• Clean Technology
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• v.28 no.4
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• pp.331-338
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• 2022

The objective of this study is to prepare bead-type and pellet-type Pt (1 wt%)/Kieselguhr catalysts as hydrogenation catalysts for the polycyclic aromatic hydrocarbons (PAHs) included in pyrolysis fuel oil (PFO). The optimal reaction temperature to maximize the yield of saturated cyclic hydrocarbons during the PFO-cut hydrogenation reaction in a trickle bed reactor was determined to be 250 ℃. A hydrogen/PFO-cut flow rate ratio of 1800 was found to maximize 1-ring saturated cyclic compounds. The yield of saturated cyclic compound increased as the space velocity (LHSV) of PFO-cut decreased. The difference in hydrogenation reaction performance between the pellet catalyst and the bead catalyst was negligible. However, the catalyst impregnated by Pt after molding the Kieselguhr support (AI catalyst) showed higher hydrogenation activity than the catalyst molded after Pt impregnation on the Kieselguhr powder (BI catalyst), which was a common phenomenon in both the pellet catalysts and bead catalysts. This may be due to a higher number of active sites over the AI catalyst compared to the BI catalyst. It was confirmed that the pellet catalyst prepared by the AI method had the best reaction activity of the prepared catalysts in this study. The majority of the PFO-cut hydrogenation products were cyclic hydrocarbons ranging from C₈ to C₁₅, and C₁₁ cyclic hydrocarbons had the highest distribution. It was confirmed that both a cracking reaction and hydrogenation occurred, which shifted the carbon number distribution towards light hydrocarbons.

• Resources Recycling
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• v.13 no.3
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• pp.27-36
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• 2004

Nickel oxide was recovered through roasting of a spent catalyst for hydrogenation reaction. Nickel on Kieselguhr catalysts were prepared by a precipitation method after a treatment of the recovered-nickel oxide with an acid. Effects of roasting temperature of the spent catalyst on recovery of nickel oxide was investigated. Most of nickel oxide could be recovered through roasting of the spent catalyst at $1000^{\circ}C$. In regeneration of catalysts by the precipitation method after the treatment of nickel oxide with an acid, the effect of promoter, precipitation condition and reduction condition on catalytic performance in vegetable oil hydrogenation were investigated. The addition of CaO or $Ce_2$$O_3$ resulted in an increase of catalytic activity.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.236-236
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• 2004

삼중수소수 오염처리의 선행공정으로 적합한 전기분해-촉매교환 결합공정(CECE process)은 수소동위원소 산화물의 수소화 전환을 위한 전해셀과 다단 액상촉매 교환탑으로 이루어진 탈삼중수소 공정이다(그림 1). 촉매탑은 수소 흐름에 수증기를 동반하도록 하는 친수층과 수증기-수소간의 수소동위원소 교환반응을 유도하는 촉매층으로 구분되며, 탑 상부에는 수소의 산화 반응기 그리고 하부에는 물의 수소화 전해셀로 구성되어 있다(그림 2).(중략)

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1003-1007
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• 1999

The activity and products distribution for the hydrogenation of butadiene and pentadiene over the gold and cobalt catalysts prepared by coprecipitation and impregnation method was investigated with using a flow reactor under atmospheric pressure. The reaction characteristics of the highly dispersed gold particles and its role were studied. The activity of the gold catalyst by coprecipitation was much higher than that by impregnation. The selectivity of butene on all gold particles was always 100% even in the absence of butadiene in the stream, but butadiene on cobalt supported catalyst was easily hydrogenated to butane. It was therefore considered that the active sites at circumferences of the gold particles possessed an unique property which took a proper affinity to hydrogen. In the hydrogenation of butadiene and pentadiene, the percentages of 1-butene and 2-pentene were 60%~70% and about 62%, respectively. The results could be simply explained by a statistical concepts of hydrogen addition.

• Clean Technology
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• v.25 no.2
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• pp.101-106
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• 2019

The aim of this study is to investigate the feasibility of an Ni-SA catalyst, which was prepared from nickel, kieselguhr, and alumina, for the hydrogenation of triglyceride in a bench-scale reactor. Ni-SA powders were prepared by precipitating nickel precursors on a silica and alumina support. The powder was reduced in a hydrogen flow, mixed with a saturated palm oil, and then cooled to prepare an Ni-SA catalyst tablet. The sizes of NiO crystals of a commercial Pricat catalyst and the Ni-SA catalyst prepared in this study were $35{\AA}$ and $38{\AA}$, respectively. The pore volume and pore size of the Ni-SA catalyst was much larger than the pore volume and pore size of the Pricat catalyst. In addition, the average particle size of the Ni-SA catalyst was much smaller than that of the Pricat catalyst. The triglyceride hydrogenation reaction was carried out in a semi-batch reactor using catalysts impregnated with oil and molded into tablets. It was found that the Ni-SA catalyst was superior to the commercial Pricat catalyst in triglyceride hydrogenation, which could be ascribed to the raw material and the products being less influenced by the diffusion resistance in the pores of the Ni-SA catalyst. The Ni-SA catalyst prepared in this study has the potential to replace the Pricat catalyst as a catalyst for use in the commercial process for hydrogenation of triglyceride.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.787-791
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• 1995

