March 7, 2024 • 32 mins
Cement is, almost literally, everywhere. It is extraordinarily useful, which is why humanity makes 4 billion metric tons of it every year. But cement is also extremely carbon intensive to produce. Leah Ellis is the co-founder and CEO of Sublime Systems. Her problem is this: How can you make cement, at scale, without emitting carbon dioxide?
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Speaker 1 (00:15):
Pushkin. You know it's amazing cement. Cement doesn't burn or
rust or rot. Cement lasts for thousands of years. See
Roman aqueducts, Mayan temples, and you can use cement to
(00:35):
build almost anything. Cement is so amazing that every year
humanity makes four billion metric tons of it. That is roughly,
very roughly a thousand pounds of cement for every man,
woman and child on planet Earth every year. Now, for
the bad news, making cement is wildly, almost absurdly carbon intensive.
(01:00):
We don't hear so much about this. Cement is generally
not what we talk about when we talk about climate change.
But in order to solve climate change, we're going to
have to figure out a better way to make cement.
I'm Jacob Goldstein and this is What's Your Problem, the
(01:21):
show where I talk to people who are trying to
make technological progress. My guest today is Leah Ellis. She's
the co founder and CEO of Sublime Systems. Lea's problem
is this, how can you make cement without emitting carbon dioxide?
Before she got into cement, Lea was in grad school
working on lithium ion batteries, and as happens to a
(01:44):
lot of grad students. She had this kind of deflating
conversation with her advisor.
Speaker 2 (01:51):
One of my last you know, walk and talks with
my PhD supervisor is like, you know, what's next in batteries?
And he was like, oh, it'll take you know, tens
of thousands of people ten years to get to the
next level.
Speaker 3 (02:05):
But I was like, oh.
Speaker 2 (02:06):
Damn, Like I don't want to be like one of
ten thousand people working for ten years.
Speaker 1 (02:12):
So you realize that you sort of missed the kind
of innovation glory days for batteries perhaps, So what do
you do?
Speaker 2 (02:21):
Well? I wanted to continue working with inventors, so I
got a Canadian government fellowship to go anywhere work with anyone,
and I chose to come to Mit to work with
Professor Yetmingchek. And it was actually Yet's idea to work
on cement. And it wouldn't have been something that I
would have ever had the audacity to jump fields like that.
Speaker 1 (02:46):
So how did that idea come up?
Speaker 2 (02:49):
Well, so Yet a year before, in twenty seventeen, had
spun out Form Energy, which is a long duration energy
storage company, and he had his eye on these trends,
you know, renewable electricity is becoming the cheapest form of electricity,
especially if it's intermittent, and you know, the utility sector
being thirty percent of house gas emissions, like, thought's going
(03:11):
to go to zero if we'ever going to achieve net zero,
and then you know what what would happen as a
consequence of that is that you have all of this
renewable capacity that then you then you can use to
decarbonise the next largest tranches of emissions, so cement and
steel being each about eight percent of global CO two emissions.
(03:31):
The thinking was like, you know, how do you decarbonise
cement assuming you are in a world with abundant and
relatively cheap renewable electrons.
Speaker 1 (03:39):
So super top down, super like macro big picture, not like, oh,
I've got this little technical idea, how can we build
it up? But it's like, Okay, I'm I'm looking at
the whole planet for the next thirty years, and I
see that like making steel and cement is like a
problem we have to solve, and we're gonna have a
lot of intermittent clean energy.
Speaker 3 (04:00):
What do you got exactly?
Speaker 1 (04:02):
And so he mentioned cement to you, what do you
know about cement. When he mentioned cement.
Speaker 2 (04:09):
Well, I assume that cement and concrete were the same thing.
I mean, that was my level of understanding at the time.
But I did know that cement was, you know, a
much larger tranch of COTO emissions than you know, lithium
ion batteries could ever address.
Speaker 1 (04:27):
And so just to be clear, when you say you
assume that cement and concrete were the same, you're saying
you didn't know anything. Because that's one that's always been
hard for me. I memorized it in preparing for this interview.
It's one thing I'll definitely get out of this AMA.
Speaker 2 (04:40):
Yeah, and you know sometimes I get those two words
mixed up even now.
Speaker 1 (04:45):
So what's the difference just for everybody?
Speaker 2 (04:47):
So, cement is the glue, it's rock glue, and concrete
is the glue plus aggregate. So cement is the glue
that holds the rocks together to meet concrete.
Speaker 1 (04:57):
Right, So all the things around us are built out
of concrete, and cement is sort of the essential ingredient
in concrete.
Speaker 2 (05:05):
That's right, It's about fifteen percent of the concrete.
Speaker 1 (05:09):
How do you start learning about cement?
Speaker 2 (05:11):
Well, I first started on Wikipedia. It's one of my
favorite always to spend time.
Speaker 3 (05:17):
So it was quite delightful.
Speaker 2 (05:20):
And from Wikipedia, you know, spent a lot of time
at the library, you know, in textbooks and then going
from textbooks to research articles and.
Speaker 3 (05:33):
Yeah, it's been really really fun.
Speaker 2 (05:36):
Honestly, lithium ion batteries are art cool and magical, but
cement is is awesome. I think if you're a material scientist,
if you're a nerd, there's like a very deep and
exciting rabbit hole that you can go down to you
once you start getting stoked about cement.
Speaker 1 (05:50):
Well, let's get stoked about cement. So first of all,
it's extraordinarily ubiquitous, right, like so ubiquitous you don't even
notice it. I was actually listening to an interview with
you a couple of weeks ago, and I happened to
be at the airport, and I realized as I was listening,
like I was of course standing on on cement on
(06:13):
concrete right on the sidewalk, but also there were like
I was it was like two decks, you know, arrivals
and departures, and so there were these like columns made
out of concrete, and then there was concrete over my head.
So I was essentially like encased in cement in concrete
as I was listening to it. So that was good.
That was that was getting me in the right in
(06:35):
the right mood for this interview.
Speaker 2 (06:36):
Yeah, once you see it, you really can't unsee it,
and it's it's really fun. And as I've gotten into
cement chemistry and durability and testing every sort of feature
in the cement you look at you can see weathering,
you can see freeze thought damage, you can see alkali
silica reaction, you can see rebark corrosion, and it really
(06:57):
makes uh, you know, a walk down the concrete jungle
a little bit more intellectually stimulating than it was before.
Speaker 1 (07:05):
So certainly there's a lot of it. Certainly it's important.
And so let's talk about how cement is made today.
This is not what you're doing, but sort of the
thing you're trying to improve upon. Right, Portland cement is
this phrase that it's basically a technique for making cement. Right,
it's a product, but it's also a way of making
(07:25):
the product that's been around for what more than one
hundred years? So briefly, what is Portland cement? How do
you make it? What do you start with.
Speaker 2 (07:34):
Yeah, Portland cement is a specific formulation of cement that
has been around one hundred and ninety nine years. So
Portland cement will celebrate its two hundredth birthday this year
on October fourth.
Speaker 3 (07:46):
That's two hundred years since, and.
