Transformation of Gaseous Technical Mixture of the Alkanes and Alkenes Into Liquid Fraction Over Ni-HZSM-5 Obtained by Ionic Exchange

2018 ◽  
Vol 69 (4) ◽  
pp. 938-943
Author(s):  
Iuliean Vasile Asaftei ◽  
Ion Sandu ◽  
Neculai Catalin Lungu ◽  
Adrian Florin Spac ◽  
Maria Ignat

Paraffin�s and olefins in the cracked naphtha can be transformed into aromatics and iso-paraffins to reduce the olefins content as well to improve the octane number of the gasoline commercial fraction. In this work Ni-HZSM-5 bifunctional catalyst was prepared by ion exchange with Ni(NO3)2 aqueous solution. The activity of Ni-HZSM-5 (wt.% 1.34% Ni) catalyst prepared by ion exchange method was investigated in the conversion of light hydrocarbons resulted as by-products of petroleum refining process (mixtures of butenes and (normal + iso) butanes as main components). The obtained Ni-based catalyst has been compare with HZSM-catalyst. The conversion experiments have been performed in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450oC, under 4 atm. (over Ni-HZSM-5) and 8 atm. pressure (over HZSM-5), respectively and at a space velocity (WHSV) of 1h-1. The catalytic activity of (Ni-HZSM-5 catalyst) monitored over 10 catalytic tests (with regeneration of catalyst after each test) using a mixtures butanes-butylenes. The catalytic activity and selectivity towards liquid products - BTX aromatic hydrocarbons and oligo(iC5-iC10, nC5-nC10, ] C10) - depends on time streaming, composition of butanes-butylenes mixture and pressure. In the first hours of each test the aromatic BTX are the main component of the liquid product (connected with butylenes consume) and after that, the oligo fraction become predominant. The initial aromatization process described as dehydrocyclodimerization of alkanes and alkenes, principally to aromatics BTX and molecular hydrogen, is accompanied by oligomerization, isomerization, cracking and alkylation processes to form finally in the liquid phase product an excessively mixture of iso- and normal - C5 -C10 and ] C10 aliphatic hydrocarbons.

2019 ◽  
Vol 70 (6) ◽  
pp. 2004-2009
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Maria Ignat ◽  
Ion Sandu

The Zn and Ni were introduced into HZSM-5 zeolite by ion exchange method with aqueous solutions of Zn(NO3)2 and Ni(NO3)2, to investigate the catalytic activity and selectivity of modified Zn-HZSM-5 and Ni-HZSM-5 catalysts for conversion of butane-butylenes technical mixtures in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450�C, at atmospheric pressure for Zn-HZSM-5 and at 4 atm. total pressure for Ni-HZSM-5 and at a space velocity (WHSV) of 1h-1. The catalysts were characterized using XRD, SEM, and NH3-TPD analysis for their structure, morphology and acidity. The catalytic activity of the same catalyst were examined during over 10 catalytic tests (with regeneration of catalyst after each test) using mixtures of butanes-butylenes.


2020 ◽  
Vol 4 (2) ◽  
pp. 678-690 ◽  
Author(s):  
Pranjal Gogoi ◽  
Atul S. Nagpure ◽  
Prabu Kandasamy ◽  
C. V. V. Satyanarayana ◽  
Thirumalaiswamy Raja

Ruthenium nanoparticles supported on NaY zeolite catalysts were synthesized by a simple ion exchange method.


2013 ◽  
Vol 781-784 ◽  
pp. 308-311 ◽  
Author(s):  
Xin Li ◽  
Wei Su ◽  
Qi Bin Xia ◽  
Zhi Meng Liu

Manganese and cerium based catalysts with different Mn/Ce molar ratios prepared by impregnation method for ethyl acetate oxidation. The activity tests of the samples were performed in a fixed-bed reactor. The effect of gas hourly space velocity (GHSV) and ethyl acetate concentration on the catalytic activity of the catalyst were also investigated. The results showed that these catalysts had high activity for the catalytic oxidation of ethyl acetate, of which the catalyst Mn0.9Ce0.1Ox/TiO2exhibitedthe bestactivity, and the temperature required for 90% conversion of ethyl acetate was at 216 °C. The catalyst Mn0.9Ce0.1Ox/TiO2still maintained high activity in the range of GHSV (16,500 to 48,500 h-1) and ethyl acetate concentration (4526 to 7092 mg/m3). In additional, experiments for measuring stability of Mn0.9Ce0.1Ox/TiO2were carried out, and experimental results showed that the good stability of Mn0.9Ce0.1Ox/TiO2was kept after it has run for 25 hours.


2011 ◽  
Vol 266 ◽  
pp. 151-156 ◽  
Author(s):  
Li Han ◽  
Jing Jing Xu ◽  
Qin Wang ◽  
Dong Yan Wei ◽  
Jian Feng Wang ◽  
...  

