The Project

Why C⁴U?

The iron and steel industry represents the largest energy-consuming manufacturing sector in the world, with average specific emissions being 1.83 tonnes of CO₂ per tonne of steel and global crude steel production reaching 1.8 Gt for the year 2018, up by 4.6% compared to 2017. This enormous CO₂ footprint of steel mills, which accounts for up to 8% of anthropogenic CO₂ emissions must be substantially reduced.

Given the urgency of emission reductions, the very different characteristics of the CO₂ containing streams emanating from steel plants and the huge quantities of CO₂ involved, a portfolio of promising CO₂ capture technologies must be developed and practically tested to high TRL to identify the optimal integration solutions that deliver the minimum cost and energy consumption.

“The critically important 2030 net zero emission target cannot be met without curtailing CO₂ emissions from the steel making industries. A multidisciplinary approach spanning technology development, safety, environmental, societal, policy and business aspects is required to tackle this huge challenge. The C⁴U project is aimed at achieving this.” – Prof. Haroun Mahgerefteh, UCL
The C⁴U Project Coordinator

How?

C⁴U CO₂ Capture Technology

C⁴U aims to advance 2 emerging carbon capture technologies, known as DISPLACE and CASOH, which have the potential to tackle up to 94% of the CO₂ sources in a steel mill.

DISPLACE – high-temperature sorption-displacement process for CO₂ recovery

CASOH – Calcium Assisted Steel mill Off-gas Hydrogen production

Both DISPLACE and CASOH technologies involve high temperatures gas-solid separation processes that reduce the exergy penalty associated with CO₂ capture. This is due to their ability to:

1. recover heat at very high temperatures that can be used for energy-demanding processes in the steel plant (i.e. reheating furnaces and CO₂-free power generation), and
2. co-produce H₂/N₂ fuel gases that can lead to the decarbonization of energy-consuming processes in the steel mill or the manufacture of high-value products.

These C⁴U capture technologies will be optimised for a wide range of operating conditions typical of steel mills, leading to a significant improvement in Key Performance Indicators (KPIs), such as the capture rate and associated energy and cost requirements.

The C⁴U capture functional materials are not on the Critical Raw Materials list of the EU.

The experimental testing at TRL7, combined with the modelling work at capture plant, steel mill and industrial cluster levels, will provide the basis for C⁴U capture technology scale-up and hence precise and reliable cost estimates at TRL9, whilst meeting the CO₂ quality requirements for pipeline transportation, utilisation and storage.

Integration into CCUS Clusters

The planned North Sea Port industrial CCUS cluster. Figure courtesy of North Sea Port, Gent, Belgium.

Regarding the connection of the CO₂ streams to the pipeline transport networks for ultimate geological storage and/or utilisation, many relevant issues need to be considered to identify techno-economic optimums. Work based on CO₂QUEST and CO₂PipeHaz projects has shown that many of the impurities in the CO₂ stream even if present in small proportions have unique and likely significant impact on the CO₂ compression work, cost of capture and ultimately the economic and safe operation of both the transportation pipeline and the storage site. These issues can be dealt with by further purification of the steelworks off-gases and/or captured CO₂ but the inevitable increase in cost may become prohibitive. As such, a whole-system approach is required balancing the different requirements of capture, pipeline transportation and storage, as well as society.

An important challenge for the development of CCUS clusters is to demonstrate and commercialise the entire value chain and to establish a framework for the long-term business case, requiring governmental and public support.

The C⁴U project will capitalise on the diversity of stakeholder knowledge and the technology base to optimise the performance of next generation capture technologies, integrated with their industrial emissions sources and operating as part of the North Sea Port CCUS industrial cluster.

C⁴U is the first project to consider technology development alongside societal, business and policy considerations for a real industrial cluster by taking into account all the major relevant factors and actors. We balance the technical demonstration with integrated and solution-focused societal readiness research, distinguishing between public and private sector stakeholders.