중수형 원자력발전소의 중수는 중성자 흡수반응에 따라 그 일부가 삼중수소화 된다. 삼중수소의 제거반응에 효율적인 고분자 백금촉매를 제조하여 회분식 반응기에서 탈삼중수소 반응실험을 수행하였다. 기액접촉반응탑내에서 고분자 촉매는 탈삼중수소 반응에 유효한 활성이 있음을 확인하였다.

• Applied Chemistry for Engineering
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• v.1 no.1
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• pp.100-105
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• 1990

Small amounts of potassium were added to the titania - supported cobalt catalysts in order to produce higher and olefinic hydrocarbons in CO hydrogenation. Titania and potassium played important roles not only for the enhancement of the production of higher and olefinic hydrocarbons, but also for the prevention of the catalyst deactivation by carbon deposits. Titania support induced the so - called SMSI, and potassium seemed to act as an electronic modifier, giving rise to an electron enrichment of the metallic phase.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.455-460
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• 2019

Hydrotreating catalysis refers to a various hydrogenation which saturate an unsaturated hydrocarbon, together with removing heteroatoms such as sulfur, nitrogen, oxygen, and trace metals from different petroleum streams in a refinery. Most refineries include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate process streams, and/or residue. Among them, hydrotreating catalysis for residue are the core of the process, because of its complexity. This article reviews recent progress in tackling the issues found in the upgrading residues by hydrotreating, focusing on the chemistry of hydrodemetallization (HDM) and hydrodesulfurization (HDS). We also discuss the composition and functions of hydrotreating catalysts, and we highlight areas for further improvement.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.566-570
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• 2005

The study on the hydrogenation and isomerization of unsaturated bicyclic hydrcarbon compounds using methylcyclopentadiene dimer (MCPD) was carried out. Exo compound was prepared through isomerization reaction after two hydrogenation reaction steps. In the first hydrogenation reaction which needs one mole of hydrogen, the formation rate of monomer was increased as dimer was decomposed at reaction temperature above $100^{\circ}C$. At first hydrogenation, DHDMCPD [dihydrodi(methylcyclopentadiene)] was formed and second hydrogenation was proceeded to produce THDMCPD [tetrahydrodi(methylcyclopentadiene)], the ratio of exo to endo THDMCPD was varied by the control of 2nd hydrogenation temperature. To improve the process, continuous 1st and 2nd hydrogenation conditions were established by using the 2nd stage heat controllable reactor. Also, catalytic activities were compared by the use of halogenized aluminum, metal halides and solid acids catalysts on the isomerization reaction from endo to exo THDMCPD.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.380-383
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• 2006

수소는 미래의 청정에너지원이다. 수소를 생산하는 효과적인 방법으로는 탄소계촉매를 이용하여 부탄을 분해하는 것이다. 촉매는 카본블랙이 사용되었으며, $500{\sim}1100^{\circ}C$의 온도 범위에서 열분해 반응과 촉매분해반응이 수행되었다. 열분해의 경우 온도가 증가함에 따라 전화율이 증가하여 $800^{\circ}C$에서 98.9%로 부탄이 거의 분해되었으며, $900^{\circ}C$ 이상의 온도에서는 전화율이 100%까지 도달하였다. 부탄 분해반응에서 기대되는 생성물은 메탄, 에틸렌, 에탄, 프로필렌, 프로판 등이다. $1000^{\circ}C$이상의 온도에서는 부탄 촉매 분해반응에서 거의 대부분 수소와 메탄만이 관찰되었다. 특히 $500-1100^{\circ}C$까지 온도가 증가하였을 때 수소의 생성율은 꾸준히 증가하는 것으로 확인되었고 촉매분해반응이 촉매를 사용하지 않은 열분해반응보다 온도가 증가함에 따라 수소의 선택도를 더욱 향상시켜 보다 많은 수소가 생성되었으며, 반응성 실험이 진행되는 동안 촉매의 비활성화는 관찰되지 않았다. 반응전후의 촉매의 특성을 분석하기 위해 TEM 및 SEM 분석을 하였다. 반응전의 촉매는 매끈한 모양이었으나 $1000-1100^{\circ}C$에서 반응후에는 표면에 돌기모양을 형성하는 것을 관찰할 수 있었다.