The study of heat energy transfer through the porous structure of the intermetallide catalyst

Abstract

Abstract. Purpose. The purpose of the work is to find verified dependences for the calculation of heat and mass exchange processes in the porous structures of intermetallide catalysts, as well as to establish interdependences between the structure of the catalyst and its thermal characteristics. Methodology. The object of study was selected intermetallide catalysts of the Ni−Al system with a various granule filling scheme: in-line and staggered arrangement. To simulate the processes of heat and mass exchange, computer simulation with grid methods was used. To obtain experimental data, tests of a known composition of the catalyst obtained under thermochemical pressing were carried out. The catalytic activity and specific surface area of the catalyst obtained were evaluated. Findings. It was established that the staggered arrangement of the catalyst granules exhibits a large catalytic activity already in the initial period of time, its activity gradually increases with increasing temperature, reaching a maximum value in the investigated temperature range at T = 300 °C. The conversion of carbon monoxide at the staggered arrangement in the initial oxidation period exceeds NiAl 3 in-line arrangement by 1.3…1.5 times. However, the use of a staggered intermetallide catalyst backfill as a catalyst in the oxidation of carbon monoxide will be subjected to coking to much greater extent than a in-line backfill (high density of backfill), as a result of which it will be deactivated much faster. Originality. Research largely eliminates the gap formed between the practice of formation of thermophysical properties and information about changes in the structure and properties of intermetallide catalysts. Practical value. Research allows us to expand the scope of high-performance methods for producing porous intermetallide alloys in the technology of catalysts and to improve their quality.