Solve for X: Rob McGinnis on global water scarcity


Uploaded by wesolveforx on 06.02.2012

Transcript:

ROB MCGINNIS: My name is Rob McGinnis.
Today I'm going to talk about global water scarcity.
Actually I described the problem.
I really should talk about the solution.
I want to talk about having all the water we Need
This is something I've been working on for a very long
time, about 16 years now.
And I'm really excited to talk to you about it.
And thank you for inviting me here today.
It's been really a pleasure meeting you so far.
Global water scarcity is not something I think I have to
spend a lot of time explaining or demonstrating or proving to
anyone here.
It's already upon us.
There are competing demands for the water resources we
have. And by water I mean fresh water, water you can put
on crops, agricultural uses, water you can drink or use for
sanitation, say in cities or villages, water for making
things, like in industry or manufacturing.
Water is part of everything we make.
This is already upon us.
And it's getting worse.
Water's already scarce.
But in 18 years, it's projected we'll have 40% less
water than we actually need.
That's just a phenomenal number.
40% less, how's that even possible?
Well, this is why.
The population growth of the planet is a hockey stick,
especially in the last 50 or 60 years.
But it's actually not just population growth, not just
people drinking water, that's causing most of the demand
increase for water.
It's actually economic activity.
It's growing food but also eating more meat.
It requires more crops to make meat to eat.
But also GDP growth.
So if you can see in the graph to my right, the dark blue
section is actually the water demand increase from GDP
growth because water's part of everything we make.
And one example, and there are many, if you make a pair of
blue jeans, it takes 2,900 gallons of water.
And that's true for cars and microchips
and everything else.
And also power generation, the famed water-energy nexus.
If you want to make a megawatt hour of electricity using a
coal plant, it takes 50,000 gallons of water to do that.
If you want to use nuclear, it takes 60,000 gallons.
Biofuel, often it takes 67,000 gallons.
A conversation I had here today told
me that that's improving.
I hope that's true.
So it's a big problem.
And, in fact, we're not going to be able to meet our needs,
this 40% gap, just by conserving, by fixing pipes or
just by using less.
We certainly need to do those things.
But I think the answer's actually to have more water
because water equals prosperity.
So on the left is the picture I showed you before.
This is actually agricultural land in Texas.
On the right is a desert in Jordan.
So what's the only difference between these two places?
Obviously you'd think the soil would be better in an
agricultural.
And the only difference is water.
On the right, they desalinated water to grow crops.
So if you have water you can turn even desert into
agriculturally productive land.
And that's a tremendous value difference.
Water not only promotes sanitation health, well being,
increases standard of living, but it also creates
prosperity.
So I argue we should be able to have more.
What's the moon shot?
The moon shot is to do that without destroying the planet,
without making things worse.
So where is the water going to come from?
Well, salt water is abundant.
Fresh water is what we talk about when
we say water scarcity.
But we've got lots of water around us.
You see the population density map on the right, bottom.
We're largely near coasts.
So depending on how far away you want to define it, 40% to
60% of the population's within, say, 200 to 400
kilometers of the coastline.
You could certainly desalinate seawater.
But it's also true, if you look at the top-- that graph
isn't very easy to read-- but it's saline water resources
here in the Central Valley.
Anytime you put irrigation water on land you create
brackish water drainage.
So the water is taken up by the plant, and it's used.
But also transpiration occurs in the plant, evaporation of
soil contributes salinity to that water.
It goes in the bottom.
And often a water district, say, in California and Texas
or anywhere in the world will have to not only source water,
put it on the land, but also manage brackish drainage and
find something to do with it.
And often what it ends up doing is it ends up going to
some piece of land that becomes more and more saline.
And so pretty soon we're going to start growing pistachios or
something else.
The salt harm-- before you know it we have
to retire the land.
And what was the one way the Romans
destroyed an enemy forever?
They salted the earth.
And we're doing that to our own cropland.
So that's obviously not a solution.
But salt water's everywhere.
If we could find some way to use this as a resource,
wouldn't that be a way to approach that moon shot of
having all the water we need?
But you can't do it using current desalination methods.
