Conversion of Methane Using Mo–MFI Zeolite Catalyst

2012 ◽  
Author(s):  
Nor Aishah Saidina Amin ◽  
Norzita Ngadi ◽  
Didik Prasetyoko
Keyword(s):  
Direct Synthesis ◽  
Synthesis Method ◽  
Packed Bed ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Packed Bed Reactor ◽  
Mfi Zeolite ◽  
Molybdenum Metal ◽  
Defect Sites ◽  
Temperature Programmed

HZSM-5 (Si/Al = 30), silikalit dan Mo-MFI dengan kepekatan logam molibdenum yang berbeza telah disintesis secara kaedah langsung. Sampel-sampel mangkin ini dicirikan dengan menggunakan teknik pembelauan sinar-X (XRD), Spektroskopi Inframerah Fourier Transformasi (FTIR) dan penjerapan suhu teraturcara bagi Ammonia (TPD-NH3). Prestasi pemangkinan sampel-sampel ini dijalankan di dalam reaktor aliran berterusan lapisan terpadat mikro. Kesan kandungan logam dalam mangkin terhadap penukaran metana dan kadar kepilihan terhadap produk dikaji. Hasil pencirian menunjukkan bahawa sampel-sampel tersebut adalah mempunyai struktur seperti MFI-zeolit dan logam molibdenum yang hadir berkemungkinan besar terletak di tapak cacat zeolit. Ubahsuaian zeolit dengan logam memberi kesan kepada peningkatan aktiviti pemangkinan. Keputusan eksperimen yang menggunakan Mo(0.1)-MFI menunjukkan kepilihan C1-oksigenat yang tinggi. Walau bagaimanapun, mangkin Mo-MFI didapati tidak sesuai untuk penghasilan gasolin. Kata kunci: MO-MFI, sintesis langsung, XRD, FTIR, TPD-NH HZSM-5 (Si/Al = 30), silicalite and Mo-MFI with different molybdenum concentrations were synthesized by direct synthesis method. The catalyst samples were characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and Temperature Programmed Desorption of Ammonia (TPD-NH3) techniques. The catalytic performance of the samples was evaluated in a continuous micro packed-bed reactor. The effects of metal content on methane conversion and products selectivity were investigated. Characterization results revealed that the samples were MFI-zeolite catalysts and the molybdenum metal most probably occluded in the defect sites of the zeolite. Modification of zeolite with metal resulted in the enhancement of catalytic activation. The experimental results using Mo(0.1)-MFI demonstrated a high selectivity of C1-oxygenates. However, Mo-MFI catalyst was found not suitable for gasoline production. Key words: MO-MFI, direct synthesis, XRD, FTIR, TPD-NH

scholarly journals Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

2017 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Yajing Zhang ◽  
Yu Zhang ◽  
Fu Ding ◽  
Kangjun Wang ◽  
Wang Xiaolei ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Co2 Hydrogenation ◽  
Precipitation Method ◽  
X Ray ◽  
Temperature Programmed ◽  
And Performance ◽  
Co Precipitation ◽  
Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

scholarly journals Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 497 ◽  
Author(s):  
Renata Sadek ◽  
Karolina A. Chalupka ◽  
Pawel Mierczynski ◽  
Jacek Rynkowski ◽  
Jacek Gurgul ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Tropsch Synthesis ◽  
Zeolite Catalysts ◽  
Beta Zeolite ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Liquid Products ◽  
Temperature Programmed

Co-containing Beta zeolite catalysts prepared by a wet impregnation and two-step postsynthesis method were investigated. The activity of the catalysts was examined in Fischer-Tropsch synthesis (FTS), performed at 30 atm and 260 °C. The physicochemical properties of all systems were investigated by means of X-ray diffraction (XRD), in situ XRD, temperature programmed desorption of ammonia (NH3-TPD), X-ray Photoelectron Spectroscopy (XPS), temperature programmed reduction of hydrogen (TPR-H2), and transmission electron microscopy (TEM). Among the studied catalysts, the best results were obtained for the samples prepared by a two-step postsynthesis method, which achieved CO conversion of about 74%, and selectivity to liquid products of about 86%. The distribution of liquid products for Red-Me-Co20Beta was more diversified than for Red-Mi-Co20Beta. It was observed that significant influence of the zeolite dealumination of mesoporous zeolite on the catalytic performance in FTS. In contrast, for microporous catalysts, the dealumination did not play such a significant role and the relatively high activity is observed for both not dealuminated and dealuminated catalysts. The main liquid products of FTS on both mesoporous and microporous catalysts were C10-C14 isoalkanes and n-alkanes. The iso-/n-alkanes ratio for dealuminated zeolite catalysts was three times higher than that for not dealuminated ones, and was related to the presence of different kind of acidic sites in both zeolite catalysts.