Speaker 1 (07:47):
You're trying to make sure it doesn't make it to
two hundred.
Speaker 3 (07:50):
And fifty, right, exactly. Yeah.
Speaker 2 (07:55):
So the way Portland cement is made, you take limestone
as the calcium source, and then you will also need
the right ratios of calcium to silica, alumina and iron.
So that Portland cement recipe is about getting those ratios right.
But the dominant ingredient is limestone.
Speaker 1 (08:13):
So limestone is the key ingredient. The thing we want
in the limestone is the calcium. But is the calcium
bound with carbon? Is that our fundamental problem?
Speaker 3 (08:23):
That's right.
Speaker 2 (08:24):
So the limestone is a calcium oxide bound to CO
two and those are chemically bound very strongly, which makes
the calcium inert.
Speaker 1 (08:34):
And the process of making cement is you want to
essentially isolate the calcium, I mean, among other things, but
a key piece of the process is that, right.
Speaker 3 (08:42):
Yeah.
Speaker 1 (08:42):
Okay, So in making Portland cement, how does that.
Speaker 2 (08:45):
Happen by heating it to the point where that bond
breaks and CO two, you know, goes as a gas
and then you get this solid solid gas separation where
you have solid calcium oxide and gashous CO two.
Speaker 1 (09:01):
Okay, And so then that CO two just goes off
into the atmosphere, go often to the chimney.
Speaker 2 (09:06):
Yeah, it's mixed with the combustion emissions and goes into
the air.
Speaker 1 (09:10):
Okay. So it's just it's just more carbon emissions. It's bad.
It's the thing we're trying to get rid of on
the planet.
Speaker 3 (09:17):
Yeah, that's right. Mean it's causing global warming.
Speaker 1 (09:20):
Okay. So you've broken down the limestone and emitted a
bunch of CO two in so doing, but you're not
done yet, right, what has to happen next.
Speaker 2 (09:30):
So once that's broken down, it's heated further to fourteen
hundred degrees celsius.
Speaker 1 (09:36):
So it's getting wildly hot. I mean, is the rock
actually like melting? Does it look lava ish if you
look at it?
Speaker 3 (09:42):
Yeah?
Speaker 2 (09:43):
And I actually have had the distinct privilege of looking
down the center of a Portland cement kiln. There there's
like a tiny hole under the fuel injection port, you
put on a welding mask. It's of course extremely hot,
and you can peer down and see the rotary kiln going.
You can see the flame coming right over your head
(10:05):
through that fuel injection port, and you can see the
molten rock rolling towards you, like red red, glowing hot.
Speaker 1 (10:12):
And so so, in addition to the carbon dioxide emitted
directly from the limestone in the first stage, presumably people
are burning a lot of fossil fuels in order to
make this rock lava hot in this stage, thereby emitting
(10:33):
more carbon dioxide into the atmosphere.
Speaker 3 (10:35):
That's right.
Speaker 2 (10:35):
And so besides, every Portland cement kiln you're going to see,
you know, a small hill of coal, and it's normally
bitchumen is coal, though there's often a blend of fuels
used to heat up the kiln to this enormous temperature.
But bitchumen is cool. Is what's necessary to get this
like highly luminous flame that creates the ideal temperatures.
Speaker 1 (11:01):
So you're not only burning fossil fuels, you're burning coal,
which is a particularly dirty, particularly carbon intensive fossil fuel.
Speaker 3 (11:09):
That's right.
Speaker 1 (11:09):
Yeah, And we make a ton of cement, so like cement.
It's like very carbon intensive, emits a lot of carbon
into the atmosphere, and we need it, and we make
literally what order of magnitude how many tons?
Speaker 3 (11:25):
Yeah, about four billion tons a year.
Speaker 1 (11:27):
Four billion tons a year. And so overall, when you
take it all together, what percent of human carbon emissions
are from making cement?
Speaker 2 (11:43):
So it's eight percent of global CO two missions from cement.
Speaker 1 (11:46):
This is a big problem, and we don't know how
to fix.
Speaker 3 (11:48):
It, that's right.
Speaker 2 (11:49):
So there are incremental approaches that chip away at the problem,
like using alternative fuels. You can swap out some of
the coal with natural gas or with burning tires. You
can use supplementary sumuntitious materials, so some antigious materials that
are less performant, you can blend them in up to
thirty even up to fifty percent to to you know,
(12:13):
reduce the emissions. But getting to zero is very difficult,
if not impossible, with things that are exist today.
Speaker 1 (12:22):
So let's talk about that, right you You are not
going for an incremental gain here, you're saying, okay, let's
start from zero and let's figure out a whole new
way to make cement that doesn't emit any carbon dioxide
and you decide that instead of using coal, you're gonna
use electricity, right.
Speaker 3 (12:42):
That's right.
Speaker 2 (12:43):
So being battery scientists and electric chemists, you know, we've
got the hammer and everything looks like a nail, right,
so we can's electricity, but we wanted to look beyond it.
Just the most obvious way, which is like to use
an electric kiln for heating, that's got as challenges. I
mean that one's the obvious way. If it was easy,
(13:04):
people would already have done it. There's various challenges with
efficiency and material so we had to find another path.
And what we derived after many brainstorming sessions and investigating
different options, was this way of breaking down the minerals
using electric chemistry instead of using heat. So by bypassing
(13:26):
the heating also allowed us to be more amenable with
the use of intermittent renewable electricity, because of course heating
requires base load electricity. It takes days to heat up
a kiln to those high temperatures, and so it doesn't
allow you to be rampable, it doesn't allow you to
(13:46):
be load following.
Speaker 1 (13:47):
Right, because that a regional kind of marching orders. The
original big idea was like we're going to have extraordinary
abundance of renewable energy, but for a while at least,
it's going to be intermittent. The sun's going to shine,
then the sun's going to go down, and so you
you don't want to build a system that requires constant
high inputs of power over days and days, because that
(14:09):
doesn't fit the kind of worldview you're building for.
Speaker 2 (14:12):
Well, yeah, that's right. But also you can get a
cost advantage. You can get the cheapest electricity if you
can take it whenever it's available.
Speaker 1 (14:20):
So okay, so go on.
Speaker 2 (14:22):
The next thing you do is technoeconomic modeling. So start modeling,
like what does it cost to do this, what are
the inputs, what are the outputs, what's the you know,
what's the capex, what's the opax, what's the labor, et cetera.
Getting quotes from vendors for specific pieces of equipment, getting
actual data from the pilot using actual numbers, and so
(14:46):
now it's like this, you know, multi tab quilt sized spreadsheete.
But getting that going was the first step, because you know,
that's what allows you to pivot quickly to see the
weaknesses of your approach. And we continue doing that, and
we still continue to do that to refine different elements
of our process.
Speaker 1 (15:09):
This process Leah is talking about, it's a whole new
way of making cement. It doesn't involve heat at all,
and Lea hopes it will be this turning point in
the millennia long history of the way human beings make cement.
In a minute, she explains how it works. So you've
(15:37):
come up with this new process. You're still refining it,
trying to make it more efficient, reliable, whatever, But how
does it work?
