• Title/Summary/Keyword: Catalyst, ZSM-5

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Effect of SiC Crystal Phase on Growing ZSM-5 on the Surface of SiC (탄화규소 결정상의 종류가 탄화규소 표면에 ZSM-5가 형성되는데 미치는 영향)

  • Jung, Eunjin;Lee, Yoon Joo;Kim, Younghee;Kwon, Woo Teck;Shin, Dong-Geun;Kim, Soo Ryong
    • Korean Chemical Engineering Research
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    • v.53 no.2
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    • pp.247-252
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    • 2015
  • ZSM-5 crystals grew on the surface of ${\alpha}$-SiC and ${\beta}$-SiC particles by hydrothermal synthesis method. SiC particles which were > $50{\mu}m$ of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on ${\beta}$-SiC at $900^{\circ}C$ in air, and it was controlled to grow ZSM-5 grew from the ${\beta}$-SiC surface with $150^{\circ}C$ synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of ${\beta}$-SiC. When the synthesis temperature was $200^{\circ}C$, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.

A Study on DME Conversion rate using New Catalyst (신 촉매를 이용한 DME 전환율에 관한 연구)

  • Jeong, I.S.
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.2
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    • pp.123-128
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    • 2011
  • It has been stand high in estimation to converse from Carbon dioxide to Dimethyl Ether in new alternative fuel energy division in 21C, especially Using of DME in point of view of transportation fuel has been discussed of a new clean energy which is very lower of exhaust gas than gasoline and diesel energy. In this paper it is used ZSM-5 and I developed new catalyst by addition of cerium to control acidity. The new catalyst was proved high conversion rate, when it was conversed from methanol to DME, there wasn't any additional material except DME and water, and I overlooked reaction temperature, reaction time, amount of catalyst, amount of added cerium, effect of water content in methanol, reaction temperature by making change of reaction time. I have conclude that conversion rate to DME was increased as increased of catalyst amounts. The best catalyst condition of without additional product was treated poisoning from ZSM-5 to 5% cerium and new catalyst was not effected in purity of fuel methanol.

A Study on Optimization of Alumina and Catalysts Coating on Tube Reactor for Endothermic Reaction of n-Dodecane Under Supercritical Conditions (고온, 고압 조건에서 n-dodecane 액체연료의 흡열분해를 위한 관벽 내 알루미나 및 촉매 코팅 최적화 연구)

  • Kim, Sung Su;Lee, Sang Moon;Lee, Ye Hwan;Lee, Dong Yoon;Gwak, Ji-Yeong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.25 no.3
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    • pp.56-61
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    • 2021
  • In this study, Al2O3 and H-ZSM-5 were coated on the inner wall of the stainless steel tube for the stable use of liquid hydrocarbon fuel and an endothermic catalyst used as coolant for hypersonic flying vehicles. Coke production is inevitable by the endothermic decomposition reaction of the liquid hydrocarbon fuel, and Fe, Ni metals induce the production of the filamentous coke by using a stainless steel tube reactor as a cooling channel. By coating the stainless steel with H-ZSM-5, Fe and Ni metals are prevented from being directly exposed to the liquid hydrocarbon fuel, and the formation of the filamentous coke is inhibited. In addition, Al2O3 is coated between the stainless steel and H-ZSM-5 to enhance adhesion bond strength.

The Effects of Zeolite-Type Catalysts on the Pyrolysis Reaction of PP to Produce Fuel-oil (폴리프로필렌 수지 이용 연료유 생성을 위한 열분해 반응에서 제올라이트계 촉매의 영향)

  • Bak, Young-Cheol;Choi, Joo-Hong;Oh, Se-Hui
    • Korean Chemical Engineering Research
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    • v.50 no.3
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    • pp.442-448
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    • 2012
  • The effects of zeolite-type catalysts addition on the thermal decomposition of the PP resin have been studied in a thermal analyzer, a Pyrolyser GC-mass, and a small batch reactor. The zeolite type catalysts tested were natural zeolite, used FCC catalyst, and ZSM-5. As the results of TGA experiments, the pyrolysis starting temperature for PP varied in the range of $330{\sim}360^{\circ}C$ according to the heating rate. Addition of the zeolite type catalysts in the PP resin increased the pyrolysis rate in the order of used FCC catalyst> natural zeolite> ZSM-5 > PP resin. Adding the used FCC catalyst in the PP reduced most effectively the pyrolysis finishing temperature. In the PY-G.C. mass experiments, addition of zeolite type catalysts decreased the molecular weight of pyrolyzed product. In the batch system experiments, the mixing of used FCC catalyst enhanced best the initial yield of fuel oil, but the final yield of fuel oil was 2% higher in the case of mixing of natural zeolite. Also in the carbon number analysis, used FCC catalyst was the most useful one in this experiments for fuel oil.

