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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

#541

Post by thinkcontext »

rmcginnis wrote: post #519
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.

But first you have to cross the valley of death. Elsewhere you refer to having to limit capital spending, wouldn't getting CO2 from a 3rd party instead of building a massive air capture facility do that? Everything I've seen says that its cheaper to capture from a point source than from the atmosphere, why would you make your costs higher than they need to be? You can of course build air capture down the road but I'd guess that you'd want to get off the ground as easily as possible.

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

#542

Post by thinkcontext »

kaennar wrote: post #168
rmcginnis wrote: post #128

Earlier quoted context omitted.

I totally agree on skepticism. We are working hard to prove our economics. We are targeting selling renewable gasoline from the air for a profit next year. It will be much better for air quality too!

How will this improve the global average of air quality? If you are removing the CO2 from the air then reintroducing it back into the same environment (assuming it is not repurposed in another sector e.g. jet fuel, commercial containers) wont the net effect be the same? I understand this will concentrate the pollution significantly and may even reduce it in the short term, but wont the average effects be the same?

By "air quality" I believe he is saying that an extra benefit to being carbon neutral is that their fuel combusts more purely than fuel made from crude oil. This means less SOx, NOx, particulates, etc.

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

#543

Post by dragontamer »

maxxxxx wrote: post #411
rfrey wrote: post #368

Earlier quoted context omitted.

Something like 55-60% of the thermal energy created by burning fossil fuels is currently wasted.

It’s kind of ironic that cars and power plants work hard on getting rid of that energy.

I know ICE engines use turbochargers to "recapture" the energy. Exhaust can be used to power the intake fan, which can increase air-pressure available to the engine's intake.

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

#544

Post by docker_up »

zaroth wrote: post #176
bluGill wrote: post #142

Earlier quoted context omitted.

I go on vacation a few times a year. Renting a car just for that is more expensive than extra cost of fuel. Not to mention most rental cars won't let me use my truck as a truck (putting rock in the back damages the bed, and a trailer is right out - both things I do only a couple times a year but I still own a truck for just those few times). IF this is as good as they claim I don't see electric cars as worth it as a…

Battery replacement is not really a factor under any kind of "normal" use. One Tesla owner driving for Tesloop was able to burn out a battery after extensively (exclusively) Supercharging from low charge to 95-100% charge after about 350,000 miles. Maintenance cost over that time was calculated as $0.05/mile. [1] With V3 Supercharging, you can drop in with your Model 3 at 15% and be at 80% in 24 minutes. In my road t…

How long are you waiting in line to get a chance to charge? I've been driving with my friend with a Tesla and he visited 2 places before giving up because the line was too long.

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

#545

Post by marauder016 »

I was excited to see the article and the response to this post is really heartening. I will echo other comments by saying that your HN pitch is well-written.

I do have a question: in conventional capture processes, the step that makes the process cost-prohibitive is regenerating the absorbent or adsorbent because it is so energy-intensive. You say above that CO2 (and water vapour) is absorbed by an aqueous electrolyte. How do you separate the CO2 from the electrolyte solution?

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

#546

Post by dwild »

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…

In Quebec our electricity can be lower than 0.05$ CAD/kWh (3.28¢/kWh based on the Rate L [1]). Our courrent lowest price is 1.384$ CAD/L. So considering that 1L would be 8.9 kWh. So all it would need is an efficiency of 33% to be profitable with an electricity cost of 0.05$ CAD/kWh. That's excluding any tax incentive to do so or any deal made with HydroQuebec to use excess power.

[1] http://www.hydroquebec.com/business/customer-space/rates/rat...

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

#547

Post by rmcginnis »

thinkcontext wrote: post #541
rmcginnis wrote: post #519

Earlier quoted context omitted.

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.

But first you have to cross the valley of death. Elsewhere you refer to having to limit capital spending, wouldn't getting CO2 from a 3rd party instead of building a massive air capture facility do that? Everything I've seen says that its cheaper to capture from a point source than from the atmosphere, why would you make your costs higher than they need to be? You can of course build air capture down the road but I'd…

Yes, we're actually agnostic on CO2 source. To get to scale we'll need to use CO2 from direct air capture, but we could by the collection from someone else.

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

#548

Post by maxxxxx »

dragontamer wrote: post #543
maxxxxx wrote: post #411

Earlier quoted context omitted.

It’s kind of ironic that cars and power plants work hard on getting rid of that energy.

I know ICE engines use turbochargers to "recapture" the energy. Exhaust can be used to power the intake fan, which can increase air-pressure available to the engine's intake.

Turbocharged engined still need a ton of cooling but yes I think they are more efficient overall .

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

#549

Post by rmcginnis »

marauder016 wrote: post #545

I was excited to see the article and the response to this post is really heartening. I will echo other comments by saying that your HN pitch is well-written. I do have a question: in conventional capture processes, the step that makes the process cost-prohibitive is regenerating the absorbent or adsorbent because it is so energy-intensive. You say above that CO2 (and water vapour) is absorbed by an aqueous electrolyt…

The CO2 is absorbed in the electrolyte, and that's where we use it in the catalysis process. It is turned into fuel within the electrolyte, then we extract that fuel from it.
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