Fouling deposit formation on heat exchangers surface arising from thermal treatments of milk and egg products is a major and severe industrial issue of food processing plants. It involves drastic and expensive cleaning measures, resulting in excessive rinsing water and harsh chemical use and accounting for 80% of the whole production costs. Modifications of heat exchanger stainless steel surface properties may in theory limit the onset of fouling, but at the state of the art no satisfying solution has been reported. The challenge of ECONOMICS project is to design non-wetting surfaces, showing food compatibility, antifouling properties and resistance to cleaning procedures.
On one hand, surface functionalization processes of high potential, i.e. sol-gel, amphiphilic coatings and self-stratifying coatings will be applied on stainless steel and assessed.
On the other hand, stainless steel will be replaced by carbon-based materials (carbon-graphite solid composite plates with engineered surfaces, mesoporous carbons, bi-continuous composites), which constitute a “disruptive” thermal technology that can lead to significant energy savings. Some of these carbon based materials designed, of controlled porosity, will also be tuned to become slippery surfaces, which are promising surfaces for antifouling applications.
All surfaces will be evaluated in milk pasteurization processes to evaluate fouling in pasteurization conditions. They will then be submitted to durability evaluation through cleaning-in-place procedures. The antifouling mechanism of action of the effective surfaces will be investigated at various scales (from nano to microscales) and their environmental impact and potential gain will be estimated by multiple criteria analyses (life cycle analysis).
The proposed project will bring further understanding of a major bottleneck limiting the dissemination of more eco-efficient cleaning surfaces in dairy industry.