One of the main tendencies of sustainable chemical engineering is to develop green technologies with the aim of eliminating pollution by preventing it in the first place

and thus

any breakthrough of single unit technology could make significant contributions to a new green technology. However

process engineering is a complex system which covers multiple units and sub-systems

including utilities

waste treatment and so on. Hence

besides single technology innovation

the whole chain covering raw material substitute

unit intensification and system should be highlighted during process development

and meanwhile considering the economic and environmental constraints. Also

along this chain

the novel materials/solvents and processes innovation are important for the process greening. On the base of the principles of system engineering and considering the research frontiers of the green process engineering

and taking new ionic liquids as key material

this article reviews the latest progresses in the aspects of raw material substitution

solvent innovation

transfer properties and process integration. The proposed viewpoints and methodology could become important bases to develop new green technologies

and also construct the science of green process system engineering subject.