88 comments

[ 9.7 ms ] story [ 450 ms ] thread
It removes 4.5lbs(about 2kg) of CO2 from the air for every 20k miles driven.
Yes, that bit is really about turning the car into a very inefficient fan.
It is not clear to me from the article, how does it clean the air?

Surely they are not claiming having a solar panel integrated, as removing CO2 from the atmosphere, as that would be an outright lie.

“This Zem car has a pair of carbon filters in the front grille that contributes to cleaning the atmosphere by removing about 4.5lb of Carbon-dioxide per 20,000 miles.”

It is not clear to me how these filters work but we can see they are not claiming the magic is in solar panels.

Carbon filter.

Though I am confused. How can a passive filter remove CO2? Don't you need to add energy and use some sort of chemical reaction?

> removing about 4.5lb of Carbon-dioxide per 20,000 miles

In familiar units: 0.05 g/km. Contrast that to the ~100 g/km emitted by a modern ICE car with decent efficiency. Of course, as mentioned:

> same amount of carbon as a mature tree absorbs annually

Is enough of a comparison to understand that this is more of a gimmick than a viable solution to anything.

Cool student project nonetheless; the "dashboard made of cooking oil", 3D printed parts and the added solar panels are likely of more significance.

> this is more of a gimmick than a viable solution to anything

It is a positive gain, even if small. Now multiply that gain across thousands of cars (assuming this tech became mass market) and you have a significant positive impact.

CO2 is a very large and global-scale problem. If everyone does just a little, all you get is a little, but on a global scale.
"In one day, the average person breathes out around 500 litres of the greenhouse gas CO2 – which amounts to around 1kg in mass."
That carbon comes from animals and plants that took it from the atmosphere in the first place. It's the normal carbon cycle: we don't drink oil. Well, not the kind that's extracted from underground and so is out of the carbon cycle.

On the other hand, if the filter was disposed of appropriately, that carbon would be removed from the carbon cycle and the atmosphere would be freed of some CO2 as a consequence.

I suspect that the physical extra effort these students made during assembly of this car (or even increased mental activity coming up with the clickbaity filter addition) completely negates the lifetime benefit of the co2 removal.

Talk about bikeshedding. The clicks are probably worth it tho.

Modern agriculture uses quite a bit of fossil fuels and the land-use penalty is there as well. In that light your quip about us not drinking oil is quite disingenuous.
Depends with values so low how many km are needed before it breaks even with the co2 production emissions ...
if you could trade your old car for one of those: definetly.

if you have to pay any amount comparable to a low-end car: maybe.

any more than that and the answer becomes: highly unlikely.

but whether or not this is a good idea or efficient under any definition of the word? idk. probably a bad idea, too consumer oriented for a problem that could be better tackled on a larger scale

Probably every technology starts out expensive and inefficient, but fortunately we don't just stop because we don't see the immediate benefit.

Computers were once huge and slow and inefficient, but now for example we have Raspberry Pi which is orders of magnitude faster, cheaper, smaller, and more energy efficient than most computers 15+ years ago.

This new carbon capture tech could see similar gains.

then go ahead and improve it, nobody is telling anyone to stop improving shit. but claiming you could use a tech at a point in time where it is not much more than a gimmick, people wont take it serious or too serious. just like with ChatGPT: just because it can return highly probable language doesnt mean its correct.

just because you can drive one "artificial tree" around doesnt mean you should pursue in making those on a scale fit to dent the problem, because in making those "trees" you just release more dead-tree-gas and make the problem worse before you can make it better.

> but claiming you could use a tech at a point in time

Where did I specify the point in time when this would be practical?

> nobody is telling anyone to stop improving shit

Look up "vitriolic". Also ask yourself why you are so angry at a stranger's neutral comments. This kind of interaction does not make the internet a better place.

who is angry?

im just stating the obvious, idk why you feel the need to defend this, but if you are affiliated with the team then just go back to the drawing board and dont waste your time trying to talk people into liking this. it's a sensationalist claim, obviously people will dispute it.

