Cradle-to-cradle modeling of the future steel flow in China

- A cradle-to-cradle model considering both market and resource dynamics is developed.
- Cost competitiveness of production route plays a crucial role in China's steel flow.
- Chinese steel flow from 2012 to 2100 is quantified and simulated.
- The impact of implementing different material efficiency strategies is analyzed.
- Insufficient scrap supply limits the benefit of reuse and remanufacturing scrap.

China is the biggest steel producer and consumer in the world. Therefore, it is important to understand the dynamic mechanisms of the steel flow, to forecast the future trends, as well as evaluate different improvement measures. Although the previous models are able to depict the dynamic material flow, the market dynamics are excluded such as production capacity planning, the cost competitiveness of each route, the market prices of resources, etc. This paper presents a cradle to cradle model to describe the comprehensive mechanism of the steel lifecycle by combing both material and market dynamics. The model is used to predict and quantify the future steel flow in China from 2012 to 2100. The results confirm that the secondary (from scrap) steel production share will increase along with the sufficient scrap supply in the long term. Meanwhile, the analyses also highlight that market dynamics has a profound impact on the steel flow. With the aim of promoting sustainable thinking in steel production and usage, this paper focuses on a number of material efficiency strategies and investigates their impact by using what-if scenario analyses. The results indicate that the benefit of reuse and remanufacturing scrap is limited when the generation of scrap is insufficient in the next two or three decades. The analyses also identified two strategies (i.e. less material for same service and more intensive use) are effective measures to improve the sustainability in China steel industry.