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Speaker 1: is Jonathan Strickland, and I wanted to talk to you
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Speaker 1: tech Stuff from how stuff works dot com. Hello again, everyone,
Speaker 1: and welcome to tech stuff. My name is Chris Poulette
Speaker 1: and I am an editor at how stuff works dot com.
Speaker 1: Sitting in for me, as is typical, is senior writer
Speaker 1: Jonathan He there right, So, Chris, one of the big
Speaker 1: issues facing the world today is access to clean, drinkable water,
Speaker 1: and so we wanted to talk to someone who's an
Speaker 1: expert in a particular form of processing water to make
Speaker 1: something that isn't drinkable into drinkable water, and we have
Speaker 1: with us from ge Eric Hansen. Eric, welcome to the
Speaker 1: to the podcast. We're excited to have you here, and
Speaker 1: we're going to talk a bit about desalination, which is
Speaker 1: a process where we're removing things like salt and other
Speaker 1: minerals from water so that you have clean drinking water
Speaker 1: as an as a byproduct, really the other one being
Speaker 1: the the salt, the salute. So we want to talk
Speaker 1: a little bit about the process that you guys use
Speaker 1: over at g the things that you're looking into, and um,
Speaker 1: how that has changed over the years. So to really
Speaker 1: start off, what what are the greatest benefits of desalination? UM?
Speaker 1: A great question. You know, the world today bases you know,
Speaker 1: ever increasing challenges and stresses on water supplies. But you know,
Speaker 1: the good news behind that is the Earth's surfaces water.
Speaker 1: So even though less than one percent of that is
Speaker 1: accessible as fresh water today, the rest of it is
Speaker 1: is seawater, and we do have the technologies today to
Speaker 1: turn that into usable water. So in fact, those technologies
Speaker 1: have been around for a really long time. You know,
Speaker 1: even hundreds of years ago, people would boil water, capture
Speaker 1: the steam from that water, and use the condensation from
Speaker 1: that that steam as purified water. So the concepts of
Speaker 1: of desalinating water using heat or thermal technologies, those aren't
Speaker 1: new concepts. They've been around for a while. Desalination has
Speaker 1: been going on for a long time, and even up
Speaker 1: through the most of the nineties, thermal technologies were still
Speaker 1: very prevalent, albeit a little bit more advanced than just
Speaker 1: simply boiling water, but the concepts were still the same,
Speaker 1: heating of the water, capturing the steam, and condensing it.
Speaker 1: In the in the nineties, different technologies started being applied. UH.
Speaker 1: Instead of heating up the water and boiling it, what
Speaker 1: we started doing was applying membranes, special kinds of of
Speaker 1: very advanced filters. UH. These membranes are able to remove
Speaker 1: the salts from the water UH with much less energy.
Speaker 1: It takes a lot of energy to boil water, so
Speaker 1: using membrane technologies, we've been able to reduce the amount
Speaker 1: of energy it takes to remove the salt from water.
