Taking carbon out of the air and putting it into concrete

Under a new partnership, Heirloom Carbon Technologies captures
carbon dioxide from the air, then passes it to CarbonCure
Technologies, which permanently sequesters it in concrete. In
this episode, CEOs Shashank Samala of Heirloom and Robert Niven
of CarbonCure give the lowdown on this pioneering carbon removal
project.


(PDF
transcript)


(Active
transcript)


Text transcript:


David Roberts


Last month saw the announcement of a pioneering project: a
company called Heirloom Carbon Technologies will capture carbon
dioxide from the ambient air and then hand it off to a company
called CarbonCure Technologies, which will inject the CO2 into
concrete made by a company called Central Concrete. It will mark
the first time ever that carbon from the air is permanently
sequestered in concrete.


Heirloom, with runs the US’s only operating direct air capture
(DAC) facility, does not use the familiar capture technique that
involves giant fans. Instead, it binds carbon to exposed rock and
then cooks it out using electric kilns — and then binds more
carbon to the rock, in a circular process. It claims the capture
is cheaper and more efficient than previous methods.


CarbonCure injects the CO2 into a concrete mixer, where it
mineralizes, becoming permanently captured even if the building
using the concrete is demolished. In the process, it strengthens
the mix, requiring less cement and cutting costs.


Direct air capture (DAC) has faced a great deal of skepticism,
and concrete has the reputation as one of the worst carbon
offenders, so this project — one of the first that can fairly be
called carbon removal — could go a long way toward convincing
investors that the former can help the latter change its ways,
with a technology that is, at least some day, commercializable.


I talked with Heirloom CEO Shashank Samala and CarbonCure CEO
Robert Niven about their respective processes, how they work
together, and what the project says about the future of carbon
removal.


All right, Shashank Samala, CEO of Heirloom Carbon Technologies,
and Robert Niven, CEO of CarbonCure. Welcome to Volts. Thank you
guys for coming.


Robert Niven


Thanks very much for having us.


David Roberts


This is really a nifty project you guys are working on together.
It's two separate pieces that normally I would probably do a pod
on each. So we're going to have to, or at least I'm going to have
to be less wordy than normal to squeeze it all in in 1 hour. I
want to talk about both halves of it. So let's start with
Shashank. The first half of this process is Heirloom’s process of
removing carbon from the air. Can you just explain quickly how
that process works, what it looks like?


Shashank Samala


Sure. So, Heirloom, if you're not aware of who we are, our goal
is to basically remove a billion tons of CO2 from the atmosphere
annually by 2035. And our whole goal is to help reverse climate
change. And the way we do that is through a process called
limestone looping. Essentially what that means is we use a rock
that is very abundant in nature, limestone, that has a natural
propensity to pull carbon from the air. What we do is we
basically give superpowers to limestone to pull a lot more carbon
than it otherwise would naturally.


So how it works is we start with limestone, we put that into a
kiln, we heat it up, and we pull out the CO2 that's already
sequestered in the limestone, which makes the leftover lime
highly thirsty for CO2. So we take advantage of that natural
property by laying it out on trays. Think about baking trays. I
lay them out on trays, and then we vertically stack those trays,
very tall, and the air brings in the CO2. And the the lime
sitting on the tray acts as a sponge, pulls up the CO2 molecules.
From there, it becomes limestone again after it pulls it up. And
we do that in about three days.


Naturally, it would take many months to pull carbon from the air.
We did that in three days using our well treated algorithms and
technology.


David Roberts


So in three days means the lime is full, absorbed as much CO2 as
it can.


Shashank Samala


Exactly. We don't go all the way up to 100%. We go up to about
85%, which is sort of the optimal point, we realized. And then,
yeah, it becomes limestone again, which is great, because that's
what you started with. So we can recycle limestone by putting it
back into the kiln, pull out the CO2 we captured, and then store
it underground or store it into concrete, which you're doing with
Carbon here.


David Roberts


Right. So one of the questions I had is you crush up this lime
and spread it out on, well, calcium carbonate is limestone.
Calcium carbonate ...


The chemical formula. Exactly right, the calcium carbonate.


And then after you bake it, take CO2 out. Then what is the
chemical remainder?


Shashank Samala


Calcium oxide.


David Roberts


Calcium oxide. Right. So you have calcium oxide laid out on
trays, becoming calcium carbonate. Then you take the calcium
carbonate, cook it, get the CO2 out of it, and then do the whole
thing over again.


Shashank Samala


Exactly. We just keep doing that. It's a super simple chemical
process to pull carbon from the air.


David Roberts


You have this calcium oxide, and it's absorbing CO2 from the air.
That just sounds like an ambient chemical process. How can it be
accelerated? What does it even mean to accelerate that?


Shashank Samala


So, technically, calcium oxide, we hydrate it, it becomes calcium
hydroxide. Basically, there's a water molecule binding onto the
calcium oxide. But essentially what we realized is that there's a
specific parameter space where particle size, particle size
distribution, thickness of the bed, humidity, temperature,
airflow, there's all these different variables that dictate how
fast calcium hydroxide likes to bind on to CO2 molecules. So it
just so happens that in nature, there's a specific parameter
space where this happens, and in nature, it doesn't see that
parameter space as often. What we do is essentially make it see
that all the time.


And how we specifically do that is really the IP. But we've
collected millions and millions of data points over the last few
years, doing lots of small experiments, adjusting thickness,
adjusting particle size, surface area, all of these things. And
we found that parameter space. And as the weather changes
throughout the day, we have to change that parameter space. So
essentially, we babysit these trays. If you look at, essentially,
what this technology looks like is you have these tall stacks of
trays, and in the middle, you have a little robot that goes up
and down, and every few hours, it's babysitting these trays so
that they can be carbonating as fast as they possibly could.


