This video is brought to you by Skillshare. When it comes to renewable energy,
solar, wind, and hydro keep coming up as number 1, but what about number 2?
Literally. I’m talking about ... well, poop. There’s a rich, carbon-neutral resource that
we could tap into: Turning crap into energy instead of flushing it down the toilet.
It could be used as a coal alternative, to sequester carbon, strengthen concrete and more.
There’s an old technology that’s starting to make a splash and might change the way you think about
number 2. Let’s see if we can come to a decision on turning waste into energy and if it’s worth it.
I’m Matt Ferrell … welcome to Undecided.
We’re always looking for clean energy in any source we can: solar, wind, crops, even the
currents at the bottom of the sea. Trying to get more and more creative to find something that
really stands out. A couple of months ago a fan of the channel put me into contact with a company
that’s doing just that … and in a way I wasn’t expecting. What if we could turn good old number 2
into a resource for generating energy or producing products we use everyday, all while cleaning up
the environment? Sounds like an idea that doesn’t stink. This was a topic right up my alley.
Usually we’re talking about new technologies,
but this tech has been around since 1913! So what gives? Why are we still literally
flushing away renewable energy, instead of taking “recycling” to a whole new level?
I’d argue that there are 3 unavoidable things in the world: death,
taxes, and bathroom breaks. Doesn’t matter how much you hate creating waste:
even the most hardcore recycler has to go sometime. Everybody poops.
I’m going to go out on a limb and guess that the vast majority of you haven’t given much thought to
what happens to your waste after you flush. I know I hadn’t. The trip to the porcelain throne is just
the beginning. After our waste travels through the sewage system, to the wastewater treatment plant,
they separate the solids from water. In rural areas, it travels to a septic tank where the
water leeches out and the sludge is removed to be treated elsewhere. The water is treated through an
intensive process (flocculation, chlorination, etc) before being discharged into local bodies
of water. The leftover solids generally get taken care of in three different ways:
You can incinerate it, which is pretty much what it sounds like: you burn it. All of those
materials—and its energy—literally go up in smoke (and into our atmosphere).
The second way is to landfill it. In the landfill those biosolids break down into methane and CO2,
depending on whether oxygen is present. If there is no oxygen, anaerobic digestion takes place,
generating CO2 and methane. If there is oxygen present, aerobic digestion occurs, generating CO2.
The third way, and the most common, is to apply those biosolids to agricultural fields.
About 50% of biosolids produced in the US are used for agriculture to grow products for animal feed.
So human waste is used to grow products to feed farm animals like dairy cows.
The problem with sewage management is that it never stops. Everybody poops about a pound per
day, give or take. Multiply that by several billion people, 365 days a year, and you
can start to get a sense of the magnitude of the problem. In the US alone, we produce an estimated
5-13 dry tons of sewage sludge (human waste, generally 25% solid). Add the water content,
and that’s billions of gallons of waste to treat every year, and it’s never going to stop.
Even after treatment, the final biosolids can still have contaminant issues.
To put this politely … sometimes things come out in the same state they went in. This doesn’t
just mean corn: it also includes things like detergents, microplastics, pharmaceuticals,
and “forever” chemicals like PFAS. This becomes an even bigger problem when these
solids are reused for fertilizer, because those contaminants are put right back into the crops,
and the cycle continues. Multiple dairy farms in Maine have already had to close production
because their milk had high levels of PFAS, leading to loss of income and public trust.
As you can imagine, this type of waste isn’t always great for the environment either. The water
content is usually treated and discharged to water bodies, but if the water isn’t treated properly,
the solids, metals, and other contaminants can choke out wildlife habitats and fisheries.
The waste is nutrient rich. If it’s dumped in a lake without treatment, it can lead to
overgrowth of certain bacteria and algae, which also disrupt the natural habitat of aquatic life.
Then there’s the energy consumption part of this to consider. Wastewater treatment
plants are estimated to consume more than 30TWh per year of electricity–that’s
about $2 billion in annual electric costs, and likely not from very clean sources.
Electricity usually takes up 25% to 40% of a wastewater treatment plant’s annual budget,
and those needs are likely to rise with population growth and tightening water quality requirements.
