Surface Morphology of a Catalytic Wall Microreactor Constructed by Direct Metal Laser Sintering Process

Micro-reactors technology have attracted considerable interest in chemical processing due to their potential advantages regarding improvements on mass and heat transfer, smaller size, energy and cost saving and safety. Various types of micro-structured reactors have been developed in the last decade. Among them, the most promising concept considers stacked systems of channelled metallic platelets, coated with active catalysts. This systems are fabricated using any traditional tooling, but in this work a relatively new technology enabling that three-dimensional parts can be easily fabricated was used. It is based on DMLS (Direct Metal Laser Sintering), a process that uses a metal powder and a laser beam to produce directly metal parts. This process is one of a few Rapid Prototyping (RP) technologies which possess the capability to produce metal parts and prototype tools directly from powders with a high precision. In this paper a micro-channels plate was fabricated using DMLS process and micro-channels surface for catalyst deposition was evaluated. The results of SEM study reveal that a porous surface on the walls was formed because powder was not wholly sintered. For microchannels plate applied for gas-phase reactions this porous surface is especially interesting because the surface area is increased and the mass of catalysts impregnated on the walls can also be increased, which consequently improves the conversion of products. Thus, the DMLS not only can facilitates the rapid development of catalytic wall microreactors, but also permit the control of the structures formed during sintering which are extremely relevant for some processes in micro-reactors for gas and liquid phase.