Chemical looping: a technology platform for upcycling low-grade industrial resources

Abstract

Ambitions towards a circular economy are increasingly vocalised across academia, policymaking and industry. The endeavour of realising these ambitions provides major opportunities and challenges in chemical engineering, and requires a tremendous roll-out of new technologies. This perspective highlights the suitability of chemical looping as a technology platform to contribute to the valorisation of material streams that are currently not used to their full potential, termed low-grade resources. Such material streams offer significant opportunities to minimise CO2 emissions and accelerate towards a circular materials economy. Apart from defining and identifying low-grade streams, both calorific and non-calorific, a non-exhaustive overview of such streams is provided. Based on a selection of case studies focusing on steel mill gases, bauxite residue, pyrite cinder, calcium carbide slag and automotive shredder residue, it is posited that the characteristics and flexibility of the chemical looping approach offer ample possibilities to efficiently reuse low-grade streams and minimise their environmental impact. Finally, an outlook on chemical looping as a technology platform and its possible role in the drive towards circularity is given, with attention for the roles of industrial, academic and governmental stakeholders. In order to assess the suitability of a chemical looping process for valorising low-grade resources, the importance of holistic technology investigations is stressed, taking into account technical, economic, ecological and societal considerations.

Probing the Performance of a Ni–Ca–Ce Dual-Functional Material for Integrated CO2 Capture and Utilization from a Synthetic Flue Gas Approximating Industrial Composition

“…Their results show that the DFM synthesized through Ca extraction by propionic acid, followed by filtration and addition of nickel nitrate with citric acid as the complexing agent, performed the best in terms of CO 2 uptake and CO yield among the studied materials. The potential synergies in upcycling both gaseous and solid industrial byproducts through CL are indeed increasingly appreciated . Another example is the work by Sun et al, who investigated the use of marble dust as functional material for ICCU-rWGS at 923 K using 10% CO 2 during the CO 2 capture stage and pure H 2 during the rWGS step .…”

“…The potential synergies in upcycling both gaseous and solid industrial byproducts through CL are indeed increasingly appreciated. 8 Another example is the work by Sun et al, who investigated the use of marble dust as functional material for ICCU-rWGS at 923 K using 10% CO 2 during the CO 2 capture stage and pure H 2 during the rWGS step. 9 The cheap and abundantly available material was found to exhibit promising rWGS activity, although its CO 2 sorption capacity decreased by 30% over 47 cycles.…”