New catalysts B–P–V–W–Ox/SiO2 of gas-phase condensation of acetic acid from formaldehyde to acrylic acid on an industrial carrier of stable chemical composition (colloidal silicon oxide, Aerosil A-200) were synthesized. It is shown that the hydrothermal treatment of the carrier allows to increase the activity and selectivity of the catalyst in the reactions of aldol condensation of acetic acid with formaldehyde.
he analysis of the actual air condition in the city of Kyiv in the areas of big overpasses and crossroads shows that the average annual concentration of formaldehyde more than 3 times exceeds the maximum permissible concentration (MPC) of this toxic substance. One of the most powerful sources of formaldehyde formation in the air of the city is motor vehicles. The role of weather factors in formaldehyde formation rate (K) depending on capacity of emissions of internal combustion engines has been analyzed in this article.
Cardanol-based novolac-type phenolic resin was synthesized with a mole ratio 1.0:0.5 of cardanol-to-formaldehyde using a dicarboxylic acid catalyst such as succinic acid. The cardanol-based novolac-type phenolic resin may further be modified by epoxidation with epichlorohydrin excess at 393 K in a basic medium to duplicate the performance of such phenolic-type novolacs. Carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) has been studied by various researches with diglycidyl ether of bisphenol-A (DEGBA) epoxy resin and epoxidized phenolic novolac resins.
Regularities of methanol oxidation by atmospheric oxygen on the catalyst Fe2(MoO4)3/MoO3/CaO = 1 : 0.7 : 0.3 have been studied. It was found that the speed of the process in a model flow reactor obeys the first order equation with the observed rate constant of 1.0 sec1 and the apparent activation energy of 65 kJ/mol. It was established that the selectivity of formaldehyde in the process with once-through conversion over 45 % sharply decreases.
The gas-phase photocatalytic oxidation of formaldehyde over illuminated amorphous titanium dioxide was investigated using a model flow reactor with the following experimental conditions: 0.1–0.5 l/min flow rate and an organic compound concentration range of 0.006–0.082 mol/m3. Mathematical model of the process which includes two sequential stages: formation of formic acid and its subsequent oxidation to CO2 was offered.