(comment deleted)
The car would be lighter and more aerodynamic and require less energy to produce without the scrubbers, the idea is a net loss.
With 1.4B personal vehicles on earth, pro tip: the future won't be clean even if they're battery powered
Genuine question, is it a good start? When does become not a gimmick? At 0.5g/km, 5g/km or 100g/km?
We need to optimize for "tonnes of CO2 scrubbed per dollar". This cost includes capital cost, and energy cost.

Because location doesn't matter, putting lots of small battery-powered mobile units is always going to lose to a large fixed industrial unit with an industrial-scale energy supply. Probably orders of magnitude worse on both CAPEX and OPEX.

Who is going to be paying for "large fixed industrial unit with an industrial-scale energy supply"?
Anyone can, that's actually another benefit. It can be funded by anyone who wants to.
Then we're at the tragedy of the commons and no one will.
Well ... yes?

I's clear that with many environmental matters, and specifically atmospheric CO2, we are at the tragedy of the commons, and have been for a long while, and strategies should be around getting us out of there.

If few will pay for it, then even fewer will pay for more expensive and less efficient mobile units.
Who is going to pay for a lot of extra power and reduced driving range for the idea in the article, the power costing far in excess per year than planting two trees (which would do more for the environment)?
> We need to optimize for "tonnes of CO2 scrubbed per dollar"

No, we need to look at externalities and real world long term side effects.

The "per dollar" part is why we're in the current situation in the first place

Solutions have to come from reality, and in reality nothing happens without money. Even socialism requires money.
> Genuine question, is it a good start?

No, because it doesn't scale, and its dramatically worse than a lot of other approaches, which range from 'also don't scale' to 'somewhat scale'.

So if we get about 2000-3000 of these for every other car in the world (there's only like a billion, right?) we should be set :)
So they installed a comically inefficient CO₂ scrubber in order to generate this headline. In order for CO₂ scrubbing to have even a chance of making sense we need big efficient dedicated plants. There is absolutely no synergy in installing the scrubber on an EV, and handling the measly amount it produces is logistically inefficient.
> logistically inefficient.

not only inefficient - the added weight of the scrubbers means that the car is now less efficient at carrying people.

CO2 scrubbing doesn't work. I think massive, industrial capture, and chemical and electrolysis conversion of CO2 into usable raw materials (such as raw carbon) is the only way forward. The energy to power that process needs to come from solar or other clean renewables.

So many questions unanswered:

They remove CO2? How? Direct air capture tech isn't exactly trivial. How much does that weight and how much does that increase the energy consumption? And most important of all: What do they do with the CO2? Do you have to drive to a geological storage site every now and then? How often?

How are those questions unanswered??? They are answered in the article - did you actually read it?
And how much CO2 was produced in the process of making and installing these filters into that car?

The amount of CO2 they capture is very low.

Does this work by pushing the air through water and relying on the co2 to desolve in the water?
Apart from the CO2 collection failure, the project is nice. I really hope small inexpensive (probably 3D printed) solar based EVs will find their market with the help of improved solar panel efficiency.
The concept of a car with solar panels on top doesn't pass the back of the envelop calculation sanity check. Even with panels capturing all the energy they receive from the sun and a car parked in a location with perfect exposure, the energy captured in a day is barely enough to make it move a few kilometers.

Relying on the (clean) grid for charging is actually the better approach.

If it's heavy like a "real" car, then yeah. It should be made relatively lightweight, like 300-400 kg in total.
We need an EV that optimizes for costs and repairability rather than looks and environmental impact.

Those students should build something they can afford...

So much this. We need something which fits in the space that 8+ year old vehicles exist in now. Which isn’t dealer serviced subscription shiny shit that costs a small fortune.
Solar panels and carbon filter on a car? Doesn't seem that smart. I could also put them in a backpack and walk around with extra kilos while cleaming I have the cleaner backpack.

It is more efficient to put them in a specialized facility where you don't have to make them mobile and can put more at the same location.

I assume the thinking is that the filters placed in a car will have (more) air flow go through them by virtue of the car moving. It's as if you placed the filters in a facility that didn't have to run fans to force air through the them.
As I understand the physics of it, to capture CO2 from the air requires energy.

