• Title/Summary/Keyword: Catalyst regeneration

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Regeneration of TS-1 Catalyst During Phenol Hydroxylation(Calcination temperature dependence) (페놀의 수산화 반응에 사용한 TS-1 촉매의 효과적인 재생 방법(소성 온도 의존성))

  • Kwon, Song Yi;Yoon, Songhun;Um, Kyung Sub;Lee, Jae Wook;Lee, Chul Wee
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.679-683
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    • 2010
  • In this study, calcination temperature dependence of TS-1 catalyst was investigated in the hydroxylation of phenol with hydrogen peroxide during the regeneration of catalyst. Catalyst was regenerated 5 times by calcining at $550^{\circ}C$ and $700^{\circ}C$, respectively. When the catalyst was regenerated at $550^{\circ}C$ after 5th regeneration phenol conversion was decreased from 22.9% to 15.1% and at $700^{\circ}C$ after 5th regeneration phenol conversion was decreased from 22.9% to 18.8%. For formation ratio of catechol/hydroquinone was increased from 1.28 to 1.45 after 5th regeneration at $550^{\circ}C$, and from 1.28 to 1.20 after 5th regeneration at $700^{\circ}C$. The main reasons for deactivation of the catalyst were suggested by analyzing chemical/physical properties with XRD, UV-vis spectra, $N_2$ adsorption/desorption and TGA, and evaluating the catalytic activity such as phenol conversion and product selectivity.

Numerical Simulation of Catalyst Regeneration Process for Desulfurization Reactor (수치해석을 통한 탈황반응기용 촉매의 재생공정 분석)

  • Choi, Chang Yong;Kwon, Sang Gu;Liu, Jay;Im, Do Jin
    • Clean Technology
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    • v.23 no.2
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    • pp.140-147
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    • 2017
  • In this study, we performed numerical simulation for the catalyst regeneration process of diesel desulfurization reactor. We analyzed the changes in regeneration process according to purge gas flow rate, catalyst permeability, reactor size, and heat loss of reactor. We have found that the regeneration process is very much affected by temperature changes whereas it is hardly affected by catalyst permeability and porosity. We also estimated the regeneration time according to purge gas flow rate and initial temperatures and have found that increasing purge gas temperature is more effect for fast regeneration. The present results can be utilized to design a regeneration process of 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.

Catalyst-aided Regeneration of Amine Solvents for Efficient CO2 Capture Process

  • Bhatti, Umair H.;Sultan, Haider;Cho, Jin Soo;Nam, Sungchan;Park, Sung Youl;Baek, Il Hyun
    • Journal of Energy Engineering
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    • v.28 no.4
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    • pp.8-12
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    • 2019
  • Thermal amine scrubbing is the most advanced CO2 capture technique but its largescale application is hindered due to the large heat requirement during solvent regeneration step. The addition of a solid metal oxide catalysts can optimize the CO2 desorption rate and thus minimize the energy consumption. Herein, we evaluate the solvent regeneration performance of Monoethanolamine (MEA) and Diethanolamine (DEA) solvents without and with two metal oxide catalysts (TiO2 and V2O5) within a temperature range of 40-86℃. The solvent regeneration performance was evaluated in terms of CO2 desorption rate and overall amount of CO2 desorbed during the experiments. Both catalysts improved the solvent regeneration performance by desorbing greater amounts of CO2 with higher CO2 desorption rates at low temperature. Improvements of 86% and 50% in the CO2 desorption rate were made by the catalysts for MEA and DEA solvents, respectively. The total amount of the desorbed CO2 also improved by 17% and 13% from MEA and DEA solvents, respectively. The metal oxide catalyst-aided regeneration of amine solutions can be a new approach to minimize the heat requirement during solvent regeneration and thus can remove a primary shortfall of this technology.

Combined Application of Burner and Oxidation Catalyst for Diesel Particulate Filter Regeneration (DPF 재생을 위한 버너-산화촉매 복합 적용)

  • Shim, Sung-Hoon;Jeong, Sang-Hyun
    • Journal of the Korean Society of Combustion
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    • v.15 no.3
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    • pp.25-31
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    • 2010
  • Combined technique of burner and DOC has been used for regeneration of Diesel Particulate Filter. Experiments has been performed to increase the temperature of engine exhaust gas to burn the collected soot in DPF at all conditions of operation of 3 liter diesel engine. Ignition temperature of soot can be successfully obtained by heats of burner flame and residual fuel oxidation at diesel oxidation catalyst even in the condition of oxygen deficiency. It is found that the load of air compressor and heat loss can be reduced to the level of practical application. It is also found that CO and THC emissions are not increase by additional combustion of regeneration burner.

Effect of Hydrogen Ratio and Tin Addition on the Coke Formation of Platinum Catalyst for Propane Dehydrogenation Reaction (프로판 탈수소화 반응용 백금촉매의 코크 생성에 미치는 수소비와 주석첨가의 영향)

  • Kim, Soo Young;Kim, Ga Hee;Koh, Hyoung Lim
    • Clean Technology
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    • v.22 no.2
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    • pp.82-88
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    • 2016
  • The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

Regeneration of Spent Nickel Catalyst for Hydrogenation (수소화 반응용 니켈 폐촉매의 재생)

  • 전종기;박영권;김주식
    • 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.