We have presented the synthesis and modification of L zeolite, and have further investigated the hydroisomerization of n-dodecane over the Pt/HL catalyst in a fixed bed reactor by changing reaction parameters such as temperature and pressure, respectively. The results showed that the combined use of ion-exchange, critric acid treatment and hydrothermal treatment could improve the Si/Al ratio of L zeolite dramatically while the high crystallinity was held. The Pt/HL catalyst showed higher stability, good regeneration property, catalytic activity and selectivity to the branched isomers under relatively low reaction pressures compared to the Pt/SAPO-11 catalyst.


2012 ◽  
Author(s):  
Nor Aishah Saidina Amin ◽  
Asmadi Ali

Mangkin zeolit HZSM–5 diubahsuai secara kaedah pertukaran ion berasid bagi menghasilkan mangkin zeolit Ga–HZSM–5. Aktiviti bermangkin bagi HZSM–5 dan Ga–HZSM–5 dikaji pada suhu tindak balas 800°C dan halaju ruang jaman masa (GHSV) 7500 jam–1. Mangkin HZSM–5 dan Ga–HZSM–5 dicirikan secara XRD, NMR, Penjerapan Nitrogen dan TPD. Hasil pencirian menunjukkan aluminium keluar dari kerangka asal. HZSM–5 yang mengandungi galium adalah mangkin yang lebih baik daripada mangkin zeolit HZSM–5 bagi menghasilkan cecair hidrokarbon. Kata kunci: Ga-HZSM-5; metana; pertukaran ion berasid; cecair hidrokarbon The HZSM–5 zeolite catalyst was modified by an acidic ion exchange method to produce the Ga–HZSM–5 zeolite catalyst. The catalytic activity of HZSM–5 and Ga–HZSM–5 were studied at reaction temperature of 800°C and gas hourly space velocities (GHSV) of 7500 hr–1. HZSM–5 and Ga–HZSM–5 catalysts were characterized by XRD, NMR, Nitrogen Adsorption and TPD. The characterization results revealed that aluminium was removed from the parent framework. Gallium loaded HZSM–5 is a better catalyst than HZSM–5 zeolite catalyst to produce liquid hydrocarbons. Key words: Ga-HZSM-5; methane; acidic ion exchange; liquid hydrocarbons


2020 ◽  
Vol 10 (7) ◽  
pp. 697
Author(s):  
Montri Thapplee ◽  
Chadaporn Krutpijit ◽  
Piyasan Praserthdam ◽  
ฺีBunjerd Jongsomjit

<p class="Mabstract">The catalytic ethanol dehydration to diethyl ether (DEE) over the synthesized beta zeolite (BEA) with different acidity on catalysts having Na and mixed Na-H forms was studied. The Na form of BEA catalyst was synthesized via the hydrothermal process, including non-calcined (Na-BEA_N) and calcined (Na-BEA_C) catalysts. The Na-BEA_C catalyst was successively used in the synthesis of different mixed Na-H forms under the ion-exchange method using the ammonium nitrate solution at 70°C for 2 h/cycle. In the present study, two different cycles were chosen, including one cycle (M-BEA_1) and four cycles (M-BEA_4) to compare the amount of acidity on catalysts. The results indicated that the M-BEA_1 catalyst exhibited a large surface area and contained the highest moderate acid site, which strongly affected the optimal catalytic activity at low temperature (&lt;250°C) with ethanol conversion of 74.6% and DEE yield of 27.3%. However, the increased number of ion-exchange cycles had not shown remarkable effects on catalytic activity due to low surface area and moderate acidity.<strong></strong></p>


2008 ◽  
Vol 9 (1) ◽  
pp. 106-110 ◽  
Author(s):  
Katsuhiro Ikeda ◽  
Yuki Kawamura ◽  
Takashi Yamamoto ◽  
Masakazu Iwamoto

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tuan Doan ◽  
Anh Dang ◽  
Dat Nguyen ◽  
Thanh Huyen Vuong ◽  
Minh Thang Le ◽  
...  

A series of Cu/ZSM-5, Fe/ZSM-5, and Cu-Fe/ZSM-5 catalysts (Si/Al in ZSM-5 = 25) were prepared by different metal loadings using the liquid ion-exchange method. Several characterization methods were conducted to explore the effects of metals on the physical and chemical properties of catalysts. Meanwhile, the electron paramagnetic resonance method is also used to assess the copper and/or iron elements’ coordination and valence state at intersections or in channels of ZSM-5. The metal-loading effects of all catalysts on the catalytic activities were studied for the removal of NOx in a fixed-bed flow reactor using selective catalytic reduction with ammonia (NH3-SCR). The results showed that the iron’s addition could markedly broaden the operation temperature range of the Cu/ZSM-5 catalyst for NH3-SCR between 200 and 550°C due to the presence of more isolated Cu2+ ions as well as additional oligomeric Fe3+ active sites and FexOy oligomeric species. This paper gives a facile and straightforward way to synthesize the practical-promising catalyst applied in NH3-SCR technology to control NOx emissions.


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