Speaker 2 (15:45):
Yeah, Basically we're breaking down the inert minerals using chemistry
and electric chemistry instead of using heat. So you know,
the heart of our system, or maybe call it the lungs,
is this electrochemical reactor that takes neutral pach water and
splits it.
Speaker 3 (16:04):
Into acid and base.
Speaker 2 (16:06):
So there's a pH gradient that forms between the two
electrodes and that's used to dissolve calcium and other minerals
from rocks. So actually the electrochemical process we use since
we're digesting the rocks instead of cooking them, we don't
have to use limestone, so we're using calcium silicate minerals
(16:28):
and industrial wastes and basically taking the rock and then
splitting it into its mineral components, drying all those off
into free flowing powders, and then reassembling a cement powder
with the right ratios of all of these elements to
make a high performance cement.
Speaker 1 (16:49):
And so you basically use electricity to turn water a
va of water into a place where like part of
the water is somewhat acidic and part of the water
is somewhat basic. And then you put the rocks into
that water, and the acidic parts of the water do
some of the words, and the basic parts of the
(17:10):
water do some of the work, and you're wet, and
you wind up with the minerals you need at a
price you can afford.
Speaker 3 (17:15):
Yeah, exactly. You said it very well, So I.
Speaker 1 (17:18):
Know you start with the idea, and I've heard you
say that. Initially you made one gram of cement, which
is like you described it as like the size of
an almond, which is particularly amazing given how heavy and
big cement is. And then you did a kilogram. Where
are you now?
Speaker 2 (17:37):
We came out of stealth about a year ago after
we built our pilot plant, which was initially sized to
produce one hundred tons a year. In the past year,
We've had about seven thousand hours of uptime. We've scaled
it up to two hundred and fifty tons per year.
We've produced tons of cement and have ran it continuously
(17:58):
under dozens of conditions to you know, optimize it.
Speaker 1 (18:02):
And that cement you've produced is it is it out
in the world. Is it just like practice cement? Is
it real cement? You know, holding up a building somewhere
or something?
Speaker 2 (18:12):
It is actually holding up a building somewhere. So we
did our first field poor about two weeks ago.
Speaker 1 (18:19):
Oh congratulations, Yeah, I like that. For field poor. Where
was the field poor?
Speaker 2 (18:23):
It was in the Boston area and a piece of
in a in a commercial construction project. It was going
underneath the construction. It's typically what's called called a mud slab.
Speaker 3 (18:33):
So yeah, so.
Speaker 1 (18:35):
That's what you're doing. Now, what have you not figured
out yet? Like, what has to happen for you to
get from here to being a real business selling lots
of cement whatever all over the world or whatever for
you to be a real business, for you to be
a real business with revenue and your cement just you
(18:56):
want your cubmit to be boring, right, you want your
to be just like whatever boring again.
Speaker 2 (19:01):
Yeah, well, there are certain things we figured out. We
figured out the product, we figured out the pros us.
But where we are today is still Even though I'm
so proud of taking this from a gram to two
hundred and fifty tons in four years, it's still a
drop in the ocean. I mean, we affectionately call our
pilot plant this cement plant for ants.
Speaker 3 (19:25):
It has to be at least three times.
Speaker 2 (19:26):
Bigger than this, but we have to get to a
million tons per year.
Speaker 3 (19:31):
We're going to compete on cost with.
Speaker 2 (19:32):
Today's Portland cement, and so going from pilot scale to
full scale, where full scale for cement is just a
titanic colossal size, our next step is to build a
minimum viable commercial scale plant. So we refer to this
as our kiloton plant. We have a site secured in
(19:54):
Holy Oak, Massachusetts, on the site of an old paper mill,
which we are in the process of removing this ancient
paper mill, but all the remnants of what makes this
a really exciting industrial.
Speaker 3 (20:09):
Site still exists. So a hydro electric.
Speaker 2 (20:11):
Dam, ready, access to rail, ready access to a workforce,
you know, industrial permits exist and so our next our
next step is to wrap up the pilot phase in
the coming months, do do the engineering and start procuring
long lead equipment so that we can start building our plant.
(20:35):
And so that is the work that you know, my
colleagues in the office are busy doing right now.
Speaker 1 (20:41):
So these are very like practical heavy industry, could be
any kind of a big factory concerns. Do you still
have engineering or technical problems to solve as well, or
do you feel like you've got it down?
Speaker 2 (20:59):
Well both, I do feel like I've got it down.
I'd say, you know, the problems never stop and also
the improvements never stop. So in the spirit of swift
and massive, we move as quickly as we can to
move from one one degree of scale to the next.
But there's you know, I have to say, I have
the distinct privilege of working with some of the smartest
(21:21):
people I have ever met in my entire life, and
I've had the pleasure of working with smart people all
throughout my education and career. But you know, we're generating
quite a lot of IP, We're generating quite a lot
of improvements. There's so many improvements that we're planning to
feather in over time as we develop the system that
I think will replace Portland cement in the next one
(21:43):
hundred years.
Speaker 1 (21:45):
And in terms of cost, I mean, obviously cost must
be to a very large degree of function of scale.
And you're scaling up at scale. Are you already cost competitive?
Do you have to find new efficiencies? I mean presumably
this is like a brutal commodity business.
Speaker 3 (22:06):
Yeah, totally brutal.
Speaker 2 (22:08):
And so we can get very close to competing on
costs with Portland cement, no carrots, no sticks, at scale
with six sons of kilawad hour electricity. So not even
using funny math, so using what we think are you know,
realistic assumptions, so you know, but we're still far out
(22:31):
from a megaton plant. But what we can say with
total confidence is that we will be cheaper than Portland
cement plus post combustion carbon capture, which is presently the
only other way to get to zero for cement making.
So every time you take a Portland cement kiln million
tons per year, you add post combustion carbon capture, you
(22:54):
add some other process. You're always adding capex to that
Portland cement plant and opex. And I think the wonderful
thing about Sublime, which is our unique advantage, is that
we're not adding onto the kilm, we're replacing the kilm.
We're not capture, we're not storage, we're carbon avoidance, and
that ultimately is much cheaper than capture and storage because
(23:14):
you're not adding onto the system.
Speaker 1 (23:18):
What are some reasons it might not work?
Speaker 2 (23:24):
You know, it might There are one thousand ways to die,
maybe even more, and I like to keep my eyes
open to all of them. And we do quite a
lot of risk registered development. We have like what we
call our three a M list quarterly, I get, you know,
everyone anyone in the.
Speaker 3 (23:45):
Like what keeps you as you.
Speaker 1 (23:47):
Worry about when you wake up at three in the morning. Yeah,
what's at the top of that list right now?
Speaker 3 (23:53):
If changes day to day. So I'm glad you said
right now.
Speaker 2 (23:56):
I mean, like, as we go into this process of
going from pilot to first commercial, I think about cost
overruns and this this isn't just you know.
Speaker 1 (24:08):
Just like building a factory, totally classic.
Speaker 2 (24:12):
And you know, hiring I'd love to hire someone who's
done this before because I think this is where you
really need someone who's done this before, because it's not
just the cost of the thing.
