 25%의 일산화탄소 및 수소의 농도가 WGS 반응기를 거친 후, 일산화탄소는 0.1% 미만으로 제거되었으며 수소는 44%로 증가하여 WGS 반응기의 성능 수준이 매우 우수함을 확인하였다. 차기 년도에 설치/가동 예정인 수소 생산용 PSA는 최대 10기압 운전 및 상압재생 방식으로 운전되며 생산된 수소는 최소 99.99%이상의 고순도를 유지할 것으로 기대된다.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.25-33
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• 2003

It summarized about the application of the membrane technology in thermochemical water-splitting iodine-sulfur process that was hydrogen production using the nuclear heat from the High Temperature Gas-Cooled Reactor (HTGR). Thermochemical water-splitting hydrogen production method using the high temperater nuclear thermal energy could be realized and remained to be solved the investigation subject. And, it is possible for mass-production of hydrogen such as one of the clean energy in future.

• Clean Technology
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• v.2 no.1
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• pp.69-79
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• 1996

Sulfur emission control in coal gasification plants implies the removal of $H_2S$ from the fuel gas in the gas clean-up system. In this study, the effects of particle size of sorbents, temperature of sulfidation and sorbent characteristics on the $H_2S$ removal efficiency of manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about $700^{\circ}C$. And that the smaller particle size, the higher the $H_2S$ removal efficiency, but that was not effective very much. As the temperature increases, the reactivity of sorbents has lowered because agglomeration of sorbents increased the intraparticle transport resistance. This phenomenon was confirmed by SEM photographs. The equilibrium ratio ($P_{H_2O}/P_{H_2S}$) obtained by experiments is represented as a ${\log}(P_{H_2O}/P_{H_2S})=5653/T-3.7909$. It was showed that the natural manganese ore could be used as a sorbent because its capacity for $H_2S$ removal is equivalent to the eariler developed sorbents.

• Clean Technology
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• v.14 no.4
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• pp.287-292
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• 2008

In this study, computer simulation works have been performed for the capture process of the $CO_2$ and $H_{2}S$ gases contained in the effluent stream using methanol aqueous solution. In order to increase the solubilities of the $CO_2$ and $H_{2}S$ in the methanol aqueous stream, the operating pressure of the absorber was raised to 30 bar and the feeding temperature of the solvent was lowered to $-20^{\circ}C$ by using refrigeration cycle. NRTL liquid activity coefficient model was used to estimate the liquid phase nonidealities for methanol and water. Soave-Redlich-Kwong equation of state was used for the vapor phase nonidealities. Henry's law option was also used to calculate the solubilities of the supercritical noncondensible gases into the methanol aqueous solvent stream.

• Clean Technology
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• v.18 no.4
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• pp.355-359
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• 2012

For effectively photochemical hydrogen production, Ti ions (0.01, 0.10, 0.50 mol%) impregnated $WO_3$ ($Ti/WO_3$) nanometer sized particles were prepared using a impregnation method as a photocatalyst. The characteristics of the synthesized $Ti/WO_3$ photocatalysts were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectra (PL), atomic force microscope (AFM), and electrostatic force microscope (EFM). The evolution of $H_2$ from methanol/water (1/1) photo-splitting over $Ti/WO_3$ photocatalysts was enhanced compared to those over pure $TiO_2$ and $WO_3$ photocatalysts; 3.02 mL of $H_2$ gas was evolved after 8 h when 0.5 g of a 0.10 mol% $Ti/WO_3$ catalyst was used.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.627-632
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• 2007

폐기물의 플라즈마를 이용한 열분해-가스화-용융 처리공정은 청정연료 형태로 정화된 합성가스를 얻을 수 있고, 이 합성가스를 WGS 반응과 PSA 공법을 이용하면 고순도 수소로의 전환 및 회수가 가능하다. (주)애드플라텍에서는 자체 보유하고 있는 3톤/일급 플라즈마 폐기물 처리설비와 수소 정제/회수시스템을 연계하여, 폐기물로부터 고순도 수소 생산 ($20Nm^3/h$ 이상)을 위한 플라즈마 폐기물 처리 수소 생산 통합시스템 개발을 진행하고 있다. 합성가스 내 질소 농도를 낮추기 위해 산소를 매질로 하는 100kW급 산소 플라즈마 토치를 제작 하였다. 수소 정제/회수 시스템은 폐기물의 플라즈마 처리 후의 합성가스 생성량과 조성의 변화에 대응할 수 있도록 하였으며 WGS 반응기로 들어가는 합성가스를 가스 컴프레서를 통하여 최대 10기압으로 승압시키고, 고농도 일산화탄소의 효과적인 제거 및 열 회수 극대화가 이루어질 수 있는 최적의 가스처리 시스템으로 구현되도록 하였다. 설치 완료된 WGS 반응기의 성능시험이 플라즈마 처리설비와 연계하여 수행되었으며 WGS 반응기를 거친 일산화탄소의 농도는 1.5% 미만으로 분석되었다. 차기 년도에 설치/가동 예정인 수소 생산용 PSA는 최대 10기압 운전 및 상압재생 방식으로 운전되며 생산된 수소는 최소 99.99%이상의 고순도를 유지할 것으로 기대된다.

