• Energy Research
• 2021-2025close

This study investigates the technical and economic feasibility of replacing throttling valves with smale-scale, oil-free turbomachinery in industrial steam networks. This is done from the perspective of the turbomachine, which has to be integrated into a new or existing process. The considered machines have a power range of P=[0.5,…,250 kW] and have been designed using real industrial data from existing processes. Design guidelines are developed, which take into account the thermodynamic process as well as engineering aspects of such a turbomachine. The results suggest that steam conditioning prior to heat exchange could be completed by small expanders to produce mechanical work, reducing exergy destruction and improving site-wide energy efficiency compared to throttling valves. Cost estimates for such machines are presented, which serve as a basis for case-specific investment calculations. The resulting payback times of less than 18 months highlight the economic potential such solutions.

The management of plastic waste is a growing concern that can harm wildlife and ecosystems, and its end-of-life policies are key to mitigating plastic environmental impact. This work presents a decision-making methodology for the thermal and material valorization of plastic waste, coupling a supply chain model with multi-objective optimization and data analytics. It highlights the challenges and vulnerabilities of plastic waste management, the importance of system integration and holistic analysis, as well as the potential for carbon capture to reduce emissions. Our results suggest that efficient incineration, coupled with simplified waste logistics, can compete with existing mechanical recycling strategies in terms of emissions and costs. This study provides insights into municipal, regional, and European waste management, with the potential for a common EU platform and savings of 210 Mton of CO2 by harvesting benefits from plastic recycling and incineration with carbon capture.

The concept of Positive Energy Districts (PEDs) has emerged as a promising approach to achieving sustainable urban development. PEDs aim to balance the energy demand and supply within a district while reducing the carbon footprint and promoting renewable energy sources. Urban–Industrial Symbiosis (UIS) is another approach that involves the exchange of energy and resources between industrial processes and nearby urban areas to increase efficiency and reduce waste. Combining the concepts of PED and UIS can create self-sufficient, sustainable, and resilient districts. As the analysis and implementation of such systems are barely studied in North America, this research study was structured to fill the gap by evaluating the financial and environmental advantages of this combination. This study proposes a methodology to design a heat transmission system; then, it is applied to the case of a paper-making factory and a multifunctional heritage building in Montreal, Canada. The results show that the building’s new heating system can generate sufficient heat while emitting near-zero direct emissions. Overall, this paper argues that combining the concepts of PED and UIS can lead to a more sustainable and resilient urban area, and provides a roadmap for achieving this goal.