• Title, Summary, Keyword: Fischer-Tropsch

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Effects of Reaction Conditions on Cobalt-Catalyzed Fischer-Tropsch Synthesis: Interactions between Operating Factors

  • Ajamein, Hossein;Sarkari, Majid;Fazlollahi, Farhad;Atashi, Hossein
    • Journal of the Korean Chemical Society
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    • v.55 no.5
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    • pp.824-829
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    • 2011
  • In Fischer-Tropsch Synthesis, because of few reactants ($H_2$, CO), scarce operating parameters affected on efficiency especially the selectivity of products. In this research, effect of operating parameters on the selectivity of Co-Mn-$TiO_2$ Fischer-Tropsch synthesis catalyst were studied by design of experimental procedure and Taguchi method. According to this research, interactions between operating factors have a crucial effect on light products selectivity. Among these interactions, (temperature${\times}$feed ratio) has the main influence on light hydrocarbons selectivity. It was concluded that temperature and feed ratio ($H_2$/CO) were the most integral operating parameters for much greater selectivity of light hydrocarbons.

Effects of Cu and K Addition on Catalytic Activity for Fe-based Fischer-Tropsch Reaction (Fe계 Fischer-Tropsch 반응에서 촉매활성에 대한 Cu와 K의 첨가 효과)

  • Lee, Chan Yong;Kim, Eui Yong
    • Clean Technology
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    • v.25 no.1
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    • pp.1-6
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    • 2019
  • Effects of the Cu and K addition and the reduction condition of Fe-based catalysts for Fischer-Tropsch reaction are studied in a continuous flow reactor in this research. The catalysts for the reaction were prepared by homogeneous precipitation followed by incipient wetness impregnation. Physicochemical properties of the $Al_2O_3$ supported Fe-based catalysts are characterized by various methods including X-ray diffraction (XRD), temperature programmed reduction (TPR), and scanning electron microscopy (SEM). Catalytic activities and stabilities of the Fe/Cu/K catalyst are investigated in time-on-stream for an extended reaction time over 216 h. It is found that a reduction of the catalysts using a mixture of CO and $H_2$ can promote their catalytic activities, attributed to the iron carbides formed on the catalysts surface by X-ray diffraction analysis. The addition of Cu induces a fast stabilization of the reaction reducing the time to reach at the steady state by enhancement of catalytic reduction. The addition of K to the catalysts increases the CO conversion, while the physical stability of catalyst decreases with potassium loading up to 5%. The Fe/Cu (5%)/K (1%) catalyst shows an enhanced long term stability for the Fischer-Tropsch reaction under the practical reaction condition, displaying about 15% decrease in the CO conversion after 120 h of the operation.

Effect of Composition of γ-Al2O3/SiO2 Mixed Support on Fischer-Tropsch Synthesis with Iron Catalyst (철 기반 촉매의 Fischer-Tropsch 합성에서 γ-Al2O3/SiO2 혼합 지지체 조성의 영향)

  • Min, Seon Ki;No, Seong-Rae;You, Seong-sik
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.436-442
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    • 2017
  • Fischer-Tropsch synthesis is the technology of converting a syngas (CO+$H_2$) derived from such as coal, natural gas and biomass into a hydrocarbon using a catalyst. The catalyst used in the Fischer-Tropsch synthesis consists of active metal, promoter and support. The types of these components and composition affect the reaction activity and product selectivity. In this study, we manufactured an iron catalyst using ${\gamma}-Al_2O_3/SiO_2$ mixed support (100/0 wt%, 75/25 wt%, 50/50 wt%, 25/75 wt%, 0/100 wt%) by an impregnation method to investigate how the composition of ${\gamma}-Al_2O_3/SiO_2$ mixed support effects on the reaction activity and product selectivity. The physical properties of catalyst were analyzed by $N_2$ physical adsorption and X-Ray diffraction method. The Fischer-Tropsch synthesis was conducted at $300^{\circ}C$, 20bar in a fixed bed reactor for 60h. According to the results of the $N_2$ physical adsorption analysis, the BET surface area decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the pore volume and pore average diameter increase as the composition of ${\gamma}-Al_2O_3$ decreases except for the composition of ${\gamma}-Al_2O_3/SiO_2$ of 50/50 wt%. By the results of the X-Ray diffraction analysis, the particle size of ${\alpha}-Fe_2O_3$ decreases as the composition of ${\gamma}-Al_2O_3$ decreases. As a result of the Fischer-Tropsch synthesis, the CO conversion decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the selectivity of C1-C4 decreases until the composition of ${\gamma}-Al_2O_3$ was 25 wt%. In contrast, the selectivity of C5+ increases until the composition of ${\gamma}-Al_2O_3$ is 25 wt%.

