scholarly journals Pembuatan dan uji aktivitas katalis htsc berbasis besi oksida

2018 ◽  
Vol 6 (3) ◽  
pp. 699
Author(s):  
Fitri Rumiani ◽  
S Subagjo
Keyword(s):  
High Temperature ◽  
Surface Area ◽  
Catalyst Surface ◽  
Catalyst Activity ◽  
Nitrate Solution ◽  
Fixed Bed ◽  
Great Influence ◽  
Temperature Shift ◽  
Fixed Bed Reactor ◽  
Preparation Procedure

High temperature shift conversion is a water gas shift reaction using water to produce carbon dioxide and hydrogen in high temperature (370-400oC). The aim of this research is examining the preparation procedure of HTSC catalyst. The catalyst made by Co-precipitation method of Fe and Cr nitrate solution with Na2CO3 as precipitating agent. The specific surface area of catalyst is determined by BET method. The crystal structure was analyzed by XRD method. The catalyst activity was evaluated in the fixed bed reactor on laboratory scale with 370oC and 1 atm. The result shows that the preparation procedure of HTSC ITB catalyst is reproducible. Based on the preparation procedure, calcinations temperature has a great influence to the catalyst surface area. The calcinations temperature at 300oC gave the highest catalyst surface area (198 m2/g), and it is comparable with the surface area claimed by Jennings (200 m2/g). The catalyst has also the highest activity by means of CO conversion resulted by the catalyst activity test (86%) which is larger than commercial catalyst conversion (81%)Keywords : Activity, Catalyst based on Fe/Cr, HTSC, Precipitation Abstrak High temperature shift conversion (HTSC) merupakan reaksi pergeseran CO menggunakan air menjadi CO2 dun H2 yang diselenggarakan pada temperatur tinggi (370-400oC). Penelitian ini bertujuan untuk mendapatkan resep dan prosedur pembuatan katalis HTSC. Katalis dibuat dengan metode kopresipitasi larutan garam nitrat dart Fe dan Cr dengan Na2CO3 sebagai senyawa pengendap. Untuk mengetahui keberhasilan penelitian ini, dilakukan penentuan luas permukaan, struktur kristal, dan aktivitas katalis yang kemudian dibandingkan dengan katalis komersial. Luas permukaan spesiftk diukur menggunakan metode BET, sedangkan struktur kristal dianalisis menggunakan XRD. Uji aktivitas katalis dilakukan dalam reaktor fixed bed skala laboratorium pada 370oC dan 1 atm. Hasil penelt.tian menunjukkan bahwa pelaksanaan prosedur pembuatan katalis HTSC ITB sudah dapat diulangi dengan hasil yang sama (reproducible). Berdasarkan prosedur tersebut, temperatur kalsinasi sangat berpengaruh terhadap lnas permukaan katalis. Dalam rentang temperatur yang dipelajari (300-400oC), kalsinasi pada temperatur 300oC menghasilkan katalis dengan luas permukaan paling tinggi yaitu 192-198 m2/g. Makin tinggi luas permukaan katalis yang dihasilkan, makin tinggi aktivitas katalis tersebut. Katalis dengan luas permukaan 192-198 m2/g menghasilkan aktivitas paling tinggi, konversi CO yang dihasilkan adalah 86 %, sedikit lebih besar dari konversi katalis komersial (81 %).Kata Kunci : Aktivitas, HTSC, Katalis berbasis Fe/Cr, Prespitasi

scholarly journals MgO Dispersed on Activated Carbon as Water Tolerant Catalyst for the Conversion of Ethanol into Butanol

2019 ◽  
Vol 9 (7) ◽  
pp. 1371 ◽  
Author(s):  
Stefano Cimino ◽  
Jessica Apuzzo ◽  
Luciana Lisi
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Fixed Bed ◽  
High Water ◽  
Fixed Bed Reactor ◽  
High Dispersion ◽  
Water Tolerance ◽  
Butanol Yield

MgO supported on activated carbon (AC) with a load ranging from 10% to 30% has been investigated as catalyst for the conversion of ethanol into butanol at 400 °C in a fixed bed reactor at different GHSV. Catalysts have been characterized by XRD, SEM/EDX, and N2 physisorption at 77 K. The high dispersion of MgO into the pores of the support provides strongly enhanced performance with respect to bulk MgO. MgO/AC catalysts have been also tested under wet feed conditions showing high water tolerance and significantly larger butanol yield with respect to an alumina supported Ru/MgO catalyst. After wet operation, the increased surface area of the catalyst leads to better performance once dry feed conditions are restored.

