Optimization of design and operation of a digestate treatment cascade for demand side management implementation

Sustainable chemical engineering through demand side management (DSM) and renewable feedstock integration e.g. in biorefineries are key to optimizing the use of fluctuating energy resources and minimizing environmental impact while conserving resources. This contribution presents the results of the economic evaluation of integrating DSM into biofuel biorefineries through a dynamic simulation approach. A previously developed decision support tool for DSM implementation was extended to describe the size of intermediate buffer tanks as a function of oversizing up- and downstream processes. Design optimization of the process cascade determined the oversizing that allows the optimal balance of operational cost reduction through flexibility and capital cost increase through oversizing. Scheduling optimization validated the results of the steady-state optimization and show that, by considering interactions between processes, buffer tank capacity can be reduced, while increasing DSM potential.