David Roberts


So is this all in a big climate controlled facility of some kind?
I mean, presumably, you have to control the climate because you
need specific conditions.


Shashank Samala


Yeah. So, fortunately, we were able to not have it be fully
climate controlled. So if you actually if you come to Brisbane,
our headquarters, where we have this pilot facility, this is
actually sitting outside in ambient conditions. Yes. So this
robot is actually creating a microclimate for each tray every few
hours. So because what we're trying to do is try to symbiotically
work with nature to pull carbon, right. And nature gives you
humidity and temperature and airflow. Right. We don't want to put
forced airflow, these large fans, pushing air through. We want to
leverage wind. We want to leverage humidity.


And then when it doesn't get enough from nature, we complement
it. We accelerate it with a few things.


David Roberts


And so when you have this calcium carbonate that's absorbed all
the CO2 and you put it in the kiln, what does that kiln look
like? How's it powered? And how hot does it have to get?


Shashank Samala


So the kiln is actually super simple. It's like your toaster
oven. Effectively, it's electric. It can be run by renewable
energy. Essentially, it's a metal tube, and you have an electric
heating element, and just like your toaster oven, that sort of
surrounds it. And then you have insulation ceramic that keeps the
heat inside. And then that's it. You essentially send calcium
carbonate through that metal tube. It stays in there for the
order of minutes.


David Roberts


And how hot is the inside?


Shashank Samala


It's about 850 to 900 degrees C.


David Roberts


Oh, wow. Really hot.


Shashank Samala


It's hot. Electric kilns can actually go way higher than that.
That's one of the questions we get. It's like, oh, you're using
electricity. Why are you not? You would think that you would use
natural gas or some other form of combustion to get that
temperature. It's like no, the electric arc furnaces for steel
actually go up to, like, 14,000, 15,000 degrees C. So, yeah, we
need about 850, 900 C. And then, you know, it's only there for
seconds to minutes.


David Roberts


Oh, really? So the CO2 comes out pretty easily.


Shashank Samala


Yeah, exactly. So there's only two things that come out. It's CO2
and calcium oxide. The CO2, it's pure. We capture that gas and
compress it. And then the calcium oxide, we reuse it again.


David Roberts


And what's the sort of energy balance here? It just strikes me
that it must take a lot of you're saving energy by letting
natural conditions do the air circulation and humidifying and all
that, but you're using a lot of energy in the kiln. I'm just sort
of curious how energy intensive this is per sort of captured ton
of CO2. I guess there's not a big comparison base of other carbon
capture technologies to compare it against, but well, the lens.


Shashank Samala


We when we first started looking for which approach to use to
pull carbon from the air, two things were important to us. One
was use abundant, abundant minerals, abundant processes.


David Roberts


Did you start with the idea of mineralization, or did you just
come to this with just a blank sheet of paper and say, what's the
best way to capture carbon?


Shashank Samala


So I actually came in from the mineralization perspective. So I
was looking at rocks. I was talking to lots of scientists working
on using rocks to pull carbon because it's just like an abundant
mineral to start. And if you want to pull gigatons of CO2. You
need to have abundant minerals that are also trillions of tons of
rock in the Earth's crust. And then we realized, actually, just
using rocks won't get you the economics and the land. We wanted
to use as little land as possible. We want to use as little water
and energy as possible.


So we needed to engineer it a little bit to ensure that we use as
little energy as possible.


David Roberts


In terms of materials, how much is lost in the full cycle of sort
of you're mining the limestone to begin with, I guess, right?
There are limestone mines around already. Limestones abundant. So
you're mining the limestone to begin with. Once the limestone
goes through, one of these whole cycles gets cooked, replaced,
absorbed, absorbed again, cooked again. How much material is lost
in those cycles?


Shashank Samala


So, so far we found very small material losses. Essentially,
that's one of our main metrics over the last couple of years as
we were scaling it up to actually putting this outside. And one
of the things we get, it's like, hey, if you put these rocks out
there, doesn't the wind blow everything off? Essentially what
happens is when this is hydrated, it actually turns into a crust.
It's like a cake. So, yeah, we've seen very small material
losses, and we will continue to tweak the entire process to
reduce it even further.


David Roberts


But your materials are pretty cheap. They're not the big cost
center.


Shashank Samala


It's not. I mean, the material itself is like less than half a
percent of the entire CapEx. Limestone is, You can buy it for $20
or $30 a ton. It's the second most mine material on the planet.
You have way more than you need.


David Roberts


One additional question I wanted to ask about the process is you
make a big deal about modularity. And this is a subject close to
the heart of Volts listeners. We just did a pod a few weeks ago
about sort of what kinds of technologies get on learning curves
and what kinds don't and sort of what features of a technology
lend it to rapid learning. And one of those features is of course
modularity is it have easily reproducible bits. So just say a
little bit about how you sort of had that in mind as you designed
the process.


Shashank Samala


It was absolutely number one for me. I come from a manufacturing
background. Before this I had an electronics manufacturing
company where we basically built lots of circuit boards in a
factory. One of the things that humanity really understands and
knows is how to build things in mass volumes with a very steep
learning curve. Right? And we saw that with solar panels,
lithiumion batteries, cars. Tell the team here it's like you're
trying to build cars, not airports. Right? Airports are on site
custom construction and the folks who are working on one airport
are not going to the next airport.


The learnings don't don't translate.


David Roberts


When people think about a big direct air capture facility. I
think probably what comes to mind is something like an airport, a
big bespoke one time thing, but you are trying to avoid that.


