Intensification of highly exothermic fast reaction by multi-injection microstructured reactor

Abstract

Microstructured reactors (MSR) with characteristic dimensions below 100 µm are warranted to maintain close to isothermal conditions when carrying out quasi-instantaneous highly exothermic reactions. Unfortunately, such small dimensions increase the risk of clogging, create high pressure drop and are costly to number-up. The multi-injection (MI) MSR, where one of the reactants is added stepwise along the reactor length, allows working with larger dimensions (diameter >500 µm) while maintaining good temperature control. Herein presented MI-MSR is made of low temperature co-fired ceramics (LTCC) with herringbone mixing structure inside the reactor channels and is shown to mix efficiently in a large range of Reynolds numbers Re = 20-130. The cyclization of pseudoionone is studied as a model of a highly exothermic fast reaction. The temperature profiles are characterized by a quantitative infrared thermography. The developed LTCC MI-MSR allows ∼8-fold reduction of hot spot temperature as compared to the adiabatic temperature rise. Moreover, ∼500-fold intensification is achieved as compared to the conventional semi-batch process with reduced solvent mass by a factor of 2 while attaining a yield of target product above 98%. n reaction order, [-]

Fine structuration of low-temperature co-fired ceramic (LTCC) microreactors

“…7c), suggesting that good mixing occurred there at a 0.47 m s −1 flow rate of feedstock (Re ≈ 75). 45 This application proves our LTCC microfabrication process as a fast, inexpensive and flexible method for developing liquid phase continuous flow channel reactors.…”

Removal of Cu2+ from Water Using Liquid‐Liquid Microchannel Extraction

“…In recent years, a new technique of liquid-liquid microextraction has been investigated by researchers due to some unique advantages offered by microchannels [15,16]. Compared to conventional extraction, liquid-liquid extraction in microchannels has faster mass transfer rates, a higher surface-to-volume ratio enabling intensified heat transfer to prevent thermal degradation, and a shorter diffusion distance improving the mass transfer performance [17][18][19][20][21][22][23][24][25].…”

Cyclization of Pseudoionone Catalyzed by Sulfuric Acid in a Microreactor

“…Moreover, microreactors can provide efficient mixing in the cyclization of PI, leading to a great reduction in sulfuric acid usage. Because of so many advantages, a lot of studies have been devoted to synthesizing ionone in microreactors [15][16][17]. BASF developed a microreactor system to handle the PI cyclization and achieved an effective improvement of the yield of ionone [15].…”

“…BASF developed a microreactor system to handle the PI cyclization and achieved an effective improvement of the yield of ionone [15]. Haber et al applied a multi-injection microreactor in the cyclization of PI, and distinct reduction of hot spot temperature could be achieved in the system [17]. Besides these studies, a deep understanding of the reaction characteristics in microreactors is still limited.…”