Since 1997, Cilian Ó Súilleabháin has been a lecturer on the degree programme in Chemical and BioPharmaceutical Engineering at Munster Technological University in Cork. Prior to that he worked at Waterford Crystal, Angus Fine Chemicals (Ringaskiddy), Arran Chemicals (Athlone). He worked also with C2HM Hill designing plants for Intel in Ireland and in the USA.  He is a Chartered Engineer.  He completed his PhD thesis ‘Modelling Hydrophilic Pervaporation Systems’ in 2019 at Dublin City University.