A number of catalysts were prepared for the desulphurization process of tail gases. Their carrier was alumina oxide while
the active phase was manganese. The catalysts were being tested in an lab apparatus. The effect of calcination temperature
and process temperature of model gas (1 vol% of SO2+99 vol% of N2) were studied. The increase in the desulphurization temperature up to about 500°C causes the efficiency of the desulphurizing
yield to be increased, a further increase of the temperature process decreases the SO2 conversion. The DTA curves of catalysts after the desulphurizing process display the additional peak at a temperature of
about 900°C being, perhaps, responsible for deactivation of the catalysts.
Microcalorimetric studies of oxygen and hydrogen chemisorption during the last decade improved the understanding of the structure
and structural dynamics of supported bimetallic catalyst particles. For example, it was found that on graphitic supports two
different reduced surface compositions/structures can be created for base metal/noble metal particles. Appropriate treatments
“switch” the surface from almost pure reduced base metal to true alloy. Calorimetric studies also indicate support interactions
play a major role in controlling bimetallic particle surface structure. In contrast to behaviour found on graphitic supports,
iron/noble metal particles supported on refractory oxides apparently do not form alloy surfaces. The reduced surface is dominated
by the noble metal. Several studies indicate the value of the models of surface composition/structure developed using microcalorimetry
for predicting the activity/selectivity of bimetallic particles.
Authors:K. Wieczorek-Ciurowa, K. Gamrat, and Ju. Shirokov
A catalytic action of the mechanochemical products of copper hydroxocarbonate with calcium carbonate was investigated in n-butyl
alcohol oxidation tests. The solid products of high-energy milling were identified using thermogravimetry supplemented by
X-ray diffraction method. It was shown that the mechanical activation induces more effective tested catalyst because it promotes
the alcohol conversion at lower temperatures than that unmilled one.
A cracking catalyst designatedSRNY was manufactured from a commercialSRNY molecular sieve (M.S.). The support consisted of kaolin, clay and SiO2. The coking behaviour of theSRNY M.S., the support and the catalyst were examined with light diesel oil (LDO) as feedstock in a microreactor. The physico-chemical properties of both fresh and aged samples, subjected to or not subjected
to the cracking reaction ofLDO, were sequentially characterized by means of pore structure determination and thermal analysis. The pore structure included
the specific surface area and the pore volume or porosity. Thermal analysis methods used included TG and DSC.
The results indicated that all coked samples exhibited obvious changes in surface pore structure and acidity in comparison
with non-coked samples. Their specific surface area and acid amount decreased with increase in the coke content of the samples.
The apparent activation energy data obtained from decoking samples in an air flow, using the temperature-programmed oxidation
(TPO) method, showed that the kinetic parameters of theSRNY M.S. differed from those of theSRNY catalyst and its support.
Authors:K. V. Novikova, M. O. Kompanets, O. V. Kushch, S. P. Kobzev, M. M. Khliestov, and I. O. Opeida
calculated from the slope of the linear plots of the volume of oxygen uptake vs. time. All kinetic measurements were carried out by using freshly prepared samples.
The catalysts were characterized by comparison of their physical properties with those
Authors:Szabolcs Harnos, György Onyestyák, and Dénes Kalló
vegetable oil at moderate temperatures (300–420 °C) with hydrogen at elevated pressures (20–100 bar). Conventional hydrodesulfurization (HDS) catalysts, such as sulfided CoMo, NiMo, or NiW supported on alumina have achieved the complete conversion of
Acid catalysis plays a vital role in many important reactions of the chemical and petroleum industries, and environmentally benign chemical processes [ 1 – 3 ]. The use of liquid phase acid catalysts suffers from
Authors:Valeria Palermo, Ángel G. Sathicq, Patricia G. Vázquez, Horacio J. Thomas, and Gustavo P. Romanelli
variety of acid-catalyzed reactions such as esterification, etherification, olefin hydration, and dehydration of alcohols, and are also attractive as catalysts for oxidation processes [ 2 ]. Recently, we have used Keggin heteropolyacids in a range of