Optimal Design and Flexible Operation of a Fully Electrified Biodiesel Production Process

TL;DR

This paper explores how buffer tanks and dynamic optimization can enhance the flexibility and energy efficiency of electrified biodiesel production processes, enabling better integration with renewable energy sources.

Contribution

It introduces a novel approach using buffer tanks and distributed optimization to improve process flexibility and energy savings in electrified biodiesel production.

Findings

Up to 29% energy savings with buffer tanks

Distributed optimization reduces computational costs by over 10-fold

Flexible operation outperforms steady-state in demand response scenarios

Abstract

The flexible operation of electrified chemical processes, powered by renewable electricity, offers economic and ecological incentives, paving the way for a more sustainable chemical industry. However, this requires a departure from the traditional steady-state operation, posing a challenge to process design and operation. We propose an approach for flexible biodiesel production by utilizing intermediate and final buffer tanks. These tanks serve to decouple the dynamics between different process unit operations. We investigate the flexibility of three different process configurations and compare the outcomes of their dynamic optimization strategies with those of a steady-state operation, considering a typical demand-side response scenario. For all strategies, we employ local gradient-based optimization and solve them using our open-source optimization framework DyOS. Our findings indicate that by incorporating intermediate buffer tanks, we fully exploit the process flexibility potential, leading to total energy savings of up to 29%. We also propose an implementation based on distributed optimization problems, yielding similar savings while significantly reducing computational costs by over 10-fold and improving convergence, thus paving the way toward online application. Overall, this study highlights the potential benefits of incorporating buffer tanks and optimization strategies in the flexible operation of electrified chemical processes, even those initially designed solely for steady-state operation.