Under the Paris Agreement adopted on 12 December 2015 and ratified a year later, over 190 countries around the world committed to limiting global warming to well below 2, and preferably to 1.5 degrees Celsius, compared to pre-industrial levels. To do so, the signatories to the agreement are to cut global greenhouse gas emissions in an aim to become greenhouse gas emissions neutral by the middle of this century.
Among others, this means that the steel sector and other energy-intensive industries must find ways to considerably reduce their emission levels. It has been calculated that to meet the 2050 European climate and energy targets, the iron and steel industry’s CO2 footprint needs to reduce by 80-95%, compared to 1990 levels, by 2050.
To that end, Germany launched in 2016 its Carbon2Chem project, a multi-centre, multi-disciplinary project participated in by the Max Planck institute, Fraunhofer Umsicht, a number of universities and eight industrial who together are working towards a solution that can be deployed worldwide in order to convert smelter gases into primary products for fuels, plastics, or fertilizers. A pilot plant, located next to the thyssenkrupp steel mill in Duisburg, has operated at full capacity since 2018. Ultimately, it is projected that around 20 million tons of the steel industry's annual CO₂ emissions in Germany could become economically viable in the long term.
The initial phase of the project ran up until last year; the German government will continue funding the project with an additional 75 million euros until 2024.
The project is divided into a number of sub-projects; Evonik, for example, is coordinating the development of catalysts able to transform CO and H2 - essential components of smelter gas - into higher alcohols and polyalcohols; BASF is focused on oxymethylene ethers (OME) as possible diesel fuel components; and Covestro on the development of polymers, with a focus on the use of carbon monoxide (CO) from steel industry metallurgical gases for the production of high-quality polycarbonates.
Having reached the second stage of this Carbon2Polymers project, Covestro has now commissioned a mini-plant at its Dormagen site, where the company will test whether the quality of the CO from metallurgical gases is sufficient for further processing.
The process has great sustainability potential: Initial life cycle analyses show that around 0.48 kilograms of CO₂ equivalent can be saved per kilogram of CO provided in the steel industry-chemical industry alliance. This means savings of more than 80 percent, the company said.
Moreover, the knowledge gained from this project could benefit other projects as well. "Coke oven gases have the advantage that they bring with them many accompanying substances,” said Stefanie Eiden, who is heading the Carbon2Polymers subproject at Covestro. “If we succeed in processing the CO in such a way that we can use it to produce our high-performance plastics, we can also do the same with other non-fossil-based CO sources."
Evaluation of the economic and ecological viability of the process will be completed by the end of the year.
The Carbon2Polymers project is a further milestone in the development of a global circular economy, said Markus Steilemann, CEO of Covestro, adding that using coke oven gases, ‘we are further advancing the repeated use of raw materials and thus closing the cycle’.
”We can only succeed in the fight against climate change if we enter into profitable cooperations. The collaboration with thyssenkrupp illustrates once again the enormous contribution industry can make on the path to greenhouse gas-neutral production."