Aldol condensation of butyraldehyde in the liquid phase catalysed by aluminium, iron and chromium sesquioxides

1979 ◽  
Vol 44 (8) ◽  
pp. 2384-2392 ◽  
Author(s):  
Lubomír Nondek ◽  
Jaroslav Málek

Aldol condensation of butyraldehyde catalysed by aluminium, iron and chromium sesquioxides has been studied in the liquid phase at temperatures from 160 °C to 210 °C, using a plug-flow stainless steel reactor. Relationships between the activity of the catalysts, surface concentrations of basic sites and the butyric acid concentration in butyraldehyde were determined. The catalytic activity depended both on the surface concentration of basic sites and on their basicity; the latter increased in the sequence Fe2O3 ##i Cr2O3 < Al2O3.

1982 ◽  
Vol 47 (7) ◽  
pp. 1838-1847 ◽  
Author(s):  
Martin Bajus ◽  
Jozef Baxa

Pyrolysis of tetraline, decaline, 1,1'-bicyclohexane, cyclohexylbenzene and gas oil was studied in stainless steel and quartz flow tubular reactors at 780 and 800 °C, residence time 0.08 to 0.5 s and at the mass ratio of steam to the raw material changing from 0.5 to 1.5. The effect of reaction temperature, the mass ratio of steam to the raw material, reactor material and of the added elemental sulphur on the yields of individual reaction products is reported. Of bicyclic hydrocarbons, condensed hydrocarbons are more stable than those with noncondensed rings, cyclanoaromates being more stable than bicyclanes. Pyrolysis of gas oil in the stainless steel reactor yields greater amounts of ethylene, propylene, butadiene and smaller amounts of methane and ethane, compared to the pyrolysis carried out under identical conditions in the quartz reactor. Elemental sulphur increases the conversion of gas oil into gaseous pyrolysis products.


1987 ◽  
Vol 52 (12) ◽  
pp. 2865-2875
Author(s):  
Josef Horák ◽  
Zdeněk Bělohlav ◽  
Petr Rosol ◽  
František Madron

Models have been used of the flow of the liquid phase in the reactor (cascade of two ideally mixed cells of different size, two equal-size cells with recycle, two equal-size cells with inlets to both cells and a model of two equal-size cells preceded with a back flow element with plug flow) to analyze the oscillatory states of an industrial reactor. Stable and instable steady states have been classified using analysis of pseudosteady states of conversion and temperature supplemented with a simulation of the dynamic behaviour. It has been that the deviations of the flow from an ideally mixed system may expand the region of the oscillatory behaviour. The detailed information about the character of the flow in the reactor and the way of feeding the reactor has been also found important for the analysis of stability.


2009 ◽  
Vol 23 (11) ◽  
pp. 5663-5676 ◽  
Author(s):  
Julien Gornay ◽  
Lucie Coniglio ◽  
Francis Billaud ◽  
Gabriel Wild

2012 ◽  
Vol 512-515 ◽  
pp. 2381-2385
Author(s):  
Xue Mei Zhang ◽  
Feng Xing Niu

We have successfully prepared a novel passivation Ni/HY catalyst by the technologies of macerate-precipitatio.The catalysts are comprised of two contents: HY as carrier, Ni as active component,and we put it into the process of preparating aromatic amines.The nature of the catalysts was discussed based on the characterization results of BET , IR , SEM , XRD , TEM ,TPD , XPS and TPR . The catalytic hydrogenation technology for 2,4-dinitrobenzene in liquid phase can be an attractive and elegant routine for production of 2,4-tolylenediamine. The catalytic activity is evaluated at 2.2 MPa, 90 °C, 750r/min, solvent with reaction materials mass ratio of 60, catalyst with reaction materials mass ratio of 0.1. In the catalytic test, The experimental results over the catalyst showed that 2,4-dinitrobenzene and 2,4-tolylenediamine conversion and selective of 99.88% and 99.16% were obtained respectively.It is found that the catalyst is highly dispersion, stable, and reusable. No obvious deactivation of the catalyst was observed after repeated using twelve times.


2017 ◽  
Vol 62 (3) ◽  
pp. 345-350 ◽  
Author(s):  
José Miguel Hidalgo-Herrador ◽  
Zdeněk Tišler

Two VOx/SBA-15 catalysts and three VOx/SiO2-fumed silica, with 5, 10 and 1, 5, 10 %wt. vanadium content respectively, were tested in a stainless steel continuous flow reactor for the partial oxidation of ethanol. The catalysts were tested at 150 – 300 °C. Products were analyzed by GC-FID, GC-OFID and GC-MS. The aim was exploring the problematics which could be found when more industrial close conditions are used. The total conversion of ethanol and selectivity to acetaldehyde were different than the expected ones. For VOx/SiO2-fumed silica, the total conversion was higher with a lower selectivity to acetaldehyde compared to VOx/SBA-15 catalysts.


Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 829 ◽  
Author(s):  
Zhang ◽  
Yuan ◽  
Miao ◽  
Li ◽  
Shan ◽  
...  

The side-chain alkylation of toluene with methanol was investigated over some Fe-modified Cs ion-exchanged X zeolite (CsX) catalysts prepared via the impregnation method using different iron sources. The absorption/activation behaviors of the reactants on the surface of the catalysts were studied by in situ Fourier-transform infrared (FT-IR) spectroscopy and temperature programmed desorption (TPD) mass measurements. Modification of CsX with a small amount of FeCl3 could result in a considerable decrease in catalytic activity, due mainly to the remarkable decrease in the density of acidic and basic sites of the catalysts. Interestingly, the Fe(NO3)3-modified CsX with an optimum Fe loading of 0.15 wt.% shows improved catalytic activity and high yield compared to the side-chain alkylation products. Modification of CsX with Fe(NO3)3 could also result in a decrease in basic sites of the catalyst. However, such a change does not bring an obvious negative effect on the adsorption/activation of toluene, while it could effectively inhibit the generation of the undesired bidentate formate. Furthermore, the introduced FeOx species (derived from the decomposition of Fe(NO3)3) may also act as new Lewis acidic sites to participate in the activation of methanol and to stabilize the formed active intermediates (i.e., unidentate formate). Therefore, modification of CsX with a suitable amount of Fe(NO3)3 may adjust its adsorption/activation ability for reagents by changing the acid–base properties of the catalyst, which can finally enhance the catalytic performance for the side-chain alkylation of toluene with methanol.


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