Application of nano-modified surfaces for fouling mitigation

Energy lost due to fouling of heat exchangers accounts for at least 2% of the total world energy production per year. The overwhelming proportion of these losses is compensated by additional consumption of fossil energy carriers. Not surprisingly, this comes with an enormous energy price-tag as well as considerable green-house gas emissions, acidification of water resources and release of chemical fouling inhibitors. Any solution towards the mitigation of fouling will, therefore, provide significant economic and environmental benefits. In the present paper, the performance of innovative nano-modified surfaces is described when subjected to calcium sulphate scale deposition during convective heat transfer. Two types of non-structured and structured nano-modified surfaces are examined. The experimental results demonstrate that such coatings will significantly increase the induction time before fouling starts and also reduce the subsequent fouling rate, in comparison with untreated stainless steel surfaces. Considering these promising results and the potential application of nanotechnology to combat fouling, the paper continues by discussing the demands on thermal and mechanical stabilities that such coatings will have to satisfy.