Shashank Samala


Yeah. So there's a difference between modularity and the plants,
right? So the plants themselves need to have modules that are
mass produceable or built in a factory so they can just be
brought to the site, bolt them to the ground, ready to go,
instead of having to build up from the ground up on the site. So
essentially you're trying to minimize on site construction. So
there's always like solar panels, right? They need to be bolted
down to the ground. There is some concrete slabs involved and
wiring and plumbing, et cetera. But you want to minimize that as
much as possible and that's the fundamental idea behind Heirloom.


Like our tray is basically the smallest module and we make lots
and lots of trays.


David Roberts


One doesn't think of trays as something that have a lot of room
for innovation. Is there anything special about the trays?


Shashank Samala


There's a few things that are custom and it so happens that the
world, we needed such large trays that we went to the vendor that
makes the largest trays in the world and they just would not make
the trays that we needed. So we actually make custom trays. Yeah,
they're large, so we make the world's largest trays. They use
traditional manufacturing processes, extrusion, thermal, formula,
et. They're not complicated and that's one of the principles
behind Heirloom too. We don't want to come up with a new
manufacturing process. The world has immense just lots and lots
of experience building all sorts of things and we just want to
leverage them and scale them to the max because that's how you
get 2 billion tons of CO2 remove it as fast as possible.


David Roberts


So the trays a module, the trays stack.


Shashank Samala


Are also and the next level of module.


David Roberts


Is a module. And presumably the kilns are pretty standard issue.
They don't have to be tweaked or whatever for individual.


Shashank Samala


Yeah, traditionally, if you go to a cement factory, kilns are
actually these massive onsite built kilns. But we use an electric
kiln technology that we're actually going to be releasing a few
weeks here that is modular. So you essentially stack a couple of
cylinders on top of each other.


David Roberts


Oh, interesting. So you did a little design work of kilns of your
own?


Shashank Samala


Yeah, we did some here. We were working with a technology partner
to do that too.


David Roberts


This whole process, presumably, if you sat down to try to figure
out what's the best process for capturing air carbon, you looked
at the traditional. I think when most people think of direct air
capture, if they think of it at all these days, the few people
who think about it at all think about the big machines out in the
desert with the fans sort of pulling air over a sorbent. Is your
process more efficient than that in terms of sort of energy and
material input versus CO2 output?


Shashank Samala


Yes. At the end of the day, what we're trying to do is use
abundant materials that are incredibly cheap and use as little
energy. That is thermodynamically possible. Really, all of our
energy is in that back end where we are regenerating the sponge,
which is common across all directory capture technologies. That's
sort of second law of thermodynamics. You have to put in some
energy to regenerate the sorbent. And for us, we want to
essentially lower that regeneration energy as much as possible
and then not use energy when we can leverage nature and other
things.


David Roberts


It strikes me then that the cost of energy is going to be one of
your big top line items. How big is the cost of energy in your
overall picture?


Shashank Samala


At scale, it's more than half. And that's exactly where you want
to be, right? Because laws of physics tells us that you have to
put in energy to do gas separation, especially gas separation
that is as hard as 400 parts per million. So if you design a
system and you look at the long term economics, you want to make
sure that, you know, at long term, almost all of all of that is
energy, because that's something you cannot beat. Like energy
creates your cost floor.


David Roberts


Right.


Shashank Samala


If your CapEx ends up being a much bigger proportion, well, you
haven't really designed or engineered it. Well, that's what I
tell the team. It's like you want your cost floor to determine by
physics and not engineering. So that's why we use very simple
trays. We're just putting a bunch of rocks and a bunch of trays
and using a metal tube, on the other hand, and putting some
insulation around it. So you want to keep that as low as possible
so that your your $100 a ton. That's really our cost target.
You've probably heard of the cost target.


$100 per ton. That's really the cost point where it's affordable
for humanity to do this at a billion ton scale and actually make
a meaningful impact.


David Roberts


And of course, it's like renewable electricity is galloping down
the aforementioned cost curve. So insofar as you can hit your
ride to it, it's going to tear you down the cost curve too.


Shashank Samala


Yeah, exactly. The nice thing about renewable energy for us is
you can pull carbon from the air anywhere, right? It can be in
the Gulf Coast. It can be New Zealand, it can be South Africa,
India, Indonesia. Wherever you go, the concentration of CO2 in
the air is exactly the same. And that's what our technology works
with. So we will go to places where renewable energy supply is
high, but the demand is low, so we don't take away the supply
that could have been used for food production or putting our
buildings.


David Roberts


So ideally then, these facilities would be colocated with some
big renewable energy just to minimize ...


Exactly.


Transmission costs and all that. Two final questions. One is, you
mentioned the $100 cost per ton target. Can you give us a sense
of where you are on the road to that? Is there a number?


Shashank Samala


Yeah, so we're in the sort of high hundreds of dollars per ton
right now and essentially we are at the demonstration scale,
right? We are building this by hand, engineers are building them.
We built a couple of Formula One cars effectively, and we need to
get to a stage where we can mass produce Toyotas off of the
factory line. What is Formula One cars cost these days? Like
millions of dollars versus $20,000 Toyota. So at the end of the
day, the material inputs are so cheap, limestone and trays and
metal tubes, that at scale, we should be able to hit that cost.


And for us, it's all about how do you get there as fast as
possible.


David Roberts


Yeah. And if you're chosen super cheap material and renewable
energy, which is super cheap, and if those are your only two
inputs, logic says you're going to get cheap eventually as you
approach the cost of the materials. So the final question is
this. At the end of this process, you have CO2, which you can do
anything with. Are you deliberately staying out of the business
of doing something with it? I mean, is the model always to just
hand off the CO2 to someone else who's going to do something with
it?