Modification of H-ZSM-5 and γ-Alumina with Formaldehyde and Its Application to the Synthesis of Dimethyl Ether from Syn-gas

  • Joo, Oh-Shim;Jung, Kwang-Deog;Han, Sung-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1103-1105
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    • 2002
  • H-ZSM-5 and γ-alumina were treated with formaldehyde and sodium carbonate. The treatment increased the amounts of weak acid sites, removing strong acid sites. The maximum temperature of weak acid sites in their ammonia TPD spectra shifted in the direction of high temperature. The modified H-ZSM-5 and g-alumina were mixed with the methanol synthesis catalyst to perform dimethyl ether synthesis from syn-gas. The modified catalysts showed better selectivity to dimethyl ether, minimizing the reforming reaction to carbon dioxide. The maximum yield of 53.3% to dimethyl ether was achieved under the reaction conditions of 54.4 atm, 523 K, and the feed rate of 4500 Lhr-1 .gcat-1.

Acidic Properties of ZSM-5 Zeolite Catalyst (ZSM-5 제올라이트 촉매의 산성도)

  • Byoung Joon Ahn;Joon Ryeo Park;Hakze Chon
    • Journal of the Korean Chemical Society
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    • v.33 no.2
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    • pp.177-184
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    • 1989
  • Acidic properties of ZSM-5 zeolite catalysts were investigated by temperature-programmed desorption technique and ir spectroscopy. Ammonia t.p.d. pattern of HZSM-5 showed three different states, designated as ${\alpha}$,${\beta}$ and ${\gamma}$. The amount of ${\gamma}$-state decreased with increasing $SiO_2/Al_2O_3$ ratio, and upon cation-exchanging with alkali cations. From the ir adsorption spectra of absorbed pyridine and the reaction study of toluene alkylation, the ${\gamma}$-state could be explained to be due to the strong Bronsted acid sites of H-ZSM-5. Also they showed that the interaction between alkali cation-exchanged ZSM-5 and bases, i.e. $NH_3$ and pyridine, was increasing with decreasing the size of cations.

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A Study on the Catalytic Decomposition of Nitric Oxide over Cu-ZSM5 Catalysts (Cu-ZSM5 촉매상에서 일산화질소 분해반응에 대한 연구)

  • Park, Dal-Ryung;Park, Hyung-Sang;Oh, Young-Sam;Cho, Won-Ihl;Paek, Young-Soon;Pang, Hyo-Sun
    • Journal of Energy Engineering
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    • v.6 no.1
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    • pp.26-33
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    • 1997
  • Highly crystalline Cu-ZSM5 was prepared without using organic templates. Several ion exchange treatments between Na$\^$+/ and Cu$\^$2+/ brought about excess loading of copper ions on the ZSM5 zeolite and the resultant zeolite was active for the decomposition of NO. This indicates that the copper ions excessively loaded on the ZSM5 zeolite are effective for the NO decomposition. When oxygen was added to a reactants, the conversion of NO decreased. NO, O$_2$TPD experiments explained that the active sites for NO decomposition and the adsorption sites of O$_2$, were the same. O$_2$, at the surface of ZSM5 zeolite was desorbed incompletely after pretreatment at 500$^{\circ}C$, and CU-ZSM5 pretreated with H$_2$at 500$^{\circ}C$ showed promoted activity at the start of reaction. Thus, it seems clear that O$_2$, adsorbed ai the surface of catalyst inhibits the catalytic activity.

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Characterization based on the dispersion of metal/zsm-5 catalyst (금속/ZSM-5 촉매의 분산도에 따른 특성화 연구)

  • Cho, Sae-Jung;Lee, Hye-Min;Lee, Min-Joo;Lee, Ju-Hun;Han, Seung-Tak;Kim, Jin-Gul
    • Proceedings of the KAIS Fall Conference
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    • 2006.05a
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    • pp.561-564
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    • 2006
  • Fe, Co, Zn, Cu, Pt 등의 전이금속과 ZSM-5 2종($SiO_2/Al_2O_3$ 몰비: 23, 50)과 ${\gamma}-alumina$를 담체로 사용하여 촉매를 합성하였다. 합성방법은 CVD(화학기상증착법) 과 Dry Impregnation (건식함침법)방법이었다. CVD 방법으로 얻은 Fe/ZSM-5는 지지체로 사용된 ZSM-5의 $SiO_2/Al_2O_3$의 몰 비가 작을수록, 즉 산점의 수가 많을수록 Fe 담지 량이 증가하는 것으로 보인다. 등온 환원 온도 $400^{\circ}C$에서 수소 환원 양이 최대로 나타나며, 이는 보고되는 $400^{\circ}C$에서의 최대 NOx 제거 반응 속도와 비례하는 것으로 나타난다.

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Highly Selective Synthesis of β-Amino Carbonyl Compounds over ZSM-5-SO3H under Solvent-free Conditions

  • Massah, Ahmad Reza;Kalbasi, Roozbeh Javad;Samah, Neda
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1703-1708
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    • 2011
  • ZSM-5-$SO_3H$ efficiently catalyzed the one-pot three-component Mannich reaction of aldehydes, anilines, and ketones. ${\beta}$-Aminocarbonyl compounds were obtained in reasonable yields and excellent stereoselectivities when the reaction was carried out at room temperature under solvent-free conditions. Simple experimental conditions and product isolation procedure makes this protocol potential for the development of clean and environment-friendly strategy for the synthesis of ${\beta}$-amino-ketones. The catalyst was recovered and reused for subsequent runs.