A physical assessment of material flows in an economy (e.g., material flow quantification) can support the development of sustainable decarbonization and circularity strategies by providing the tangible physical context of industrial production quantities and supply chain relationships. However, completing a physical assessment is challenging due to the scarcity of high-quality raw data and poor harmonization across industry classification systems used in data reporting. Here we describe a new physical extension for the U.S. Department of Energy's (DOE's) EEIO for Industrial Decarbonization (EEIO-IDA) model, yielding an expanded EEIO model that is both physically and environmentally extended. In the model framework, the U.S. economy is divided into goods-producing and service-producing subsectors, and mass flows are quantified for each goods-producing subsector using a combination of trade data (e.g., UN Comtrade) and physical production data (e.g., U.S. Geological Survey). Given that primary-source production data are not available for all subsectors, price-imputation and mass-balance assumptions are developed and used to complete the physical flows dataset with high-quality estimations. The resulting dataset, when integrated with the EEIO-IDA tool, enables the quantification of environmental impact intensity metrics on a mass basis (e.g., CO$_2$eq/kg)) for each industrial subsector. This work is designed to align with existing DOE frameworks and tools, including the EEIO-IDA tool, the DOE Industrial Decarbonization Roadmap (2022), and Pathways for U.S. Industrial Transformations study (2025).

翻译：对经济体中物质流进行物理评估（例如，物质流量化）可为工业生产规模和供应链关系提供切实的物理背景，从而支持可持续脱碳与循环战略的制定。然而，由于高质量原始数据稀缺且数据报告使用的行业分类系统间协调性不足，完成物理评估面临挑战。本文针对美国能源部工业脱碳环境扩展投入产出模型提出新的物理扩展方法，构建出兼具物理维度与环境维度的扩展型EEIO模型。在该模型框架中，美国经济被划分为商品生产与服务生产两大子部门，通过整合贸易数据与物理生产数据对每个商品生产子部门进行质量流量化。鉴于并非所有子部门都能获得原始生产数据，本研究开发并应用价格估算与质量平衡假设，以高质量估算值完善物理流数据集。该数据集与EEIO-IDA工具集成后，可实现各工业子部门基于质量单位的环境影响强度指标量化。本工作旨在与现有能源部框架及工具保持协同，包括EEIO-IDA工具、能源部《工业脱碳路线图》及《美国工业转型路径研究》。