Process Integration and Electrification for retrofit: Case studies of milk evaporator systems

Abstract

Industrial Process Integration and Electrification represents a critical path to harnessing renewable electricity for a net-zero future, particularly through advancements in heat pump and vapour recompression technologies for industrial applications. This paper addresses the challenge of decarbonising an energy-intensive aspect of dairy processing plants, milk evaporation, which is a critical processing step in milk powder production. Employing three different milk evaporator case studies, it introduces a retrofit methodology that merges Process Integration with Electrification technologies to achieve energy, emissions and cost savings. The study leverages Heat Pump Bridge Analysis, extended to evaluate process unit operations, and work consumption and generation, facilitating a comprehensive retrofit analysis for optimal energy use. The study concludes with several retrofit solutions, notably replacing steam ejectors with mechanical vapour recompression fans, resulting in energy savings of 13.7 %–41.6 % and emissions reductions of 14.5 %–47.3 %. This approach offers a holistic framework for industrial electrification, demonstrating significant efficiency and sustainability gains in dairy processing.

Keywords

• Process integration
• Process retrofit
• Bridge analysis
• Process electrification
• Heat pumps
• Dairy industry