Speaker 1: And over the last twenty years there have been just
Speaker 1: a lot of advances in that in that field, which
Speaker 1: I'm sure we'll go into a little bit more in
Speaker 1: our conversation. Sure, making the cost of the salinating water
Speaker 1: come down, you know, every year, right, And so you're
Speaker 1: talking about these these semi permeable membranes. Essentially we're looking
Speaker 1: at a process of reverse osmosis really um forcing the
Speaker 1: using pressure essentially to force water that has various minerals
Speaker 1: and salt in it through this membrane. The membrane separates
Speaker 1: out the minerals the salts, and the water passes through. Normally,
Speaker 1: when you have a membrane between a solute and a solvent,
Speaker 1: the solvent is going to pass through the membrane until
Speaker 1: there's a an equilibrium there and osmosis pressure is osmotic
Speaker 1: pressure is built up. So in this case, we're actually
Speaker 1: applying energy on one side so that we get water
Speaker 1: on one end of the membrane and everything else is
Speaker 1: on the other. Is that that sort of a bird's
Speaker 1: eye view of what that technology is all about. Yeah,
Speaker 1: you described it very well. You know. One of the
Speaker 1: biggest difference between membrane filtration and the types of filtration
Speaker 1: that most people are familiar with is when most people
Speaker 1: think of a filter, they imagine a barrier of some
Speaker 1: kind with one stream of water flowing into it, things
Speaker 1: being removed by that barrier, and then one stream of
Speaker 1: water flowing out the other side, and then after a
Speaker 1: while you have to do something to get all this
Speaker 1: stuff you've removed off that barrier. So membrane technology doesn't
Speaker 1: exactly work that way. You still have a barrier and
Speaker 1: it's the membrane, but in membrane technology, the feed stream
Speaker 1: is actually flowing across the membrane, so you have one
Speaker 1: stream in, but then you're applying pressure, so some waters
Speaker 1: making it through the membrane, and that's the purified water
Speaker 1: without much salt in it, and all the salt, all
Speaker 1: the salt is staying on the other side of the membrane.
Speaker 1: So in membrane technology, instead of one stream in and
Speaker 1: one stream out, you actually have one stream in but
Speaker 1: two streams out purified the saltier stream, so that salt
Speaker 1: here stream the brine. I know that that has caused
Speaker 1: some problems in the past, simply because Brian, you know,
Speaker 1: what do you do with that after you've gone through
Speaker 1: the desalination process? Now, Brian, because it has this concentrated
Speaker 1: amount of salts and minerals, and it's actually denser than
Speaker 1: sea water. So if you were to simply dump that
Speaker 1: Brian into the sea, then it would it would sink
Speaker 1: to the bottom of the sea floor where it could
Speaker 1: potentially cause damage depending upon the environment that you're in. Uh,
Speaker 1: can you talk a little bit about some of the
Speaker 1: approaches to to take care of that problem. I know
Speaker 1: there's some about mixing the brian in with other water
Speaker 1: that's going to be running into the sea, so it
Speaker 1: it dilutes it. So I mean, if you step back
Speaker 1: and look at the desalination process, you know from from feet, uh,
Speaker 1: it can simply be considered really part of the normal
Speaker 1: water cycle, the hydrological cycle. So yes, there's water with
Speaker 1: more salt going back into the ocean, but the water
Speaker 1: that's purified and it is then used ultimately that goes
Speaker 1: back into the ocean as well, whether it comes through
Speaker 1: municipal wastewater and sanitary sewers and it's treated you know
Speaker 1: in many other ways. You know that water all does
Speaker 1: essentially return to the hydrological cycle at some point. So
Speaker 1: you know, from a high level, the mass balance is fine.
Speaker 1: The oceans aren't going to get saltier because of this
Speaker 1: because we are returning the purified water back to the
Speaker 1: oceans at some point as well. So really the the
Speaker 1: more immediate concern is just that very point at which
Speaker 1: you're introducing the brine back into the ocean, and depending
Speaker 1: on the characteristics of the seabed and what's living in
Speaker 1: that area, UH, sometimes there are special considerations that are taken. UH.
Speaker 1: And you know, there are many different ways you can
Speaker 1: return the brine back into the ocean. You can just
Speaker 1: have a pipe that puts it right into the ocean.
Speaker 1: You can create an elaborate grid of pipes underneath the
Speaker 1: seabed to uh, to blend it a little bit better.
Speaker 1: There's a number of different methods and UH, even though
Speaker 1: the salination may seem like a niche to some people,
Speaker 1: there are actually quite a few specialties within it. And UH,
Speaker 1: you know, really thinking through how the brine is going
Speaker 1: back into the ocean and how it's going to affect
Speaker 1: marine life is uh is quite a science in itself.