Evaluation of Catalyst Deactivation and Regeneration Associated with Photocatalysis of Malodorous Sulfurized-Organic Compounds (악취유발 황화유기화합물질의 광촉매분해에 따른 촉매 비활성화와 재생 평가)

  • Jo, Wan-Kuen;Shin, Myeong-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.11
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    • pp.965-974
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    • 2009
  • This study evaluated the degradation efficiency of malodorous sulfurized-organic compounds by utilizing N- and Sdoped titanium dioxide under visible-light irradiation, and examined the catalyst deactivation and regeneration. Catalyst surface was characterized by employing Fourier-Transform-Infrared-Red (FTIR) spectra. The visible-light-driven photocatalysis techniques were able to efficiently degrade low-level dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) with degradation efficiencies exceeding 97%, whereas they were not effective regarding the removal of high-level DMS and DMDS, with degradation efficiencies of 84 and 23% within 5 hrs of photocatalytic processes. As compared with DMS, DMDS which containes one more sulfur element revealed quick catalyst deactivation. Catalyst deactivation was confirmed by the equality between input and output concentrations of DMD or DMDS, the obsevation of no $CO_2$ generation during a photocatalytic process, and the FTIR spectrum peaks related with sulfur ion compounds, which are major byproducts formed on catalyst surfaces. The mineralization efficiency of DMS at 8 ppm, which was a peak value during a photocatalytic process, was calculated as 144%, exceeding 100%. The catalyst regenerated by high-temperature calcination exhibited higher catalyst recovery efficiency (53 and 58% for DMDS and DMS, respectively) as compared with dry-air and humid-air regeneration processes. However, even the calcined method was unable to totally regenerate deactivated catalysts.

A Study on the Regeneration of Ni Catalyst for Hydrogenation (I) (수소첨가반응용 니켈 폐촉매의 활성재생에 관한 연구 (I))

  • Park, Paul Worn;Lim, Ki-Chul;Lee, Ho-In
    • Applied Chemistry for Engineering
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    • v.2 no.1
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    • pp.38-46
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    • 1991
  • Regeneration of Ni catalyst deactivated by carbon-deposition and sulfur-poisoning was studied. When a carbon-deposited catalyst was regenerated by hydrogen, the final recovery of catalytic activity for benzene hydrogenation was large but relatively long period of regeneration was required, and futhermore the deposited carbon could not be removed completely. In case of oxygen-treatment, the regeneration rate was high and the deposited carbon could be removed almost completely after a subsequent reduction treatment. When a sulfur-poisoned catalyst was regenerated by hydrogen and water vapor, the catalytic activity was not recovered. The regeneration treatment with oxygen at $650^{\circ}C$ recovered the catalytic activity up to 60 % of the initial value. When $Cl^-$ was added to oxygen, the activity was easily recovered to 45 % of the initial value even after treatment at $500^{\circ}C$. Sintering of the dispersed Ni particles was enhanced by water vapor but was hindered by oxygen and chlorine addition.

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A Study on the Regeneration Effects of Commercial $V_2O_5-WO_3/TiO_2$ SCR Catalyst for the Reduction of NOx (질소산화물 제거용 상용 $V_2O_5-WO_3/TiO_2$ SCR 폐 촉매의 재생 효과 고찰)

  • Park, Hea-Kyung
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.8
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    • pp.859-869
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    • 2005
  • The commercial $V_2O_5-WO_3/TiO_2$ catalysts which had been exposed to the off gas from incinerator for a long time were regenerated by physical and chemical treatment. The catalytic properties and NOx conversion reactivity of those catalysts were examined by analysis equipment and NOx conversion experiment. The characterization of the catalysts were performed by XRD(x-ray diffractometer), BET, POROSIMETER, EDX(energy dispersive x-ray spectrometer), ICP(inductively coupled plasma), TGA(thermogravimetric analyzer) and SEM (scanning electron microscopy). NOx conversion experiment were performed with simulated off gas of the incinerator and $NH_3$ was used as a reductant of SCR reaction. Among the regeneration treatment methods which were applied to regenerate the aged catalysts in this study, it showed that the heat treatment method had excellent regeneration effect on the catalytic performance for NOx conversion. The catalytic performance of the regenerated catalysts with heat treatment method were recovered over than 95% of that of fresh catalyst. For the regenerated catalysts with the acid solution(pH 5) and the alkali solution(pH 12), the catalytic performance were recovered over than 90% of that of fresh catalyst. From the characterization results of the regenerated catalysts, the specific surface area was recovered in the range of $85{\sim}95%$ of that of fresh catalyst. S and Ca element, which are well known as the deactivation materials for the SCR catalysts, accumulated on the aged catalyst surface were removed up to maximum 99%. Among the P, Cr, Zn and Pb elements accumulated on the aged catalyst surface, P, Cr and Zn element were removed up to 95%. But the Pb element were removed in the range of $10{\sim}30%$ of that of fresh catalyst.