You can't use fossil fuels to desalinate water.
This is a graph showing the IPCC projections for water
redistribution from climate change.
So the orange and the yellow sections, these are areas that
are going to get less water.
And the blue sections are going to get more water.
Well, the blue sections are not
necessarily much better off.
Flooding, erosion of soil is not a great situation.
And, of course, the water scarcity gets worse.
So if you burn fossil fuels to desalinate water, you
exacerbate climate change.
You make it more arid.
It's a vicious cycle.
And, in fact, the very first time I started working on
this, or starting caring about this, I was a young guy in the
Persian Gulf War.
And I was a Navy diver.
And I was sitting in a little black rubber boat with two
other guys with my diving gear on.
And I saw this enormous plant on the coast. I said what is
that thing?
What does that thing do?
And the guy next to me said, well, that's where they
desalinate water, man.
They put oil in one end, and they have water come out the
other end, and they drink it.
That's just crazy.
Why would you do that?
And I decided then I would fix that problem.
I would solve it somehow.
So I've been working on it ever since.
And I think the answer to desalinating without having
that oil in and water out solution is to use heat.
Heat is all round us.
It's quite abundant.
And the sources don't necessarily involve burning
fossil fuels.
So in the bottom right is a geothermal map, so obviously
that's a really easy one.
And the top right is solar thermal.
I think this is one that you can do very inexpensively,
particularly in distributed systems. We're talking about
the kind of heat that heats the hot water in your house,
not concentrated solar thermal with a tower or
some sort of parabolic.
This is just you can roll out a black mat with tubes in it,
and it gets hot.
And the top left shows the total energy you save in the
energy system of the United States.
And the bottom right is all the arrows that go to
electricity or the sort of things we get
from the fuel we consume.
But the big, fat arrow on the top left is the
waste heat, often 2/3.
So if you could use that without burning any more
fossil fuels, well, then, you'd start to actually have a
way to desalinate water without
making the world worse.
You'd make it better.
And you could start to have all the water you need.

So this is how we've tried to do that in the past. We tried
to boil water.
So this is the oldest form of desalination.
We take water from the ocean.
We put it into some sort of vessel.
We burn something underneath it.
It turned the water from liquid into gas.
Well, any chemical engineers here know that that's a
tremendous amount of energy.
The enthalpy of vaporization of water from liquid to gas
because the surface tension of water doesn't like to be gas.
And then we cool it.
And it turns back into water again.
And we leave the salts behind.
This is not the way to do it.
It uses a tremendous amount of heat.
And it usually has to have that heat at a pretty high
temperature where it could do other work.
It could make electricity, or it could do
other things for us.
So now to explain how I've been trying to approach this
technical breakthrough, I'm going to
use a u-tube osmometer.
Anyone recognizes this?
It has a membrane in the middle.
This membrane is special in that it allows water to pass
through but not salt.
And we have membranes like this.
And, in fact, we've made some that are quite advanced.
Now, normally what happens you have a brackish water on one
side or seawater, brackish water, and
freshwater on the other.
And what happens is just osmosis.
The natural tendency of the water is to go from the
freshwater to the saline water.
Now, there are a lot of ways to think about this.
No one will ever give you a good, definitive answer on
what osmosis is.
But the way I like to think about it is that those salt
molecules want to expand in the universe.
They want to exercise their eternal purpose for entropy.
And the ones in the freshwater want to do that, too.
But there's a lot less of them.
And the only thing keeping one or the other where
they are is the water.
So the water goes where the salts want to expand.
That's how I like to think about it.
Don't ask me to prove it mathematically because it
can't be done.
Now, if you exert hydraulic pressure on the salt water,
you can actually prevent this flow of water from occurring.
And this is really odd, if you think about it, because this
is what you do when you do reverse osmosis.
You exceed the hydraulic--
you can see the osmotic pressure with
more hydraulic pressure.
So now what's happened is you've taken some sort of fuel
source or some sort of, say, renewable, like wind power
that could have displaced coal for electricity, and you have
created work to create pressure, to counteract this
osmotic pressure.
And some of these things are equivalent.
They're interchangeable.
Fascinating.