Speaker 1: But you know, there's been a ton of progress on
Speaker 1: that really in just the last ten years. And you know,
Speaker 1: I think in nearly all cases we're now able to
Speaker 1: come up with with special schemes and the right technology
Speaker 1: to blend U without harming marine life. Fantastic. Uh. Well,
Speaker 1: moving on to another question, what what's the greatest barrier
Speaker 1: to adoption of desalination? I mean, why, uh, what's keeping
Speaker 1: this technology from being more widespread it and used in
Speaker 1: more areas of the world. You know, I think there
Speaker 1: are you know, you could probably classify it into two
Speaker 1: different barriers. One of one of them is, uh is
Speaker 1: more perception. Uh. You know, there are some areas where
Speaker 1: the public still isn't really that on board with it yet,
Speaker 1: just for you know, things they've read in the news
Speaker 1: and their own ideas about it. Other parts of the
Speaker 1: world are doing this uh often, you know, in the
Speaker 1: Middle East or in Southeast Asia. You find de cell
Speaker 1: plants all over the place. They have largely solved all
Speaker 1: the environmental issues that people should be worried about. Um.
Speaker 1: You know, but some people are slower to adapt than others,
Speaker 1: and it takes a while to to come to terms
Speaker 1: with with some of that mentally. UM. So that you know,
Speaker 1: that's a harder problem to solve. The easier problems to
Speaker 1: solve really are are the energy problems. Because when you
Speaker 1: do desalination, it isn't the cheapest way to get water.
Speaker 1: If there's other uh subs lies of water available to
Speaker 1: you UH that don't have so much salt in them,
Speaker 1: they're most likely going to be less expensive than desalination.
Speaker 1: So today people are doing desalination really only in areas
Speaker 1: where they don't have a lot of other alternatives, where
Speaker 1: they're in a water scarce area and they simply need
Speaker 1: to do it. So driving down the energy cost is
Speaker 1: really the primary goal and desalination, and it has been
Speaker 1: for the last twenty years, and there have been a
Speaker 1: lot of different improvements over the last really fifteen years
Speaker 1: that have really made progress in driving that down UH,
Speaker 1: and they're in a number of different areas. Obviously, the
Speaker 1: amount of energy that you need to drive the salt
Speaker 1: out of the water is a big deal, and you
Speaker 1: can lower that through advances in the membrane chemistry, so
Speaker 1: actually improving the membranes. You can do it through advances
Speaker 1: in the efficiencies of pumps UH, and you can also
Speaker 1: do it through advances in energy recovery devices. So there's
Speaker 1: a you know a number of different areas that people
Speaker 1: are working on. And then in addition to that, you know,
Speaker 1: simply the operation of these plants. You know, it requires
Speaker 1: a the amount of manpower just to keep these things running.
Speaker 1: So we've also been making a lot of improvements and
Speaker 1: innovations in the pre treatment to these plants. So as
Speaker 1: as the pre treatment to the water gets better, they're
Speaker 1: lower operating costs as well. So lots of different levers
Speaker 1: to pull in order to lower the operating costs. You know,
Speaker 1: I was wondering a little bit about the equipment itself.
Speaker 1: I mean, the process itself seems pretty uh, pretty straightforward,
Speaker 1: but um, you know, is the is the equipment itself large?
Speaker 1: Does it take up a lot of space or or
Speaker 1: does it require a lot of high pressure to make
Speaker 1: it work? Yeah, that two different things. In terms of size.
Speaker 1: It doesn't take up really any more space than a
Speaker 1: traditional water treatment plant for the same capacity would. But
Speaker 1: the big difference is pressure. The more salt that have
Speaker 1: dissolved in any in any given amount of water, the
Speaker 1: higher the osmotic pressure of that water, something Jonathan referred
Speaker 1: to in his earlier explanation. So the more salt, higher
Speaker 1: the osmotic pressure, the more pressure you need to apply
Speaker 1: to the water to drive the salt out of it.