The problem then is - where are you getting that energy from?

For CO2 capture, it must be green energy - not emitting CO2 itself - and you need to capture CO2 at volumes great enough to have a global impact.

Doing so at such volume requires massive development of green energy sources - and given we're not even building enough green to replace ditry (currently globally, we're building lots of green and lots of dirty, too), the idea we will then additionally build another civilization-scale supply of green energy for CO2 capture seems improbable.

> Doing so at such volume requires massive development of green energy sources - and given we're not even building enough green to replace ditry (currently globally, we're building lots of green and lots of dirty, too), the idea we will then additionally build another civilization-scale supply of green energy for CO2 capture seems improbable.

This is entirely depending on whether you think nuclear is "green enough".

But anyway the original article is bs.

I think the energy required to capture co2 is needed to run fans that force the air through filters. The filters themselves are passive.
I may be wrong, but I think the filters are not passive.

There is in fact a chemical reaction going on, and energy (stored in the chemistry of the filters) is being consumed to capture the CO2.

There are rocks - concrete does it too - which absorb CO2. This also is a chemical reaction, where the rocks and the concrete are giving up energy to capture the CO2.

Those CO2 scrubbers on the car don’t move the needle in an appreciable way. It would be cheaper and better to plant a single tree.

To really move the needle in terms of carbon capture, it needs to be at scale, with a plan to do something with the carbon. It needs to be positive return on investment.

Something like scrubbing the CO2 from a steel plant and reusing the carbon in the furnace. (https://www.economist.com/science-and-technology/2023/02/15/...). The reason this could succeed is that it makes steel cheaper to make because you don’t need to buy coal anymore. The environment benefits because fewer fossil fuels are burned but that’s not the driving factor for potential widespread adoption. Economics is.

The aero penalty, weight penalty, and production energy penalty likely outputs an order of magnitude more co2 every 20k miles than they scrub.
Unquestionably correct, at least in the US.

In the US, .855 lbs of CO2 are produced per kWh (in 2021). If that moves the car 5 miles (same as a Model 3), the car gets 26.3 miles per 4.5 lbs CO2. Since the car absorbs 4.5 lbs per 20k miles, it absorbs .132% as much CO2 as was produced by driving it.

If the filters increase the weight (and drag) of the car by .132%, then the extra consumption will cancel out the absorbed CO2. What's .132% of, say, 3500 lbs?

4.6 lbs. If the filters weigh more than 2.3 lbs, the weight of the captured CO2 will cause more CO2 to be emitted than is captured.

> This Zem car has a pair of carbon filters in the front grille that contributes to cleaning the atmosphere by removing about 4.5lb of Carbon-dioxide per 20,000 miles.

Using the US fleet average (26.4 mpg), an average car produces 4.5 lbs CO2 every 6 miles. These filters can absorb .03% of the CO2 emissions of a combustion car.

I'll have 10!
7! is sufficient to offset a single ICE car; no need to go all the way to 10!.
Many more pounds of CO2 yielded in the production of the device.

Greenwashing is going to end up doing more harm in the long run. Instead of coming up with real solutions, we’re burning even more fuel to pretend to reclaim a fraction of a percent of the production costs.

I wish we had better solutions but I don't see greenwashing as being more harm than good, if we're just talking about replacing ICE vehicles with EVs and such. Some people will think they're doing a good thing for the environment, when in reality it's merely just less bad than their previous means. But I don't get what alternative there is that's actually feasible and still keeps us on a greener trajectory. Make it illegal to promote anything as environmentally friendly unless it's near perfectly environmentally friendly in every aspect?
Nobody is going to market this as a serious proposal. This is an art project.
This is a student project, the whole car is made from recycled plastic and cooking oil and whatnot. It's not really supposed to save our standard of living by itself.

Otherwise I fully agree, CO2 scrubbing makes the most sense at the point of large scale emissions. Government taxes on emissions are also required so people start doing this before they all find a way to make economic use of the carbon.

(comment deleted)
Exactly! Here are my calculations:

TLDR; We need 2,318 ZEM cars to remove same amount of CO2 as one diesel car produces per year.

