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hello and welcome to technically speaking where scientists and Engineers come together to chat about a common interest share knowledge and satisfy some curiosity I'm Ellie and I'm joined by Jasmin and Laura to talk about direct capture of carbon dioxide from the air so I as I said know nothing about this but Jasmin you're somewhat of an expert can you tell me more so direct air capture is different to other forms of carbon dioxide removal in that it's removing carbon dioxide directly
from the air itself so is this different to like carbon capture storage which is focusing on removing carbon dioxide from like combustion flu gas perfect and Laura you're not an insert in the same way as Jasmine but what's your interest so I am in the energy industry to an extent currently so I work for the national nuclear lab as well as doing some freelance science communication and as far as I'm aware from both of those jobs there are lots of industries that be
really difficult to decarbonize so to not have any carbon or carbon related emissions going into the atmosphere and from what I've heard the sort of carbon capture that Jasmine has just talked about could be essential for meeting some climate change targets yeah I mean it sounds quite scary to me but let's get into it Jasmine kick us off tell us all about it let's talk about the tech let's talk about some definitions yeah so direct air capture is the removal of car dioxide directly
from the air it does this by using a process so like he use chemicals that will react with the carbon dioxide to remove it from the air and this can be either be a liquid chemical or a solid chemical that you can use once the carbon dioxide has been removed from the air you then need to release it from the chemical that's just absorbed it and you would typically do this by heating it up so you heat up the chemical and then that releases the carbon dioxide in a
high Purity stream you then separate that out and you can either send that off to be stored in deep geological facilities for carbon capture and storage or you can actually use it there are projects for direct air capture but they're still fairly on the smaller scales so I think for actual use of carbon dioxide it's more around like using them in green houses to enhance productivity in there are other ways you can use a carbon dioxide so in like chemical manufacturing you can use it to
make synthetic chemicals or in other processes that need carbon dioxide such as in like breweries where you need carbon dioxide to make fizzy drinks in a nutshell that's what direct air capture is so you mentioned before that there was solid and liquid ways you need some sort of chemical substance to pull the carbon dioxide out of it so how does that work for example the solid type of chemical that you would use it's more similar to like what you would using
conventional carbon capture storage so you use an amine chemical that reacts with the carbon dioxide in solid direct air caps you use what's known as kind of like a filter so you just imagine like the air passes through a filter and then you need to like heat up the material in that filter to release the carbon dioxide in liquid it's a different chemical it's potassium hydroxide that will react with the carbon dioxide and then that goes through a further series
of chemical reactions because from the reaction of carbon dioxide with pottassium hydroxide you then need to go on to create calcium carbonate and calcium oxide and then that eventually decomposes into carbon dioxide oh I have questions about the pottassium hydroxide but a means I came across it was in my PhD cuz my PhD was it was looking at a very specific type of carbon capture technology that was in development and I think the aines were of particular interest because they had a nitrogen
atom stached three other atoms kind of similar to ammonia but that nitrogen atom had a charge that was quite favorable for attracting the um the oxygen in the carbon dioxide molecule to I think yeah as also remind how amines work as a way of removing carbon dioxide from basically anything where are we getting the aans from in the first place is someone making them are they naturally occurring are we sourcing them from somewhere I think Laura would know better I just know that we get them from
the chemicals industry you a chemical engineer I know but I don't work on how they're made um it's not something I've researched actually uh but I would assume that it would involve some sort of reaction of ammonia with some other carbon containing material so you've got to think about where that feed stock comes from and where you're getting all the materials and then the energy intensity of that process as well yeah I was just going to say because you said uh Jasmine about heating up the like
filter so presumably that is also requiring energy of some kind to be that from like the burning of fossil FS or from like wind or or whatever yeah so in the solid version the temperature is much lower than in the liquid um so in the solid you can use just electricity which can be renewable electricity but it depends on like how you get get your energy in this liquid you can also potentially use entire High electricity but because it's a much bigger heat demand you would typically use like
natural gas for heat or other forms of heat rather than electricity by itself and how long is this process taking is this you know say we want to extract a ton of carbon dioxide from the air how long do you reckon that would take is it hourly is it 24 hours is it 3 weeks it's actually pretty quick so these direct air capture plants at least the bigger ones that are currently in operation they've got pretty big capacity the two companies that are currently leading the market right now they are
