Life Cycle Assessment of an Integrated Steel Mill Using Primary Manufacturing Data: Actual Environmental Profile

Abstract

The current dependency on steel within modern society causes major environmental pollution, a result of the product’s life cycle phases. Unfortunately, very little data regarding single steel production processes have been found in literature. Therefore, a detailed analysis of impacts categorized in terms of relevance cannot be conducted. In this study, a complete life cycle assessment of steel production in an integrated German steel plant of thyssenkrupp Steel Europe AG, including an assessment of emissions from the blast furnace, the basic oxygen furnace, and casting rolling, is carried out. The functional unit is set to 1 kg hot-rolled coil, and the system boundaries are defined as cradle-to-gate. This study models the individual process steps and the resulting emitters using the software GaBi. Total emissions could be distributed into direct, upstream, and by-product emissions, where the biggest impacts in terms of direct emissions from single processes are from the power plant (48% global warming potential (GWP)), the blast furnace (22% GWP), and the sinter plant (79% photochemical ozone creation potential (POCP)). The summarized upstream processes have the largest share in the impact categories acidification potential (AP; 69%) and abiotic depletion potential fossil (ADPf; 110%). The results, including data verification, furthermore show the future significance of the supply chain in the necessary reduction that could be achieved.

Global warming and ozone depletion potentials caused by emissions from HFC and CFC banks due to structural damage

“…For reference, according to [35] producing 1 kg of concrete results in 3.5E−5 g of 𝐶𝐹𝐶-11 𝑒𝑞 , with minor variations based on the process specifications. Similarly, producing 1 kg of steel reportedly gives rise to 4.5E−5 [62] or as little as 1.6E−8 [36] g of 𝐶𝐹𝐶-11 𝑒𝑞 . As a result, when [63] estimated the ODP of several buildings based on their materials alone, the values ranged from 2E−3 up to 1E−2 g 𝐶𝐹𝐶-11 𝑒𝑞 /𝑚 2 for residential ones.…”

Application of Life Cycle Sustainability Assessment in the Construction Sector: A Systematic Literature Review

“…There is a high demand for concrete production, due to which the CO 2 emissions of the construction industry are responsible for about 7% of the global emissions, similar to the iron and steel industries [8][9][10].…”

Comparative Lifecycle Assessment of Methanol and Urea Produced from Steel Mill Gases

“…For comparison of results obtained from this study with previous studies mentioned in the Introduction section of the article, the values were adjusted for the functional units defined in this study. The functional unit in this study considered steel production as well, for which the footprint of 2.1 kg CO2-eq kg steel -1 was considered [36]. For the five methanol scenarios, the studies of Kang et al [5] and Li et al [6] resulted in slightly higher values of GWI than reported in this study.…”