Process Integration and Design of Amino Acid Purification Processes for Energy Savings: An Industrial Case Study

Energy minimization study is applied to an amino acids downstream process for L-methionine production currently in operation and energy-saving options that can be implemented in practice are systematically identified with the application of Process Integration (PI) design method. Structural changes in process flowsheets or reconfiguration in stream-mixing patterns are considered for the debottlenecking of bioprocesses for energy reduction, which allows the energy-efficient use of steam for the purification of bioproducts and its effluent management, leading to maximum 18% saving in steam use to be achieved. Reduction in cold utility is investigated with the strategic use of cooling water reuse, as a means of cold utility minimization, with which up to 33% of cooling water use can be reduced. The introduction of multi-level expansion for the provision of refrigeration utility is further identified, leading to 35% reduction in compression power. The retrofit case study clearly demonstrates the usefulness of Process Integration method for energy minimization in bioprocesses in operation and its results provides practical design guidelines for energy-saving projects in amino acids production.