Shashank Samala


Yeah, there's a lot of things you can do with CO2, but for us,
there's only two things you can do so far. One we are looking at
is concrete, working with folks like CarbonCure and putting it
underground. And both are permanent. And an incredibly important
principle is permanence because CO2 stays in the air for 1000
years. So you don't want to pull carbon from the air only for
that gas to go back in the air ten years later, 100 years later,
we're just pushing the buck into the future. So for us, it's
incredibly important that we permanently sequester it into
something so it doesn't come back out.


And the only two things we've found so far with that type of over
1000 year durability is concrete, where essentially you're
binding CO2 into a rock, it mineralizes and then putting it
underground. And that is something that humanity has over five
decades of experience putting CO2 underground. And it's permanent
and we know it's safe.


David Roberts


But are you planning at all to get into the permanent storage
business? Or is the idea that you produce the carbon and some
other entity is running the storage facility, how does that work?


Shashank Samala


Some other entity is running the storage facility. We're going to
be focused on really building an incredibly efficient,
cost-effective capture system. And we will work with a whole set
of partners to put a billion tons of CO2 stored somewhere
permanently.


David Roberts


I've heard you say this in other interviews, too. But just to be
clear, the vast bulk of it, especially once we get scaling up
towards whatever, billions and billions of tons, the vast bulk of
that is going to be stored in underground caverns. The amount
that can be used in a way that permanently sequesters it is a
relatively small fraction of the total amount that's going to be
produced.


Shashank Samala


Yeah, I mean, as much as possible, every ton of concrete we can
put CO2 into, we will do that. That is our first priority. Right?
Because essentially you're creating a stronger building material.
It's a value added product and it's permanent. You're checking
all the boxes and that's better than putting the waste
underground. So every ton of concrete, we can do that. We will
absolutely want to do that. And when we can't, we will put that
underground. And most likely at a gigaton scale, most of that
will likely be underground, but it's hard to predict the future,
right?


David Roberts


Right.


Rob, let's talk to you then, because here is where we get to the
part of the relay race where Shashank hands you the baton, or
rather hands you a bunch of tanks of CO2. So describe for us then
the CarbonCure process, which starts with a source of CO2. You
get the CO2 from Heirloom and then what?


Robert Niven


Sure, I'd be happy to jump into that just to help the audience
understand, is we're both carbon removal companies, but coming at
it from both ends of the process.


Shashank on the capture ourselves on the relay race, receiving
that CO2 and doing something with it. CarbonCure has been in
business for about ten years. We're a Canadian company and we
have about 700 plus customers worldwide that every day are using
CO2 to mineralize it in concrete. To make a better, stronger
concrete that provides some cost efficiencies by cement
efficiency. By making stronger concrete, you need less cement
which provides that economic incentive.


And low carbon concrete is in great demand in the market, not
only private sector, but we're seeing a lot of policy incentives
as well.


David Roberts


So you're in the business, you're sequestering carbon, you're
doing it today, you're getting CO2 from someone and sequestering
it in concrete. Do you have any what's the current scale so we
can get our heads around kind of what's involved there?


Robert Niven


We have everything connected through the cloud and you can
actually pull up our our home page and you can see the numbers go
up every second about how many metric tons and it's just about
250,000 metric tons to date. So the key difference here is that
most of our CO2 to date is received from what's called
post-industrial sources. So these are our large emitters and
rather than diverting those emissions into the atmosphere,
they're capturing it, compressing it. And companies that are
industrial gas companies are taking that CO2 and selling it to a
multitude of different industries.


And we're a relatively new user of that CO2.


David Roberts


The big one is beverages.


Robert Niven


Food and beverage is a big one. Yes, food and beverage. Also some
CO2 is used in things like enhanced oil recovery which some other
DAC companies are pursuing. So lots of different ways that you
can use CO2. But the main point is there's a large existing
commodity market for CO2. The key thing here and what's really
special about our work with Heirloom is that this is direct air
capture source of CO2, right? And by getting CO2 from the air it
allows you to actually reverse the effects of climate change and
pull down the parts per million of CO2 in the air rather than
limiting and reducing the rate of emissions that go into the air,
so there is a distinction.


David Roberts


Additionality is the term of art here. This is 100% additional
CO2.


Robert Niven


Well, I would still say that it's also additional if you're using
postindustrial CO2. The key difference here is like this actually
enables you to get into removal, a pure removal kind of category.


David Roberts


Right.


Robert Niven


For ourselves, we've always seen this as we'll develop huge and a
multitude thousands of storage centers, which is also called a
concrete plant to most people. We'll run ahead as fast as we can
and develop all of this demand for CO2. And then as DAC gets
online is that we'll have the optionality to be able to use that
CO2 when it's available.


David Roberts


Will there be degrees of greenness of concrete depending on the
source of CO2? Have you thought about that? Sort of like
different levels of concrete?


Robert Niven


I think so. We sell carbon credits as part of our business model
and we definitely hear from our credit buyers is that they're
willing to pay more if it's using atmospheric sources of CO2.


David Roberts


Interesting.


Robert Niven


Such as DAC or biogenic source or whatever it is, whatever can
get CO2 out of the air. There is a demand for that. The other
group that really matters are the people that purchase the
concrete. So these would be architects, engineers, building
owners. They're also really excited and probably not as
sophisticated on the CO2 sourcing question, but I wouldn't be
surprised if that starts to become higher in their consideration.
The other point that was brought up by Shashak earlier was
permanence. That is very, very important for everybody is we
don't want to be going through all of this trouble to put away
CO2 for it to just bubble out again in 30 days, like what's the
point? So that's very important.


David Roberts


So when you say you inject CO2 into the concrete process, spell
out a little bit what that means, what that looks like for people
who are not that familiar.


