3D printed catalytic converters with enhanced activity for low-temperature methane oxidation in dual-fuel engines

Abstract

Catalytic converters with non-linear channel structures were prepared using 3D printing and tested in the oxidation of methane in a simulated dual-fuel engine exhaust stream. The design used a simple repeating angular offset between adjacent layers, which was sufficient to introduce complexity with minimal software programming. All 3D printed substrates were mechanically stable and, following washcoating with a composite catalyst, demonstrated higher catalytic activity in methane oxidation than a commercial honeycomb substrate.The methane conversion at e.g. 510 °C was 12.6% on the commercial sample, 72.6% for 90 °, 80.1% for both 30 ° and 45 °, and 89.6 % for the 60 ° oriented structures. This enhancement is attributed to the increased turbulence/mass transfer and surface area than are possible using conventional straight-channelled substrates.Computational fluid dynamics (CFD) analysis confirmed that the higher methane conversion over 3D printed substrates is due (at least partially) to its higher turbulence kinetic energy. Backpressures over the 3D printed structures were also experimentally measured and compared with the conventional honeycomb monolith.

A Novel Method of 3D Printing High‐Loaded Oxide/H‐ZSM‐5 Catalyst Monoliths for Carbon Dioxide Reduction in Tandem with Propane Dehydrogenation

“…However, the handful of reports that have compared fluid behavior over printed and powdered geometries strongly suggest that our theory is correct, as the open‐cell structure produces lesser entrance effects compared to powdered materials, thereby lowering contact time and enhancing catalyst stability. [ 47,48 ] Be that as it may, it is imperative that our newly‐formed monoliths be compared to their powdered analogs by such studies to better elucidate these effects. Nonetheless, because this work's novelty deals with developing and analyzing a new printing method for 3D catalysts—that is, direct ink writing of oxide/zeolite pastes without incipient impregnation to allow for increased loading—these experiments should be the target of their own work.…”

Review on Additive Manufacturing of Catalysts and Sorbents and the Potential for Process Intensification

“…Whilst this has its inherent disadvantages, many of the studies mentioned do realize significant process intensification. More specifically, the use of modelling to decide upon the ideal structure is reported for several of these applications (Chaparro-Garnica et al, 2020;Hajimirzaee and Doyle, 2020); a consideration which is mostly absent in the studies listed in Tables 1 and 2. At the same time, these works demonstrate that the highly regular structures with custom unit cells are able to provide quantitative benefits over the more randomly structured foams.…”

3D‐Printed Acidic Monolithic Catalysts for Liquid‐Phase Catalysis with Enhanced Mass Transfer Properties

“…[16][17][18] 3D printing monoliths allows a high flexibility in design, interlocking or hierarchical channels, tailored and enhanced transport properties like increased turbulence and improved fluid/surface contact. [7,14,[19][20][21] Additive manufacturing methods have already been successfully deployed in various research fields facilitating applications for microfluidic devices, [22] biomaterials, [23] electrochemical devices [24] and catalysis. [25][26][27][28][29] The specific printing process of fused deposition modelling (FDM) features melt extrusion and the deposition of various kinds of thermoplastic polymeric filaments.…”

“…Emerging fabrication methods such as 3D printing played a key role in promoting the design and research process in this field [16–18] . 3D printing monoliths allows a high flexibility in design, interlocking or hierarchical channels, tailored and enhanced transport properties like increased turbulence and improved fluid/surface contact [7,14,19–21] …”