Speaker 3 (24:22):
I mean, we think.
Speaker 2 (24:23):
We've got that lockdown with solid research, solid quotes, just timeline.
You know, imagine like you're missing like some widget and
you find out this little dinky piece is like I'm
gonna show up a year later than everything else, and
your companies, you know, you've got your burn rate of
the whole company.
Speaker 3 (24:39):
So that's that's just one way to die.
Speaker 1 (24:42):
I mean, yeah, it's a classic. That is a classic
way to die.
Speaker 2 (24:46):
Yea running out of money. Your heart stops beating it,
you know.
Speaker 1 (24:53):
So that's the sad story. There is some happy story
where it works and you build a factory and you
start selling cement, clean cement. Like if you go I
don't know, say ten years into the future, what does
the world look like if it's the happy story.
Speaker 2 (25:15):
Yeah, well I may go more than ten years in
the future, and I maybe go one hundred years in
the future. I like to think about a post carbon world,
like what does it look like when you know, you know,
you're penalized for your CO two emissions the same way
you're penalized for you know, mercury emissions or something like that.
Speaker 3 (25:34):
And you know, I like to think that if we're successful.
Speaker 2 (25:38):
The most wildly successful version of Sublime Systems is that
We've changed the way humans make cement the same way
you know, Romans changed the way we made cement, same
way the British and French with Portland cement changed the
world way we made cement. I think, you know, humbly, cautiously, optimistically,
what Sublime is doing could change the way humans make
(26:01):
cement forever. And I think that's really exciting because it's
it's such a monumental thing. Like when you go to
when you go to Egypt, you see, you know, construction,
things that were made to last, you know, you go
see the aqueducts, you go see things, and these things
that were built are a testament and a monument to
(26:23):
the values of the people that created them. And so
I think, you know, you know, the coolest thing for
me is to have like enduring significant buildings that are
made with you know, the cement of the future and
having like archaeologists one thousand and two thousand years from
now looking back and being like, oh, there was this
(26:43):
period before where the world was a certain way, and
then there was something that happened where co two levels
crusted and then they came down and at that point
in time, like we can see how their buildings materials
change to adapt to that.
Speaker 3 (26:59):
I think. I think that's pretty cool.
Speaker 2 (27:00):
I mean, I don't think you can get closer to
a monumental legacy than to really change building materials in.
Speaker 1 (27:07):
That way, the way literal monuments are built. Yeah, we'll
be back in a minute with the lightning round. After
(27:27):
that big think and we're going to do a small
think lightning round to conclude. What's your favorite concrete structure
or concrete thing?
Speaker 2 (27:40):
Oh, you know, it's the things that folks on my
teammates so often. You know, we're doing tests on our
cement pace, and so we have a bunch of molds
of like you know, frogs and dragons and snowmen and
whales and turtles and so. I yeah, my favorite concrete
things are it's probably the dragon.
Speaker 3 (28:00):
I like the dragon the most.
Speaker 1 (28:02):
How big is the dragon?
Speaker 2 (28:04):
Oh?
Speaker 3 (28:04):
It fits on the palm of my hand.
Speaker 2 (28:05):
I sometimes take it with me to conferences, you know,
just to meet people.
Speaker 3 (28:09):
You know, seeing is believing, and so sometimes it travels
with me.
Speaker 1 (28:14):
What's your least favorite concrete thing?
Speaker 3 (28:21):
I would probably say New York City.
Speaker 2 (28:23):
Just something about that city just makes me despair. I
don't know what it is like just never been a fan.
Speaker 3 (28:31):
I'm trying.
Speaker 2 (28:31):
I'm trying to be open minded about New York City,
but you know, I fail each time I go.
Speaker 3 (28:35):
No offense, not my cup of tea.
Speaker 1 (28:38):
Fair. It's not for everybody. It's for millions of people,
but it's not for everybody. So you rode your bike
across Africa from north to south. What was the worst
day of that trip?
Speaker 2 (28:56):
You know, there were days when I was extremely sick,
so it would probably be.
Speaker 3 (29:03):
Those days.
Speaker 1 (29:05):
And you still had to ride. Yeah, often, Yeah, Okay,
what was the best day?
Speaker 3 (29:14):
I mean, every day was the best day, even if
I was totally sick.
Speaker 2 (29:17):
I mean, I like to say that doing that trip
across Africa, which was about four months, twelve thousand kilometers,
about one hundred kilometers a day on average. I mean,
it's something I would recommend both to my best friends
and my worst.
Speaker 3 (29:32):
Enemies, because.
Speaker 2 (29:35):
I think it does is extremely character building, and you
get very comfortable with discomfort, and you know, your pain
tolerance gets through the roof. You become extremely physically fit.
So yeah, even the good days and the.
Speaker 3 (29:53):
Bad days, we're all character building.
Speaker 1 (29:57):
As a chemist or as a material scientist, what do
you think you understand about the physical world that most
people don't.
Speaker 3 (30:08):
Well.
Speaker 2 (30:09):
A lot of people think chemistry is scary. I think
people think chemicals are scary. I think chemistry is one
of the most fascinating things you can do. Is like
turning one form of matter into another form of matter
by blending them together and heating them up and pressurizing them. Yeah.
(30:30):
I'm always surprised when people say that they didn't like
chemistry or they found it scary in high school.
Speaker 3 (30:36):
To me, it's just pure magic.
Speaker 1 (30:41):
I'm going to run my first marathon this year. I
know you have run many marathons. What's one piece of
advice you would give me?
Speaker 3 (30:51):
Don't walk.
Speaker 2 (30:51):
Once you start walking, like, you'll never be able to
run again.
Speaker 3 (30:55):
So even if you're you think you're if you're faced.
Speaker 2 (30:58):
With a hill, you're like, oh, I could walk up
that hill just as fast as I could keep running.
Just don't let your body know that walking is an option,
because you will end up walking those last five kilometers
as I did first time I did the marathon.
Speaker 1 (31:12):
That is good advice. Is there anything else we should
talk about? Did we not talk about anything that we
should talk about?
Speaker 3 (31:25):
You know, I've.
Speaker 2 (31:27):
Yeah, I mean one thing that I feel strongly about
is carbon avoidance, and you know, this need to avoid
carbon emissions, and I just believe so much, not only
in my own technology, but but in others that are
coming out in steel and ammonia and industrial processing.
Speaker 3 (31:45):
That is about efficiency.
Speaker 2 (31:47):
It's about doing things smarter and not making things more complicated,
and it you know, I love nothing more than like
really elegant solutions. I'm biased, but in my biased opinion,
Sublime it's one of these elegant solutions that will be
obvious in retrospect. And I think it's a very exciting
time to be to be technologists, to work at startups,
(32:11):
and to really force these new inventions into reality with
help from the industry incumbents, which I think are moving
faster than an ever before.
Speaker 3 (32:21):
To create the future. It's a really fun time.
Speaker 1 (32:28):
Pleiah Ellis is the co founder and CEO of Sublime Systems.
Today's show was produced by Gabriel Hunter Cheng. It was
edited by Lyddy jeene Kott and engineered by Sarah Bruguier.
