• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.98-103
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• 2007

The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas compostion and flow rate of exhaust gas are important parameters in DPF evaluation, especially regeneration process. Engine dynamometer and degment tester are generally used in DPF evaluation so far. But these test method couldn't reveal the effect of various parameters on real DPF, such as O2 concentration, amount of soot and exhaust gas temperature. This research has studied the possibility using dump combustor that used to take an approach lean premixed combustion in gas turbine for a DPF power and optimized. It is possible that utilize the system as DOC (Diesel Oxidation Catalyst) and SCR(Selective Catalytic Reduction) assessments test as well as DPF evaluation

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.339-341
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• 2008

Catalytic trimerization of isobutene to produce triisobutenes has been performed over cation-exchange resin and zeolite catalysts. Resin catalysts have the advantage of long lifetime and high trimers selectivity even though the regeneration of an aged catalyst is not satisfactory. On the contrary, zeolite catalysts can be regenerated facilely by simple calcination in air even though the lifetime is short and trimers selectivity is low probably due to small pore size and strong acidity, respectively. It is, therefore highly desirable to develop an inorganic acid catalyst with macro- or meso-pores to show catalytic performances similar or superior to those of macroporous resin catalysts.

• 공업화학
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• 제3권1호
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• pp.7-17
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• 1992

100% $H_2SO_4$($H_0=-11.93$)보다 더 강한 산을 초강산이라고 한다. 그러나 고체초강산 촉매는 액체초강산촉매에 비하여 촉매와 반응생성물의 분리의 용이성, 촉매의 반복사용가능, 촉매의 재생가능 등과 같은 많은 이점을 가지고 있다. 이 총설에서는 고체초강산 촉매의 종류, 제법, 그리고 화학반응에서의 응용에 대하여 소개한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.55-58
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• 2007

To check the feasibility of SMART (Steam Methane Advanced Reforming Technology)system, an experimental investigation was conducted. A fluidized bed reactor of diameter 0.052 m was operated cyclically up to the $10^{th}$ cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone (domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) system. However, the hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased.

• 한국연소학회지
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• 제12권3호
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• pp.16-23
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• 2007

Employing an after-treatment system has almost become a mandatory requirement for Diesel vehicles, which results from a reinforced exhaust regulations as the number of vehicles powered by a Diesel engine increases. The Diesel Particulate Filter (DPF) system is considered as one of the most efficient method to reduce particulate matter (PM); however, the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas composition and flow rate of exhaust gas are important parameters in DPF evaluation processes, especially during a regeneration process. Engine dynamometer and segment tester are generally used in DPF evaluation so far. These test methods, however, could not completely evaluate the effect of various parameters on real DPF, such as oxygen concentration, amount of soot and exhaust gas temperatures. The evaluation of DPF systems using a dump combustor has been verified experimentally and this dump combustor system is likely to be appropriate for the DOC (Diesel Oxidation Catalyst) and SCR (Selective Catalytic Reduction) assessments test, too.

• 대한환경공학회지
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• 제30권1호
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• pp.54-60
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• 2008

본 연구에서는 오리멀젼 연소 발전소 SCR 설비의 최적 운전과 폐촉매의 재생 기술개발을 위해 기초가 되는 촉매의 피독정도와 원인을 촉매의 특성 분석 및 반응 시험을 통해 규명하였다. 시험 결과 비활성화된 촉매의 활성은 350$\sim$450$^{\circ}C$의 반응온도에서 약 5$\sim$10% 감소하였으며 SO$_2$의 산화율은 약 0.59% 증가하였다. 성분 분석 결과, 다량의 V, Mg, S 성분이 비활성화된 촉매에서 증가하였으며 이중 V 성분과 S 성분은 오리멀젼 연료 성분에 기인하고 Mg 성분은 V에 의한 SO$_2$의 SO$_3$로의 산화를 방지하기 위해 주입되는 MgO 성분에 기인한다. 촉매담체의 결정구조는 신촉매의 결정구조와 같은 anatase 형태의 결정구조를 유지하여 운전에 따른 촉매의 열적 소결현상은 관찰되지 않았다.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.27-31
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• 2007

The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Therefore, the present study evaluates the effect of fuel injection characteristics on regeneration performance in a DOC and a catalyzed CR-DPF system. The temperature distribution on the rear surface of the DOC and the exhaust gas emission were analyzed in accordance with fuel injection strategies and engine operating conditions. A temperature increase more than BPT of DPF system was obtained with a small amount fuel injection although the exhaust gas temperature was low and flow rate was high. This increase of temperature at the DPF inlet cause PM to oxidize completely by oxygen. In the case of multi-step injection, the abrupt temperature changes of DOC inlet didn't occur and THC slip also could not be observed. However, in the case of pulse type injection, the abrupt injection of much fuel results in the decrease of DOC inlet temperatures and the instantaneous slip of THC was observed.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.345-351
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• 2016

