Car Science #1: toilet humour
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Thanks for reading or subscribing to this, the only summary newsletter about the research-edge of car technologies written by a woman with purple hair that I, personally, know about. (if there's others, lemme know I wanna subscribe)
Basically, every week I scour the academic papers and pick out the stuff I think is interesting about batteries, hydrogen, synthetic fuels, even sometimes engine technologies or specific stuff like tyre particulate collection. It's something I do anyway because I'm interested in this stuff but I figured I might as well share it. Sometimes the papers might not be particularly accessible but I'll do my best to write it up like an idiot (me) can understand it and stick to open access research as much as possible because absolutely fvck science being paywalled.
And sometimes I just talk about some things I'm thinking about this week, for whatever reason. (It's inefficient fuel cells, they haunt me all the time)
It's all a bit chatty and it's meant to be a bit like you sit down in the pub and have the foolish idea to ask me what I've been reading about this week, then watch a human not take a breath for 45 minutes.
First, let's talk about car poop.
Why we need to put more stuff on cars
If you drive a car that's got an exhaust then you'll be aware stuff comes out of it. Generally, that's not great and you've probably heard of this whole global warming thing that's been causing a lot of problems. One of the ways we can try and address climate change is direct carbon capture, which means taking carbon out of the air and hopefully, blocking it up and putting it back in the ground - which is where it was, lurking around as fossil fuels, until we started mass-burning them.
Problem is, to effectively capture carbon you need to a) use a massive amount of energy to get air and pump it through a filter and b) preferably move around, all of which is fairly inefficient. There've been some slightly out-there ideas like building special carriages for freight trains that use the energy from the train braking and the train's own movement to do it in a way that's not accidentally going through so much power it's making more carbon than its capturing and there're some other, low energy options that are more ambient carbon capture. But basically, it's not an ideal process and that's why carbon capture tends to be at the source of say, industrial processing, preventing it being released (which is good) instead of hunting down what's in the atmosphere already.
Catalytic converters were introduced to cars to capture harmful tailpipe emissions and they do capture lots of nasty stuff we don't want out there. Also, unrelatedly, are part of a gigantic (and global) crime wave where people are stealing them for the expensive metals they contain. But at the moment they're not for capturing carbon out of the exhaust emissions and there's not been a way of doing that that was low-cost enough to be put on millions of cars and not clunky or fragile. This isn't even the first research published this month working on this but most of the rest of the solutions require metals, which instantly makes them more expensive and potentially unscalable.
Engine enthusiasts rejoice, though because we might have a way to do that. Researchers at Berkeley have used melamine (which is an inexpensive laminate) along with pool chlorine chemical cyanuric acid and good old taxidermist's friend formaldehyde to make a filter that's intended for industrial flues but which could be scaled down to, amongst other things, tailpipes. It's as efficient at taking CO2 out of emissions as the current-best flue-based method (which is metal-organic frameworks but you don't need to worry about that) but is much cheaper. Haiyan Mao, a research fellow who led a lot of the work, said it was essential to the project that it had to be cheap, so that it could be rolled out at scale, in order to be effective. So: that's frickin' rad.
We could make a very major difference to air quality if we got these on cars in a fairly rapid way. Beyond the greenhouse gases, CO2 pollution in cities is bad stuff because although it's not a toxin it makes the air hotter and more humid when there's a lot of it around, which causes smog and is also just, y'know, gross. But cars probably shouldn't be the first target - if freight vehicles are fitted with these, we have a really good way to decarbonise logistics or well, not fully but improve things by a hell of a lot. Which is exciting and cool.
We're living in an era where cars are going to get a lot more obligatory attachments, regardless of what they run on, to stop them polluting. The disaster that is tyre rubber particulates is something that urgently needs addressing on basically any non-rail vehicle, with the way it's filled the ocean with tiny black specs that are killing everything; conservatively, tyre particulates are about 45% of ocean microplastics but realistically it's as much as 65%.
