Aug 2, 2024 · 46m · catalyst
Pathways to decarbonizing steel
0:00 / 0:00
gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
In this episode of Catalyst, host Shayle Kann and industrial decarbonization expert Rebecca Dell explore the technical and economic pathways to clean up global steel manufacturing. They evaluate hydrogen direct reduced iron, molten oxide electrolysis, scrap recycling limitations, and the immense global scale of primary steel production.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. Shayle holds 21.2% of the talking time here. How this is scored →
Shayle as informed peer 5.9 Guest teaching 5.1 Guest disagreement 1.3 Shayle pushing back 1.7
speaking balance: gold is Shayle, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 31:08 Playful investor bias tease
Rebecca jokingly warns the audience to be skeptical of Shayle's commentary regarding direct electrification startup Boston Metal due to his venture fund's investment.
Hardest push from Shayle ▶ 7:15 Economic growth vs. recycling steady-state challengeShayle challenges the assumption of scrap steel limits by asking if stopping global economic growth would theoretically drop virgin steel demand close to zero.
Biggest teaching moment ▶ 34:45 Dispersed chimney stacks kill CCS retrofit viabilityRebecca explains that large point sources only make up about 60% of steel mill emissions, leaving dozens of distributed reheat burners that render carbon capture cost-prohibitive.
Shayle holds their own ▶ 12:12 Breaking down the dual chemical emissions in ironmakingShayle articulates the chemical process of carbon binding with oxygen in iron oxide alongside combustion emissions, comparing it to the decarbonization challenges in cement production.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | Shayle as informed peer | Guest teaching | Guest disagreement | Shayle pushing back | Why |
|---|---|---|---|---|---|---|
| Global Mineral Extraction Scale and Steel Decarbonization Context | 6 | 5 | 1 | 2 | Shayle opens with detailed statistics on global mineral extraction and probes the math behind recycling rates versus economic growth. Rebecca explains how lag times in durable goods and saturation curves affect primary steel demand. | |
| Blast Furnace Chemistry and Direct Reduced Iron Mechanics | 7 | 5 | 1 | 2 | Shayle articulates the core chemical challenge of blast furnaces and natural gas limitations, prompting Rebecca to detail the mechanical role of solid metallurgical coal and the commercial status of methane DRI. | |
| Opportunities and Obstacles in Hydrogen Direct Reduced Iron | 5 | 5 | 1 | 1 | Rebecca explains the technical viability of syngas blending up to 70% hydrogen and highlights cost and ore quality constraints, with Shayle underscoring the downstream economic implications. | |
| Mid-Roll Commercial Break: Power Infrastructure and VPP Technologies | 6 | 5 | 2 | 2 | Following the mid-roll ad read, Rebecca outlines the massive electrical demand of molten oxide electrolysis and playfully jokes about Shayle's investment conflict with Boston Metal, which Shayle acknowledges. | |
| Evaluating Carbon Capture and Storage Hurdles in Steel Mills | 5 | 6 | 2 | 2 | Rebecca details why CCS struggles in steel mills due to dispersed minor emission sources across the plant, reframing Shayle's query on why retrofits have largely stalled after earlier European pilot trials. | |
| Major Global Steel Producers and Advanced Hydrogen DRI Projects | 6 | 5 | 1 | 2 | Shayle draws a parallel to shipping and methanol adoption, leading Rebecca to survey leading hydrogen DRI projects across Sweden, Germany, and the United States. | |
| Material Substitution Limitations and Structural Steel Efficiency | 6 | 5 | 1 | 1 | Shayle investigates the viability of material substitution. Rebecca explains the strict geographic limits on mass timber and compares manufacturing cost and energy intensity with aluminum. |
Statements from this episode (20)
Dell: Steelmaking emits more greenhouse gases than anything except electricity
“Making steel emits more greenhouse gases than anything else except making electricity.”
Dell: Global steel emissions exceed four billion tons of CO2 equivalent annually
“The total emissions of the global steel industry from all sources is a bit more than four billion tons of CO₂ equivalent every year, which means that it's, you know, maybe like eight-ish percent of, ah, greenhouse gas emissions, depending on exactly how you co…”
Dell: Steel is the most recycled material in the world
“Steel is actually the most recycled material of all, full stop.”