You can email us at problem at Pushkin dot FM.
I'm Jacob Goldstein and we'll be back next week with
(32:49):
another episode of what's your problem,
Pushkin. You know it's amazing cement. Cement doesn't burn or
rust or rot. Cement lasts for thousands of years. See
Roman aqueducts, Mayan temples, and you can use cement to
(00:35):
build almost anything. Cement is so amazing that every year
humanity makes four billion metric tons of it. That is roughly,
very roughly a thousand pounds of cement for every man,
woman and child on planet Earth every year. Now, for
the bad news, making cement is wildly, almost absurdly carbon intensive.
(01:00):
We don't hear so much about this. Cement is generally
not what we talk about when we talk about climate change.
But in order to solve climate change, we're going to
have to figure out a better way to make cement.
I'm Jacob Goldstein and this is What's Your Problem, the
(01:21):
show where I talk to people who are trying to
make technological progress. My guest today is Leah Ellis. She's
the co founder and CEO of Sublime Systems. Lea's problem
is this, how can you make cement without emitting carbon dioxide?
Before she got into cement, Lea was in grad school
working on lithium ion batteries, and as happens to a
(01:44):
lot of grad students. She had this kind of deflating
conversation with her advisor.
Speaker 2 (01:51):
One of my last you know, walk and talks with
my PhD supervisor is like, you know, what's next in batteries?
And he was like, oh, it'll take you know, tens
of thousands of people ten years to get to the
next level.
Speaker 3 (02:05):
But I was like, oh.
Speaker 2 (02:06):
Damn, Like I don't want to be like one of
ten thousand people working for ten years.
Speaker 1 (02:12):
So you realize that you sort of missed the kind
of innovation glory days for batteries perhaps, So what do
you do?
Speaker 2 (02:21):
Well? I wanted to continue working with inventors, so I
got a Canadian government fellowship to go anywhere work with anyone,
and I chose to come to Mit to work with
Professor Yetmingchek. And it was actually Yet's idea to work
on cement. And it wouldn't have been something that I
would have ever had the audacity to jump fields like that.
Speaker 1 (02:46):
So how did that idea come up?
Speaker 2 (02:49):
Well, so Yet a year before, in twenty seventeen, had
spun out Form Energy, which is a long duration energy
storage company, and he had his eye on these trends,
you know, renewable electricity is becoming the cheapest form of electricity,
especially if it's intermittent, and you know, the utility sector
being thirty percent of house gas emissions, like, thought's going
(03:11):
to go to zero if we'ever going to achieve net zero,
and then you know what what would happen as a
consequence of that is that you have all of this
renewable capacity that then you then you can use to
decarbonise the next largest tranches of emissions, so cement and
steel being each about eight percent of global CO two emissions.
(03:31):
The thinking was like, you know, how do you decarbonise
cement assuming you are in a world with abundant and
relatively cheap renewable electrons.
Speaker 1 (03:39):
So super top down, super like macro big picture, not like, oh,
I've got this little technical idea, how can we build
it up? But it's like, Okay, I'm I'm looking at
the whole planet for the next thirty years, and I
see that like making steel and cement is like a
problem we have to solve, and we're gonna have a
lot of intermittent clean energy.
Speaker 3 (04:00):
What do you got exactly?
Speaker 1 (04:02):
And so he mentioned cement to you, what do you
know about cement. When he mentioned cement.
Speaker 2 (04:09):
Well, I assume that cement and concrete were the same thing.
I mean, that was my level of understanding at the time.
But I did know that cement was, you know, a
much larger tranch of COTO emissions than you know, lithium
ion batteries could ever address.
Speaker 1 (04:27):
And so just to be clear, when you say you
assume that cement and concrete were the same, you're saying
you didn't know anything. Because that's one that's always been
hard for me. I memorized it in preparing for this interview.
It's one thing I'll definitely get out of this AMA.
Speaker 2 (04:40):
Yeah, and you know sometimes I get those two words
mixed up even now.
Speaker 1 (04:45):
So what's the difference just for everybody?
Speaker 2 (04:47):
So, cement is the glue, it's rock glue, and concrete
is the glue plus aggregate. So cement is the glue
that holds the rocks together to meet concrete.
Speaker 1 (04:57):
Right, So all the things around us are built out
of concrete, and cement is sort of the essential ingredient
in concrete.
Speaker 2 (05:05):
That's right, It's about fifteen percent of the concrete.
Speaker 1 (05:09):
How do you start learning about cement?
Speaker 2 (05:11):
Well, I first started on Wikipedia. It's one of my
favorite always to spend time.
Speaker 3 (05:17):
So it was quite delightful.
Speaker 2 (05:20):
And from Wikipedia, you know, spent a lot of time
at the library, you know, in textbooks and then going
from textbooks to research articles and.
Speaker 3 (05:33):
Yeah, it's been really really fun.
Speaker 2 (05:36):
Honestly, lithium ion batteries are art cool and magical, but
cement is is awesome. I think if you're a material scientist,
if you're a nerd, there's like a very deep and
exciting rabbit hole that you can go down to you
once you start getting stoked about cement.
Speaker 1 (05:50):
Well, let's get stoked about cement. So first of all,
it's extraordinarily ubiquitous, right, like so ubiquitous you don't even
notice it. I was actually listening to an interview with
you a couple of weeks ago, and I happened to
be at the airport, and I realized as I was listening,
like I was of course standing on on cement on
(06:13):
concrete right on the sidewalk, but also there were like
I was it was like two decks, you know, arrivals
and departures, and so there were these like columns made
out of concrete, and then there was concrete over my head.
So I was essentially like encased in cement in concrete
as I was listening to it. So that was good.
That was that was getting me in the right in
(06:35):
the right mood for this interview.
Speaker 2 (06:36):
Yeah, once you see it, you really can't unsee it,
and it's it's really fun. And as I've gotten into
cement chemistry and durability and testing every sort of feature
in the cement you look at you can see weathering,
you can see freeze thought damage, you can see alkali
silica reaction, you can see rebark corrosion, and it really
(06:57):
makes uh, you know, a walk down the concrete jungle
a little bit more intellectually stimulating than it was before.
Speaker 1 (07:05):
So certainly there's a lot of it. Certainly it's important.
And so let's talk about how cement is made today.
This is not what you're doing, but sort of the
thing you're trying to improve upon. Right, Portland cement is
this phrase that it's basically a technique for making cement. Right,
it's a product, but it's also a way of making
(07:25):
the product that's been around for what more than one
hundred years? So briefly, what is Portland cement? How do
you make it? What do you start with.
Speaker 2 (07:34):
Yeah, Portland cement is a specific formulation of cement that
has been around one hundred and ninety nine years. So
Portland cement will celebrate its two hundredth birthday this year
on October fourth.
Speaker 3 (07:46):
That's two hundred years since, and.
Speaker 1 (07:47):
You're trying to make sure it doesn't make it to
two hundred.
Speaker 3 (07:50):
And fifty, right, exactly. Yeah.
