Thermal Conductivity of Composite Catalysts Containing Metallic Copper as a Reinforcing Component
Theoretical Foundations of Chemical Engineering
, E-ISSN: 1608-3431
Kutateladze Institute of Thermophysics SB RAS
Boreskov Institute of Catalysis SB RAS
The dependences of the electrical and thermal conductivities of porous composite materials containing a metallic component (copper) on the volume copper content are investigated experimentally. The measured thermal conductivities of samples prepared according to the proposed technique indicate that the thermal conductivity of monolithic catalysts with a copper content of no less than 15 vol % exceeds 1 W m−1 K−1. This corresponds to the formation of a connected cluster consisting of conducting spheres in a random packing of conducting and insulating spheres. A comparative analysis of the thermal and electrical conductivities of the composites demonstrates that, at a copper content of higher than 20 vol %, the thermal conduction through a percolation cluster formed by copper particles makes the dominant contribution. In employing composite materials containing a catalytically active component in exothermic catalytic processes (Fischer-Tropsch synthesis, steam conversion of carbon monoxide CO, etc.), their high thermal conductivity is an important advantage that makes it possible to decrease the temperature gradient across the porous composite catalyst bed. A semiempirical method for calculating the thermal conductivity of composites is developed. The results of the calculations performed using the proposed method are in good agreement with experimental data.