While various companies and institutes (FRI, SRI, etc) will continue to make incremental performance improvements in internals, it sounds like you want to focus on really new technology.
I have a couple ideas for you that I have encountered in the last few years:
1) Fractionating condensers (i.e. dephlegmators) and other equipment which I can envision where the energy advantages of differential heat input can be exploited. Currently this technology seems to be applicable in high energy cost applications (cryogenic), but the theory is sound and if energy prices continue to increase I expect there may be further developments along these lines.
2) Reactive distillation which can have lower capital cost, energy usage, and better selectivity and yield over some conventional reactor-seperator technology. A lot of work has gone on in recent years with respect to how to hold solid catalysts in the distillation tower.
3) Divided wall designs are now common in the new chemicals processes of my company because one tower can generate 3 pure streams at a lower capital cost than two conventional towers.
4) Don't overlook the various innovations in distillation ancillaries. For example many of our newest columns are using platefin type internal condensers to reduce capital cost, and we have been experimenting with some innovative vacuum system designs, etc.
I have also seen some basic changes in seperation technologies involving shifts to (or from) distillation which might fall in the scope of your study. In my own experience we are replacing some liquid-liquid extraction technologies with heterogenous azeotropic distillations or extractive distillation with improved solvents. I also see in this forum that pervaporation and other membrane seperation technologies have come a long way, etc.
best wishes on your search,
sshep