Speaker 1: So take for example, the middle East, in the Gulf,
Speaker 1: in the Middle East, that's really some of the saltiest
Speaker 1: water in the world. So on on detail plants, they're
Speaker 1: we're running them as high as eight p s i,
Speaker 1: which is pretty high pressure. Uh. In other parts of
Speaker 1: the world, like say the Caribbean, the water is a
Speaker 1: little less salty, still absolutely seawater, but it's not quite
Speaker 1: as stalene as as the Middle East. So there you
Speaker 1: because it has slightly less salt, you can use slightly
Speaker 1: less less pressure. Now, are these plants often um sort
Speaker 1: of piggybacked onto other plants like power generation. That was
Speaker 1: wondering if there was a lot of cogeneration going on
Speaker 1: with desalination plants. Yeah, that's a great question. Uh. And
Speaker 1: this is actually one of the reasons that g is
Speaker 1: is uh, you know, so active in this market. Uh.
Speaker 1: You know, there's just an inex Uh. There's a there's
Speaker 1: a obvious tie between energy and water. So to produce energy,
Speaker 1: you know, power plants need water to produce energy. Infect
Speaker 1: almost ten percent of all global water withdrawals go to
Speaker 1: the production of water, so that's a pretty significant amount. Uh.
Speaker 1: And then the reverse of that is to desalinate water,
Speaker 1: you need energy to do it. So power plants and
Speaker 1: deesel plants are are are very linked. In the past,
Speaker 1: when the technologies were more thermal based, that was another
Speaker 1: advantage of tying the plants together because many power plants,
Speaker 1: especially power plants in the past, had a lot of
Speaker 1: waste heat, so they could use some of that heat
Speaker 1: uh for the thermal desalination. Power Plants today are much
Speaker 1: more efficient, so there isn't so much waste heat coming
Speaker 1: from them. Uh. And the membrane technologies come to a
Speaker 1: point where really that's the propolan technology for desalination. So
Speaker 1: we're not seeing them tied together as much anymore because
Speaker 1: of waste heat from the power plant, but we are
Speaker 1: seeing them tied together simply because the power plant needs
Speaker 1: water uh and the decail plant needs power. Excellent, So
Speaker 1: what is GE doing to make desalination more feasible to
Speaker 1: address water scarcity issues? So we're working in a number
Speaker 1: of different areas. We've worked a lot in the past
Speaker 1: on the membranes and uh, you know, there are really
Speaker 1: some very high quality membranes now used in desalination. Uh.
Speaker 1: They're not an entitlement yet. There are still some games
Speaker 1: to be made there. UM. But they're they're getting close.
Speaker 1: The membranes are very efficient today. UM pre treatment is
Speaker 1: very important. So when when we talk about membranes and
Speaker 1: how they take this all out of water, they're great
Speaker 1: at taking the salt out of water, but they aren't
Speaker 1: great at taking suspended solids out of water. So you
Speaker 1: don't want to put salt or sticks or stones or
Speaker 1: anything like that into a membrane. That's bad for it.
Speaker 1: So pretty much every membrane plant in the world has
Speaker 1: some kind of pre treatment in front of it to
Speaker 1: take the suspended solids out before it gets to the membranes.
Speaker 1: UH and G has been leading in this area as well.
Speaker 1: We have some terrific advanced prefiltration another type of membrane
Speaker 1: called an ultrafiltration membrane, and it it provides really superior
Speaker 1: UH suspended solids removal, so that the water that gets
Speaker 1: to the the reverse us most of the membranes is
Speaker 1: as clean as it can be, still salty, but it's
Speaker 1: had everything else removed and that makes the life of
Speaker 1: those membranes lasts a lot longer, which in turn lowards
Speaker 1: the overall cost of ownership UM. Then the other pieces
Speaker 1: of the pumping side there are a lot of different
Speaker 1: kinds of pumps in the marketplace. The most fishing types
Speaker 1: of pumps are positive displacement pumps. If you think of
Speaker 1: pumping water, you can imagine you have a fixed geography
Speaker 1: fixed geometry of water. The most efficient way to raise
Speaker 1: the pressure of it is just to push on it
Speaker 1: um and that works today in in relatively small sizes,
Speaker 1: but as plants get larger and larger, uh, there aren't
Speaker 1: so many good positive displacement pumps. So instead what people
Speaker 1: use their centrifugal pumps. So that's more like spinning the water.
