Microreactors with electrical fields

The use of electric fields in chemistry is considered an important concept of process intensification. The combination of electricity with chemistry becomes particularly valuable at smaller scales, as they are exploited in microreaction technology. Microreactor systems with integrated electrodes provide excellent platforms to investigate and exploit electric principles as a means to control, activate, or modify chemical reactions, but also preparative separations. One example which is discussed in detail in this chapter is a microplasma, which allows chemistry at moderate temperatures with species which have a reactivity comparable to that at very high temperatures, with potential advantages in energy efficiency. Another highlighted topic is electrokinetic control of chemical reactions, which requires the small scale to operate efficiently. Electrokinetic concepts can be used to control fluid flow, but also to transport or trap particles and molecules. Several less known concepts like electric wind, electric swing adsorption, electrospray, and pulsed electric fields, are discussed, as well as examples of their application. Novel principles to control adsorption and desorption, as well as activity and orientation of adsorbed molecules are described, and the relevance of these principles for the development of new reactor concepts and new chemistry are discussed.