Optimal catalyst activity profiles in pellets. 5. Optimization of the isothermal fixed-bed reactor

1986 ◽  
Vol 25 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Massimo Morbidelli ◽  
Alberto Servida ◽  
Sergio Carra ◽  
Arvind Varma
Keyword(s):  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor

scholarly journals Experimental and Computational Demonstration of a Low-Temperature Waste to By-Product Conversion of U.S. Oil Shale Semi-Coke to a Flue Gas Sorbent

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3195 ◽  
Author(s):  
Kathleen Dupre ◽  
Emily Ryan ◽  
Azat Suleimenov ◽  
Jillian Goldfarb
Keyword(s):  
Surface Area ◽  
Flue Gas ◽  
Oil Shale ◽  
Gas Adsorption ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ex Situ ◽  
High Temperature Treatment ◽  
Dynamics Modeling ◽  
Gas Treatment

The volatility of crude oil prices incentivizes the use of domestic alternative fossil fuel sources such as oil shale. For ex situ oil shale retorting to be economically and environmentally viable, we must convert the copious amounts of semi-coke waste to an environmentally benign, useable by-product. Using acid and acid + base treatments, we increased the surface area of the semi-coke samples from 15 m2/g (pyrolyzed semi-coke) to upwards of 150 m2/g for hydrochloric acid washed semi-coke. This enhancement in porosity and surface area is accomplished without high temperature treatment, which lowers the overall energy required for such a conversion. XRD analysis confirms that chemical treatments removed the majority of dolomite while retaining other carbonate minerals and maintaining carbon contents of approximately 10%, which is greater than many fly ashes that are commonly used as sorbent materials. SO2 gas adsorption isotherm analysis determined that a double HCl treatment of semi-coke produces sorbents for flue gas treatment with higher SO2 capacities than commonly used fly ash adsorbents. Computational fluid dynamics modeling indicates that the sorbent material could be used in a fixed bed reactor to efficiently remove SO2 from the gas stream.

Effect of Catalyst Synthesis Parameters on the Performance of CO2 Hydrogenation to Methanol over SBA-15 Supported Cu/ZnO-Based Catalysts

2020 ◽  
Vol 400 ◽  
pp. 159-169
Author(s):  
Sara F.H. Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Maizatul Shima Shaharun ◽  
Duvvria Subbarao
Keyword(s):  
Surface Area ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Methanol Production ◽  
Synthesis Conditions ◽  
Metal Loading ◽  
Synthesis Parameters ◽  
Metal Support Interaction ◽  
Active Metal

Bimetallic Cu-ZnO-based catalyst were systematically prepared via impregnation technique under controlled synthesis conditions of active metal loading, ratio of active metal Cu:Zn and synthesis pH. The effect of the synthesis condition on the performance of the Cu-ZnO supported catalysts with respect to the hydrogenation of CO2 to methanol in micro-activity fixed-bed reactor at 250°C, 2.25 MPa, and 75% H2/25%CO2 ratio. The synthesized catalysts were characterized by transmission electron microscopy (TEM) and temperature programmed desorption, reduction, oxidation and pulse chemisorption (TPDRO) and the surface area determination was also performed. The results demonstrate that the catalytic structure, activity, and methanol selectivity was strongly affected by the synthesis parameters. Increasing of synthesis pH from 1 to 7 shows better metal particles distribution, Cu desperation of 29%, higher BET surface area as well as Cu surface area, while further increasing on pH revealed on particles agglomeration and weak metal-support interaction. In addition, increasing of the active metal loading from 5 to 15 % resulted in dramatic increase in the conversion of CO2 and methanol production while further increase caused lower catalytic performance. Moreover, catalyst with total loading of 15%, Cu:Zn ratio of 70:30 synthesized at pH of 7 exhibit higher catalytic activity of 14%, methanol selectivity of 92%, and TOF of 1.24×103 s-1 compared with other catalyst prepared under various conditions

scholarly journals High‐Pressure High‐Temperature Transparent Fixed‐Bed Reactor for Operando Gas‐Liquid Reaction Follow‐up

