From Steel to Ethylene: Super Dry Reforming of CO2

Closing the carbon cycle in energy intensive industries (EIIs) (steel, fuels, chemicals, cement, etc.) is a major objective for the EU and the associated Green Deal to enable a climate-neutral, Circular Economy by 2050.^1-3 Although EIIs have reduced greenhouse gas (GHG) emissions by 36% between 1990-2015, a further decrease is necessary to meet EU targets and EIIs commitments. This is only possible if different actors across the value chain of the EIIs combine forces, resulting in a fade away of the traditional borders between these sectors.

A crucial step to address GHG emissions in steel manufacture is to close the C-cycle by using the emitted CO₂ to create a value chain and produce carbon-neutral fuels and chemicals. This approach will amplify the CO₂ equivalent reduction compared to capture/storage-only solution (baseline to achieve the carbon footprint reduction). In fact, together with a reduction of GHG direct emissions there is an enhanced CO₂ eq. reduction due to substitution of fossil fuels (FF) and by promoting direct use of renewable energy (RE). In addition, this concept will foster symbiosis and circularity with other industrial sectors (use CO₂ from other EIIs).

The value chain that will be discussed is as follows:

• conversion of CO₂ to CO via the innovative Super Dry Reforming (SDR) technology
• adding innovative elements to the SDR technology: electrification with renewable energy innovative reactor designs and alternative carbon sources (e.g. non-recyclable plastic waste)
• gas fermentation of CO to ethanol
• coupling of the core technologies of SDR and gas fermentation to commercial value chain technologies

The SDR pilot plant is currently under construction and should be able to provide the first results if COVID does not interfere.

Our calculations show that the SDR technology combined with Lanzatech's ethanol production technology will be able to achieve less than 20 g CO₂ eq./MJ and be a true game changer in achieving an ethanol production with acceptable climate impacts. Additional innovations to the SDR technology will even lower this impact further. Producing isopropanol rather than ethanol, and extending the value chain to produce, in a flexible way, C₂-C₃ olefins such as ethylene and propylene (with market sizes > 120 Mton/y and > 300 B€/y), will further consolidate the economics, and expand market opportunities.