But this is no way to desalinate water because it
requires that high-value electricity or that shaft
work, which you can use for transportation, heating,
cooling, so many other purposes.
So what have I done?
I've started trying to think about how to use osmosis in a
different way.
And, so, what I decided to do is I would make
my own salty solution.
And this is called a draw solution because no work goes
into this system.
It's just osmosis.
But this draw solution in salts that I
chose or special salts.
They're very, very concentrated, create a very
high osmotic pressure.
And the tendency of this water is to go into the draw
solution, even when that feed solution is three, four times
the salinity of seawater.
I can cause this flow to occur very rapidly in a very small,
inexpensive system.
Well, great, so now you've got salty water again.
It's a little more salty.
How is that better?
What's better is that these special salts can be removed
in a special way.
See, if you put ammonia and carbon dioxide into water,
they form salts.
They form ammonium bicarbonate.
You can actually use that to bake cookies instead of sodium
bicarbonate people use to make gingerbread cookies.
Pretty cool.
Ammonium carbonate and ammonium
carbomate, for instance.
And these are great salts for creating osmotic pressure.
They're highly soluble--
10 molar, 12 molar.
They bounce off that membrane just like
sodium chloride does.
But what's really cool about them, the thing that really
makes all this explode with possibility, is when you heat
them, they come out of solution with gases.
So now you're putting heat into a system not to change
liquid water into steam but to turn salts into gases.
Well, that's cool.
And when you cool them off again, they turn back into
salts again.
You keep using them over and over again.
And now you've got a way to take very low temperature,
very low quality, and very little thermal energy and
create osmotic pressure and create hydraulic pressure to
create power or to create separation.
And we're talking about very, very low quality energy.
And that matters.
A mega-joule is not a mega-joule when you're talking
about work.
Think about a Carnot engine.
Anyone studies the physics of turning heat into work?
The heat in a coffee cup is not the same as the heat
coming out of a rocket engine.
One mega-joule or one kilowatt or one megawatt or whatever
you want to say-- there's not a megawatt in a coffee cup,
but go with me there.
You could put a Stirling engine in a coffee cup, and
you make it spin around.
It's pretty cool.
It made a little breeze.
But it's not going to do very much work.
But that same, say kilowatt, fair enough, out of that
rocket engine, you could probably harness that to do
something useful.
So it's not about using less kilowatts or megajoules.
It's about using the ones that don't have any fuel
associated with them.
It's using the ones that don't change the climate change
equation and have very, very low cost.
So it's not to use less energy, although we do.
Obviously it's less energy to turn salt into gases than it
is to turn water into steam.
But it's, generally, to use less energy resources, less
electricity, less fuel--
big difference here.
So I want to use the kind of energy that comes out of a hot
cup of coffee in a room, not the kind that comes out of a
back of a rocket engine.
So I want to digress a little bit into some of
the technical details.
I understand people like that, here especially.
The very first thing I had to do when I formed a company to
commercialize this is to make a special membrane.
And so membranes exist for reverse osmosis where you take
the hydraulic pressure, and you push the
water through the membrane.
But they're built like civil engineering projects.
They're designed to withstand hydraulic pressure, so they're
thick, and they're very durable.
But we needed to make one that was nice and loose, more like
a cell of a membrane.
So it's only diffusion and osmosis that causes the water
to flow through.
So on the left bottom, you see that's a cross
section of an SCM.
But this is a schematic representation.
You see you've got an active layer.
It's about 100 nanometers thick.
This is a polyamide layer formed by inner-facial
polymerization.
It's just very thin polyamide.
That's where all the work gets done.
The water goes through it by solution diffusion.
The salts, they don't like to go through it.
They bounce off 99.5 percent reject it.
And, of course, support because a 100 nanometer thin
film is something you have to handle and slide in and out of
tubes and carry on trucks.
It needs to be a little more robust. So you make that out
of a porous material.
You can see in that picture that you've got a very thin
layer, spongy [? McEvoy's ?]
paper underneath.
That's what you see in that SCM.
So what's happening, he's got flowing on one side,
[? the accolator, ?]
draw the solution flowing the other.
And you've got water going through, but the salts are
bouncing off.
