Coupling Computer-Aided Process Simulation and Estimations of Emissions and Land Use for Rapid Life Cycle Inventory Modeling
Smith, R., G. Ruiz-Mercado, D. Meyer, M. Gonzalez, J. Abraham, W. Barrett, AND P. Randall. Coupling Computer-Aided Process Simulation and Estimations of Emissions and Land Use for Rapid Life Cycle Inventory Modeling. ACS Sustainable Chemistry & Engineering. American Chemical Society, Washington, DC, 5(5):3786-3794, (2017). https://doi.org/10.1021/acssuschemeng.6b02724
As part of its mission, the USEPA is tasked with overseeing the use of chemicals in commerce. This can include consideration of a chemical's potential impact on health and safety, resource conservation, clean air, climate change, clean water, and sustainable materials management. Life cycle assessment (LCA) is a suitable tool for this purpose because of its ability to simultaneously evaluate multiple impacts using a systems perspective intended to minimize trade-offs and burden-shifting while maximizing benefits to achieve environmentally sustainable solutions. The current challenges for applying LCA in Agency decisions are the large data requirements and inability of the impact assessment methods to address impacts from direct (or near-field) exposure to chemicals in consumer and building products. The Life Cycle Human Exposure Modeling Project in the Chemical Safety and Sustainability National Research Program is developing methods to address these limitations and tailor LCA for use in Agency decisions for chemical management, including applications such as chemical screening and prioritization and chemical alternatives design and assessment.
A methodology is described for developing a gate-to-gate life cycle inventory (LCI) of a chemical manufacturing process to support the application of life cycle assessment in the design and regulation of sustainable chemicals. The inventories were derived by first applying process design and simulation to develop a process flow diagram describing the energy and basic material flows of the system. Additional techniques developed by the U.S. Environmental Protection Agency for estimating uncontrolled emissions from chemical processing equipment were then applied to obtain a detailed emission profile for the process. Finally, land use for the process was estimated using a simple sizing model. The methodology was applied to a case study of acetic acid production based on the Cativa tm process. The results reveal improvements in the qualitative LCI for acetic acid production compared to commonly used databases and top-down methodologies. The modeling techniques improve the quantitative LCI results for inputs and uncontrolled emissions. With provisions for applying appropriate emission controls, the proposed method can provide an estimate of the LCI that can be used for subsequent life cycle assessments.
Coupling Computer-Aided Process Simulation Exit