Microwave‐Assisted Reaction Engineering: Microwave Apparatus at Mini‐Plant Scale with Online Analysis

Abstract

Communications cyclopentadiene by singlet oxygen has been chosen as a model reaction. The explosive endoperoxide, which is formed as an intermediate, was reduced to give 2-cyclopenten-1,4-diol (see Scheme 1), which is of pharmaceutical importance [8] and is produced as batch product where the explosive intermediate is formed in greater amounts [9,10].

Continuous flow-microwave reactor: Where are we?

“…To scale up chemical synthesis to kilogram scale, a pilot plant microwave reactor was built by MLS GmbH (ETHOS PILOT 4000) [22]. The system consists in a vertical tubular reactor of 0.88 L (700 mm length) placed on a multimode microwave cavity equipped with four magnetrons that deliver a microwave power up to 200 W and two truncated pyramids mode stirrers.…”

“…The system consists in a vertical tubular reactor of 0.88 L (700 mm length) placed on a multimode microwave cavity equipped with four magnetrons that deliver a microwave power up to 200 W and two truncated pyramids mode stirrers. This system can operate with a pressure up to 60 bar and 240 C with flow rates between 0.2-20 L/h [22,23]. Four IR sensors and two Ni-Cr/Ni thermocouples are used to record the temperature respectively along the tubular reactor and at the output of both the reactor and the cooler.…”

Development and Design of Reactors in Microwave‐Assisted Chemistry

“…In the last 5-10 years, several papers have been published with examples of scale-up under microwave-assisted conditions [94][95][96][97][98][99][100][101][102][103][104][105]. Of special interest were the topics of reaction optimization, the energy efficiency of microwave heating, and the challenge of scale-up.…”

“…MLS and the Jena group have together developed a microwave-based miniplant setup named Ethos Pilot (Figures 2.12 and 2.13). The Pilot 4000 system was characterized by Bierbaum and co-workers [104,110]: reaction products flow from the top (scale-up from grams to kilograms) into a water-cooled heat exchanger. In-line sensors permit continuous monitoring of the reaction temperature.…”

Development of microwave chemistry through a co-operation between a university and an equipment manufacturer

“…A common requirement associated with the introduction of new technologies, is the possibility to scale-up the respective process, fi rstly to a mini-plant scale and then to the production scale [47] .…”