Challenges in Cleaning: Recent Developments and Future Prospects

Abstract There is considerable scope for the optimization of processes subject to fouling by effective management of cleaning. The cleaning cycle starts with the (often complex) material generated during the fouling cycle. The nature of the deposit determines the most appropriate cleaning method, which can often be optimized significantly via the knowledge of the key mechanisms involved in deposit removal. Links between deposit aging and cleanability need to be established and quantified. There is a wide range of cleaning methods available, and attention is focused here on cleaning-in-place (CIP) techniques. Modern instrumentation allows cleaning (and deposit materials behavior) to be probed to greater degree than ever before, but the removal technology is only part of the cleaning process. Monitoring and validation of cleaning are equally important, particularly for the process plant used in flexible manufacture or subject to batch assurance requirements. Individual sensors are unlikely to meet all monitoring criteria, so future approaches will require the reconciliation and interpretation of online data from multiple devices. Many industries stand to learn from the practice and approaches in the food, pharmaceuticals, and electronics sectors, where these concepts are well established. The definition of cleanliness will vary from sector to sector, but the needs of minimizing environmental impact, accurate monitoring, assurance, and suitable training for operators are common to all.