So this creates concentration, polarization.
The salts are more
concentrated towards the surface.
Now salts are trying to come in.
The draw solution is trying to come in and do their job,
bring that water across.
But they're being pulled away by the water the whole time.
These are classic phenomena inside actual systems. And so
you get this
concentration-polarization profile.
And so instead of having this big difference in osmotic
pressure of the pie--
the top of the pie at the bottom--
you end up with a very small difference.
So you had this huge driving force and this
tiny driving course.
And it's all because the membrane's getting in the way.
And so the very first thing we had to when we formed the
company is four guys spent one year making the most fantastic
membrane for osmosis that's ever existed.
The membranes that were available to us when we
started to do one gallon of water per square foot of
membrane area per day, one GFD.
And these can be 20 GFD in the same environment.
No energy input whatsoever, just osmosis.
Amazing.
They have a lot of applications.

So this is the process overall.
You can see you can make it out of open tanks.
It's not pressurized.
Inexpensive plastics.
And the idea is the water comes in-- very nasty water.
We're talking about things people have done with osmotic
separation systems like this--
landfill leach it, anaerobic [UNINTELLIGIBLE], orange juice
pulp, which doesn't sound that bad because it's tasty, but
it's bad for membranes usually.
And the membrane is very robust [UNINTELLIGIBLE]
because there's no hydraulic pressure pushing all the
stuffing against the membrane.
It just sloughs away.
It keeps itself clean.
On the other side we have our draw solution circulating.
And then what do we do to keep it all going?
Just put a little heat in the bottom.
So you can use this to generate power, called an
osmotic heat engine.
That's not what I'm talking about today, although if you
want to ask me about it, I'd love to tell you about it.
But we use this for water separation because out of the
bottom of that separation device, that thermal device on
the right, comes fresh water because we didn't have to
change the water from liquid to steam
and into liquid again.
It was liquid the whole time.
We just traded one salt for another and then
evaporate the salts.
And we use them over and over again.
So that's the process overall.
So what have we done with this so far?
We're kind of at an interesting point today.
One of the reasons that it's exciting to talk to you about
it is because I've already gone through the process of
thinking about it, inventing it, forming a company, and
creating a pilot, and finishing the pilot.
We finished a pilot, and what we did was we did
was called a pivot.
We went to--
talked about seawater desalination initially, but we
also said we need to do something valuable fast. This
is a company after all.
We've proven that we can treat very, very difficult waters,
industrial waters.
So on the left, the raw feed, that's the water from
hydraulic fracturing of Marcellus Shale.
Anyone read about fracking?
This is the worst water you can get, two, three times the
salinity of seawater, lot of sand, lot of bacteria, a lot
of oil, grease.
And we turn it into water that is better than what you get
out of the tap here, likely.
Over 80,000 gallons of it.
And fantastic and economics--
very inexpensive equipment, very, very low energy
utilization, great economics.
So it's great for the company.
But it's just a start.
It's not solving the world's-- it's not a moon shot.
It's a cool business, not a moon shot.
This is my last slide.
So what the moon shot is to use this technology platform
and do all the other things that have to be done, which is
to go and take seawater provided to cities, as much as
you need, but not to do that without burning fossil fuels
or emitting carbon dioxide or make the planet worse.
Take the water from the cities that's already been used, but
it's still good and maybe clean it and put it on crops.
And then recycle water in that you irrigation, brackish
water, drainage, irrigation, control the salinity of the
soil, reclaim salinified soil, control the sodium absorption
ratio, control fertilizer application, and close the
loop and have all the water we need.
So this hasn't been done yet.
But the technology platform, I', telling you, can do it.
And so this is what I want to work on next.
Thank you.

Let us define x.
x is a solution, a solution to a seemingly insurmountable
problem, like climate change or cancer, one
that affects the world.
But what if we redefine x as a challenge, an opportunity for
radical thinking, a chance to light up the world with
breakthrough ideas and cutting-edge technology, the
stuff of science fiction that just might fly after all.
Solving for x requires wonder and imagination and a vision
to build seemingly impossible solutions to the world's
biggest problems. Solve for x, moon-shot thinking.