• Clean Technology
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• v.20 no.4
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• pp.425-432
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• 2014

The effect of two important parameters of a catalytic membrane reactor (CMR), hydrogen selectivity and hydrogen permeance, coupled with an Ar sweep flow and an operating pressure on the performance of a water gas shift reaction in a CMR has been extensively studied using a one-dimensional reactor model and reaction kinetics. As an alternative pre-combustion $CO_2$ capture method, the feasibility of capturing a pressurized and concentrated $CO_2$ in a retentate (a shell side of a CMR) and separating a purified $H_2$ in a permeate (a tube side of a CMR) simultaneously in a CMR was examined and a guideline for a hydrogen permeance, a hydrogen selectivity, an Ar sweep flow rate, and an operating pressure to achieve a simultaneous capture of a concentrate $CO_2$ in a retentate and production of a purified $H_2$ in a permeate is presented. For example, with an operating pressure of 8 atm and Ar sweep gas for rate of $6.7{\times}10^{-4}mols^{-1}$, a concentrated $CO_2$ in a retentate (~90%) and a purified $H_2$ in a permeate (~100%) was simultaneously obtained in a CMR fitted with a membrane with hydrogen permeance of $1{\times}10^{-8}molm^{-2}s^{-1}Pa^{-1}$ and a hydrogen selectivity of 10000.

• Clean Technology
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• v.29 no.3
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• pp.217-226
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• 2023

The amount of hydrogen adsorbed in arrays of single walled carbon nanotubes (SWNTs) was studied as a function of nanotube diameter and distance between the nearest-neighbor nanotubes on square arrangements using a grand canonical Monte Carlo simulation. The influence of the geometry of a triangle array with the same diameters and distances was also studied. Hydrogen-carbon and hydrogen-hydrogen interactions were modeled with Lennard-Jones potentials for short range interactions and electrostatic interactions were added for hydrogen-hydrogen pairs to consider quantum contributions at low temperatures. At 194.5 K, Type I isotherms for large-diameter SWNTs and Type IV isotherms without hysteresis between adsorption and desorption processes for wider tube separations were observed. At 200 bars, the gravimetric hydrogen storage capacity of the SWNTs was reached or exceeded the US Department of Energy (DOE) target, but the volumetric capacity was about 70% of the DOE target. At 77 K, a two-step adsorption was observed, corresponding to a monolayer formation step followed by a condensation step. Hydrogen was adsorbed first to the inner surface of the nanotubes, then to the outer surface, intratubular space and the interstitial channels between the nanotube bundles. The simulation indicated that SWNTs of various diameters and distances in a wide range of configurations exceeded the DOE gravimetric and volumetric targets at under 1 bar.

• Clean Technology
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• v.28 no.3
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• pp.238-248
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• 2022

The world is striving to transition to a carbon-neutral society. It is expected that using hydrogen instead of hydrocarbon fuel will contribute to this carbon neutrality. However, there is a need for combustion technology that controls the increased NOx emissions caused by hydrogen co-firing. Flameless combustion is one of the alternative technologies that resolves this problem. In this study, a numerical analysis was performed using the 1D opposed-flow diffusion flame model of Chemkin to analyze the characteristics of flameless combustion and the chemical reaction of methane-hydrogen fuel according to its hydrogen content and flue gas recirculation rate. In methane combustion, as the recirculation rate (K_v) increased, the temperature and heat release rate decreased due to an increase in inert gases. Also, increasing K_v from 2 to 3 achieved flameless combustion in which there was no endothermic region of heat release and the region of maximum heat release rate merged into one. In H₂ 100% at K_v 3, flameless combustion was achieved in terms of heat release, but it was difficult to determine whether flameless combustion was achieved in terms of flame structure. However, since the NOx formation of hydrogen flameless combustion was predicted to be similar to that of methane flameless combustion, complex considerations of flame structure, heat release, and NOx formation are needed to define hydrogen flameless combustion.

• Clean Technology
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• v.21 no.4
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• pp.229-234
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• 2015

Recently, there are increasing numbers of study regarding hydrogen fuels but researches on desulfurization of diesel are rare. In this study, we performed diesel desulfurization reactor design by computation fluid dynamics simulation. By analyzing the change in flow and sulfur concentration at the outlet according to the changes in flow rate, reactor length, and reactor diameter, we have found the minimum catalyst performance for the given flow rate condition and the relation between the reactor performance and the reactor size and shape. We also studied the effects of permeability of the packed bed on the flow and sulfur concentration distribution. The present work can be utilized to design a diesel desulfurization reactor for a fuel cell used in ships. Furthermore, the present work also can be used to design low sulfur diesel supply in oil refineries and therefore contribute to the development of clean petrochemical technology.