Generic model for determining the environmental impact of process steam supply

On the pathway toward CO₂ neutrality, the process industry is undergoing a profound transformation, which poses substantial challenges for the ecological assessment of processes. Due to the generalized and predominantly retrospective character of conventional life cycle assessment (LCA) background datasets, these databases can represent ongoing and future developments only to a limited degree. Furthermore, primary plant-level data are frequently unavailable. Consequently, alternative data sources are required to evaluate and optimize emerging process technologies. This contribution presents an open-source, generic simulation model for determining the specific impact of process steam supply. The model enables the explicit consideration of plant- and process-specific parameters within product LCAs and thereby supports process optimization with respect to multiple environmental objectives. The influence of key parameters, such as the required heat demand temperature, is systematically investigated. In addition, the impact of different approaches to handling multifunctionality on the outcomes of prospective LCAs of thermal energy demand is examined. A sensitivity analysis of the simulation model is performed to assess its robustness and reliability, and the resulting variance is compared with that obtained from a Monte Carlo simulation applied to a benchmark dataset. The results indicate that disregarding distribution losses can lead to an underestimation of the environmental impacts associated with steam supply by approximately 5–15%. These findings highlight the critical importance of adequately representing steam distribution and utilization in LCAs of chemical processes. Moreover, the proposed approach enables the critical evaluation of established steam distribution topologies and facilitates a more accurate representation of the influence of steam systems on process-level LCA outcomes.