Modeling of Liquid Hold-up in Fixed-bed Reactor for Fischer-Tropsch Synthesis (고정층 Fischer-Tropsch 반응기의 액상 왁스 정체 현상 모델링)

  • Park, Chansaem;Jung, Ikhwan;Park, Seongho;Na, Jonggeol;Kshetrimayum, Krishnadash;Han, Chonghun;Lee, Jong Yeol;Jung, Jongtae
    • Journal of the Korean Institute of Gas
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    • v.18 no.4
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    • pp.63-67
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    • 2014
  • Fischer-Tropsch synthesis mainly produces a wax which is a viscous liquid for long carbon chain. When a catalytic fixed-bed reactor is used for Fischer-Tropsch synthesis, the wax generated on a catalyst surface can keep adsorbing on the catalyst surface. This liquid hold-up causes significant pressure drop and clogging problems through the reactor. Thus, the model for liquid hold-up is required to design the size of reactor and catalyst particles. In this study, the liquid hold-up model considering structural and operational conditions was proposed based on empirical equations for convective mass transfer between the syngas flow and the wax-adsorbed catalyst. The developed model was validated by comparing with the experimental data from Knochen's work (2010). The influence of reactor length and coross section on the wax hold-up in reactor were analyzed and the optimal reactor size were proposed.

Kinetic Study of the Fischer-Tropsch Synthesis and Water Gas Shift Reactions over a Precipitated Iron Catalyst (철 촉매를 이용한 Fischer-Tropsch 합성 반응과 수성 가스 전환 반응에 대한 반응 속도 연구)

  • Yang, Jung-Il;Chun, Dong Hyun;Park, Ji Chan;Jung, Heon
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.358-364
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    • 2012
  • The kinetics of the Fischer-Tropsch synthesis and water gas shift reactions over a precipitated iron catalyst were studied in a 5 channel fixed-bed reactor. Experimental conditions were changed as follows: synthesis gas $H_2$/CO feed ratios of 0.5~2, reactants flow rate of 60~80 ml/min, and reaction temperature of $255{\sim}275^{\circ}C$ at a constant pressure of 1.5 MPa. The reaction rate of Fischer-Tropsch synthesis was calculated from Eley-Rideal mechanism in which the rate-determining step was the formation of the monomer species (methylene) by hydrogenation of associatively adsorbed CO. Whereas water gas shift reaction rate was determined by the formation of a formate intermediate species as the rate-determining step. As a result, the reaction rates of Fischer-Tropsch synthesis for the hydrocarbon formation and water gas shift for the $CO_2$ production were in good agreement with the experimental values, respectively. Therefore, the reaction rates ($r_{FT}$, $r_{WGS}$, $-r_{CO}$) derived from the reaction mechanisms showed good agreement both with experimental values and with some kinetic models from literature.

Setting-Up of a Fischer-Tropsch Catalyst Testing Apparatus (Fischer-Tropsch 觸媒試驗裝置의 試作)

  • Lee, Chai-Sung;Koh, Kwang-Gook
    • Journal of the Korean Chemical Society
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    • v.5 no.1
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    • pp.66-72
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    • 1961
  • A small size Fischer-Tropsch Catalyst testing apparatus, designed for an operating pressure of 150 psig, was test fabricated from ordinary schedule 40 iron pipes. The operability of the apparatus was tested by charging the reactor tube with the Lurgi Fischer-Tropsch iron Catalyst and passing through it the water gas obtained by gasifying the Korean anthracite using steam and oxygen. With the kind of catalyst charged, the apparatus was proven to daily produce about 50c.c. of synthetic greasy product, water and water soluble compounds, by running at a temperature of $250^{\circ}C$ and at a space velocity of 180 volume of gas per volume of catalyst/hr. About 20 consecutive days of operation is claimed to be sufficient for gathering an enough amount of synthetic products for such ordinary tests as distillation analysis, density measurement, iodine value determination etc. This trial fabrication of apparatus may be the first case of its kind in Korea in that the work has been conducted out in much a pilot plant scheme rather than a routine laboratory way which depends on small glass ware apparatus.

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Catalytic Performance of Iron-Based Fischer-Tropsch Catalysts Promoted by $SiO_2$ Using Different Sources ($SiO_2$ 원료물질에 따른 Fischer-Tropsch 합성반응용 Fe계 촉매의 성능변화)