Biosolids also have a greenhouse gas problem. As I mentioned before, they break down in the
landfill to methane and CO2. The problem there is that methane is 25X times potent than CO2
as a greenhouse gas (although it does have a shorter lifespan). Municipal solid waste
landfills are the third-largest source of human-related methane emissions in the U.S.
Throughout history, humans have simply moved bowel movements out of sight and out of smell-range.
Some of these sewage disposal methods have been in practice for nearly one hundred years, mostly
because nobody has come up with a better way to deal with poop. There’s got to be a better way.
That’s where this old, 1913 technology comes in.
And the company that's taking this old idea and commercializing it to innovate
and change their entire business model. But before we get to that ... and also related to
it ... if you want to learn how to innovate and set your company or business apart,
you might want to check out the "Creative Business Model Innovation" class at Skillshare. If you're
anything like me, then you like learning new things. Skillshare has built an incredible online
learning community with thousands of classes to learn new skills in a wide array of topics.
For me, I've been trying to optimize how I work and to be more productive, and one of the classes
I've found super helpful is Thomas Frank's "Real Productivity: How to Build Habits That Last." I
often have too many things I want to do and get done, and it's helped me to set clear goals.
Everything on Skillshare is focused on learning, so there aren't any ads and they're always
launching new premium classes. Every time I log in I see something new that I want to watch and learn
from. And for the non-English speakers out there, the entire catalog is available with subtitles in
multiple languages. The first 1,000 people to use the link or my code undecidedwithmattferrell will
get a 1 month free trial of Skillshare. Thanks to Skillshare, and to all of you, for supporting
the channel. Now back to the old technology that's being used to change an industry...
Hydrothermal carbonization (HTC), also known as subcritical water or hot compressed water
carbonization, was first identified in 1913 by the German Nobel prize chemist, Dr. Bergius.
Right after this find, however, the 20th century had other plans for Germany,
including a World War, the rise of Nazism, another World War, the breakup, a wall,
and reunification of East and West Germany. With all this turmoil, it wasn’t until 2006 that it
got its foothold at the Max Planck Institute for Colloidal Science in Potsdam Germany.
This waste-management alternative has been seeing a surge in popularity in recent years.
I had a chance to talk to Dan Spracklin from SoMax where they are commercializing the technology.
> “What hydrothermal carbonization, or HTC, is, essentially most simple way of thinking
about it is, an industrial size pressure cooker. But it runs continuously, so it's not like you
would have at home where you have maybe cooking some chicken in a pressure cooker or a crock pot
where you do it in a batch. We do it consistently. What happens is, we apply heat and pressure to the
material. Applying pressure puts water into a subcritical state.” -Dan Spracklin <!--09:48-->
When you put water into a subcritical state that means it starts to boil, but the pressure
won’t let it turn into steam. This all happens with 10-50 bars of pressure at about 180-250C.
This is the perfect temperature to have that water act as a reagent … meaning it sets off
a whole chain of chemical reactions, which separate the larger molecules in the mix.
> “What we're doing essentially is taking large molecules, first, we chop them up
and then we pull off some oxygen atoms and some hydrogen atoms to make a more stable compound
and smaller molecules. Then the last step is we recombine those molecules to
make useful products and those products are essentially coal. We're mimicking the way
that mother nature formed coal. Typically earth does it over the period of hundreds
of millions of years, so coal is typically about 250 to 360 million years in formation.
We're able to do this with sewage sludge in less than an hour.” -Dan Spracklin <!--10:40-->
The resulting product doesn’t just look like coal: it can be used as a coal alternative.
The fuel value is similar to that of lignite coal, and treatment plants have used these solids to
co-fire in coal-handling infrastructure. And, in spite of its origins, the high temperature has
killed all bacteria and other biological threats, making the new fuel sanitary.
As part of this process, the solid-phase of HTC produces a liquor-rich process water as a
byproduct that is chock full of VOCs, formic acid, acetic acid, phenols and other derivatives (yum).
So what do we do with the HTC process liquid? This is where it gets exciting. That process
liquid can be used alongside anaerobic digestion to produce biogas. That’s right:
this liquor “byproduct” can be used as fuel in itself! This is why HTC has been suggested
as an intermediate step for producing biodiesel. Certain governments, including Germany and Italy,
heavily subsidize the practice of generating biogas from wastewater plants. Europe’s biogas
production from industrial and urban sewage sludge increased by 40 percent between 2013 and 2017.