Robert Niven


Most people, if they're familiar with CarbonCure are aware of our
readymix technology. But CarbonCurever the last three years has
expanded by creating technologies that use CO2 in the concrete
value chain in different ways. But let's start off with the ready
mix technology. So whenever concrete, if anyone's visited a
concrete plant, there's about 125,000 of these locations
worldwide, about 7000 of them in the US. They're basically all
the same. They are mixing sites that take aggregates, rocks,
cement, water and a few performance enhancing chemicals to mix
those all up in a huge mixer. And then they pour that into a
concrete truck, which you are all aware of and seen driving
around the road.


And then that's delivered to the construction site so that if we
go back and look at that mixer is all those ingredients are being
added. And just like Shashank is like if we're really going to
meet scale is we want to have a modular system that in our case
retrofits these existing concrete plants very, very cheaply and
very very quickly without disrupting their production. In fact,
it takes us a day, we don't charge any CapEx and the system
starts to use that is enabled to start using that CO2 and becomes
a carbon removal factory. It starts mineralizing CO2 the next day
and it has all these value added benefits without creating a
price premium on the product.


David Roberts


Oh, interesting. So this is not some bespoke process that you
have to build a concrete plant around. You're literally just
going to an existing concrete plant, slapping something on that
takes a day to add and then from the concrete plant owner's
perspective, that's it. Nothing else changes. They don't have to
do anything else operationally to accommodate this at all.


Robert Niven


We automate everything. That's the key. And it's the same design
principles that Shashank has brought into his company. Of course,
he's done it fully, separately is you want to make this as simple
as possible to scale because the concrete industry just does not
have the discretionary budget to start. Spending a lot of risk
capital in these kinds of solutions. So we've done all that for
them.


David Roberts


And they're very small C conservative too, for obvious reasons.


Robert Niven


Perhaps it comes in all different flavors of concrete producers,
but they all want to work on this, but they have a lot of
limitations. So what we've tried to do is make it as simple as
possible, but also do it in a way that they receive the most
rewards and that can be in the form of cost efficiencies and
production, being able to tap into this rapidly growing demand in
the market for low, so they can sell more. We always recommend to
keep the price at parity and also participate in carbon markets.
So we create the incentive structure and make it really simple to
adopt and quick so that producers can start to mineralize CO2 as
quick as possible.


So back to your question how the process looks like is we're
actually adding CO2 into the mixer and please come to our website
as well. We actually have footage and video of what's happening
and then we also have some animation on what's happening at the
chemical level. But essentially by adding CO2, it's a very
similar type of reaction and thermodynamics as Heirloom. And that
that CO2 is very quick to react in seconds with the concrete and
it reforms a mineral, a calcium carbonate, if we go back to that
again, but in a specific size called it's a nanomaterial, which
provides all these performance benefits for concrete as it
develops its strength, which then leads to some commercial
benefits.


And then we also use CO2 to treat the main wastewater from the
plant and that's called our reclaimed water technology. So it's a
second way that we can mineralize a lot more CO2 on the concrete
plant, but at a different site of the concrete plant where all
their wastewater is being collected is we can actually treat that
water to have it upcycled so it can be reused instead of version
cement and water. And then finally we can make CO2 into
aggregates, but all three of those can be bundled together to be
able to drive down the carbon footprint of concrete.


David Roberts


Yeah, this was my question when I was looking at your website. If
I'm a concrete plant owner, can I get all of those versions?
Like, can I get CO2 in my wastewater and CO2 in my mixer and CO2
in my aggregate? And are they additive? Like, will that result in
three times the carbon removal?


Robert Niven


Yeah. And that's how we're building this business, is to create
multiple ways to mineralize CO2 in the concrete value chain and
then surround that by doing all the enabling work. So we make it
a very easy decision for concrete producers to do that. I will
caveat that we don't have the aggregate technology
commercialized, but the other two we do. In fact, we had the
first pilot with Heirloom that was at the Central Concrete
Facility, which is a division of Vulcan Materials in San Jose,
California. That plant is the first in the United States to have
the reclaimed water and the ready mixed technology.


So they're one of now two plants in the US. That are able to
provide that combo, which is really exciting,


David Roberts


Interesting and do the strengthening benefits you're talking
about, do you get double those too? When you do both the stages
of adding carbon.


Robert Niven


The ready mix technology gives you that strength benefit and then
on the reclaimed water, jury is still out on redefining the
strength benefit. But what it definitely does is it allows you
it's a substitution effect, is that you're actually able to
recover the cement in that wastewater and then use that instead
of virgin cement. So at the end of the day, it's the same effect
using less virgin cement to make concrete.


David Roberts


Right.


Robert Niven


But you're achieving that by mineralization. What's cool about
the reclaimed water technology is we actually won the Carbon
Xprize for this technology, which was defined as the world's most
scalable CO2 utilization technology.


David Roberts


Interesting. What happens to the water today? Is it just thrown
out or what happens to the reclaimed water?


Robert Niven


Most of it just gets thrown out today. The traditional way of
doing that is it would go into large settling ponds, they would
scoop out the settled material, which by the way, is valuable
cement and chemistry. That producer paid a lot of money for. And
there was a lot of CO2 release to make that that would often just
get landfilled and then the water would get sometimes treated for
PH and then discharged. So we're able to turn all that process
and eliminate it by reusing it in a circular manufacturing type
of design.


David Roberts


Interesting, a question about the strength benefits, are the
strength, by which we just mean the cement is a little stronger
and so you have to use a little bit less cement in the concrete.
So your savings that way, are those savings in terms of strength
enough to pay for the thing? Or do you have to value the
sequestration on some level to make this pencil out?


