Energy-separating-agent processes

While heat is the most common energy-separating agent used. Table 2.3 provides examples of separation processes using gravitational, electric and magnetic fields. 

Separation processes use mass- and/or energy-separating agents to perform the separation. Mass-separating agents can be a solid, liquid or gas. Heat is the most common... 

Hence, at the level Reactor-Separators-Recycles the material balance can be brought in a narrow optimal region. On this basis can be started the process integration steps regarding the optimal management of energy, mass separation agents, process water, waste minimisation, etc. 

The topic covered in the 10 papers of the first section is commonly referred to as salt effect in vapor-liquid equilibrium and is potentially of great industrial importance. This salt effect leads to extractive distillation processes in which a dissolved salt replaces a liquid additive as the separating agent the replacement often results in a greatly improved separating ability and reduced energy requirements. Two papers in this volume, those by Sloan and by Vaillancourt, illustrate the use of such processing to concentrate nitric acid from its aqueous azeotrope. Nevertheless, the effect has not been exploited by industry to nearly the extent that would seem to be merited by its scientific promise. 

Since little is yet known about efficiency on the technical scale, future investigation should focus on (i) efficiency with respect to separation yield, energy demand and amount of mass separation agents required, (ii) long-term re-use options of auxiliary agents such as extractants or adsorbents and (iii) ease of scaling up. Furthermore, a crucial point for further development of regeneration will be to identify the pollutants that disturb the main process as well as their critical concentration levels in the electrodeposition process. 

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