Decarbonisation Technology - August 2024 Issue

Role of heat integration in a sustainable, low-carbon future How different technologies are playing respective roles in minimising energy consumption and reducing emissions in industrial settings

Warren Chung Solex Thermal Science

T he ongoing pursuit of a more efficient, equitable, and environmentally conscious energy future is commonly framed within the sustainability-based concepts of the energy transition and a circular economy. At their core, these discussions focus on reducing carbon footprint, whether through lowering primary energy consumption or minimising waste and pollution. The global response to climate change has added another layer of complexity. Policymakers worldwide have introduced various mechanisms to influence behaviours and decision-making, aiming to reduce emissions and promote carbon-reducing innovations. Geopolitical uncertainties and dynamic monetary policies in response to inflation concerns have further intensified volatility in the energy market. Consequently, many industrial operators are proactively implementing risk- mitigation strategies, ranging from deploying financial instruments and hedges to re-evaluating and enhancing physical operations. Public pressure also plays a significant role. As of November 2023, approximately 145 countries have announced or are considering net zero targets, covering nearly 90% of global emissions. Investors around the world continue to call for increased action, urging companies to improve their sustainability programmes and adopt their own net zero goals. Financial performance remains a fundamental factor in commercial decision-making, yet its calculation has become increasingly complicated due to emissions pricing and compliance costs in the global market. As a result, many companies are strategically investing in energy efficiency

initiatives, as these are considered low risk technically and financially. This approach not only decreases emissions but also improves environmental performance, reduces production costs, and enhances overall financial health. Enhancing energy recovery and efficiency through heat integration Implementing heat integration mechanisms into existing operations is highly effective and low risk, and can be a high-return approach for minimising energy consumption in industrial settings. The concept of heat integration is not novel, but its practical application has, at times, been hindered by factors ranging from high cost of adoption, complexity of integration, and technical restrictions of existing technologies. Although many industrial processes already incorporate some level of heat integration, difficult-to-handle process streams frequently remain unutilised due to perceived constraints. Tapping into otherwise wasted heat from these previously overlooked streams presents a significant opportunity for operators to incrementally reduce costs and lower emissions. Heat pipe heat exchangers (HPHE) and moving bed heat exchangers (MBHE) are two heat integration technologies that take very different approaches to improving the energy performance of industrial processes. However, both can play a similar role in optimising energy usage and enhancing sustainability in industrial settings. Heat pipe heat exchangers Combustion flue gases hold substantial potential for energy recovery. Extracting energy from these streams has historically