Enabling Power Production from Challenging Industrial Off-Gas – Model-Based Investigation of a Novel Heat Recovery Concept

Abstract

Off-gas from the metal industry is a significant surplus heat source that is often not utilized due to lack of internal and external heat demands. Power production from the surplus heat in the off-gas could be a promising option for utilization. This work considers an off-gas at 150 °C from a metallurgical process, suitable for a Rankine Cycle (RC). Metallurgical off-gas typically contains particles that can deposit on heat exchanger surfaces, therefore requiring specialized heat recovery solutions for robustness and consistent performance. To maximize competitiveness of an RC implementation, it is crucial to recover the surplus heat at the highest possible temperature. We explore a novel plate-type heat exchanger concept for improved heat recovery from scaling-prone off-gas. Simulations show that the investigated concept can be competitive both in terms of weight and compactness compared to both a clean gas reference exchanger and alternative dirty gas concept