Life-cycle-based reconfiguration of sustainable carbon black production: Integrated conventional technique with waste tire pyrolysis and its future improvement potentials

Abstract

Excessive reliance on fossil resources, as well as high energy consumption and pollution, poses a serious threat to the conventional carbon black (CB) production industry. This study proposed an integrated process of waste tire pyrolysis and carbon black production (IntTech) which can help to establish a closed-loop process between rubber tire manufacturing and CB production. The pyrolytic oil generated from the pyrolysis process replaces the raw and fuel oil required for CB production, aiming to reduce dependence on fossil resources while effectively disposing of end-of-life tires. Life cycle assessment (LCA) and economic analysis were employed to compare and analyze IntTech and the conventional process. The primary contributor to conventional CB production is the added feedstock oil which accounts for over 30% of all environmental impacts. The LCA results indicate that IntTech has significantly lower environmental impacts. IntTech replaces natural gas and a portion of the feedstock oil in CB production with pyrolytic oil which plays a major positive role in the six indicators. Primary Energy Demand (PED), which has the least positive impact of pyrolytic oil on the environment, reduces the environmental impact by 43.48%. Weighted and normalized results identify PED as the priority issue, whose contribution to the overall environmental impact reaches up to 71.72% in the conventional process and 1.21% in IntTech. Economic analyses indicate that IntTech creates more benefits. The return on investment of the conventional process is 18.22%, while the return on investment of IntTech is 94.62%. Based on these analyses, potential improvements were put forward in IntTech, such as incorporating bamboo waste pyrolysis. IntTech not only reduces pollution and energy consumption in CB production but also ensures profitability, which demonstrates higher feasibility in practical production and provides a perspective for the reform and development of green industries in the CB and rubber tire industries.