Dr Paul Grassia
Reader
Chemical and Process Engineering
Area of Expertise
Foam Science and Engineering
Suspension/Sludge Rheology
Multiphase Flows and Multiphase Mass Transfer
Ink Jet Printing and Direct Write Processes
Prize And Awards
- Foam Improved Oil Recovery (Fellowship Funded by CONICYT Chile)
- Recipient
- 1/5/2015
- Visiting Senior Lecturer, University of Manchester
- Recipient
- 1/2/2015
Qualifications
PhD (University of Cambridge) 1990--1994
BSc (Hons, 1st class) (University of Western Australia) 1985--1989
Publications
- Surfactant transport upon foam films moving through porous media
- Grassia Paul, Rajabi Hamed, Rosario Ruben, Torres-Ulloa Carlos
- Colloids and Surfaces A: Physicochemical and Engineering Aspects Vol 679 (2023)
- https://doi.org/10.1016/j.colsurfa.2023.132575
- A model for foam fractionation with spatially varying bubble size
- Grassia Paul, Torres-Ulloa Carlos
- Chemical Engineering Science Vol 281 (2023)
- https://doi.org/10.1016/j.ces.2023.119163
- Transport of convected soluble surfactants on and within the foam film in the context of a foam fractionation process
- Rajabi Hamed, Rosario Ruben, Grassia Paul
- Chemical Engineering Science Vol 281 (2023)
- https://doi.org/10.1016/j.ces.2023.119100
- Viscous froth model applied to multiple topological transformations of bubbles flowing in a channel : three-bubble case
- Torres-Ulloa Carlos, Grassia Paul
- Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences Vol 479 (2023)
- https://doi.org/10.1098/rspa.2022.0785
- Quasistatic model for foam fractionation
- Grassia Paul
- Chemical Engineering Science Vol 275 (2023)
- https://doi.org/10.1016/j.ces.2023.118721
- Foam propagation with flow reversal
- Torres-Ulloa Carlos, Grassia Paul
- Transport in Porous Media Vol 147, pp. 629-651 (2023)
- https://doi.org/10.1007/s11242-023-01925-5
Research Interests
Dr Grassia's research focuses on foams and allied multiphase systems including solid-liquid suspensions and liquid-liquid emulsions.
Chemical engineering applications abound. Foams are used in froth flotation for extracting valuable metals, in foam fractionation for purifying proteins, and in manufacturing polymeric materials to name a few. Foams flowing in porous media can be used for soil remediation and aquifer remediation, for immobilising captured waste gases like CO2, and for storing useful gases like hydrogen. Foams can also be a major nuisance in bioreactors, whilst even laundry wash detergents tend to contain additives to reduce the volume of foam. Solid-liquid suspensions meanwhile are processed in minerals tailings operations, and also when treating sewage sludges so as to extract clean water from waste and reduce waste volumes. Liquid-liquid emulsions meanwhile form the basis of many foodstuffs, and household and personal care products.
What all of the above systems have in common is that they consist of a discrete phase (whether gas bubbles, solid aggregates or liquid droplets) suspended in a continuous liquid phase. Moreover the energetics of the interface between the discrete and continuous phase dominate the system behaviour, whilst the individual discrete phase elements interact with their neighbouring discrete phases. These interfacial properties and interactions, make foam (second perhaps only to graphene!) simultaneously both very light but very tough.
To understand these systems one needs to understand both their physics and their physical chemistry. Moreover one needs to understand the physics and chemistry at a multitude of scales ranging from the nanometre scale of individual surfactant molecules within a foam film to the kilometre scale over which foam might propagate in improved oil recovery operations. Multiple time scales also determine the behaviour: individual surfactant molecules can enter and leave molecular aggregates called micelles on the order of microseconds, whereas the supermarket shelf life of a chocolate mousse can be up to some weeks.
In summary, foams have attracted the attention of humanity ever since the goddess Aphrodite (literally `risen from foam') was said to have been born from the sea foam on the shore of the Mediterranean. In the 21st century, foams continue to exert both their scientific fascination and their engineering utility.
Professional Activities
- Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (Journal)
- Editorial board member
- 31/3/2016
Projects
- Foam Improved Oil Recovery: Effects of Flow Reversal
- Lue, Leo (Principal Investigator) Grassia, Paul (Co-investigator)
- 01-Jan-2021 - 31-Jan-2023
- Really Small Science in Colombia
- Grassia, Paul (Principal Investigator) Haw, Mark (Co-investigator) Leckie, Joy Susan (Co-investigator)
- 01-Jan-2018 - 31-Jan-2019
- Building Capacity in STEM for enhancing socio-economic development in regional Chile
- Ventura-Medina, Esther (Principal Investigator) Ferreiro-Rangel, Carlos Augusto (Co-investigator) Grassia, Paul (Co-investigator) Magueijo, Vitor (Co-investigator)
- 21-Jan-2016 - 20-Jan-2016
- Exploiting microbiology & rheology to improve treatment of Palm Oil Mill Effluent - (Newton Fund)Poh-Phaik-Eong-Newton-Collaboration-Programme
- Grassia, Paul (Principal Investigator) Knapp, Charles (Co-investigator)
- Exploiting microbiology % rheology to improve treatment of Palm Oil Mill Effluent - Poh-Phaik-Eong-Newton-Collaboration-Programme
- 01-Jan-2016 - 30-Jan-2017
Contact
Dr
Paul
Grassia
Reader
Chemical and Process Engineering
Email: paul.grassia@strath.ac.uk
Tel: 548 2241