So how much energy can you actually get from this, and does it balance out with the energy
needed to make it happen? As with everything: it depends. When it comes to sewage in particular,
HTC shows some strong energy potential. The energy requirement of sewage sludge’s
drying process is reduced up to 62% from normal drying techniques.
Traditionally, wastewater treatment plants consume a tremendous amount of energy and
that’s a huge chunk of their operating costs. Those savings can add up quickly. Some studies
even say that the economic benefit from the hydrochar production for energy recovery
has exceed the profits from biogas production per tonne of sewage sludge.
Translated: the plant can produce more biogas (possibly up to 5%) while saving on energy costs.
The best part? That source of energy is ALWAYS plentiful. You don’t have
to wait for the sun to shine or the wind to blow to collect that energy.
You can treat waste 24/7, 365 days a year, and the material never stops flowing in.
You can also make some pretty cool things from the HTC process besides coal and biogas:
there are diamonds to find in the roughage here.
One promising application is to replace the sand in concrete with the solid products of HTC. The
construction industry is already infamous for their negative environmental impacts:
they contribute a whopping 40% of the world’s energy-related CO2 emissions.
Part of that is because they require a ton of virgin materials to produce things like brick
and concrete. By using the solid products of HTC, they no longer need to mine these materials.
In 2019, engineers from Australia’s Royal Melbourne Institute of Technology
tested bricks made up of up to 25 percent biosolids
and found that these hybrids cut down energy use by nearly half during the firing process.
Companies like SoMax are working with sewage sludge to replace sand in the concrete mix.
At just 10% replacement, you could offset all the emissions from cement production.
We’re not just “recycling” here either: incorporating biosolids
into construction materials is also a powerful carbon sequestration tool.
These companies can use biosolids to offset sand consumption while also sequestering the
carbon from the biosolids for thousands of years in the concrete. You can break it, reuse it,
toss it: no matter what, that CO2 isn’t going to magically come out.
Also, remember that biosolid fertilizer problem earlier? With HTC in the mix,
you can create a carbon-neutral fertilizer from the hydrochar, only this time, you can get rid
of that pesky PFAS. This is no small feat. PFAS is called the “forever chemical” for a reason:
they’re made up of carbon-fluorine bonds, which are one of the strongest bonds around.
That makes it great for weather-resistant clothing and Teflon, but not so much for the environment.
But for HTC? It doesn’t give a crap. You’re breaking those molecules apart and getting rid
of those potentially harmful pollutants at the same time (with some energy generation to boot)
That pollutant-destroying aspect of HTC also makes it a good candidate for making another
important resource: drinking water. (Ok, hear me out here.) HTC is just creating a carbon product,
so you can activate it chemically or thermally, which opens the pores to filtration.
That’s right – activated carbon, a crucial product to filtering drinking water .
Remember, HTC is literally tearing these molecules apart and sticking them back together.
On a chemical level, the end product is different from what you started with.
It’s essentially a giant autoclave.
> “That's what we're essentially doing is acting as a large autoclave. I would never
do this and grab sewage sludge or biosolids, but I have no problem going and grabbing hydrochar,
smelling it. I don't recommend eating it. It won't kill you, but I'm sure it doesn't taste well.
But yeah, it's completely safe material.” -Dan Spracklin <!--25:45-->
Depending on what you use as feedstock, HTC can pretty much make everything from supercapacitor
materials, to anode materials for fuel cells, to energy, to syngas, to steel,
to concrete and cement. The general process is the same: toss it in, cook it, and bam:
at the end, you have carbon. (It’s like the world’s largest, and grossest, Easy Bake Oven.)
An economic study in Switzerland found that HTC-treatment per dry ton digested sewage
sludge with industrial-size plant costs around $600-700
(compared to current sewage sludge treatment costs of $660-1000). Similar studies in
Germany reported that HTC reduced the costs involved in sludge treatment and disposal.
Treating biosolids with HTC can not only reduce energy costs, but at the end of it, you literally
have less crap that you need to get rid of, which really puts a dent in those operational costs.
