ENSSLED - Engineering Nanoparticles' Surface for Sustainable Descaling

Lead Research Organisation: Imperial College London
Department Name: Chemical Engineering

Abstract

Calcium carbonate (CaCO3) scaling of pipeline and flow systems is a long-standing and intractable problem, affecting many critical
industries. Current descaling approaches involve labour-intensive manual scraping of scales, or the use of specialized chemicals to
dissolve the scales or to stop them from forming. Unfortunately, these approaches incur cost and time, are not universally applicable
to all kinds of flow configurations and have otherwise raised environmental concerns as well. ENSSLED builds instead on an
alternative approach of using nanoparticles that can nucleate scales on themselves, rather than on the pipe walls. These sacrificial
nucleants (SN) after scaling can be removed from the flow stream. But in practice, they often stick to the pipe walls due to their
random and disordered shapes (rhombohedral crystals or RC) attained during scaling. Conversely, ENSSLED proposes to investigate
the use of spherically shaped SN, synthesized from a bio-based environmentally friendly material called chitosan. Owing to its aminerich
surface property, chitosan can induce film-wise mineral growth (by a biomimetic process called biomineralization). ENSSLED
applies these principles to control scaling around the SN in the form of films rather than disordered RC. By retaining the spherical
shape of the SN during scaling, the adhesion of the SN with that of the pipe walls could be minimized, thereby deterring scale
formation on the pipe walls and enabling complete recovery of the SN afterwards. This distinctive biomimetic strategy could offer an
industrially acceptable and sustainable approach toward passive descaling. ENSSLED plans to achieve these goals through a
multidisciplinary approach involving SN synthesis, chitosan (biopolymer) processing, scaling analysis, and contact mechanics-based
adhesion measurements (between SN and the pipe walls).

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