Speaker 1: The water that gets thrown to the outside has a
Speaker 1: higher pressure. So you know, we've been working developing a
Speaker 1: new pump which is a positive displacement style pump, but
Speaker 1: it's much larger than other positive displacement style pumps on
Speaker 1: the marketplace. That's a pretty new product for us, but
Speaker 1: we expect that within the next year we're gonna start
Speaker 1: seeing more of more of that pump out in de
Speaker 1: cel plant and that's going to knock as much as
Speaker 1: another ten percent of the energy off, so that when
Speaker 1: we get that fully commercialized, not in the marketplace, it's
Speaker 1: gonna lower the electrical costs by about ten percent more,
Speaker 1: which is really significant when you're talking about, you know,
Speaker 1: the cost of desalination. Sure. So, so that's where it
Speaker 1: leads into what do you see as the future of desalination?
Speaker 1: Where do you see us going in another few years,
Speaker 1: like another decade or two decades. Yeah, that's a great
Speaker 1: question and a hard question because there are many many
Speaker 1: technologies out there today. Uh, you know, I I think
Speaker 1: most people in the industry, myself included, really see reverse
Speaker 1: osmosis as continuing to be the most prevalent technology for
Speaker 1: at least the next five or seven or ten years. Um.
Speaker 1: It's certainly possible that some other technologies could could come along,
Speaker 1: and you know, honestly, if there are other technologies that
Speaker 1: will dramatically lower the cost of desalination, that would be
Speaker 1: great for the planet. Um. But I I you know,
Speaker 1: I think over the next five or seven years, what
Speaker 1: we're going to see is people figuring out how to
Speaker 1: link the cell plants more to other renewables. So already
Speaker 1: we're starting to see people thinking about how do you
Speaker 1: combine a de cell plant with wind turbines and a
Speaker 1: wind farm, or how do you combine a de cil
Speaker 1: plant with a solar farm. You know, it turns out
Speaker 1: that a lot of places in the world, the neat desalination,
Speaker 1: places that are water scarce, are also places that have
Speaker 1: quite a bit of sun. So there there's some nice
Speaker 1: natural links between you know, combining solar with de cell.
Speaker 1: In some ways, there's also challenges because you know, in
Speaker 1: addition to having on his sun, you know, some of
Speaker 1: these places also have a lot of sand and it's dusty,
Speaker 1: and and dust and solar don't don't always pair so well,
Speaker 1: but dust coats the panels and may become less efficient.
Speaker 1: But you know, now we're talking about some pretty um
Speaker 1: discreete challenges. You know, people are doing us now, they're learning,
Speaker 1: they're getting better at it. There's not a lot of
Speaker 1: solar plus D cell or wind plus D cell out
Speaker 1: there today, but I think in the next five to
Speaker 1: ten years we're probably gonna start to see a lot
Speaker 1: more about Yeah, it's really exciting and to give our
Speaker 1: listeners an idea of the impact that these sort of
Speaker 1: technologies have made so far. Uh, it wasn't that long
Speaker 1: ago that the estimated population that could not get access
Speaker 1: to clean water was around twenty but according to the
Speaker 1: World Health Organization, they had a two thousand twelve report
Speaker 1: which took numbers from two and took a look at that. Uh,
Speaker 1: they said that it's is still a massive problem. Still
Speaker 1: seven million people lack access to safe drinking water, according
Speaker 1: to this report, and that's a you know, that's a
Speaker 1: sobering number. But the silver lining here is that that's
Speaker 1: that's half of what it was before, so that the
Speaker 1: numbers of people who are getting access to safe and
Speaker 1: water there on the rise, which I mean, that's obviously
Speaker 1: the way we want to see this trend go. So
Speaker 1: it's exciting to see this sort of technology combined with
Speaker 1: the efforts of other organizations out there dedicated to making
Speaker 1: sure that that people across the world get access to
Speaker 1: this water. Yeah. I couldn't agree more. You know, one
Speaker 1: of the statistics that that I often hear is that
Speaker 1: today it's one and every six people today doesn't have
Speaker 1: access to clean water, which is, as you said, really
Speaker 1: a sobering number. Um. You know, I think there's an
Speaker 1: interesting combination here where you read a lot about this today.
