Micro-Reactor System for Complete Oxidation of Volatile Organic Compounds

Abstract

Based on previous Computational Fluid Dynamics (CFD) design results, an 11 channel microreactor of dimensions (0.5 mm × 0.5 mm × 100 mm) (width × depth × length) and optimal manifold geometry was fabricated, coated with a newly-developed Au/SBA-15 catalyst and then integrated in an experimental rig specifically built for this research. Propane (as model volatile organic compound) oxidation experiments were conducted at three different flow velocities, 12.5, 15.4 and 17.5 m/min, respectively, at six temperatures, 150, 200, 225, 250, 275, and 300 °C, respectively. The catalyst was prepared by one-pot sol-gel synthesis of SBA-15 with MPTMS (3-mercaptopropyl-trimethoxy-silane) before loading with HAuCl4 gold precursor and then characterized by SEM/EDX, TEM and wide angle XRD. A novel catalyst coating technique was developed, using airbrush (0.3 nozzle) to spray a catalyst slurry into the microchannels that produced a thin, firm and uniform layer of Au/SBA-15 catalyst coating inside the microreactor. The experimental measurements revealed that propane conversion increased as the flow feed rates decreased and increased with increasing temperatures in the reactor. For the built microreactor and for the flows and temperatures set, the combustion of propane was possible with measurable conversions and reasonable reactor stability, the performance of the catalyst appeared to be central to the satisfactory operation of the reactor.

Microreactor-based micro/nanomaterials: fabrication, advances, and outlook

“…This is due to the ability of microreactors to operate on the concept of small surface areas, which means that the frequency of molecular collisions is kinetically and significantly increased, ultimately speeding up the production of products. Broadly, these complex chemical reactions carried out in microreactors usually involve multiple phase states that do not mix, which can be divided into liquidliquid reactions 27,101,102 and gas-liquid reactions. [103][104][105] However, the mixing process in microchannels of small volume is not governed by the same laws as macroscale mixing but instead mainly occurs in chaotic advection and involves a laminar regime.…”

Combining computational fluid dynamics, photon fate simulation and machine learning to optimize continuous-flow photocatalytic systems

“…CFD can provide critical insights into the behavior of microreactors, allowing researchers to explore the effect of different geometrical configurations and operating conditions on the device performance, for example, emphasizing flow non-idealities. 66 This tool is essential for fully comprehending how chemical processes work to improve photochemical reactions. Questions about the mass transfer rates, the presence of dead zones, velocity fields, and radiation transport in microreactors can be answered.…”

Simultaneous oxidation of aromatic compounds using Sr‐doped lanthanum manganites as catalysts

“…Catalytic oxidation is the most effective technique for VOC oxidation into CO 2 , water, and other less harmful compounds 5 . It can be operated at lower temperatures than the thermal oxidation process (523–773 K or even lower in the presence of a suitable catalyst) and used for diluted effluent streams, which contain less than 1% of VOCs 11,12 . Transition metal oxides are being investigated as a promising and affordable alternative to noble metal‐based catalysts, especially Pt and Pd.…”

“…5 It can be operated at lower temperatures than the thermal oxidation process (523-773 K or even lower in the presence of a suitable catalyst) and used for diluted effluent streams, which contain less than 1% of VOCs. 11,12 Transition metal oxides are being investigated as a promising and affordable alternative to noble metal-based catalysts, especially Pt and Pd. Perovskite metal oxides stand out due to their variable and flexible composition, high thermal stability, and excellent redox properties.…”