Speaker 2 (07:55):
So the way Portland cement is made, you take limestone
as the calcium source, and then you will also need
the right ratios of calcium to silica, alumina and iron.
So that Portland cement recipe is about getting those ratios right.
But the dominant ingredient is limestone.
Speaker 1 (08:13):
So limestone is the key ingredient. The thing we want
in the limestone is the calcium. But is the calcium
bound with carbon? Is that our fundamental problem?
Speaker 3 (08:23):
That's right.
Speaker 2 (08:24):
So the limestone is a calcium oxide bound to CO
two and those are chemically bound very strongly, which makes
the calcium inert.
Speaker 1 (08:34):
And the process of making cement is you want to
essentially isolate the calcium, I mean, among other things, but
a key piece of the process is that, right.
Speaker 3 (08:42):
Yeah.
Speaker 1 (08:42):
Okay, So in making Portland cement, how does that.
Speaker 2 (08:45):
Happen by heating it to the point where that bond
breaks and CO two, you know, goes as a gas
and then you get this solid solid gas separation where
you have solid calcium oxide and gashous CO two.
Speaker 1 (09:01):
Okay, And so then that CO two just goes off
into the atmosphere, go often to the chimney.
Speaker 2 (09:06):
Yeah, it's mixed with the combustion emissions and goes into
the air.
Speaker 1 (09:10):
Okay. So it's just it's just more carbon emissions. It's bad.
It's the thing we're trying to get rid of on
the planet.
Speaker 3 (09:17):
Yeah, that's right. Mean it's causing global warming.
Speaker 1 (09:20):
Okay. So you've broken down the limestone and emitted a
bunch of CO two in so doing, but you're not
done yet, right, what has to happen next.
Speaker 2 (09:30):
So once that's broken down, it's heated further to fourteen
hundred degrees celsius.
Speaker 1 (09:36):
So it's getting wildly hot. I mean, is the rock
actually like melting? Does it look lava ish if you
look at it?
Speaker 3 (09:42):
Yeah?
Speaker 2 (09:43):
And I actually have had the distinct privilege of looking
down the center of a Portland cement kiln. There there's
like a tiny hole under the fuel injection port, you
put on a welding mask. It's of course extremely hot,
and you can peer down and see the rotary kiln going.
You can see the flame coming right over your head
(10:05):
through that fuel injection port, and you can see the
molten rock rolling towards you, like red red, glowing hot.
Speaker 1 (10:12):
And so so, in addition to the carbon dioxide emitted
directly from the limestone in the first stage, presumably people
are burning a lot of fossil fuels in order to
make this rock lava hot in this stage, thereby emitting
(10:33):
more carbon dioxide into the atmosphere.
Speaker 3 (10:35):
That's right.
Speaker 2 (10:35):
And so besides, every Portland cement kiln you're going to see,
you know, a small hill of coal, and it's normally
bitchumen is coal, though there's often a blend of fuels
used to heat up the kiln to this enormous temperature.
But bitchumen is cool. Is what's necessary to get this
like highly luminous flame that creates the ideal temperatures.
Speaker 1 (11:01):
So you're not only burning fossil fuels, you're burning coal,
which is a particularly dirty, particularly carbon intensive fossil fuel.
Speaker 3 (11:09):
That's right.
Speaker 1 (11:09):
Yeah, And we make a ton of cement, so like cement.
It's like very carbon intensive, emits a lot of carbon
into the atmosphere, and we need it, and we make
literally what order of magnitude how many tons?
Speaker 3 (11:25):
Yeah, about four billion tons a year.
Speaker 1 (11:27):
Four billion tons a year. And so overall, when you
take it all together, what percent of human carbon emissions
are from making cement?
Speaker 2 (11:43):
So it's eight percent of global CO two missions from cement.
Speaker 1 (11:46):
This is a big problem, and we don't know how
to fix.
Speaker 3 (11:48):
It, that's right.
Speaker 2 (11:49):
So there are incremental approaches that chip away at the problem,
like using alternative fuels. You can swap out some of
the coal with natural gas or with burning tires. You
can use supplementary sumuntitious materials, so some antigious materials that
are less performant, you can blend them in up to
thirty even up to fifty percent to to you know,
(12:13):
reduce the emissions. But getting to zero is very difficult,
if not impossible, with things that are exist today.
Speaker 1 (12:22):
So let's talk about that, right you You are not
going for an incremental gain here, you're saying, okay, let's
start from zero and let's figure out a whole new
way to make cement that doesn't emit any carbon dioxide
and you decide that instead of using coal, you're gonna
use electricity, right.
Speaker 3 (12:42):
That's right.
Speaker 2 (12:43):
So being battery scientists and electric chemists, you know, we've
got the hammer and everything looks like a nail, right,
so we can's electricity, but we wanted to look beyond it.
Just the most obvious way, which is like to use
an electric kiln for heating, that's got as challenges. I
mean that one's the obvious way. If it was easy,
(13:04):
people would already have done it. There's various challenges with
efficiency and material so we had to find another path.
And what we derived after many brainstorming sessions and investigating
different options, was this way of breaking down the minerals
using electric chemistry instead of using heat. So by bypassing
(13:26):
the heating also allowed us to be more amenable with
the use of intermittent renewable electricity, because of course heating
requires base load electricity. It takes days to heat up
a kiln to those high temperatures, and so it doesn't
allow you to be rampable, it doesn't allow you to
(13:46):
be load following.
Speaker 1 (13:47):
Right, because that a regional kind of marching orders. The
original big idea was like we're going to have extraordinary
abundance of renewable energy, but for a while at least,
it's going to be intermittent. The sun's going to shine,
then the sun's going to go down, and so you
you don't want to build a system that requires constant
high inputs of power over days and days, because that
(14:09):
doesn't fit the kind of worldview you're building for.
Speaker 2 (14:12):
Well, yeah, that's right. But also you can get a
cost advantage. You can get the cheapest electricity if you
can take it whenever it's available.
Speaker 1 (14:20):
So okay, so go on.
Speaker 2 (14:22):
The next thing you do is technoeconomic modeling. So start modeling,
like what does it cost to do this, what are
the inputs, what are the outputs, what's the you know,
what's the capex, what's the opax, what's the labor, et cetera.
Getting quotes from vendors for specific pieces of equipment, getting
actual data from the pilot using actual numbers, and so
(14:46):
now it's like this, you know, multi tab quilt sized spreadsheete.
But getting that going was the first step, because you know,
that's what allows you to pivot quickly to see the
weaknesses of your approach. And we continue doing that, and
we still continue to do that to refine different elements
of our process.
Speaker 1 (15:09):
This process Leah is talking about, it's a whole new
way of making cement. It doesn't involve heat at all,
and Lea hopes it will be this turning point in
the millennia long history of the way human beings make cement.
In a minute, she explains how it works. So you've
(15:37):
come up with this new process. You're still refining it,
trying to make it more efficient, reliable, whatever, But how
does it work?
Speaker 2 (15:45):
Yeah, Basically we're breaking down the inert minerals using chemistry
and electric chemistry instead of using heat. So you know,
the heart of our system, or maybe call it the lungs,
is this electrochemical reactor that takes neutral pach water and
splits it.