SoMax has seen these energy savings first hand.
> “In the case of our project in Phoenixville Pennsylvania, we're able to meet 153% of the
energy demand of that treatment plan. It goes from being the largest consumer of energy in
that municipality to a net energy producer, and we're going to produce 153% of the energy demand.
That extra energy is going back out onto the grid to run things like City Hall,
street lights, stop lights. It'll run the police station, and the fire station,
and provide them with electricity 24/7.” -Dan Spracklin <!--12:27-->
So if this is such a great system,
why haven’t we been hearing more about it? Besides the fact we’re talking about poop.
Google the studies on HTC, and you’ll soon see just how much it’s exploded across academia in
the past few years. (You’ll even find a few that aren’t behind a paywall!) However, the lab-scale
applications are still catching up to real-life applications (and with it, the real-life funding).
> “It has not attracted the investment that say oil and gas gets, or other, solar. You're not
seeing hundreds of billions of dollars invested in this because A, the investors don't know. B, even
the so-called sustainability or carbon experts aren't aware of this process, because it hasn't
really made its way out of academia into the real world. By building this plant in Pennsylvania,
the first one in North America, we're bringing it out into the world to make people aware of it.
This was, to us, it's really a coming out party. We've been operating in stealth mode until
October of last year when there was a public announcement that our technology was selected
by the US Department of Energy as the technology that should be implemented
at small and medium wastewater treatment plants across the country.” -Dan Spracklin <!--21:11-->
While HTC has a lot of technical aspects to consider, the biggest challenge right now may
actually be regulatory. Remember, this isn’t just a plumbing issue: it’s a public health issue. HTC
requires biomass, and biomass comes with quite a bit of red tape. This red tape is due to the fact
that poop is a biohazard and can harbor disease, but the legal paperwork can take years to process.
> “So even we've got the stamp approval from the US Department of Energy to implement
this process at wastewater treatment plants across the United States.
In Pennsylvania it's taken us three year to get the permit
to even try this process out at a wastewater treatment plant.” -Dan Spracklin <!--30:30-->
If you tell people about the environmental value, back it up with the economic benefits,
and have leaders lead by example, that’s when the magic happens.
It may not be polite conversation, but talking about the literal power of crap is the first step.
Still surprised that biosolids can do so much? You’re not alone–just ask Dan!
> "One of the final questions I do want to ask you is, "What is one of the most
surprising things about this type of work in your experience?" What is the thing that's caught you
kind of off guard that you weren't expecting? Is there anything? -Matt Ferrell <!--32:02-->
> “The most surprising thing is that everything works. We have a little game we play in our lab
here, on Wednesday we have a will it carbonize Wednesday. So, we just take off the wall things
and say, "Will it carbonize?" So I've brought in some t-shirts that they had holes and them stuff,
so we cut up the t-shirts and we put it through this process. Guess what? They carbonized.
So it's everything from macadamia nuts, to sunflower seeds, to flowers themselves. We've
actually processed flowers whole, and even carcasses. The unique thing about that is the
whole thing will carbonize. The bones will remain the shape but once you touch the bone it just
goes into powder. Huge surprises for me were about the raw sludge converted into hydrachar.
Actually, how well it acted as an activated carbon to filter out pollutants. That was surprising to
me. I thought, "That will never work." But yeah, it did.” -Dan Spracklin: <!--32:19-->
For me the decision seems pretty clear. HTC is a great, two birds-one stone solution.
We have to deal with our crap … literally. Why not get some extra use out of it? Academia and
industry leaders like Dan Spracklin agree: this tech has the potential to make a difference now.
The question seems to be how to get over that gulf between the theoretical and
full-scale application. Simply put, it may be time to carbonize, or get off the pot.
So are you still undecided? What do you think about HTC and poop power? Is it number 1 or
still number 2? Jump in the comments and let me know. And if you have knowledge on this,
or work in the industry, please share your experience so we can learn more together.
And thanks as always to my patrons. All of your direct support really helps
with producing these videos and to reduce my dependence on the almighty YouTube algorithm.
Speaking of which, if you liked this video be sure to check out one of the
ones I have linked right here. And subscribe and hit the notification
bell if you think I’ve earned it. Thanks so much for watching and I’ll see you in the next one.