Robert Niven


We are able to provide the low carbon concrete to the market in
combination through our carbon credit sales and through these
manufacturing efficiencies of using less cement, we're able to
provide that concrete at no price premium by using a blend of
both contributions. And that's very important. Like a year ago,
if you go onto your podcast catalog, Rebecca Dell was on the show
talking about how green premium is really, really important. We
need to find ways to eliminate that to unlock adoption in
building materials. And green premium is really anything can
inhibit mass adoption. That's what's really important is that we
don't apply that green premium.


So that the market whether that be the government which is the
largest buyer and we're seeing a lot of buy clean type
legislation or private sector which have a lot of sustainability
targets from corporate actors are able then to make these kinds
of procurement decisions without compromising on price and
certainly not compromising on quality, and working with the same
suppliers that they've worked with for years prior.


David Roberts


Maybe this is a naive question, but if I'm a concrete
manufacturer and I can have this done and installed in a day,
it's not going to affect my operations. It's going to save me a
little money on reducing cement, it's going to make me a little
money on selling carbon credits. And otherwise I'm selling a more
or less identical product at a more or less identical price. Why
wouldn't I do that? What would stop someone from doing this?


Robert Niven


Yeah, I would say just education. But we're already, like I would
say I don't know for sure, but probably the fastest growing
technology in the concrete sector. Concrete sector is not known
to be rapidly adopting new technologies, but I would say we are
growing at a very rapid rate. And certainly there are different
kinds of concrete producers which normally adopt technology
faster than other types of producers profiles. And we're seeing
that happen. And the rate of adoption is happening far faster
when we see those market signals like the procurement policies or
even requiring environmental product declarations in the
procurement process.


So those kinds of things really accelerate this transition to the
market. There's a reason why so much innovation is happening in
San Francisco in the concrete sector, is because there's a lot of
companies that operate there that are really walking the talk.
And the concrete industry is enabled, empowered to bring their
best forward. But if concrete producers are in markets where
they're never hearing someone talk about decarbonisation, yeah,
they have 20 other things that, that they can prioritize, that
they need to work on.


David Roberts


Right? So you need some valuation of the carbon benefits to kind
of push this up to the priority list.


Robert Niven


And it doesn't have to be a premium, right. When you say
valuation, it just needs to be identified. Like an example would
be of Microsoft. When they're building, they're asking all of
their suppliers to say, I want to reduce our carbon target by X.
And then they go around and they say, what can you do for me?
What can you do for me? What can you do for me? When the concrete
producer hears that loud and clear, and they may win that bid
over a competitor if they have some ideas and they can bring
something to the table.


David Roberts


I want to get a sense of scale before we move on from the
process. Sort of if I'm producing concrete and I'm using your
process to inject CO2, say I do both of the available options and
I get CO2 injected into my wastewater and I get CO2 injected into
my mixer, is the end product of that carbon negative or how close
is it to carbon negative? Give a sense of scale, like how much of
the carbon in the process is being offset by this?


Robert Niven


Yeah, it's one piece of the pie. To get to carbon negative or
neutral concrete is we're going to need some substantial changes
on the cement side as well. And there are some fellow companies
within our investors portfolio. A great example would be like a
Brimstone who are working on the cement side. We're working with
whatever cement is coming down the line and we're adding if you
sort of combine the reclaimed water and ready mix, you're getting
another 10% to 15%. But that's 10% to 15% off of a global
commodity with a huge volume and we can do it today with very
little CapEx and it's permanent.


So if you think about a marginal abatement cost curve, it's like
this is the furthest left on that curve. This is the thing that
is easy to implement at scale. It has a significant percentage
reduction, but off of a huge number, the volume of concrete is
enormous. There's about 40 billion tons of concrete produced or
4.2 billion tons of cement.


David Roberts


And what's the number? I think it's 8% of global emissions,
something like that.


Robert Niven


We use the word the number 7% and most of that's cement. And the
reason it's so big is because so much concrete is being used,
it's second only to drinking water in production. Yeah.


David Roberts


So you can take 10% to 15% of the CO2 basically out of the final
product, but more than that is going to require deeper changes in
the process.


Robert Niven


And that doesn't include our aggregate technology. So that will
layer in a lot more. But we need to work together all the way
along the value chain. The traditional cement sector are doing
things like they're using supplementary cementitious materials
instead of cement and that means using things like fly ash and
slag. The problem is those materials are declining in
availability, they're doing things like fuel switching, so using
waste materials, energy efficiency, all those traditional things
should be done. But then there's also some real deep tech stuff
going on right now about fundamentally changing the cement
process or chemistry.


But that's going to take a lot of money and we still have a lot
of time ahead of us. So we need to get going today on those
immediately deployable solutions.


David Roberts


Right, so you've got a solution here you can just slap on
existing concrete, plant boom, you get your ten to 15, maybe a
little bit more CO2 out.


Robert Niven


And we've shown that this is not only applicable in the United
States, but we're operating in many many emerging markets and
really only about 2% of cement is being produced in the US. It's
the emerging markets. That's where we really impact climate.


David Roberts


Right. And that's where it's growing.


Robert Niven


That's where people is in concrete they haven't built out.
There's a lot of population growth and we're already going into
those markets now because we know that it takes a bit of
incubation time and in some markets we're seeing that already
entering into that scaling phase.


David Roberts


So you need CO2 as an input to your process. Is there any supply
issue? CO2 easy to get and I'm also curious how much you pay for
Heirlooms CO2 versus more traditionally acquired CO2? Is there a
big price differential?


Robert Niven


So the first part of your question is, is there supply chain
issues? Yes. Our industry, the concrete industry has been
massively impacted over the last twelve months by cost and supply
of cement and in our case cost and supply of CO2. Really? Believe
it or not you can't buy CO2 in certain markets.


