Effects of the internal structures of monolith ceramic substrates on thermal and hydraulic properties: additive manufacturing, numerical modelling and experimental testing

Abstract

Rigorous emission regulations call for more efficient passive control catalysts for exhaust gas aftertreatment without affecting the internal combustion process and CO2 emissions. Although the state-of-art ceramic honeycomb substrate designs provide high surface area and a degree of flexibility for heat and mass transfer adaptations, additional emission reduction benefits can be achieved when more flexible designs to provide effective thermal management are introduced. The conventional cordierite honeycomb substrates are manufactured by extrusion; therefore, only substrates with straight channels can be fabricated. This study aims to highlight any design limitations of conventional substrates by employing additive manufacturing as the main method of manufacturing diamond lattice structures using DLP (digital light processing) technology. Both conventional substrates and diamond lattice structures are studied numerically and experimentally for flow through resistance and temperature distribution. Numerical predictions and experimental results showed good agreement. The results show the increase of the axial temperature distribution for diamond lattice structures and a significant decrease of the pressure drop (38–45%) in comparison with the benchmark honeycomb with similar surface area.

Selective catalytic reduction of NO over hierarchical Cu ZSM-5 coated on an alumina foam support

“…A higher trade-off index for the catalyst support gives a higher conversion with a smaller pressure drop. 19,42 The trade-off calculations for this particular foam catalyst at 450 °C show the highest trade-off index at a Re of 18.…”

“…The surface area of α alumina foam of 1 m 2 g −1 increases to 55 m 2 g −1 on coating Cu ZSM-5-20 on alumina foam which results in a slight increase in pressure drop due to deposition of catalysts which resists the flow. 42 The friction factor coefficient evaluated from eqn ( 10) is fitted as shown in Fig. 16 for the Cu ZSM-5 foam catalyst.…”

Numerical Simulation of Sintering of DLP Printed Alumina Ceramics

“…Multiscale modelling can also be adopted in order to investigate the interactions at different scales and for evaluating cross-interactions, although even more modelling complexities have to be taken into account, starting from the various interactions that are present across the different scales. However, due to the particular interest that AM of ceramics has attracted, and due to its application to a huge variety of fields-including monolithic catalysts [29,30], aerospace, biomechanics, dentistry, microelectromechanical systems [31], and automotive ones, to mention only a few-it seems necessary to deepen the knowledge of AM techniques and their effects when applied to ceramics. This is particularly useful in the aerospace sector, since AM of ceramics is able to provide lighter, more detailed components with enormous structural strength, hardness, and temperature resistance.…”

Enhanced Fluid Dynamics in 3D Monolithic Reactors to Improve the Chemical Performance: Experimental and Numerical Investigation

“…In particular, a rising number of publications explore the rational design and preparation of 3D monolithic catalytic systems with nonconventional geometries. − The most common ones are the honeycomb monoliths with interconnected straight channels ,,,,, and also cross-channel structures. , More complex ones are honeycomb monoliths with asymmetrical channels either by a progressive decrease in the channel section along the monolith or by alternating wide and narrow channels . In addition, parallel channels with new cell morphologies, i.e .…”

“…In addition, parallel channels with new cell morphologies, i.e . diamonds, stars, waves, etc., and most disrupted like monoliths with a completely different internal periodic structure, such as tetrakaidecahedron, tetrahedron, cylinders, or diamonds, have been successfully fabricated.…”