If you write about EVs then you get a lot of people saying "yeah but what about all the ICE vehicles already on the roads, scrapping those for EVs would be a carbon disaster" and you know what? Yeah it would. But we equally can't keep running them in the ways that we have been. So stuff like extra exhaust filters and tyre particulate collectors (they've been designed and IMO, motorsport should be testing them even if it'd piss engineers off something chronic) are ways to clean up the cars on the road already without junking every chassis.
I just wanted to talk about ammonia for a bit here because everyone else is
Having got poop out the way it's time to ask: is piss the future? Or well, ammonia, as the journal Fuel is currently doing a special on and which comes up really quite a lot. I'll be perfectly honest with you here and say: generally I think ammonia is a terrible idea. Ammonia and methanol keep coming up as potential electric car fuels - I know, that sounds backwards and it is but not in the way that's obvious - and they're just like. Bad. I've tried to think through ways they're not bad but they really are.
The problem is, making a high-energy fuel takes a lot of energy. Making ways to store energy also costs a lot of energy - lowballing things, it's about 40kWh of electricity to make a single kWh of storage. The good thing about batteries (and there are plenty of bad things, too) is that when you've done that once you can keep cycling the thing, whereas if you're storing energy as ammonia or methanol or even hydrogen, once it goes through the vehicle it's powering then you just gotta make more.
Ammonia is a pretty low energy form of fuel, compared to pretty much any other option. We have a lot of it, too; it's one of the side-effects of chicken farming (it's partly why the poop smells so goddamn terrible) and comes out of a bunch of industrial processes, as well as being made on a massive scale via the Haber-Bosch process for agriculture. Ammonia is why we have enough food to eat and it's a super important chemical, it's just also one of those buzzword-y things that's getting chucked around as a potential fuel cell solution and honestly? I'm goddamned sick of it and it makes no sense.
Idk if I really have any truck with the concept of green hydrogen or green methanol or the halfway state of 'blue' either. Green hydrogen means it's made by electrolysis from splitting water, using renewable energy. But that's an at best (and honestly, this is a fictional number) 80% efficient - so you'll get 20% less energy out of the hydrogen than you used to make it. And then storing hydrogen is a complete nightmare because you need such rigid, impermeable tanks for it and it's a pain in the ass to transport.
Which is why the idea of making hydrogen and storing it (with captured carbon) as ammonia is appealing. Ammonia's still semi-annoying to transport (it is a chemical) but it's a lot more common to move around and doesn't need as specialist stuff as hydrogen. And then people look at it and go: hey, what if we put ammonia in cars?
Ammonia combustion is something we can save for another time but ammonia fuel cells make me weep. Fuel cells generally just aren't as efficient as batteries and you need enormous stacks to be able to get a decent kW output from them. Direct ammonia is particularly low, in terms of output, to the point 75W (not a typo, that's watts not kilowatts) is considered 'high performance' - so that's not going to be powering vehicles any time soon.
All too often what an ammonia fuel cell is conceptualised as is a hydrogen fuel cell, with a stage of reformation to extract the hydrogen from the ammonia. Which makes carbon an emission, a suboptimal outcome for many reasons and also if you think about making hydrogen, losing 20% of the energy you used to make it, making it into ammonia and then making it back out of ammonia you might as well just go dig something fossilised out the ground, in efficiency terms. I know I've had a moan about methanol reformers in the past but ammonia's big future role seems to be as hydrogen storage and I'm just not convinced this is a good idea.
One of the ways it might happen is with, for instance, the Brexity promise of hydrogen supplied to the UK from Australia. Clearly, that's rather a long distance to bring pressurised tanks so putting it in ammonia is an option. Except Australia already makes all its hydrogen out of fossil fuels and so there's oh you know what, this is giving me a headache. Ammonia: it's a load of piss. Just get a battery if you want to store energy.
Trying to understand batteries
Oh, speaking of batteries (of course) here's a fun one. So there's this sort of them that's called a flow battery. So called because you get two electrolyte solutions, you charge one nergatively and one positively (I'm simplifying a little here but basically this is the principal) and then you run 'em back together to make charge. Because the electrolyte just sits there chilling out, it's a great way of mass-storing electricity and there's a few plants in Japan and the US where it's used for massive battery sites that help grid capacity and can store renewable energy while it's being made, to be put out when there's a demand for it.