scholarly journals Membrane Reactor for Methanol Synthesis Using Si-Rich LTA Zeolite Membrane

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 505
Author(s):  
Masahiro Seshimo ◽  
Bo Liu ◽  
Hey Ryeon Lee ◽  
Katsunori Yogo ◽  
Yuichiro Yamaguchi ◽  
...  
Keyword(s):  
Methanol Synthesis ◽  
Membrane Reactor ◽  
Synthesis Method ◽  
Packed Bed ◽  
Zeolite Membrane ◽  
Packed Bed Reactor ◽  
Co2 Conversion ◽  
Experimental Conditions ◽  
Reaction Field ◽  
Lta Zeolite

We successfully demonstrated the effect of a membrane reactor for methanol synthesis to improve one-pass CO2 conversion. An Si-rich LTA membrane for dehydration from a methanol synthesis reaction field was synthesized by the seed-assisted hydrothermal synthesis method. The H2O permselective performance of the membrane showed 1.5 × 10−6 mol m−2 s−1 Pa−1 as H2O permeance and around 2,000 as selectivity of H2O/MeOH at 473 K. From the results of membrane reactor tests, the CO2 conversion of the membrane reactor was higher than that of the conventional packed-bed reactor under the all of experimental conditions. Especially, at 4 MPa of reaction pressure, the conversion using the membrane reactor was around 60%. In the case of using a packed-bed reactor, the conversion was 20% under the same conditions. In addition, the calculated and experimental conversion were in good agreement in both the case of the membrane reactor and packed-bed reactor.

Treatment of Urea Waste Water over Coconut Shell Activated Carbon Tethered Urease

2013 ◽  
Vol 295-298 ◽  
pp. 1359-1363
Author(s):  
Lei Wang ◽  
Sha Wang ◽  
Di Xiong ◽  
Chun Rong Xiong
Keyword(s):  
Waste Water ◽  
Activated Carbon ◽  
Packed Bed ◽  
Catalytic Performance ◽  
Relative Activity ◽  
Packed Bed Reactor ◽  
Coconut Shell ◽  
Temperature Range ◽  
Ph Range ◽  
Coconut Shell Activated Carbon

Urease was successfully tethered onto coconut shell activated carbon (AC) granules. Degradation of urea was carried out in packed bed over the tethered urease. For 75% of retained activity, the tethered urease shows a broader temperature range of 42~80°C, compared to 45~75°C for the free enzyme. Similarly, the tethered urease has an increased resistance against the changes of pH. For a relative activity of 80%, the free urease had a pH range of 6.2-7.4, while it was 6.5–8.0 for the tethered urease. The Km values of the free and tethered ureases were 22.60 mg/mL and 7.43 mg/mL, respectively. And the Vm values were actually very close (~23.5 mg/min ) for both the tethered and free ureases. The catalytic performance of the tethered urease was tested in a packed bed reactor. The relative activity was maintained over 80% after 50 h of running in degradation of urea.

Characteristics of integrated micro packed bed reactor-heat exchanger configurations in the direct synthesis of dimethyl ether

2013 ◽  
Vol 70 ◽  
pp. 77-85 ◽  
Author(s):  
Fatemeh Hayer ◽  
Hamidreza Bakhtiary-Davijany ◽  
Rune Myrstad ◽  
Anders Holmen ◽  
Peter Pfeifer ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Dimethyl Ether ◽  
Direct Synthesis ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Synthesis Of Dimethyl Ether
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