  • Chun, Dong Hyun;Kim, Hak-Joo;Hyun, Sun-Taek;Lee, Ho-Tae;Yang, Jung-Il;Yang, Jung Hoon;Jung, Heon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.114.1-114.1
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    • 2010
  • Fe계 촉매는 FT(Fischer-Tropsch) 합성반응에 매우 유망한 촉매로 주목받고 있으며, $280^{\circ}C$ 미만의 저온 FT 합성반응의 경우, 침전법이 Fe계 촉매의 가장 전형적인 제조방법으로 알려져 있다. Fe계 촉매에 첨가되는 조촉매로는 Cu, K, $SiO_2$ 등이 가장 대표적이며, 이 중에서 특히 구조 조촉매로 첨가되는 $SiO_2$는 Fe계 촉매의 기계적 강도를 향상시킬 뿐만 아니라, 촉매의 성능에도 크게 영향을 미치는 것으로 보고되고 있다. 본 연구에서는 침전법을 이용하여 저온 FT 합성반응용 Fe계 촉매를 제조하였고, 구조 조촉매로 첨가한 $SiO_2$의 원료물질에 따른 Fe계 촉매의 성능변화를 조사하였다. $SiO_2$의 원료물질로는 콜로이드 $SiO_2$와 분말 $SiO_2$를 이용하였으며, 분말 $SiO_2$를 이용한 촉매가 콜로이드 $SiO_2$를 이용한 촉매보다 다소 높은 CO 전환율 및 중질탄화수소 선택도를 나타내는 것을 확인하였다.

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Fischer-Tropsch synthesis in the novel system: cobalt metallic foam catalyst and heat-exchanger typed reactor (코발트 금속 폼 촉매와 열교환형 반응기를 이용한 Fischer-Tropsch 합성 반응)

  • Yang, Jung-Il;Yang, Jung Hoon;Ko, Chang-Hyun;Kim, Hak-Joo;Chun, Dong Hyun;Lee, Ho-Tae;Jung, Heon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.133.2-133.2
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    • 2010
  • Fischer-Tropsch synthesis (FTS) was carried out in heat-exchanger typed reactor with cobalt metallic foam catalyst. Considering the heat and mass transfer limitations in the cobalt catalyst, a Co-foam catalyst with an inner metallic foam frame and an outer cobalt catalyst was developed. The Co-foam catalyst was highly selective toward liquid hydrocarbon production and the liquid hydrocarbon productivity at $203^{\circ}C$ reached to $52.5ml/(kg_{cat}{\cdot}h)$, which was higher than that obtained by the Co-pellet. Furthermore, the heat-exchanger typed reactor was developed to efficiently control the highly exothermic reaction heat. The reaction heat generated in the FTS reaction on the cobalt active site was easily transferred to reactor wall by the metallic foam in the catalyst and the transferred reaction heat was directly removed by the hot oil which circulated the wall side of the heat-exchanger typed reactor.

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Synfuel Production Technology : Catalyst for Fischer-Tropsch Synthesis (합성액화연료 생산 기술: Fischer-Tropsch 합성용 촉매)

  • Park, Jo-Yong
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.4
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    • pp.726-739
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    • 2013
  • Fischer-Tropsch synthesis (FTS) converts synthesis gas (CO and $H_2$) into longer chain hydrocarbons by a surface polymerization reaction. Cobalt- or iron-based catalysts normally show excellent activity for syngas conversion to petroleum products leading to super clean diesel fuels. The catalytic activities of the catalysts in FTS depend on the number of active sites on the surface. The number of active site was determined by the active metal particle size, loading amount, reduction degree and support-active metal interaction. The investigation adopts new methodology in preparing FT catalyst, which contains the controlled synthesis of active metal. The main focus of this paper is to give an overview of the types of catalysts, also including their preparation and reduction; the types of FT reactors; and also including the reaction conditions.

Effect of Template Existence on the Textural Properties of Iron-based Catalyst for Fischer Tropsch Reaction

  • Sirikulbodee, Papahtsara;Tungkamani, Sabaithip;Phongksorn, Monrudee;Ratana, Tanakorn;Sornchamni, Thana
    • International Journal of Internet, Broadcasting and Communication
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    • v.7 no.2
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    • pp.96-104
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    • 2015
  • Fischer Tropsch reaction is one of the interesting topic for renewable and clean energy. Polymerization of carbon monoxide or carbon dioxide with hydrogen over metal supported catalyst can produce long chain hydrocarbons. Synthetic liquid hydrocarbons are promising alternative to fossil fuels. This research work has been focused on the synthesis of Fe based catalyst for Fischer Tropsch reaction. Mesoporous silica (MS) support prepared by a precipitation method using two different washing solution, distilled water (DW) and acid in ethanol solution (ET), and different calcination temperature. Then, Fe/MS was prepared by an incipient wetness impregnation method. All of samples were systematically characterized using various physical and chemical techniques. TEM and XRD analysis were used to ensure that the cubic Ia3d mesostructure is stable after calcination. FTIR spectra are useful to ascertain the existence of template in the support. TPR studies were also used to understand the nature of Fe species and their reducibility. The results reveal that washing the support with distilled water and calcination at $550^{\circ}C$ can efficiently remove the triblock copolymer templates. The existence of template in the support affects the textural properties of all catalyst investigated.