They're one of the most scalable forms of battery and don't suffer loads of loss of energy or efficiency even if they sit around for awhile, as well as being really safe. The main drawback, essentially, is that the energy density is really low so big ol mass storage on a huge site for sure, tiny little devices absolutely not and even cars aren't gonna get far on a couple of tanks of electrolyte.
Obviously because there's nothing new on the planet, some people have tried to (or claimed they actually have) put these in cars. Every now and then I check in on the guys at NanoFlowcell and I don't know. They can't be totally making the whole thing up but I just don't really believe - well, I definitely don't at all believe they've got a car that does 2000 kilometres on a single charge, sorry, that'd be energy density from an alien dimension - that they're actually doing it. I assume I haven't quite found the disclaimer on their site that's like 'lol, actually this is just an example of how the Quantino would look, with the technology available to drop in as soon as someone gives us lots and lots of money.'
Anyway, the mysteries of niche Swiss automakers aside, one of the things that's a bit of a pain about flow batteries is to get a decent energy density you have to use vanadium, which as you can guess from the way it sounds like something out of the MCU, is not massively plentiful or easy to get at. So it's neat that some scientists have developed a way to make an efficient battery that uses organic elements in its electrolyte instead.
In other battery news, it turns out we really don't understand them very well at all. One of the problems with studying them (and actually, this is a really neat use-case for automotive and motorsport stuff in particular, given all the onboard data gathering) is that when we're creating very complex maps of the way that energy is being chemically or physically moved around in the battery as charge states change, we tend to do it when they're, well, not charging. Nature Communications has summed up a load of complicated (but worth it if you have time to give yourself some major brainache) papers where the battery being documented has actually been in operation, which for lab tech is super important.
Energy generally is a little bit mysterious still. We know it doesn't go anywhere apart from sometimes on the quantum level it does and no one really properly knows why; quantum batteries are really interesting for this, made out of all kinds of weird inks and stuff that semi-defy time as a concept. But that's probably a topic for next week.
Making good use of the things that we find
Things that everyday industrial processes leave behind...
Dairy farming is just an environmental nightmare on every conceivable level (soz, cows) and one of the worst - well, no, sorry, it's probably not even in the top five but one of the issues that barely gets a look in is the fact there's all this runoff that's got loads of cow poop and stuff in. Which is ghoulish stuff to deal with and you don't want it going into the water system untreated and just generally it's a bad time.
So great work by the scientists that saw that nasty brown stuff and said what happens if we run it through some algae, can we make bioethanol? The answer is: yes. Well, it's actually the algae that have feasted on its horrible contents that you ferment to make ethanol but still, using wastewater to grow algae to make bioethanol is a good way to generate it (rather than using food crops or less easily fermented things like wood chippings) and it deals with the bad cow juice at the same time.
Bioethanol isn't a perfect solution, in sustainability terms, by any means and as a fuel it still produces greenhouse gases when burned but it doesn't share some of the bad properties of fossil fuels, which is that thing I talked about earlier where we're taking carbon that's been safely sequestered into the earth as oil or whatever and putting it in the air.
Also, having moaned on and on about ammonia earlier, there's a way of recovering clean water and green ammonia (ok fine, I'll bite) from effluent. Anything we can do to get clean water from dirty is very good, given we're going to be living with drought for a long time now, so: hooray, sometimes you're ok ammonia.
Meanwhile and kinda on a cows theme, people at the University of Manchester have uncovered 'the holy grail of catalysis' which is taking methane (very bad, do not let into atmosphere, one of the worst greenhouse gases) and turning it directly into methanol using just light. By running the methane over a metal-organic framework, with oxygen-rich water, it transforms into methanol, catalysed by the iron hydroxyl that it's flowing over.
Methanol can be turned into synthetic fuels (in a slightly chaotic process that's still not fully nailed down and is a lot more alchemical than companies like you to think) and it stops the methane being released, so this is all extremely good stuff.
