메탄 부분산화반응 촉매에 La 첨가 및 제조방법에 따른 촉매활성에 미치는 영향

천한진(Han Jin Cheon),신기석(Ki Seok Shin),안성환(Sung Hwan Ahn),윤철훈(Cheol Hun Yoon),함현식(Hyun Sik Hahm) 한국가스학회 2010 한국가스학회지 Vol.14 No.2

메탄의 부분산화에 의하여 합성가스를 제조하였다. 저렴하며 본 반응에 활성이 좋은 것으로 알려진 Ni을 활성물질로, 우수한 산소 저장능력과 높은 산화?환원 특성을 지닌 CeO₂를 담체로 하여, 함침법과 우레아법으로 촉매를 제조하였다. 반응은 고정층 반응기를 이용하여 1 atm, 650~800℃에서 실시하였다. 표면적 측정 장치를 이용하여 촉매 제조법에 따른 표면적 차이를 비교해 본 결과 우레아법으로 제조한 촉매가 함침법으로 제조한 촉매보다 표면적이 약 11배 이상 큼을 알 수 있었고, SEM으로 표면 구조를 조사해본 결과 우레아법으로 제조한 촉매가 훨씬 더 미세하고 균일함을 알 수 있었다. 우레아법으로 제조한 촉매가 함침법으로 제조한 촉매보다 더 높은 메탄 전환율 및 합성가스 선택도를 나타내었다. 본 반응의 문제점인 탄소 침적을 줄이기 위하여 La을 첨가하여 탄소 침적에 미치는 La의 영향을 알아보았다. TGA(열중량 분석기) 분석 결과 La이 첨가되지 않은 촉매에는 약 16%의 탄소 침적이, La을 첨가한 촉매에는 약 2%의 탄소 침적이 형성되었다. 따라서 La 첨가는 탄소 침적을 줄여서 촉매 비활성화를 막은것으로 추정된다. Synthesis gas was produced by the partial oxidation of methane. For the preparation of catalysts, Ni, known to be active in this reaction and cheap, was used as the active component and CeO₂, having high oxygen storage capability and high redox ability, was used as the support. The catalysts were prepared by the impregnation and urea methods. The catalyst prepared by the urea method showed about 11 times higher surface area and finer particle size than that prepared by the impregnation method. The catalysts prepared by the urea method showed higher methane conversion and synthesis gas selectivity than that prepared by the impregnation method. In this reaction, carbon deposition is a problem to be solved, so La was added to the catalyst system to reduce the carbon deposition. TGA analysis results showed that there was 2% carbon deposition with La-added catalysts and 16% with La-free catalysts. It was found that the addition of La decreases the amount of carbon deposition and prevents catalyst deactivation.

메탄 부분산화반응 Ni/CeO2 촉매에 La 첨가의 영향

천한진 ( Han Jin Cheon ),신기석 ( Ki Seok Shin ),안성환 ( Sung Hwan Ahn ),윤철훈 ( Cheol Hun Yoon ),함현식 ( Hyun Sik Hahm ) 한국유화학회 2010 한국응용과학기술학회지 Vol.27 No.1

니켈 담지촉매를 이용한 합성가스 제조 시 담체의 영향

김상범 ( Kim Sangbeom ),박은석 ( Park Eun Seog ),천한진 ( Cheon Han Jin ),김영국 ( Kim Yeong Gug ),임연수 ( Im Yeon Su ),박홍수 ( Park Hong Su ),함현식 ( Ham Hyeon Sig ) 한국유화학회 2003 한국응용과학기술학회지 Vol.20 No.4

N/A Synthesis gas is produced commercially by a steam reforming process. However, the process is highly endothermic and energy intensive. Thus, this study was conducted to produce synthesis gas by the partial oxidation of methane to cut down the energy cost. Supported Ni catalysts were prepared by the impregnation method. To examine the activity of the catalysts, a differential fixed bed reactor was used, and the reaction was carried out at 750~850℃ and 1 atm. The fresh and used catalysts were characterized by XRD, XPS, TGA and AAS. The highest catalytic activity was obtained with the 13wt% Ni/MgO catalyst, with which methane conversion was 81%, and H_(2) and CO selectivities were 94% and 93%, respectively. 13wt% Ni/MgO catalyst showed the best MgNiO_(2) solid solution state, which can explain the highest catalytic activity of the 13wt% Ni/MgO catalyst.

니켈 담지촉매의 니켈 담지량에 따른 활성 변화

김상범 ( Kim Sang Beom ),박은석 ( Park Eun Seog ),천한진 ( Cheon Han Jin ),김영국 ( Kim Yeong Gug ),김명수 ( Kim Myeong Su ),박홍수 ( Park Hong Su ),함현식 ( Ham Hyeon Sig ) 한국유화학회 2003 한국응용과학기술학회지 Vol.20 No.3

N/A Syntheses gas is commercially produced by a steam reforming process. However, the process is highly endothermic and energy-consuming. Thus, this study was conducted to produce syntheses gas by the partial oxidation of methane to decrease the energy cost. Supported Ni catalysts were prepared by the impregnation method. To examine the activity of the catalysts, a differential fixed bed reactor was used, and the reaction was carried out at 750~850℃ and 1 atm. The fresh and used catalysts were characterized by XRD, XPS, TGA and AAS. The highest catalytic activity was obtained with the 13wt% Ni/MgO catalyst, with which methane conversion was 81%, and H_(2) and CO selectivities were 94% and 93%, respectively. 13wt% Ni/MgO catalyst showed the best MgNiO_(2) solid solution state, which can explain the highest catalytic activity of the 13wt% Ni/MgO catalyst.