Speaker 1: You know, ten years ago you didn't generally see water
Speaker 1: articles in mainstream media, and today, you know, every week
Speaker 1: you're going to see an article in mainstream media talking
Speaker 1: about water scarcity, and you know, it is a serious
Speaker 1: problem and it is alarming. But the plus side of
Speaker 1: this publicity is that they're more entrepreneurs, more large companies
Speaker 1: like GE, just more people out there starting to think
Speaker 1: about what are some possible solutions, uh, And there's lots
Speaker 1: of them. You know. The salination is a great example
Speaker 1: of ways that we can solve water scarcity. Water reuse
Speaker 1: is another great example of ways that we can solve
Speaker 1: water scarcity. Water reuse is just taking water that's already
Speaker 1: been used for one purpose, uh, and treating it and
Speaker 1: cleaning it up and finding a way to use it
Speaker 1: for another purpose. So, you know, I think all the
Speaker 1: current press that we hear about water scarcity is actually
Speaker 1: helping to feed a pipeline of new innovations and new
Speaker 1: ideas that will actually help solve the problem in the
Speaker 1: long rust. Fantastic, Eric, Uh. That that's a great look
Speaker 1: at the desalination process and what g E is doing
Speaker 1: to to really push this technology forward. And we really
Speaker 1: appreciate you coming on the show and talking with us.
Speaker 1: It's been a really educational experience for me and especially
Speaker 1: as as as liberal arts majors whose background and engineering
Speaker 1: is saying, Wow, that's cool. Uh, it's really great to
Speaker 1: get people like you on our show to talk about
Speaker 1: this and and give our listeners this uh this sort
Speaker 1: of Uh look, is there anything else you would like
Speaker 1: to say before we wrap up? Well, you know, Jonathan Chris,
Speaker 1: I'd just like to say thanks, thanks for having me
Speaker 1: on the show. Um. You know, at GE, we're doing
Speaker 1: a lot of really interesting and innovative things to solve
Speaker 1: the very problems that we were just talking about for
Speaker 1: the last half hour. Uh. You know, one of the
Speaker 1: great things about being in this kind of business is
Speaker 1: when you come up with innovations, you can actually see
Speaker 1: that they're helping people. Uh. So you know, it's it's
Speaker 1: a rewarding business to be and GEE is very committed
Speaker 1: to it. We're investing a lot and solving problems today
Speaker 1: and in the future and and uh, you know, I
Speaker 1: love talking about it and I'm really excited about where
Speaker 1: this can all go over the next Thank you so much.
Speaker 1: Thank you, Eric, and and uh, We're always glad to
Speaker 1: have people who advocate that sort of mindset to to
Speaker 1: really get people interested in science, technology, engineering. These are
Speaker 1: areas that are they're they're leading the way to the
Speaker 1: future of what our world is going to be. And uh,
Speaker 1: you know, if we have students out there listening, feel
Speaker 1: free to let us know. Tell us what you are
Speaker 1: interested in, let us know what what areas we should
Speaker 1: cover in our future podcasts. You can let us know
Speaker 1: by sending us an email that addresses tech Stuff at
Speaker 1: Discovery dot com, or drop us a line on Facebook
Speaker 1: or Twitter. You can find our handle at both of
Speaker 1: those locations. It's tech Stuff hs W and Chris and
Speaker 1: I will talk to you again really soon for more
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