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Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

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Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#511

Post by ossie »

ascar wrote: post #474
ossie wrote: post #126

The unit economics around this are by no means perfect but the BIG point here that should probably be in all caps is that fact that the thermal process is displaced by the use of electricity. We could argue on what is used to generate said electricity, but that is beside the point since this innovation opens up many more possibilities than are stated here. We could also argue about the comparative cost of produced en…

> I also think this innovation has a larger impact if it were used to bring existing generators of emissions closer to being carbon neutral. It also reduces the burden of being cost efficient on Day 1 since the carbon intensity of large emission generators is already a cost they'd be glad to mitigate or get rid of I can't follow this argument. What exactly are you proposing? His process still has a ~50% efficiency-lo…

In its base form this technology is mining a resource - carbon. Would you rather mine in areas of low or high atmospheric intensity? Would you rather capture it where you fund the whole operation yourself, or where someone else (existing polluters) is willing to pay you to take it out of the air because there is a regulatory cost to them putting said carbon in the air?

Maybe i should have been clearer. I wasn't suggesting using the energy from a fossil plant to power this, but co-locating it to areas where there might be more environmental and cost incentives to do so.

As i said in my earlier post, arguments on cost/efficiency are beside the point. The huge deal here is the use of electricity (of any form including all the advances to come in the future...solar cells in space, nuclear fusion etc), to remove CO2 from the atmosphere. One can now envision a future (regardless of cost or efficiency today) where we can sustainably keep the earth whole.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#512

Post by hunta2097 »

icelancer wrote: post #423
Damorian wrote: post #19

How could the math possibly work out on this? If a gallon of gas holds 33.70 kWh of energy, and you can get cheap electricity for $0.1/kWh, you're looking at $3.37/gallon if you have a magical process that converts with 100% efficiency. Even if you hit your efficiency goal, which would be impressive, who is paying $7/gallon for gas? Just buy an electric car. This can only possibly be useful when all of the oil is gon…

>> who is paying $7/gallon for gas A lot of people in the world. And Americans would pay close to that without subsidies + rising gas prices.

In the UK, a gallon of Petrol is currently about $7.97 (about £1.20/litre).

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#514

Post by rmcginnis »

phonebucket wrote: post #510

What happens with the gasoline after it’s made? Does it get burnt again? I’m guessing the energy released from burning that gasoline must necessarily be less than the energy used in creating it. Then the net is going back to square one with regards to CO2, but with a net loss of renewable energy? I may well be off the mark here, so would appreciate it if someone could tell me what I’m missing.

The energy content of the gasoline is less than the energy used to make it (only 50-60% efficiency), but the CO2 released is the same as the CO2 used. So the energy efficiency is low, but the net CO2 emission is still zero.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#515

Post by rmcginnis »

radres wrote: post #513

I still don't see any theoretical proof that your carbon nanotubes are going to do this job more efficiently. If they do, will they need any replacement? Are they reusable? How low the reuse cost can be?

There should be a peer review article with this data by the end of the summer. Mattershift, the company that makes the membranes, got a DOE RAPID grant to get bench and pilot data for this: https://www.aiche.org/rapid/news/08-27-2018/rapid-manufactur...

The membranes are robust and should have a long life in this application.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#516

Post by ossie »

simonh wrote: post #484
ossie wrote: post #126

The unit economics around this are by no means perfect but the BIG point here that should probably be in all caps is that fact that the thermal process is displaced by the use of electricity. We could argue on what is used to generate said electricity, but that is beside the point since this innovation opens up many more possibilities than are stated here. We could also argue about the comparative cost of produced en…

So we bleed energy off a hydrocarbon fueled generator system that produces CO2, to power a machine for capturing CO2 to create hydrocarbon fuels. That seems a little pointless. The advantage of this system is you can use excess renewable energy sources to mitigate hydrocarbon energy generators. If you are running a hydrocarbon powered system, don't use energy to power this capture system at the same time. That's madn…

That is not what I was suggesting.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#519

Post by rmcginnis »

brilee wrote: post #428

A few questions from a chemistry major 1. why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? The higher CO2 density of the effluent will make things more efficient. 2. Your key innovation isn't the part where you pull CO2 out of the air; it's the nanotube-based reverse osmosis process for separating ethanol from water. This process could just as easily…

We want to replace fossil fuels with renewable fuels, at the largest possible scale, over 300 billion gallons of fuel per year. Point sources of CO2 and biofuels can't scale to this level.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#520

Post by effie »

Robotbeat wrote: post #434
effie wrote: post #339

Earlier quoted context omitted.

CO2 seems much worse pollutant than water long term, because it stays in the air. Water at high altitudes condenses, reflects some radiation back to space and then falls back down.

At high altitude, the water stays up long enough and has such a huge impact that even its long term averaged impact is greater than the CO2.

Could you give a source for that? My understanding after some search is that effect of high-altitude water is hard to evaluate. I agree that at high altitudes contrails may evaporate and the water then may not fall down... Is it possible that jet exhaust water vapor accumulates in stratosphere? That would be terrible.
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