합성가스 제조에서 탄소의 침적

김영국,김상범,천한진,함현식 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - Synthesis gas was produced by the partial oxidation of methane, and carbon deposition in the synthesis gas production was investigated. The catalysts used were supported Ni catalysts and they were prepared by the impregnation method. The reaction was carried out at 1 atm, 750℃, and CH_4:O_2 = 2:1. The highest catalytic activity was obtained with 13wt% Ni/MgO catalyst 750℃ and 150mL/min of total flow rate. The lowest carbon deposition was obtained at 750℃ and 100mL/min of total flow rate.

니켈촉매를 이용한 메탄의 부분산화에 의한 합성가스 제조

김상범,신기석,박은석,곽윤철,천한진,함현식 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.1

메탄의 부분산화에 의하여 힙성가스를 제조하였다. 촉매는 니켈 담지 촉매를 사용하였으며, 담지된 니켈의 양은 10-15 wt%이었다. 담체로는 BaO, CaO, MgO를 사용하였다. 촉매는 함침법으로 제조하였으며, 반응은 CH_4:O_2의 비가 2:1, 1 atm, 750℃에서 수행하였다. 반응결과, MgO를 담체로 사용하였을때 가장 좋은 촉매활성을 보여주었으며, 니켈의 담지량이 13 wt%일때 촉매의 활성이 가장 좋았다. 이 13 wt% Ni/MgO 촉매의 경우 80%의 메탄 전화율과 93% 및 94%의 CO 및 H_2 선택도를 각각 얻을 수 있었다. 또한 이 촘매는 약 180시간 정도의 반응 후에도 촉매의 활성이 감소하지 않았다. 논란 중인 반을 기구에 대하여 조사해 보기 위하여 펄스방식으로 반응물을 투입하며 촉매 상 · 하층의 온도를 측정하였고, 반응시간에 따른 반응물과 생성물의 몰수 변화, 그리고 O_2-TPD 실험을 수행하였다. 그 결과 메탄으로부터 합성가스가 생성되는 경로는 2단계반응으로써 메탄이 완전 산화되어 CO_2와 H_2O가 생성되고, 이 생성된 CO_2 및 H_2O가 미반응 메탄과 각각 개질반응을 하여 합성가스가 생성됨을 알 수 있었다. Synthesis gas producution by partial oxidation of methane has been investigated using BaO, CaO and MgO supported Ni catalysts. The catalysts were prepared by the impregnation method. The reaction was carried out at I atm, 750℃, and CH_4:O_2=2:1. The highest catalytic activity was obtained with MgO support when Ni loading was 13 wt%. With the 13 wt% Ni/MgO catalyst, methane conversion was 80%, and CO and H_2 selectivities were 93% and 94%, respectively. The activity of the catalyst remained nearly constant after 180h of the reaction. To investigate the reaction mechanism of this reaction, the temperature of the actalyst bed at top and products were determined with time; and O_2-TPD experiment was carried out. From the results, it is deduced that the reaction takes place by a two-step reaction-first, total oxidation of methane to CO_2 and H_2O takes place, and then the produced CO_2 and H_2O are further reacted with CH_4 to give synthesis gas.

수용성 아크릴 점착제의 점착특성 및 응용

곽윤철,박지영,신기석,박은석,천한진,김상범,함현식 한국공업화학회 2002 응용화학 Vol.6 No.2

Acrylic pressure sensitive adhesives are prepared by emulsion polymerization of butyl acrylate(BA), butyl methacrylate(BMA), and acrylonitrile(AN). No cross-linking agent was used. However, to make cross-linking in the course of polymerization, acrylic acid(AA) and 2-hydroxy ethyl methacrylate (2-HEMA) were used. The PSAs synthesized were suitable for automotives, and by introduction of BMA, water resistance was increased. With the increase in degree of cross-linking, tensile strength increased, and the films of the PSAs were easily removed by peeling, moreover, heat resistance was also increased.

니켈촉매를 이용한 메탄의 부분산화에 의한 합성가스 제조

함현식,김상범,신기석,박은석,곽윤철,천한진 한국공업화학회 2002 응용화학 Vol.6 No.2

Synthesis gas was produced by the partial oxidation of methane with using supported 10~15 wt% Ni catalysts. The highest catalytic activity was obtained with MgO support when Ni loading was 13 wt%. With the 13 wt% Ni/MgO catalyst, methane conversion was 80%, and CO and H_2 selectivities were 93% and 94%, respectively. The activity of the catalyst remained nearly constant after 180 h of the reaction. To investigate the arguing reaction mechanism of this reaction, the temperature of the catalyst bed at top and bottom of the bed were measured with pulses of the reactants (CH_4:O_2 = 2:1); the changes in the moles of the reactants and products were tested with time; and O_2-TPD experiment was carried out. As a result, it is found that the reaction takes place by a two-step reaction - first, total oxidation of methane to CO_2 and H_2O takes place, and then the produced CO_2 and H_2O are further reacted with CH_4 to give synthesis gas.