Development of a Quantitative Exergy-Based Measure of Sustainability

可持续发展已迅速成为变革的关键关注点和驱动力，但可持续发展的真正含义是什么？像“减少、再利用、再循环”这样的原则有助于指导我们的思维，但它们并没有提供一个定量的、普遍适用的衡量标准，可以用来理性地做出困难的决定。同样，目前量化可持续性的方法，包括碳足迹和排放，往往只关注可持续性的一个特定方面，如气候变化，而忽视了环境退化的众多问题。例如，在比较煤电和核电的碳足迹时，核电容易胜出；然而，这一评估忽略了围绕核废料的明显环境问题。与这些重点狭窄的措施不同，经济成本可以提供量化可持续性的普遍基础；但是，它受到可以人为操纵的其他因素（例如，通过投机或政府补贴）的影响，并不总是准确地反映资源的真正价值及其使用对环境的影响。能源，一种资源中的可用能源，提供了可持续性的一般、严格的热力学度量。在工业过程（例如，发电和化学制造）、环境工程、城市规划和生态系统中，火能被广泛用于表征可持续性。至关重要的是，能量可以用来量化过程中的效率低下，比较技术途径，量化对生态系统造成的损害，并估计生态系统恢复的成本。尽管它有优点，但它没有考虑许多重要的实际因素，例如时间的价值，以及利用给定资源所需的技术的可用性、效率和成本。该项目将在扩展能源概念的基础上开发一种新的可持续性定量测量方法，以包括这些实际因素。最初的工作是将改进的火用分析与标准方法（如热经济分析和夹紧技术）进行比较，以确定工程过程。然后，它将转向更当前的问题，例如生物质增值中的原料和产品选择。该项目将提供一个有效的工具，指导政策制定者、公司和个人做出决定，更好地利用我们非常有限的资源。

Sustainable development has rapidly grown to become a key concern and driver for change, but what does it truly mean to be sustainable? Principles like "reduce, reuse, recycle" help to guide our thinking, but they do not provide a quantitative, generally applicable measure that can be used to rationally make difficult decisions. Similarly, current methods of quantifying sustainability, including carbon footprints and emissions, tend to only focus on one particular aspect of sustainability, such as climate change, and neglect the multitude of problematic issues with environmental degradation. For example, when comparing the carbon footprints of coal-generated power to nuclear power, nuclear power easily wins; however, this assessment neglects the obvious environmental issues surrounding nuclear waste. Unlike these narrowly focused measures, economic cost can provide a universal basis to quantify sustainability; however, it is influenced by other factors that can be artificially manipulated (e.g., through speculation or government subsidies) and does not always accurately reflect the true value of resources and environmental impact of their use. Exergy, the usable energy within a resource, provides a general, rigorous thermodynamic measure of sustainability. Exergy has been used extensively to characterize sustainability in industrial processes (e.g., power generation and chemical manufacture) environmental engineering, city planning, and ecosystems. Crucially, exergy can be used to quantify inefficiency within processes, compare technological pathways, quantify the damage inflicted on an ecosystem and estimate the costs of ecosystem restoration. Despite its merits, it does not consider many important practical factors, such the value of time, and the availability, efficiency and cost of the technology required to utilize a given resource. This project will develop a novel quantitative measure of sustainability, based on extending the concept of exergy to include these practical factors. The initial work will compare the modified exergy analysis to standard methods, such as thermoeconomic analysis and pinch technology, for well-established engineering processes. It will then move to more current problems, such as feedstock and product selection in biomass valorisation. The project will provide an effective tool to guide policy makers, companies, and individuals to make decisions to make better use of our very limited resources.