Is the steel industry's carbon problem actually a resource problem in disguise?

In this episode of Wicked Problems, we explore one of the most promising, and least-discussed, frontiers in industrial decarbonisation. Dr Harriet Kildahl is the CTO and co-founder of Perocycle, a deep tech spin-out from the University of Birmingham focused on eliminating carbon emissions from heavy industry through a closed-loop thermochemical process. As a chemical engineer and entrepreneur with a background in pioneering industrial decarbonisation, Harriet brings both the scientific rigour and the commercial ambition needed to tackle one of the hardest problems in the green transition.

Perocycle's approach is grounded in a deceptively simple insight: the CO2 that steel furnaces emit is not just a waste product, it is also the raw material needed to keep the process running. By splitting that CO2 back into carbon monoxide and recycling it directly into the furnace, Perocycle creates a loop that displaces coal, coke, and natural gas without requiring carbon capture and storage.

In this episode, we cover:

• Why fossil fuels in steelmaking are not just an energy source but a chemical input, and why that makes decarbonisation so difficult
• How Perocycle's thermochemical catalyst splits CO2 into carbon monoxide and recycles it back into the furnace in a continuous loop
• The difference between blast furnace and direct reduced iron (DRI) steelmaking, and how Perocycle's process works with both
• Where Perocycle sits on its commercialisation journey, from lab-scale catalyst work to a mobile pilot plant targeting 1,000 tonnes of CO2 per year
• Why the economics of decarbonisation matter as much as the science, and how Perocycle's model is designed to save steel mills money, not just emissions
• How a lean, partnership-led approach is helping Perocycle de-risk its path to first commercial deployment
• What the green transition looks like as a second industrial revolution, and why the UK needs to be quicker at turning innovation into execution

Whether you are an investor tracking the industrial decarbonisation space, an operator in the steel or heavy industry sector, or a green tech founder navigating the path from deep tech to commercial scale, this episode offers a clear-eyed and technically grounded view of what the transition to a closed carbon economy could look like in practice.

Chapters

00:00 — The Only Way Decarbonisation Happens Is If It Saves Money 00:18 — Why the UK Must Execute on Green Innovation, Not Just Invent It 01:00 — Introducing Perocycle: Deep Tech Spin-Out With a Closed Carbon Loop 02:28 — How Steel Is Made, and Why Carbon Is So Hard to Remove 04:42 — The Circular Process: Splitting CO2 and Putting It Straight Back In 05:13 — How the Thermochemical Catalyst Actually Works 06:40 — From Lab Reactor to Mobile Pilot Plant 21:22 — Ambition and Innovation as Bedfellows: Building for Scale 22:26 — Staying Lean: Team Structure and the Partnership Approach 27:57 — Decarbonisation Only Works If It Makes Economic Sense

Resources

Wicked Problems wickedproblems.fm

Perocycle perocycle.com

Perocycle on LinkedIn linkedin.com/company/perocycle

Zero Cycle Newsletter (Perocycle) perocycle.com

UK Government Net Zero Strategy gov.uk/net-zero

UK Industrial Decarbonisation Strategy gov.uk/industrial-decarbonisation-strategy

University of Birmingham Clean Futures birmingham.ac.uk