Dell: Rich countries recycle about 85% of end-of-life steel
“In places where we have good statistics, which tend to be higher income countries, we usually find something like 85% of end-of-life steel Is collected and recycled. That's probably pretty close to a practical limit. We might be able to push that up to 90%, bu…”
Dell: Steel demand saturates once countries reach high-income status
“Demand for steel tends to saturate. So, you know, of all the things that I listed, like, ah, you know, buildings, infrastructure, vehicles, ah, equipment, those are things that, like, when a country moves from being low income to being middle income, They're b…”
Dell: Over 90% of Virgin Iron Is Made in Blast Furnaces
“So, the iron making process, that's really where the major driver of all the greenhouse gas emissions from the, ah, the steel industry come from, and more than 90% of iron made today is made with a single piece of equipment, which is called the blast furnace.”
Dell: Almost Every Steel Mill Produces More CO2 Than Steel
“So if you look at, like, the total process Of the iron making and the steel making together for a vet, just like a very typical conventional blast furnace facility, you're usually going to end up with more than two tons of CO two per ton of steel, which is kin…”
Dell: Existing DRI furnaces can handle up to 70% hydrogen without changes
“The companies that make these furnaces, they all say that, like, basically you can get up to 70% hydrogen with no changes. You can just keep operating your furnace as normal with up to 70% hydrogen”
Dell: The steel industry universally believes hydrogen DRI is technically viable
“I have talked to at least dozens of people in the steel industry over the years, and I've literally never heard anybody be like, I don't think hydrogen DRI is going to work. Everybody believes it will work.”
Dell: Current DRI Technology Requires Higher-Grade Iron Ore Than Blast Furnaces
“The current DRI technology requires a higher quality iron ore than a blast furnace does, and so it, we could not take, if we were just gonna use the iron ore that we are currently mining, we can't straightforwardly just put all of that in a shaft furnace”
Dell: Electrifying a single standard steel mill requires four gigawatts of power
“If you were to fully electrify this process, that might be something like four gigawatts of electricity. Average load. Not peak load. Average load. So we're talking about, like, four nuclear power stations to run one normie steel mill.”
Dell: Electrolysis to hydrogen incurs a 25% to 30% energy conversion loss
“If we can save the, like, 25 or 30% of the electricity that we would lose converting to hydrogen in the middle, that would be very valuable.”
Dell: Boston Metal's commercial iron cell should deploy in one to two years
“We're still waiting for the commercial deployment of the sort of the actual iron-making cell, which should come in the next, I think, year or two, but honestly, you would know better than me.”
Dell: No steel company is commercializing large-scale blast furnace carbon capture
“There's very little going on in the world of carbon capture in the steel industry right now. There are a there are no large-scale efforts to commercialize this technology. Like, there isn't a single steel company anywhere in the world that's like, we're gonna …”
Dell: Half of global steel is produced in China
“Geographically, half of all the steel in the world is made in China.”
Dell: Six large-scale hydrogen DRI steel projects are under development globally
“Now maybe we can claim that there are six, kind of, Serious, large-scale hydrogen DRI projects that are underdeveloped development, underdevelopment development around the world. There's two in Sweden, two in Germany, and two in the U.S.”
Dell: Germany pledged €3B in subsidies for Thyssenkrupp and Salzgitter hydrogen DRI
“And so they have pledged three billion euros of support to these two German companies a combination of both capital support and hydrogen subsidies for them to do commercial scale hydrogen DRI projects.”
Dell: Mass timber substitution is viable only in North America and Northern Europe
“Really, like, North America and maybe some small parts of Northern Europe are the only places in the world that, like, have the trees. And Everywhere else, if you did that, you would be driving deforestation that would make the whole thing counterproductive.”
Dell: Buildings use 50% to 100% more structural material than codes require
“When people do studies on these type of thing, they typically find that buildings use between 50 and a hundred percent more structural material than is required to comply with building codes, and they do that because the structural material, mainly steel and c…”