Speaker 3 (16:04):
Into acid and base.
Speaker 2 (16:06):
So there's a pH gradient that forms between the two
electrodes and that's used to dissolve calcium and other minerals
from rocks. So actually the electrochemical process we use since
we're digesting the rocks instead of cooking them, we don't
have to use limestone, so we're using calcium silicate minerals
(16:28):
and industrial wastes and basically taking the rock and then
splitting it into its mineral components, drying all those off
into free flowing powders, and then reassembling a cement powder
with the right ratios of all of these elements to
make a high performance cement.
Speaker 1 (16:49):
And so you basically use electricity to turn water a
va of water into a place where like part of
the water is somewhat acidic and part of the water
is somewhat basic. And then you put the rocks into
that water, and the acidic parts of the water do
some of the words, and the basic parts of the
(17:10):
water do some of the work, and you're wet, and
you wind up with the minerals you need at a
price you can afford.
Speaker 3 (17:15):
Yeah, exactly. You said it very well, So I.
Speaker 1 (17:18):
Know you start with the idea, and I've heard you
say that. Initially you made one gram of cement, which
is like you described it as like the size of
an almond, which is particularly amazing given how heavy and
big cement is. And then you did a kilogram. Where
are you now?
Speaker 2 (17:37):
We came out of stealth about a year ago after
we built our pilot plant, which was initially sized to
produce one hundred tons a year. In the past year,
We've had about seven thousand hours of uptime. We've scaled
it up to two hundred and fifty tons per year.
We've produced tons of cement and have ran it continuously
(17:58):
under dozens of conditions to you know, optimize it.
Speaker 1 (18:02):
And that cement you've produced is it is it out
in the world. Is it just like practice cement? Is
it real cement? You know, holding up a building somewhere
or something?
Speaker 2 (18:12):
It is actually holding up a building somewhere. So we
did our first field poor about two weeks ago.
Speaker 1 (18:19):
Oh congratulations, Yeah, I like that. For field poor. Where
was the field poor?
Speaker 2 (18:23):
It was in the Boston area and a piece of
in a in a commercial construction project. It was going
underneath the construction. It's typically what's called called a mud slab.
Speaker 3 (18:33):
So yeah, so.
Speaker 1 (18:35):
That's what you're doing. Now, what have you not figured
out yet? Like, what has to happen for you to
get from here to being a real business selling lots
of cement whatever all over the world or whatever for
you to be a real business, for you to be
a real business with revenue and your cement just you
(18:56):
want your cubmit to be boring, right, you want your
to be just like whatever boring again.
Speaker 2 (19:01):
Yeah, well, there are certain things we figured out. We
figured out the product, we figured out the pros us.
But where we are today is still Even though I'm
so proud of taking this from a gram to two
hundred and fifty tons in four years, it's still a
drop in the ocean. I mean, we affectionately call our
pilot plant this cement plant for ants.
Speaker 3 (19:25):
It has to be at least three times.
Speaker 2 (19:26):
Bigger than this, but we have to get to a
million tons per year.
Speaker 3 (19:31):
We're going to compete on cost with.
Speaker 2 (19:32):
Today's Portland cement, and so going from pilot scale to
full scale, where full scale for cement is just a
titanic colossal size, our next step is to build a
minimum viable commercial scale plant. So we refer to this
as our kiloton plant. We have a site secured in
(19:54):
Holy Oak, Massachusetts, on the site of an old paper mill,
which we are in the process of removing this ancient
paper mill, but all the remnants of what makes this
a really exciting industrial.
Speaker 3 (20:09):
Site still exists. So a hydro electric.
Speaker 2 (20:11):
Dam, ready, access to rail, ready access to a workforce,
you know, industrial permits exist and so our next our
next step is to wrap up the pilot phase in
the coming months, do do the engineering and start procuring
long lead equipment so that we can start building our plant.
(20:35):
And so that is the work that you know, my
colleagues in the office are busy doing right now.
Speaker 1 (20:41):
So these are very like practical heavy industry, could be
any kind of a big factory concerns. Do you still
have engineering or technical problems to solve as well, or
do you feel like you've got it down?
Speaker 2 (20:59):
Well both, I do feel like I've got it down.
I'd say, you know, the problems never stop and also
the improvements never stop. So in the spirit of swift
and massive, we move as quickly as we can to
move from one one degree of scale to the next.
But there's you know, I have to say, I have
the distinct privilege of working with some of the smartest
(21:21):
people I have ever met in my entire life, and
I've had the pleasure of working with smart people all
throughout my education and career. But you know, we're generating
quite a lot of IP, We're generating quite a lot
of improvements. There's so many improvements that we're planning to
feather in over time as we develop the system that
I think will replace Portland cement in the next one
(21:43):
hundred years.
Speaker 1 (21:45):
And in terms of cost, I mean, obviously cost must
be to a very large degree of function of scale.
And you're scaling up at scale. Are you already cost competitive?
Do you have to find new efficiencies? I mean presumably
this is like a brutal commodity business.
Speaker 3 (22:06):
Yeah, totally brutal.
Speaker 2 (22:08):
And so we can get very close to competing on
costs with Portland cement, no carrots, no sticks, at scale
with six sons of kilawad hour electricity. So not even
using funny math, so using what we think are you know,
realistic assumptions, so you know, but we're still far out
(22:31):
from a megaton plant. But what we can say with
total confidence is that we will be cheaper than Portland
cement plus post combustion carbon capture, which is presently the
only other way to get to zero for cement making.
So every time you take a Portland cement kiln million
tons per year, you add post combustion carbon capture, you
(22:54):
add some other process. You're always adding capex to that
Portland cement plant and opex. And I think the wonderful
thing about Sublime, which is our unique advantage, is that
we're not adding onto the kilm, we're replacing the kilm.
We're not capture, we're not storage, we're carbon avoidance, and
that ultimately is much cheaper than capture and storage because
(23:14):
you're not adding onto the system.
Speaker 1 (23:18):
What are some reasons it might not work?
Speaker 2 (23:24):
You know, it might There are one thousand ways to die,
maybe even more, and I like to keep my eyes
open to all of them. And we do quite a
lot of risk registered development. We have like what we
call our three a M list quarterly, I get, you know,
everyone anyone in the.
Speaker 3 (23:45):
Like what keeps you as you.
Speaker 1 (23:47):
Worry about when you wake up at three in the morning. Yeah,
what's at the top of that list right now?
Speaker 3 (23:53):
If changes day to day. So I'm glad you said
right now.
Speaker 2 (23:56):
I mean, like, as we go into this process of
going from pilot to first commercial, I think about cost
overruns and this this isn't just you know.
Speaker 1 (24:08):
Just like building a factory, totally classic.
Speaker 2 (24:12):
And you know, hiring I'd love to hire someone who's
done this before because I think this is where you
really need someone who's done this before, because it's not
just the cost of the thing.
Speaker 3 (24:22):
I mean, we think.
Speaker 2 (24:23):
We've got that lockdown with solid research, solid quotes, just timeline.
