Mart H. J. M. de Croon

Recent Changes in Patenting Behavior in Microprocess Technology and its Possible Use for Gas–Liquid Reactions and the Oxidation of Glucose

The miniaturization of continuous processes has been of increasing interest in the past decade, and microreaction technology and flow chemistry have moved from academic and industrial research to commercial applications. With industry taking up such innovations, this trend is also reflected in the patenting behavior of companies active in this area. This review is a continuation of the review paper on microreactor patents published by Hessel et al. and indicates major changes in patenting trends since 2006. Moreover, a different patent database search algorithm is presented, which complements the algorithm explained in the previous review. In addition, the preservation of intellectual property is analyzed for multiphase reactions and particularly solid-catalyzed gas-liquid reactions in microreactors, which play an important role in the chemical and pharmaceutical industries and are reactions that benefit largely from microprocessing. Among other results, we show that the number of patents has increased in this field, with solid-catalyst design and deposition, control of the flow pattern, and ensured stable flow as the main challenges.

Advances in continuous crystallization : toward microfluidic systems

Abstract Continuous crystallization methods are reported in this review, with a particular focus on microfluidic systems. Advances in the nonmicrofluidic crystallization systems include multistage crystallization and intensifying the mixing of plug flow devices and generally improve the product quality and yield but do not resolve the scale-up issues. Microfluidic systems lead to an extremely reproducible particle production with numbering-up possibilities for large-scale applications. An overview of microfluidic devices is reported, focusing on the points of improvement and the challenges that still remain.

Design of a thick-walled screen for flow equalization in microstructured reactors

A systematic computational fluid dynamics (CFD) approach has been applied to design the geometry of the channels of a three-dimensional (thick-walled) screen comprising upstream and downstream sets of elongated channels positioned at an angle of 90° with respect to each other. Such a geometry of the thick-wall screen can effectively drop the ratio of the maximum flow velocity to mean flow velocity below 1.005 in a downstream microstructured reactor at low Reynolds numbers. In this approach the problem of flow equalization reduces to that of flow equalization in the first and second downstream channels of the thick-walled screen. In turn, this requires flow equalization in the corresponding cross-sections of the upstream channels. The validity of the proposed design method was assessed through a case study. The effect of different design parameters on the flow non-uniformity in the downstream channels has been established. The design equation is proposed to calculate the optimum values of the screen parameters. The CFD results on flow distribution were experimentally validated by Laser Doppler Anemometry measurements in the range of Reynolds numbers from 6 to 113. The measured flow non-uniformity in the separate reactor channels was below 2%.

Low Pressure Chemical Vapor Deposition as a Tool for Deposition of Thin Film Battery Materials

Low Pressure Chemical Vapor Deposition was utilized for the deposition of LiCoO2 cathode materials for all-solid-state thin-film micro-batteries. To obtain insight in the deposition process, the most important process parameters were optimized for the deposition of crystalline electrode films on planar substrates. Also the electrochemical activity of the obtained LiCoO2 films was demonstrated.

Towards High Energy Density 3D-integrated Lithium-ion Micro-batteries

To investigate the feasibility of a 3D integrated all-solid-state micro-battery, the deposition of several battery materials was investigated. Deposition techniques where used that are in principle able to deposit step conformally in 3D structures: ALD was used to create a conductive Pt current collector, and LPCVD was applied for the deposition of poly-silicon anodes and LiCoO2 cathodes. The layers, initially deposited on planar substrates, showed the expected physical and electrochemical behavior and are in principle suitable for solid state micro-batteries.