David Roberts


a shortage of CO2.


Robert Niven


And the price is skyrocketing because of it.


David Roberts


No kidding.


Robert Niven


It's a really perverse situation. So we need a lot more air loops
and we need them to get them into market faster to start to
diversify the supply of CO2 because some of the traditional
emitters that you would have been collecting that CO2 are now
changing their process so that that CO2 isn't becoming available
anymore. Ethanol is the largest supplier of CO2 in the industrial
gas market in the United States. So today if the price varies so
much it's largely dependent on transportation. Very commonly
we're paying well over $500 a ton for CO2. We haven't gotten to
that stage with Heirloom where they have the volume, the capacity
to have those discussions yet but we really encourage them to
move along as fast as they can to get to that billion ton target
because that gives us a lot more CO2 that we can work with.


So we're exploring all different options for CO2 supply because
just from a supply constraint or supply chain disruptions we're
very encouraged to solve for that problem now.


David Roberts


It's just something that sort of kind of confuses me. And maybe
you both can take a swing at this answer, but I'm seeing a
process here at your demonstration plant where we're digging a
limestone up, doing a bunch of stuff that strips the CO2 out of
it, and then injecting the CO2 back into the concrete process,
where it then becomes limestone again. Why not just dig up the
limestone and put it directly in the concrete? It seems like a
lot of physical processes to sort of end up where you started.
Maybe just sort of help me understand that kind of how is this
not kind of running in place in sort of energetic and CO2 terms?


I'm sorry if that was a very vague question.


Shashank Samala


What we are trying to do is pull CO2 that is already in the air
so you need a sponge to pull up that carbon and we find that
calcium oxide which is derivative of calcium carbonate is highly
alkaline. It's highly thirsty for that CO2 and then that's how
you create the limestone and then you're essentially looping the
limestone through the cycle.


David Roberts


The limestone you're finding that you're mining has already
absorbed CO2, right? That's what it's been doing. It's what it's
been doing. So in a sense, it's already absorbed it. Why not just
put it directly into the concrete, do you know what I mean?


Robert Niven


Yeah, maybe my perspective solves that on that bit better. The
way that I think about Heirloom is if you take a sponge and you
put it into your kitchen sink and then you pick up collects water
and then you squeeze it out, then you put it back in and squeeze
it out. So it just happens to be calcium. But for our process,
there may be some listeners who are from civil engineering and
understand concrete a bit deeper, and they say, well, concrete
already carbonates, right? So there is a natural process that's
already happening, but that's limited to the exterior skin of
concrete and it's not value added, it doesn't provide those
performance benefits.


So some way of looking at that is like, yeah, if you left
concrete exposed to the air for 1000 years, which not too many
buildings are around for a thousand years, is you might get that
full carbonation extent. But even if you did that, you wouldn't
get all the benefits, the performance enhancing benefits that
come from carbonating actively in a certain way that create this
nanomaterials, which provides the cement savings. And it's also
done in a very short time frame within seconds. And so that's a
key difference here is the time. And the other thing is, if you
let carbonation happen passively, that's called weathering
carbonation is it actually has the opposite effects on
performance.


David Roberts


Oh, really?


Robert Niven


Yeah, it'll actually cause the PH to drop and then it will make
the steel corrode, which makes said structure made with that
concrete to have durability issues and may fail. So engineers
like myself are trained to limit carbonation because you don't
want that carbonation layer to get to the steel, because then
that causes that concrete to fail. So you take many, many steps
to stop that from happening. The way that we're doing it is
different in that we're actually deliberately carbonating to a
certain extent. So you get all these performance enhancing
benefits and that's a really important nuance.


David Roberts


One question is this sort of demonstration project of Heirloom on
the one side, CarbonCure on the other side, pulling CO2 out of
the air, putting it in concrete. I obviously see the benefits in
terms of like educating the public, making carbon capture and
sequestration more real and tangible to people, showing investors
that things are happening here, all these effects. But looking
down the roadways is the sort of direct capture to concrete
pipeline. Is that going to be a real business? Is that going to
scale up? Or is this mostly just for demonstration purposes?


Robert Niven


If they can provide CO2 for less than $500, we've already shown
it scalable. Right. So for us, that's the marker. And we're more
than happy to work with Shashank and Heirloom because if they can
provide us cheaper CO2 on a reliable supply and the market would
prefer atmospheric CO2, I'll do that all day, every day. But
we're already showing today that using CO2 and concrete is
immediately scalable and used in emerging markets, developed
economies, what have you.


Shashank Samala


Yeah, the awesome thing about concrete is it's the most abundant
commodity, the industrial commodity that we produce. It's like 12
billion tons of concrete that we make. So that's the awesome
thing, right? That's why this demonstration, I think, is so
powerful. This is not just a small test, that it is a signal for
what's to come. And I tell Rob every time I see him, tell me what
is the price where we can put CO2 in every ton of concrete that
they're at and plants that they're not yet at? Right. To reduce
that cost per ton on the concrete plant side, where it is just
economical, no brainer for a concrete plan to add Heirloom CO2
into the CarbonCure process.


So, yeah, that's the thing that's exciting.


David Roberts


Has anyone done the math on the total sequestration potential of
concrete globally? I mean, do we have a sense of scale here? The
limits?


Robert Niven


Well, the theoretical limit is half the weight of cement could be
carbonated.


David Roberts


Oh, wow.


Robert Niven


But I'm not saying you want to do that. I'm saying,
theoretically, that Stoichiometry says that if there's 4.2
billion tons of cement, you could conceivably mineralize 2.1
billion tons. And that doesn't include all the aggregate. So you
put all the aggregate on on top of that. And aggregate is the
vast majority, about 85% 90% of the of the mass of of concrete.
So you could really get to certainly hundreds of millions low
billion tons of CO2 mineralization in the concrete value chain
through carbonating, directly through concrete, like what we're
doing, or by using CO2 to make aggregates.