You know, imagine like you're missing like some widget and
you find out this little dinky piece is like I'm
gonna show up a year later than everything else, and
your companies, you know, you've got your burn rate of
the whole company.
Speaker 3 (24:39):
So that's that's just one way to die.
Speaker 1 (24:42):
I mean, yeah, it's a classic. That is a classic
way to die.
Speaker 2 (24:46):
Yea running out of money. Your heart stops beating it,
you know.
Speaker 1 (24:53):
So that's the sad story. There is some happy story
where it works and you build a factory and you
start selling cement, clean cement. Like if you go I
don't know, say ten years into the future, what does
the world look like if it's the happy story.
Speaker 2 (25:15):
Yeah, well I may go more than ten years in
the future, and I maybe go one hundred years in
the future. I like to think about a post carbon world,
like what does it look like when you know, you know,
you're penalized for your CO two emissions the same way
you're penalized for you know, mercury emissions or something like that.
Speaker 3 (25:34):
And you know, I like to think that if we're successful.
Speaker 2 (25:38):
The most wildly successful version of Sublime Systems is that
We've changed the way humans make cement the same way
you know, Romans changed the way we made cement, same
way the British and French with Portland cement changed the
world way we made cement. I think, you know, humbly, cautiously, optimistically,
what Sublime is doing could change the way humans make
(26:01):
cement forever. And I think that's really exciting because it's
it's such a monumental thing. Like when you go to
when you go to Egypt, you see, you know, construction,
things that were made to last, you know, you go
see the aqueducts, you go see things, and these things
that were built are a testament and a monument to
(26:23):
the values of the people that created them. And so
I think, you know, you know, the coolest thing for
me is to have like enduring significant buildings that are
made with you know, the cement of the future and
having like archaeologists one thousand and two thousand years from
now looking back and being like, oh, there was this
(26:43):
period before where the world was a certain way, and
then there was something that happened where co two levels
crusted and then they came down and at that point
in time, like we can see how their buildings materials
change to adapt to that.
Speaker 3 (26:59):
I think. I think that's pretty cool.
Speaker 2 (27:00):
I mean, I don't think you can get closer to
a monumental legacy than to really change building materials in.
Speaker 1 (27:07):
That way, the way literal monuments are built. Yeah, we'll
be back in a minute with the lightning round. After
(27:27):
that big think and we're going to do a small
think lightning round to conclude. What's your favorite concrete structure
or concrete thing?
Speaker 2 (27:40):
Oh, you know, it's the things that folks on my
teammates so often. You know, we're doing tests on our
cement pace, and so we have a bunch of molds
of like you know, frogs and dragons and snowmen and
whales and turtles and so. I yeah, my favorite concrete
things are it's probably the dragon.
Speaker 3 (28:00):
I like the dragon the most.
Speaker 1 (28:02):
How big is the dragon?
Speaker 2 (28:04):
Oh?
Speaker 3 (28:04):
It fits on the palm of my hand.
Speaker 2 (28:05):
I sometimes take it with me to conferences, you know,
just to meet people.
Speaker 3 (28:09):
You know, seeing is believing, and so sometimes it travels
with me.
Speaker 1 (28:14):
What's your least favorite concrete thing?
Speaker 3 (28:21):
I would probably say New York City.
Speaker 2 (28:23):
Just something about that city just makes me despair. I
don't know what it is like just never been a fan.
Speaker 3 (28:31):
I'm trying.
Speaker 2 (28:31):
I'm trying to be open minded about New York City,
but you know, I fail each time I go.
Speaker 3 (28:35):
No offense, not my cup of tea.
Speaker 1 (28:38):
Fair. It's not for everybody. It's for millions of people,
but it's not for everybody. So you rode your bike
across Africa from north to south. What was the worst
day of that trip?
Speaker 2 (28:56):
You know, there were days when I was extremely sick,
so it would probably be.
Speaker 3 (29:03):
Those days.
Speaker 1 (29:05):
And you still had to ride. Yeah, often, Yeah, Okay,
what was the best day?
Speaker 3 (29:14):
I mean, every day was the best day, even if
I was totally sick.
Speaker 2 (29:17):
I mean, I like to say that doing that trip
across Africa, which was about four months, twelve thousand kilometers,
about one hundred kilometers a day on average. I mean,
it's something I would recommend both to my best friends
and my worst.
Speaker 3 (29:32):
Enemies, because.
Speaker 2 (29:35):
I think it does is extremely character building, and you
get very comfortable with discomfort, and you know, your pain
tolerance gets through the roof. You become extremely physically fit.
So yeah, even the good days and the.
Speaker 3 (29:53):
Bad days, we're all character building.
Speaker 1 (29:57):
As a chemist or as a material scientist, what do
you think you understand about the physical world that most
people don't.
Speaker 3 (30:08):
Well.
Speaker 2 (30:09):
A lot of people think chemistry is scary. I think
people think chemicals are scary. I think chemistry is one
of the most fascinating things you can do. Is like
turning one form of matter into another form of matter
by blending them together and heating them up and pressurizing them. Yeah.
(30:30):
I'm always surprised when people say that they didn't like
chemistry or they found it scary in high school.
Speaker 3 (30:36):
To me, it's just pure magic.
Speaker 1 (30:41):
I'm going to run my first marathon this year. I
know you have run many marathons. What's one piece of
advice you would give me?
Speaker 3 (30:51):
Don't walk.
Speaker 2 (30:51):
Once you start walking, like, you'll never be able to
run again.
Speaker 3 (30:55):
So even if you're you think you're if you're faced.
Speaker 2 (30:58):
With a hill, you're like, oh, I could walk up
that hill just as fast as I could keep running.
Just don't let your body know that walking is an option,
because you will end up walking those last five kilometers
as I did first time I did the marathon.
Speaker 1 (31:12):
That is good advice. Is there anything else we should
talk about? Did we not talk about anything that we
should talk about?
Speaker 3 (31:25):
You know, I've.
Speaker 2 (31:27):
Yeah, I mean one thing that I feel strongly about
is carbon avoidance, and you know, this need to avoid
carbon emissions, and I just believe so much, not only
in my own technology, but but in others that are
coming out in steel and ammonia and industrial processing.
Speaker 3 (31:45):
That is about efficiency.
Speaker 2 (31:47):
It's about doing things smarter and not making things more complicated,
and it you know, I love nothing more than like
really elegant solutions. I'm biased, but in my biased opinion,
Sublime it's one of these elegant solutions that will be
obvious in retrospect. And I think it's a very exciting
time to be to be technologists, to work at startups,
(32:11):
and to really force these new inventions into reality with
help from the industry incumbents, which I think are moving
faster than an ever before.
Speaker 3 (32:21):
To create the future. It's a really fun time.
Speaker 1 (32:28):
Pleiah Ellis is the co founder and CEO of Sublime Systems.
Today's show was produced by Gabriel Hunter Cheng. It was
edited by Lyddy jeene Kott and engineered by Sarah Bruguier.
You can email us at problem at Pushkin dot FM.
I'm Jacob Goldstein and we'll be back next week with
(32:49):
another episode of what's your problem,
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