- Average diesel car makes 144g CO2 per 1 kilometer (0.62 miles).

- Zem car removes 2,000g of CO2 per 32,200 kilometers or 0.062g of CO2 per kilometer.

- Zem car needs to drive 2,318 km to remove 144g of CO2 that Diesel car produce on 1 kilometer.

- Average person drives around 21,726km per year and produce around 3,128,564g of CO2 (if Diesel).

- If Zem car would theoretically drive the same 21,726km per year, it would remove 1,349g / year.

- That means that we need 2,318 ZEM cars to remove same amount of CO2 as one diesel car produces.

- Makes sense to produce it, right?

Someone explain why we can't capture CO2 into wood and cardboard and paper products.
You can, until they break down or burn. So you’d have to bury them deep underground to keep the carbon trapped. But it would make way more sense to stop digging up the carbon already trapped underground than to be digging it up and burying it at the same time
Seems like building buildings out of the wood would work right? Most of those aren’t going to be burned down.

Also, if we want to reverse global warming carbon sequestration is non-negotiable. We can’t just stop digging up coal and oil cold turkey, and the earth has already warmed enough (and will continue to warm to about 2C) that we will need to go carbon negative, not just neutral.

The cleanest vehicle is the vehicle that can move some quantity of weight using the least amount of energy possible. No way around those basic physics.
Right, 80% of electricity is from gas and coal, but this car has NEGATIVE "CO2" impact.

I really wish we would adopt lighter cars. Extra tax on SUVs, trucks and so on. But the reality is we ban light highly efficient gas cars, in favor of 2 ton monsters!

Where I live, 0% of the electricity would be from gas or coal, and that’s becoming increasingly common.

There’s no such thing as an efficient ICE.

That coal meme belongs in the same museum as ICE engines.

ICE engines waste 60%+ energy as heat, and this is unfixable. OTOH stationary coal and gas plants have modern efficient steam turbines that capture most of that heat energy.

Even a 100% coal-powered EV emits less CO2 than an ICE engine.

Yes this isn’t going to solve carbon capture in one fell swoop. It’s a student project, incredibly impressive. What was your student project, HN commentors?

Technology demonstrators that push the limits like this may not be immediately 100% economically useful but that doesn’t mean they’re not valuable in other ways.

Incredible project!

It's much easier and cheaper not to emit CO2 than to capture already-emitted CO2. The whole idea of carbon capture is a subsidy of current polluters by future generations that will have to bear the costs.
Audi has a pilot system that removes particulates(so brake dust, bits of tyres etc.) instead:

https://www.audi-mediacenter.com/en/press-releases/audi-urba...

Technically, combustion cars already do that because the air in the combustion chamber must be ideally free from any contaminants - they just add other pollutants via the tailpipe.

I think it's a neat and relatively cheap way to deal with this problem in EVs - existing radiator fans are more than enough for this task.

That’s actually an fascinating idea.

From the page it looks like it just sucks in from the front grill, I wonder if it could suck from the wheel wells too, to grab brake dust at the source?

isn't it going to hurt range? I think radiator intake is ones of things that are not very aerodynamic, but are necessary evil for combustion cars. Also I think break dust is not that big deal as in EVs that's just "emergency" breathing method as you want to use regenerative breaking when possible
How would that work with dirt roads? It seems like the filter would get clogged in no time at all.
It's the same principle(and scale) as an air intake filter in a combustion car. Since you can drive a such car on a dirt road, this shouldn't be a problem.
I'm not sure if it's a feature of capitalism or just human nature, but we try really hard to come up with complex solutions to simple problems. I'm not sure if this is a solution looking for an investor, or an excuse to not try and change our behavior.
Why not just put a windmill on the car and reduce CO2 by increasing efficiency?

Well, this doesn't actually work because the drag of the windmill, even if you do something clever like put it in a tunnel, costs more than the energy recovered. Even an EV is still running mostly fossil based energy on average.

Drag is the big energy cost on a vehicle. Anything you mount on the vehicle to purposefully catch air is going to be a net negative.

Far more effective to just grow kudzu in the backseat.
(comment deleted)
Why is this article here (or even written for that matter).