Papers by Keyword: Micro Reactor

Abstract: A macro-micro modeling method was presented for simulating the phenomenon in three-dimensional micro reactor. This paper discusses the use of macro-micro modeling method to predict the concentration variation of various reactants in the reactor. The macro model was used to predict the overall behavior of the reactor. The micro model was used to predict the local behavior of the reactor. With the macro-micro modeling method, the computational efficiency has been significantly improved. The macro-micro modeling method will facilitate design of the micro reactor.

Abstract: How to keep combustion stability and less carbon deposit in micro-channel for the methane wet-air auto-thermal reforming combustion technology is a hot research area all over the world now. Even if there are some literatures with respect to this area, but there are many problems to keep studying. In this paper, the effects on the carbon deposit rule, hydrogen and methane conversion characteristics under lean oxygen at pressure have been studied below 973K by thermodynamic analysis with constant feed gas mass flow. Results show that the carbon deposit increases with increasing the temperature first, and then, it decreases. At the same time, the carbon deposit always decreases with increasing reaction pressure. At the different reaction pressure, the temperature zone of carbon deposit is changed, but the upper temperature limit is around 850K. H2 mass fraction and CH4 conversion ratio are raised with increasing the temperature, decreased with increasing the pressure. Adding pressure helps to reduce carbon deposit and maintain a certain H2 mass fraction and CH4 conversion ratio. All results show the reasonable reaction pressure is 0.2MPa in micro reactor.

Abstract: A thick film anemometer for in situ control of the flow rate in fluidic systems was designed, manufactured and characterized. The sensor is integrated in a retention modulus consisting of Low Temperature Cofired Ceramics (LTCC). These materials allow the cost-effective realisation of fluidic microsystems with integrated electronics. The challenge of the work is to design an anemometer under the exclusive use of thick film technologies. The necessity to trim resistors causes the external use of relevant pastes. Therefore, the use inside of a closed fluidic system requires the leak of process gases and, at the same time, a maximal heat-insulating of the sensor element from the substrate. Free-standing elements necessitate the control of stress due to shrinking mismatch, TCE mismatch, density gradients and deformation during the lamination. In the presented solution, embossed flue channels prevent blow forming on a free-standing bridge. The anemometer has a linear sensor characteristic for flow rates up to 0.1 ml/min. The layout guarantees that the fluid gets only in contact with the basic ceramic material, which is compatible with a wide range of biological substances. Therefore the sensor is applicable in contact with cell fluids or PCRreagents.

Abstract: Three synthesis procedures of Cu/ZnO catalyst for steam reforming of methanol were tested for loading in a micro reactor. The best procedure that resulted in the strong adhesion to the wafer was determined out of the tested procedures. The molecular structure of the synthesized catalyst was examined by XRD and its performance in methanol conversion was measured. A micro fabrication method that incorporates the catalyst loading and micro structure processing was developed. A MEMS methanol steam reformer was built by this process and the completed device resulted in methanol conversion of 93%.

Abstract: A microreactor is a continuous flow reactor, which can control reaction conditions precisely. We applied the microreactors to CdSe based nanocrystals synthesis and tuning particle size, optical properties. Furthermore, homogeneous coating of ZnS and its coating amount tuning was possible for optical properties improvement.