Application of Life Cycle Assessment to Reduce Energy Use and Carbon Emissions of Industrial Drying Process

Abstract

Industrial drying is an energy-intensive operation, and its environmental performance depends on the drying technology, energy source, material properties and boundaries used for assessment. This review examines the application of life cycle assessment (LCA) to energy consumption, carbon emissions and other environmental impacts associated with drying processes. Relevant publications were identified through a Web of Science search and examined using bibliometric analysis, keyword co-occurrence networks and comparisons of published applications. The review covers drying of fruits and vegetables, grains, coal, textiles, wood, sewage sludge, porous nanoscale materials, bioactive products, and paper and paperboard. Across these applications, LCA provides a framework for identifying environmental hotspots and assessing trade-offs between drying technologies, including alternatives based on heat pumps, renewable energy and process integration. The reviewed studies indicate that reductions in operating energy demand do not necessarily produce improvements across all environmental impact categories, particularly when equipment manufacture, upstream inputs and regional electricity supplies are considered. The literature also shows uneven coverage among material classes and differences in functional units, system boundaries, databases and impact assessment methods. These differences restrict direct comparisons between reported results. Greater consistency in assessment practice, improved inventory data and closer integration of experimental evidence with industrial operating conditions could strengthen the use of LCA in identifying opportunities for energy conservation and emission reduction in industrial drying process.