Modelling and Evaluating Industrial Symbiosis in Agri-Food Networks through Advanced Simulation - Moving Towards Circular Economy in the UK

工业共生（IS）是工业生态学领域内一个专门领域的概念，其主要目标集中在实体之间的协同关系。这些关系包括材料、能源和服务的有形交换，这些交换经过战略性安排，以产生并行的经济和环境优势。工业共生网络（ISN）可以被视为复杂的适应系统，网络促进这些共生关系，为企业提供一个框架，以有效地识别，建立和管理资源交换。在北方爱尔兰（NI），乳制品生产和加工业占农业总产值的31%（DAERA，2022）。农场、啤酒厂和厌氧消化器等企业也在NI的总产量中发挥着关键作用。这些部门的大量生产还产生大量副产品，废物处理不当造成严重的环境影响。例如，农业废物的大量排放被怀疑是英国最大的淡水湖内湖污染的主要原因之一，内湖为北爱尔兰提供了40%的饮用水（BBC新闻，2023）。虽然这些行业传统上都采取了环境措施，但在推行可持续生产做法方面，特别是在有效封闭材料循环方面，仍然存在着持续的挑战。文献确定了这些副产品的许多应用，这些副产品可以重新用于其他目的或生产。例如，在奶基肥皂中使用奶酪乳清作为原料奶的替代品，在农场中使用谷物废料作为动物饲料。这为发展ISN创造了机会，ISN包括可以共享或交换资源的行业。虽然以前的研究已经探讨了先进的建模和模拟技术在个别行业，有一个显着的稀缺文献，其应用到材料交换业务在ISN的背景下。因此，重要的是通过利用物质流分析（MFA）来跟踪物质流和先进的模拟，以将动态特性，如市场和技术中断的模型进行综合分析的ISN模型。这种分析对于理解ISN的好处和减轻任何潜在风险至关重要，ISN专注于副产品的再利用。农业食品供应链和网络中的信息流、技术和数据管理被认为是ISN的关键推动因素。本研究旨在通过开发以乳品加工商为核心的ISN模型，为理论和实际应用做出贡献。根据文献和现有数据，考虑的共生伙伴是啤酒厂，厌氧消化器，肥皂生产商和动物农场。这一网络促进了这些设施之间的副产品交流，形成了一个共享副产品流的合作系统。在这个项目中，一个先进的仿真模型被用来审查中断所产生的技术和市场波动不同的实体之间的ISN，同时评估相关的网络，经济和环境指标。区域ISN至少对四个联合国可持续发展目标（UNSDG）产生积极影响- UNSDG 7，9，11和12。这项研究有助于可持续供应链，运营和循环经济的文献。它通过MFA和模拟模型对ISN进行建模来实现这一目标，从而通过实现更好的资源效率和可持续性目标来使参与公司受益。此外，从这项研究中获得的见解可以使乳制品行业及其共生合作伙伴受益，增加他们对副产品再利用的知识，创造新的商业模式，并释放共生关系的其他潜在优势。

Industrial Symbiosis (IS) represents a concept in a specialised domain within the field of Industrial Ecology, with its primary objective centred on synergistic relationships among entities. These relationships encompass a tangible exchange of materials, energy, and services strategically orchestrated to yield concurrent economic and environmental advantages. Industrial Symbiosis Network (ISN) can be viewed as complex adaptive systems where the network facilitates these symbiotic relationships, providing a framework for businesses to identify, establish, and manage resource exchanges effectively. In Northern Ireland (NI), the dairy production and processing industry accounts for 31% of the overall gross agricultural output (DAERA, 2022). Businesses like farms, beer breweries and anaerobic digesters also play a pivotal role in NI's gross output. The significant production in these sectors also generates substantial by-products, and inadequate waste handling results in severe environmental repercussions. For example, large discharge of farming waste is suspected to be one of the main reasons for the contamination of Lough Neagh, the largest freshwater lake in the UK, supplying 40% of NI's drinking water (BBC News, 2023). Although the industries have traditionally incorporated environmental measures, there are persistent challenges in pursuing sustainable production practices, particularly concerning the effective closure of material loops. The literature identifies numerous applications of those by-products, which can be re-utilised for other purposes or production. For example, the use of cheese whey in milk-based soaps as replacement for raw milk and spent grains as animal feed in farms. This creates an opportunity to develop ISN comprising industries that can share or exchange resources. While previous studies have explored advanced modelling and simulation techniques within individual industries, there is a notable scarcity of literature regarding their application to material exchange operations in an ISN context. Therefore, it is important to conduct a comprehensive analysis of the ISN model by utilising Material Flow Analysis (MFA) to track the material flows and advanced simulation to incorporate dynamic characteristics such as market and technical disruptions in the model. This analysis becomes essential to comprehend the benefits and mitigate any potential risks in an ISN that focus on the reutilisation of by-products. Information flow, technology and data management in the Agri-food supply chain and networks are considered key enablers for ISN. This research project aims to contribute to theory and practical application by developing an ISN model with dairy processors at its core. Based on the literature and available data, symbiotic partners considered are a beer brewery, an anaerobic digester, a soap producer and animal farms. This network facilitates the exchange of by-products among these facilities, fostering a cooperative system of shared by-product streams. In this project, an advanced simulation model is employed to scrutinise the disruptions to ISN arising from technical and market fluctuation between different entities while assessing the associated network, economic and environmental metrics. A regional ISN positively impacts at least four United Nations Sustainable Development Goals (UNSDG) - UNSDG 7, 9, 11, and 12. This research contributes to the literature on sustainable supply chains, operations, and the circular economy. It achieves this by modelling the ISN through MFA and simulation model to potentially benefit the participant companies by achieving better resource efficiency and sustainability goals. Moreover, the insights derived from this study can benefit the dairy industry and its symbiotic partners, adding to their knowledge on reusing by-products, creating a new business model and unlocking additional potential advantages of symbiotic relationships.