There's a few companies that are doing that as well. So it does
become sizable. But I really want to emphasize it's, the value
added nature and the immediate nature of this, like the time
value of carbon is important in climate change discussions.


David Roberts


Yeah.


Robert Niven


A lot of solutions are targeting to come online and start scaling
in 2030-something. This is happening now, right? And we need to
do as much that we can, especially if there's very little CapEx
requirement and no price premium.


David Roberts


So I've kept you long enough, I guess I'd ask the same question
to each of you to conclude it's the nature of carbon removal that
it's not producing a product that is valuable enough in and of
itself to pay for itself. There's going to have to be a market
created for removed CO2. We're going to have to sort of generate
a market around this if it's going to pay for itself. So I guess
I just asked both of you, by way of concluding shashank you
first, what sorts of policies can help you or would most directly
help you scale up?


Shashank Samala


So two types of policies. One is a compliance market that
essentially requires corporations to effectively price carbon as
an externality and have a cap for carbon emitted so that carbon
that is not abated or reduced needs to be offset and removed. And
there's a price for that.


David Roberts


And this is something a few companies are doing kind of
voluntarily, right? Like the stripe constellation of companies
are basically sort of modeling what that would look like. But
that's got to be made law at some point, right? You're not going
to get enough voluntary companies to ...


Shashank Samala


No, according to APCC. We need to be removing five to 10 billion
tons of carbon from the air by 2050. And if you want to see that
type of scale, if you want to see that type of it's a trillion
dollar market at $100 a ton. That's a trillion dollars of revenue
every year that we need to get to. So it's amazing and we're so
fortunate to work with folks like Frontier Stripe, Shopify,
Microsoft, who are all early buyers of this technology, but we
need thousands more and policy and compliance markets is what
gets us there.


The second type of policy is what 45Q is doing today. You may
have heard of it. It's a tax credit. It's a direct pay for direct
recapture that is stored permanently. So, you know, we're
fortunate and, and, you know, really we, we appreciate everyone
who, who worked on the Inflation Reduction Act, having that
passed last year, that is such an important element. It's at $180
per ton subsidy. It's it's stackable on top of what customers pay
us that helps us bring down the cost of, of carbon removal so it
is affordable to everyone. So, you know, that is something that,
you know, not just the US.


But, you know, every other count ry, europe and Asia should adopt
something similar. So compliance markets and subsidies like 45Q
really help us come down the cost curve.


David Roberts


Is there a country doing more than the US for this or they are
their models to look to where they're going more sort of
gangbusters on on DAC?


Shashank Samala


Canada is actually pretty close. I don't think they've passed
this yet, but there's a pretty large CapEx, I think it's called
the Production Tax Credit that might be even more compelling than
45Q depending on how that's written. So, yeah, super fortunate
that US and Canada, that is the type of competitive battle we
want, right? This sort of geopolitical competition to see which
country can help us decarbonize the planet. And in the past it
was some countries in Europe that were sort of good hearted and
have these policies like the subsidy for solar in the early
2000s.


But now you're seeing countries compete against each other to
bring clean tech and climate tech into their country. So I think
it's warring from a good hearted nature to a competition, which
is exactly what the planet wants. So that's what we should all be
up to, optimistic and excited about.


David Roberts


And how about you, Rob? What's your policy wish list? What's on
top?


Robert Niven


I would echo what Shashank said, certainly. And about we need
many more credit buyers of some of the same names, like the
Shopifys and Stripes. That really the Microsoft's and Patches
that drove the world of demand for these credits. 45Q, for sure.
For us, though, the most important policy are these low carbon,
concrete, or buy-clean type procurement policies.


David Roberts


Right.


Robert Niven


New Jersey just passed landmark policy just a couple of weeks
ago. It was based upon similar work done in New York and Hawaii
and California. We saw a lot of it in the Federal Infrastructure
Act. That's what really drives us.


David Roberts


Are there federal procurement buy-clean elements in the
Infrastructure Act?


Robert Niven


Yes. If I recall, it's about $4 billion in incremental spend on
low carbon material purchases. That is very important for our
business, and that's what will drive the storage piece within
concrete especially. And then that in turn will drive the DAC
side or the carbon capture side. So that was really important.
And they're designed in a way that also requires a strong
reporting element using LCA documents like environmental product
declarations, and you need those to compare the different options
in a third party verified way. So that procurement policy is very
important based upon the kind of models like we're seeing in New
Jersey with its LECCLA Bill.


David Roberts


Interesting. Well, thank you guys for coming on and walking us
through. It's really interesting. I think if nothing else takes a
very abstract discussion, what can often be a very abstract
discussion about carbon and carbon removal and all this and just
makes it very tangible. One of the things I love about this is
that on both sides, this is not PhD chemistry or whatever. It's
trays of rocks and squirting CO2 into a mixer. I love the there's
a ruggedness, I guess, to simple processes that I really like. So
it's been really fun to talk through.


Robert Niven


You're welcome. Although I will say we have a lot of PhDs working
on our team as well, so I don't want to diminish the great work
that they're doing to make it look this simple. You need to work
extra hard.


Shashank Samala


Yeah, exactly. There's just a lot of engineering and science that
goes into making things simple and scalable. So, yeah, you have
lots of PhDs and great engineers on the team.


David Roberts


All right, Shashank Samala and Rob Niven, thank you so much for
coming on and talking us through. This is super fascinating.


Shashank Samala


Thank you so much for having us.


David Roberts


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