2019 ◽  
Vol 42 (3) ◽  
pp. 655-660 ◽  
Author(s):  
Marisa De Sousa Duarte ◽  
Matthieu Rolland ◽  
Corinne Sagnard ◽  
Didier Suire ◽  
Frederic Flacher ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Liquid Reaction ◽  
High Pressure High Temperature

scholarly journals Stable Continuous Production of γ-Valerolactone from Biomass-Derived Levulinic Acid over Zr–Al-Beta Zeolite Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Clara López-Aguado ◽  
Marta Paniagua ◽  
Juan A. Melero ◽  
Jose Iglesias ◽  
Pablo Juárez ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Hydrogen Transfer ◽  
Zeolite Catalyst ◽  
Continuous Production ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Transfer Hydrogenation ◽  
Fixed Bed Reactor ◽  
Beta Zeolite ◽  
Thermal Regeneration

The one-pot conversion of biomass-derived platform molecules such as levulinic acid (LA) and furfural (FAL) into γ-valerolactone (GVL) is challenging because of the need for adequate multi-functional catalysts and high-pressure gaseous hydrogen. As a more sustainable alternative, here we describe the transfer hydrogenation of LA to GVL using isopropanol as a hydrogen donor over a Zr-modified beta zeolite catalyst in a continuous fixed-bed reactor. A stable sustained production of GVL was achieved from the levulinic acid, with both high LA conversion (ca. 95%) and GVL yield (ca. 90%), for over at least 20 days in continuous operation at 170 °C. Importantly, the small decay in activity can be advantageously overcome by the means of a simple in situ thermal regeneration in the air atmosphere, leading to a complete recovery of the catalyst activity. Key to this outstanding result is the use of a Zr-modified dealuminated beta zeolite with a tailored Lewis/Brønsted acid sites ratio, which can synergistically catalyze the tandem steps of hydrogen transfer and acid-catalyzed transformations, leading to such a successful and stable production of GVL from LA.

The Mo Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

2012 ◽  
Vol 229-231 ◽  
pp. 126-129 ◽  
Author(s):  
Yan Gao ◽  
Tao Luan ◽  
Tao Lv ◽  
Hong Ming Xu
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Catalytic Efficiency ◽  
Fixed Bed Reactor ◽  
Exhaust Gas ◽  
Impregnation Method ◽  
Gas Composition ◽  
Loading Effect ◽  
Tio2 Catalyst ◽  
Temperature Window

The V(1)-W(4.5)-Mo(x)/TiO2 catalysts was prepared by the incipient dry impregnation method. The catalyst samples were ground and sieved for 0.3~0.6 mm. The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of Mo enhanced the catalytic efficiency of V(1)-W(4.5)-Mo(x)/TiO2 catalysts at low temperature region, while lessened that at high temperature, especially at the temperature above 400 °C. Increasing the loading of Mo from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 78% to 99% and enlarged the temperature window of the catalyst. The acceptable NO conversion (>60%) was attained at temperature as low as 240 °C for V(1)-W(4.5)-Mo(7.5)/TiO2 catalyst. The presence of Mo promoted the N2O generation. The V(1)-W(4.5)-Mo(0)/TiO2 catalyst showed higher catalytic selectivity for NO compared to the catalysts loading Mo.

Effect of Cu-Doped ZnO Sorbents for Desulfurization

2017 ◽  
Vol 728 ◽  
pp. 335-340
Author(s):  
Amphon Nitthaisong ◽  
Sumittra Charojrochkul ◽  
Sutin Kuharuangrong
Keyword(s):  
Surface Area ◽  
Monoclinic Phase ◽  
Single Phase ◽  
Hexagonal Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Breakthrough Time ◽  
Small Grains ◽  
Doped Zno ◽  
Desulfurization Efficiency

The purpose of this work is to synthesize undoped and Cu-doped ZnO sorbents by citrate-gel method and compare desulfurization efficiency, particularly H2S, at 150°C and 300°C. The undoped ZnO result shows a single phase of hexagonal zincite while the CuO monoclinic phase appeared with ZnO hexagonal phase in Cu-doped compositions (denoted by ZCx where x = mol% of Cu). The microstructure and surface area have been investigated by SEM and BET, respectively. The surface area decreases with the amount of Cu and all of them have a porous structure with small grains. The desulfurization performance of all specimens have been investigated by fixed-bed reactor. The results from breakthrough time indicate ZC20 sorbent has highest sulfur sorption capacity at 300°C. The XRD results show ZnO and CuO in ZC20 can absorb sulfur and completely transform to ZnS, cubic CuS and hexagonal CuS at 300°C.

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