Towards the use of CO2 and heat from steel industry emissions to prepare new materials

Project Description

Here we propose to utilise the emitted CO2 and waste heat from steel industry as main resources to prepare new materials. The vision behind this proof of concept is that CO2 within gas emissions from steel industry will be used as a reagent and the heat from processes in the steel making will be used to power the reaction.

Oxides will be used as starting materials for high temperature solid-gas reactions with CO2. Here, the chosen oxides are photocatalysts due to the relevance of photocatalysis as a green approach to many environmental problems, such as cleaning of water from pollutants and, more recently, decomposing and/or upcycling of plastics. The PI, MGF, has just completed a research project sponsored by Research England (Sunburst), focused on upcycling of poly lactic acid (PLA) via photocatalysis (see MGF’s CV). In Sunburst, she trialled several photocatalysts, among which the MO3 (M = W, Mo, Re) family of compounds, reported to show potential as visible light photocatalysts. Visible light photocatalysts are the ultimate goal, as the energy source, visible light, is constantly renewable with zero costs. The MO3 compounds proved not to be effective for the decomposition/upcycling of plastics, with contradictory results. Chemical modification of solids is a robust approach to tailor the properties of materials towards specific applications. MGF has reported the use of solid-gas reactions between starting oxides and CO2 to modify the chemical formula and the crystal structure of the starting oxide and lead to oxide-carbonates.

In this project, our first objective is to use CO2 and heat as the tools to modify the selected photocatalysts, to induce improved performance when used in reactions towards the upcycle of plastic materials. In an unseen approach, CO2 will be reacted with compounds in the MO3 series (all polymorphs) to induce chemical and structural changes towards improved photocatalytic efficiency (see WP1 for details).

For the high temperature solid-gas reactions of CO2 with MO3, candidate high-grade waste heat sources from steel making process will be selected and integrated to a full-scale system using process simulation and techno-economic tools (see WP2 for more details). Our second objective is to assess the potential technical and economic benefits of the proposed approach of CO2 utilisation and upcycling of plastic, against the integration of carbon capture and storage into the steel making process in order to decarbonise the sector and versus business as usual.