What is Process Intensification?

Processes in the bulk chemical industry tend to be large. Chemical reactors and heat exchangers can have diameters of several meters, distillation columns can reach tens of meters high and a chemical plant in itself can occupy several square kilometers. Cost is the reason for this exceptional scale. Increasing the scale will reduce the specific cost of an installation. Per ton capacity a factory which is 100 times as large will require an investment which is only 10-20% of the cost per ton for a smaller plant.

Obtaining precise control by scaling-down

In each step in a chemical process we try to control the process conditions. By adding or removing heat we control the temperature. By mixing reactants and additives and removing products we create the right composition. Being able to control a process more precisely, is the important to make chemical processes less energy consuming. 
The increase in scale to reduce the specific investment comes at a cost, because maintaining precise control becomes more complicated as you scale-up. It is possible achieve a more or less uniform temperature distribution in a small reactor. But as a reactor becomes larger, temperatures differences within the reactor become larger, concentrations will vary. In other words, transport of heat and mass become an issue in scaled-up systems.

Typical PI solutions are:

•  to use (micro) structures to organize flows into predictable patterns
•   to integrating different processes on the millimeter scale
•  supply energy in more directly than by heat, for example using electromagnetic waves or vibrations.

An extensive overview of processes was made as part of the European Process Intensification Roadmap.