scholarly journals Determination of pressure drop in a fixed bed catalytic reactor during ammonia oxidation on nanostructured catalyst

2021 ◽  
2017 ◽  
Vol 68 (7) ◽  
pp. 1496-1500
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ancuta Trifoi ◽  
Minodora Pasare ◽  
Ionut Banu ◽  
...  

Hydrodesulphurization of dimethyldisulphide was performed on Ni-Co-Mo /�-Al2O3 catalyst. The catalyst was characterized by determining the adsorption isotherms, the pore size distribution and the acid strength. Experiments were carried out on a laboratory echipament in continuous system using a fixed bed catalytic reactor at 50-100�C, pressure from 10 barr to 50 barr, the liquid hourly space velocity from 1h-1 to 4h-1 and the molar ratio H2 / dimethyldisulphide 60/1. A simplified kinetic model based on the Langmuir�Hinshelwood theory, for the dimethyldisulphide hydrodesulfurization process of dimethyldisulphide has been proposed. The results show the good accuracy of the model.


Author(s):  
A. Brito ◽  
M. E. Borges ◽  
R. Arvelo ◽  
F. Garcia ◽  
M. C. Diaz ◽  
...  

The transesterification reaction is the most utilized process to obtain biodiesel. Fried oil transesterification reactions with methanol have been studied using several zeolites Y and interchanged with CsCl and KOH. The reaction has been carried out both in a slurry reactor and a fixed bed catalytic reactor. The catalytic effects of zeolites have been tested within a temperature range of 60-476°C, 2.5-5% catalyst/waste oil weight ratio, and 6:1 - 100:1 methanol/oil molar ratio. Cosolvents (THF, n-hexane) in the reaction feedstock effect have also been studied as well as catalyst regeneration effects. Viscosity of both the oil and the transesterification reaction products was determined as an initial guide to investigate the degree of conversion to biodiesel as well as FAME content by GC. When interchanged zeolites are used conversions are improved, getting the best yields (98% FAME) for the Y756 zeolite interchanged with KOH. Viscosities of the reaction product obtained reached values next to diesel standard ones.


2021 ◽  
pp. 41-47
Author(s):  
B. Stepasiuk ◽  
◽  
T. Haievska ◽  
O. Spaska ◽  
Yu. Bilokopytov ◽  
...  

The paper is devoted to experimental development of method for 1,1,2-trichlorethane (TCE) dehydrochlorination (DHC). The economic and environmental issues of organic chlorinated compounds processing are described. The basic principle and possible products of TCE processing are presented. The DHC of TCE, which is one of the chlorinated organic wastes produced in the ethylene dichloride process, to vinylidene chloride (VDC) was carried out over over CaO, MgO supported on SiO2 and modified with CsCl catalysts. This process was carried out in a continuous flow fixed-bed reactor. The prepared catalysts were characterized by surface area and base properties before/after reaction. The methodology for determining properties of catalyst is described. Laboratory activity test apparatus was developed, and the schematic diagram is presented in the paper. The method of determination of TCE concentration of was calculated from its partial saturation vapor pressure at a given temperature is presented. Encouraging results were obtained on the catalyst containing 10 % CsCl/CaO·SiO2. The direction of the DHC reaction changed radically under described conditions: VDC was not formed at all and the major products were cis- and trans-1,2-dichloroethene. Interesting results were obtained with the catalytic system comprising 10 % (MgO-CsCl) (1:1) supported on SiO2. DHC of 2 % TCE/Ar at 302 °C proceeds quantitatively over 20 h with selectivity for VDC of more than 80%. These systems are suitable to study the factors providing the binding and removal of HCl from the reaction zone. A possible way to increase the selectivity for VDC is the creation of the conditions favoring the DHC of TCE into VDC by the radical mechanism, which was observed in experiments with 10% CsCl/CaSiO3. The directions for future researches are formulated and described.


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