Carbon fibre is very handy for making cars and you might think, with the wild abandon Formula E throw it around a race track, that it was a relatively cheap composite but it's really not. It's important for making vehicles lower weight, which we need to work on so it's cool that someone's found a way to make a high-quality, next-gen version of carbon fibre out of lignin, basically a runoff product of oil refinement.
Also from oil refinery runoff, scientists have found a way to extract a good yield of lithium from horrible water from gas and oil work. Yeah!!! This is so rad; you get lithium without having to frack the Arctic or any of the other bad ways we get hold of it and you deal with some gross stuff that shouldn't be out in the wild. It's an act of molecular engineering to make it happen but oh boy is this some good frickin science.
And this is another one where you can hear how much the scientists enjoyed doing it. Bacteria make energy molecules, as one of the weird things they do and there's a particularly strange one that, if you harvest it, can become a biological rocket fuel. This is big news because this would be an actually sustainable (which doesn't mean emissions-free but...) fuel, with a lot greater viability than a lot of the more complicated processes because the bacteria provide the energy for it, from consuming plant matter. They're a lot more efficient than our processes for reorganising hydrocarbons on a molecular level so, although this seems a bit out-there, it could play a very definite part in the future of combustion fuels.
Some other bits
Should propane get used to turbocharge air conditioning in our warming world? I don't really know enough about air conditioning to have a view on this one but it's a novel concept, apparently liquid propane can be a good coolant. But I also feel like maybe there's a reason we have not used it previously.... 💥
Doping sodium-ion battery cathodes with niobium massively improves charging time, which is cool. Idk if sodium-ion is really going to be a thing for cars (I think it'll probably go metal-air or molten salt, as things are currently developing but it's good to see developments in sodium-ion because we're going to need a LOT of energy storage in the coming decades and given the abundance of sodium, it's got a lot of potential.
I'm largely including this because it contains my favourite scientific graphic of the week. Behold! Duckweed, dark fermentation! But actually, as curmudgeonly as I am about hydrogen this sort of process (which uses a bio-fermentation method involving, yes, duckweed, to generate hydrogen) is actually good. I love weird innovations that are basically "what if we made some sort of pond-flavour beer and then used a nano-composite of graphene and hydroxyapetite to make it go faster?" (that's not the actual process but dark fermentation is too fun a concept, in any case)
I nearly put this in the main because it's so cool but it's not really a directly automotive-related thing, just some weird battery stuff. Scientists made a material that, using sea salt as something that absorbs water, is ultra-thin and self-charges. It can hold charge, so it's sort of a battery but it's also kind of an... I mean, I don't really want to call it an engine but it is kind of an engine, in the sense it uses the cycle of moisture condensing and evaporating out of the air to create charge.
Is solid-state hydrogen for faster fuel cell refuelling really necessary? Probably not but someone's done the work on it anyway.
A thing I get asked a lot
This or a version of it might take up permanent residence at the end of these emails because I feel like it's important to say: I am not a scientist. I've studied a bit of engineering but my last science-science qualification was a combined GCSE 20 years ago and I can't even remember what grade I got. Sometimes I will get things wrong and sometimes I'll have to skip things that might be super relevant to this newsletter because I just cannot frickin understand them. I'm not particularly clever and everything I know about cars I wouldn't say I taught myself (because that takes away from the patient people who wrote stuff explaining it that I just read and half-remembered) but it definitely wasn't drilled into me in any structured or sensible way.
So when people ask: how come you know all this stuff? It's literally just cus I was interested in it and I read about it. There's some other factors, like if you work in a male-dominated industry and you're not, you get asked technical questions (that most people can't answer) to try and trip you up or catch you out and if you're ever wrong, it'll be a crowing victory for whoever's trying to gatekeep. And I hate not winning. So I'm semi-motivated by hate.
Anyway, so: my understanding of all of this is very broad strokes. I know a lot more about it than the average person but that's just cus I've spent time consciously looking into it, which not a lot of people would do because a lot of it is very boring or obscure. Which is why I'm writing this because I think it's interesting to share the cool bits. Hopefully you've enjoyed it - feel free to let me know what you think or what you'd like to see more/less on.
Right, that's a load of science (and waffling) - see you next week
Hazel
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