called clim Works who are just specialized in the solid type of direct air capture and there's also carbon engineering who are specialized more in the liquid so the liquid type has bigger capacity so that means like cuz the plant's bigger you can you can remove more carbon dioxide whereas the solid it's more of a modular design so the capacity is much smaller with the liquid the current plant that carbon engine ing has it has a capacity of 1 million tons of carbon dioxide per year it's a lot so
this is being done this is being done across the world already we're already doing this process yeah well not AC exactly across the world but in certain countries where these companies are based so clim works is uh Swiss and they have projects in Switzerland but also one in Iceland it's quite interesting and carbon engineering they are Canadian right now there are no like UK specific air capture companies or projects that I'm aware of we could potentially see UK based carbon dioxide companies or
projects in the upcoming years just because there are certain sectors that are really difficult to decarbonize so you kind of need to have direct air capture as a way offsetting the emissions so that our net emissions are going down the way that we need them to be but if we've got Big Industry with this CO2 emission would it be better to use carbon capture bolted onto their plants rather than waiting for it to get into the atmosphere and then removing it yeah so for some sectors like cement so
cement is interesting because most of the CO2 that's produced by it isn't actually from any like fossil fuel use rather it's from like lime or calcium containing materials just decomposing and releasing carbon dioxide into the atmosphere so for like stuff like cement it would be more beneficial just to have carbon dioxide capture and storage just attached to it but there are other sectors which would be slightly more difficult to decarbonize like Road Transport like we could go all electric
but it really depends on a lot of stuff that the normal person doesn't have much influence on the UK's industrial sector and clusters they have to meet certain emission reductions by 20135 and by 2050 so that the sector as a whole is in line with what the UK needs to meet its law abiding Net Zero pledges and basically by 2050 emissions from the Jal sector have to be reduced by at least 90% which is a lot yeah but I like the question on the audience which is specific they're asking about what I
would views on Taylor Swift's massive emissions of carbon dioxide from more extensive use for private jets are ah as a Swifty I have many thoughts on me yeah but that's one that's hard to decarbonize right because um you need a high energy density for the fuel for the plane yeah and we've had like a previous uh live episode where we had people from a company that were making an alternative aviation fuel on you can like try to decarbonize AV by using like synthetic fuels which are made from
using carbon dioxide and hydrogen but the carbon dioxide is circular uh circular quotation marks in that um you get it from direct air capture the carbon cycle is really complicated sometimes but basically because it's a renewable or circular source of carbon dioxide when you end up emitting it from when you're burning the synthetic aviation fuel it doesn't add more carbon because you've already captured it to make the fuel in the first place yeah you've already captured it yeah is
Taylor Swift investing in that technology do anyone now I mean she's got the money to right maybe we should pitch it to her she could like fund our research or fund my research at the year's tour in August I'll see if I can mention that yeah just like have a big sign that blocks everyone's behind you's view saying fund our research please Taylor Swift I mean I'm way up in the gods so I don't think she'll be able to see but you mentioned that we might see like UK direct carbon capture companies
popping up or it might be more common in the next 5 10 years what is their sort of land use footprint like how does it compare to something like a nuclear power plant or coal or you know one of those massive oil rigs that you see in the middle of the ocean for like a direct air catch plant it depends again on like what capacity you want and also whether or not you go for a solid or a liquid so the solid is a modular design so their land footprint is smaller um so
they're good if you want like small scale or if you also because they're basically like way to describe what they look like is if you imagine like a freight container or a crate that just has a fan inside and then a membrane behind it that's basically what they kind of look like so you can they could have quite a small land footprint in that you can just stack one on top of another yeah but like because they are modular when you get to certain sizes in terms of how much carbon dioxide you
want your direct air capture plant to remove um at a certain point it becomes more economical to just go for liquid which has a bigger land footprint and also bigger energy usage but it is more economical to just go for liquid direct air capture if you want to like remove carbon dioxide in mag like millions of tons per year I saw um a research review that mentioned some of these things uh was published a few years ago and they cited their sources but I don't think it