This study was carried out to determine an optimal lean $NO_x$ trap (LNT) regeneration condition based on a $NO_x$ storage fraction. The LNT regeneration was performed by an in-cylinder post fuel injection method. A $NO_x$ storage fraction is defined by the ratio of current cumulated $NO_x$ amount in the LNT to the $NO_x$ storage capacity: 0 means empty and 1 fully loaded. In this study five engine operating conditions were chosen to represent the New European Driving Cycle. With various $NO_x$ storage fractions each engine operating condition, the LNT regeneration was executed and then $NO_x$ conversion efficiency, additional fuel consumption, CO and THC slip, peak catalyst temperature were measured. The results showed that there exist an optimal condition to regenerate the LNT, eg. 1500 rpm 6 bar BMEP with below 0.7 $NO_x$ storage fraction in this experimental constraint.

• 한국환경과학회지
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• 제22권1호
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• pp.73-81
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• 2013

The present work has been devoted to the catalytic reduction of $N_2O$ by $H_2$ with $Pt/SiO_2$ catalysts at very low temperatures, such as $110^{\circ}C$, and their nanoparticle sizes have been determined by using $H_2-N_2O$ titration, X-ray diffraction(XRD) and high-resolution transmission electron microscopy(HRTEM) measurements. A sample of 1.72% $Pt/SiO_2$, which had been prepared by an ion exchange method, consisted of almost atomic levels of Pt nanoparticles with 1.16 nm that are very consistent with the HRTEM measurements, while a $Pt/SiO_2$ catalyst possessing the same Pt amount via an incipient wetness technique did 13.5 nm particles as determined by the XRD measurements. These two catalysts showed a noticeable difference in the on-stream $deN_2O$ activity maintenance profiles at $110^{\circ}C$. This discrepancy was associated with the nanoparticle sizes, i.e., the $Pt/SiO_2$ catalyst with the smaller particle size was much more active for the $N_2O$ reduction. When repeated measurements of the $N_2O$ reduction with the 1.16 nm Pt catalyst at $110^{\circ}C$ were allowed, the catalyst deactivation occurred, depending somewhat on regeneration excursions.

• 청정기술
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• 제27권1호
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• pp.9-16
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• 2021

Active Matrix Organic Light-Emitting Diode (AMOLED) 봉지 공정은 수분과 산소에 매우 취약하기 때문에, 수분과 산소의 함량이 최소화된 고순도의 질소를 사용하여야 한다. 본 연구의 목적은 AMOLED 봉지 공정에 사용하는 질소에서 산소를 제거하기 위한 용도로 사용되는 구리계 촉매를 최적화하는 것이다. CuO, Al2O3, 또는 ZnO의 조성으로 이루어진 2성분계 및 3성분계 촉매를 공침법을 통해서 제조하였다. 제조된 촉매들을 BET, XRD, TPR, XRF의 분석장비를 활용하여 촉매의 특성을 분석하였다. 촉매의 산소 제거 성능을 확인하기 위해 고정층 반응기에서 촉매 산소 제거 반응 실험을 수행하고 산소 분석기를 통해 산소 함량을 측정하였다. 또한 사용된 촉매의 반복 재생을 통해 촉매의 재사용 성능을 검증하였다. CuO와 Al2O3 비율이 6 : 4, 7 : 3 및 8:2로 제조된 2 성분계 촉매의 특성과 산소 제거 능력을 비교하였다. CuO와 Al2O3의 비율이 8:2인 촉매의 환원성이 가장 높았는데, 이는 CuO의 분산도가 가장 높기 때문이다. 결과적으로, 2성분계 촉매 중에서 CuO와 Al2O3의 비율이 8 : 2 인 촉매의 산소 제거 능력이 가장 우수한 것으로 나타났다. CuO : Al2O3 의 비율이 8:2인 촉매에 ZnO를 2 wt% 넣어준 촉매가 3성분계 촉매 중에는 가장 우수한 산소제거 능력을 보였으며, 이는 뛰어난 환원성에 기인한다고 할 수 있다. 또한 이 촉매는 재생 실험을 통해서도 산소 제거능력이 유지된다는 것을 확인하였다.