was hugely comprehensive but the statistic they mentioned was that to use a direct air capture plant that's been engineered by people so using either the liquid or the solid filters that you mentioned you'd need a land area about 6.6 times the size of New York to remove a certain amount of CO2 from the atmosphere over a certain time frame but using just trees so doing naturally with forests would require a land area almost seven times the size of all of the
United States oh wow yeah because I was going to ask you because we've talked a lot about this Tech right but carbon capture or carbon conversion is literally what trees are doing the whole time photosynthesis so do we even really need this like are trees not just doing the work for us trees are nice and they're very pretty to look at and they're very useful but the amount of carbon dioxide that they remove per individual tree is just so much smaller than these engineered Alternatives
depending on the type of tree species the amount of CO2 that they can remove per year it's like anything between a little over 1 to 12 kg of CO2 per year per tree so it's pretty to 12 kg seems I reckon not that bad per tree not that bad but but compare that with millions of tons what resources do a tree need um they require quite a lot of water in comparison to engineered methods apparently Al also land yeah it was like Laura was saying that you need a phenomenal amount of land they do have
the benefit of being a habitat for animals and creatures though yeah they do so if anyone is to buy carbon offsetting credits for example if you're going to take a flight and you want to feel better about flying you can buy carbon credits to offset your emissions and usually it's from like forestry management projects the thing with any kind of Forestry management project or like tree planting project there's a really high uncertainty in how much carbon dioxide is going to get removed
because a lot of it depends on how well the tree grows how quickly it grows and whether or not it actually lives past a certain age the longer a tree lives the more car doct that it can remove over its lifespan but once they've passed their juvenil stage the rate at which they can remove car I just really plummets oh I see cuz they're growing so much more when when they're younger yeah but yeah trees also have other benefit I was going to ask you about waste as well
because trees have very little waste I suppose you can count the leaves in the autum all the rest of it is there waste involved in direct air capture yeah so you get some chemical waste so for the solid after a while you would have to renew the amines any other chemicals basically replace the filter in the direct air capture unit you would have to replace that every so often um but with the liquid you would get waste in ter in the form of I think it's calcium
carbonate or might be calcium oxide it's one of the two you would also have like waste from the potassium hydroxide solution that you're using because if you're doing any maintenance on your facility you will need to like drain that and then pump in some new pottassium hydroxide solution so I mean it's like anything isn't it have Frozen cont and there's always waste of like chemical processes it doesn't sound like it's particularly difficult waste to deal with though I might be wrong there
it's not radioactive yeah no it's not radioactive yeah I think we potassium hydroxide an industrial waste water plant or Industrial Waste Water facility should be able to handle it um but with the solid it really depends on what chemicals they use cuz I'm not entirely sure how you deal with the waste management of amines in particular especially when they're in a solid form what's also interesting is that should we even do this obviously carbon emissions are going up they're much
higher it's because of human activities largely and things like deforestation things like industry expansion massive urbanization should we be investing not in taking carbon dioxide out of the air in this way but in lifestyle changes for people you mentioned lots of Industries are very hard to decarbonize should we be not flying should we be reducing our agriculture what do you guys think I think Taylor Swift should definitely be flying Less on the Taylor Swift point
right she can't fly commer that's just not an option for her she she can't she's too famous she would get absolutely badgered by every single person on the plan there's no way she couldn't walk through an airport safe the amount of like stalking and harassment she's dealt with hasn't her legal team like filed something and G so there's a US University student who like has like Twitter account that he like basically tweets the like where people's private chats are flying to and didn't
Taylor Swift team like file like something a and desist a against him yeah I think they did but it's a privacy issue right like if I was Taylor Swift I wouldn't want people knowing where I was at all times and tracking my whereabouts is a bit creepy but um yeah I mean lifestyle changes and just like changes to the way that we use energy and that we eat food would make a impact it's just that the way that if we want to maintain our current Lifestyles like certain things would need very drastic
changes very quickly so for like all the chemicals and materials like Metals cement that we use like they would need like really drastic changes really quickly and don't see it happening don't really see it happening and also like especially if we focus on the UK I mean industry is kind of dying to a certain extent because tataa steel are closing I think it's tataa steel they're closing their South Wales facility they're not closing it are they not closing it
they're stopping using their um their existing process which produces a lot of CO2 and switching to um an electric Arc furnace that sounds much better that sounds much better yeah well no because a lot of people will lose their jobs because it requires fewer people to run it okay that's the what what it was it has less emissions and it's recycling scrap steel rather than making new steel but there isn't currently enough scrap steel in the world to keep up with
demand yeah exactly so you still need to keep making virgin steel and it's not made in the UK it's going to be made somewhere else which will have less stringent environmental and social targets yeah I'd also add that recycling steel is really difficult because there's a lot of different grades of Steel and when you're like mixing two different grades of Steel it can you can often result in like a really inferior quality of Steel so be interested to see how that goes for T Steel yeah it sounds
like setting themselves up some very different challenges but I think that also feeds into my point of like you were saying that we could change habits and we should change habits right yeah but the easiest way to meet the climate targets so we only have a certain amount of emissions going into the atmosphere is just to kind of stop doing stuff yeah and that's not how Modern Life Works that would mean a lot of people would not be able to have jobs like I what
would I not be able to do not much cuz I don't drive I and I get the train everywhere but for some people you can see that you wouldn't be able to get anywhere at all getting food would be a challenge even just like heating your home um I have a gas fired boiler if we don't have a gas Network anymore I'd have to change my heating system there'd probably be a limit on how much electricity we can supply to homes you'd have to decide who gets electricity and who doesn't oh back to the rolling
blackouts yeah yeah really really is like an extreme in terms of like emission reductions that we would need to see them like what kind of Behavioral changes we would need 2020 so like a really big drop in emissions but that's because no one could go anywhere or do anything yeah so we'd need like that kind of level of changes to Lifestyles to really make any Dent towards meeting our Net Zero pledges by 2050 but obviously 2020 was miserable yeah no one could do anything that's the thing isn't
it it's the lifestyle changes so extreme no one wants to do that I quite like Sumer 2020 because there weren't very many cars on the road so you could cycle anywhere you wanted you also live somewhere where it's rural I was living in of London in a FL and it was miserable I can imagine I heard stories it did sound quite Grim I think I would have struggled as well there's a question in the chat that kind of feeds into this in the Q&A um about why are we spending all this money on other
projects that aren't necessarily saving the world when we could be spending it all on trees and CO2 capture devices I guess an example from an earlier episode is um investing in space travel and space exploration oh yeah should we be doing that now which is also contributing to missions although it's quite small yeah we have this debate before about if you were in charge right you've got the money to decide and the political power are you giving it to things like tree planting environmental
projects direct air capture or are you spreading the options across you know the nhf obviously health is very important obviously agriculture is very important you can't sort of negate all other aspects for this one thing or should we what do you guys think is this the most important issue I would say it's definitely up there and should probably rank higher than space travel or o this might be a controversial answer um there was that project we talked about where some lab somewhere
else in the world has managed to get funding to bring back the woly mammoth oh yes is that the one to make the woly mammoth meatball yeah colossal I'm not sure but I think we agreed that the idea of bringing back the wlly mammoth is probably fairly stupid also where is it going to live like it doesn't have a habitat anymore that's why it went extinct the idea of all the genetics research that would enable that could improve people's lives was probably quite worth worthwh so I would say there
should be more money spent on tackling climate change but it's not just about the research it's about changing habits and developing more infrastructure to do it yeah but there are other projects like healthc care and um tackling inequality that are just as important they're all part of sustainability essentially yeah it's knock on effect isn't it if we invested lots of money in this who knows what else we could find as a byproduct you know what would those waste a means be used for we don't we
don't know yet potentially we don't have enough research to say yeah and it we could be using a completely different material in 10 20 years versus what we're using now yeah that's so true we don't know how the technology will move on maybe we'll get even better at direct air capture and then simultaneously solve global warming and climate crisis while also discovering the potential use of a means in healthcare who knows yeah who knows well I think that sounds like
a good place to leave it we've covered everything from what direct air capture is to if we should even use it and whether Taylor Swift could be a future investor in the direct air capture industry thank you for listening to this episode of technically speaking the views expressed in this podcast belong entirely to the person that said them they did not represent any industry or organization if you enjoyed listening to these views it would really help us out if you could
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