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A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

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Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#221

Post by neotek »

IgorPartola wrote: post #150
onlyrealcuzzo wrote: post #127

Earlier quoted context omitted.

Thermodynamically, no. But is that the question? We're a long way away from consuming so much energy we thermodynamically scorch the Earth, right? It seems like they want to know if you can be mostly carbon neutral and generate existing fuels. If that's the case, then if you have access to a cheap form of renewable energy -- huge amounts of geothermal, tidal, or solar -- you could generate a ton of something-like-gas…

It is the question. You need to break up the CO2 molecule and reconstitute it as gasoline. That will take more energy than the gasoline had initially. So you have a process where you take say solar energy and convert it into gasoline chemical bonds. Great, what is your efficiency of this process? Because if it is close to 100%, great. But chances are it is much closer to 0, at which point you’d be better off just usi…

>But chances are it is much closer to 0, at which point you’d be better off just using that electricity for something else.

Unless your ultimate goal is not just to use energy efficiently, but to recapture carbon dioxide.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#222

Post by macspoofing »

rayiner wrote: post #5

This is really, fundamentally important technology. Emissions reduction will not work: https://www.scientificamerican.com/article/nations-are-not-r... > The authors of the report stated in a press release that the kind of drastic, large-scale action the planet desperately needs has yet to be seen, even though global emissions have reached record levels at 53.5 billion metric tons in 2017, with no signs of peaking. >…

>The only serious solution to climate change is carbon recapture.

No. There's a major problem with carbon recapture that will never make it feasible, namely, carbon is a tiny percentage of the atmosphere - meaning you have to pump huge amounts of atmosphere through whatever filtering system you set up to get any significant carbon out. So that's the first major unsolvable problem. The second is that you need to put energy in to convert Carbon into some sort of fuel. That's your second problem.

So this will NEVER work. It will NEVER be cost effective. You are fighting thermodynamics every step of the way and you will not win.

The only serious solution to climate change is nuclear power (because nukes are the only energy source that can totally replace carbon-based power generation) and continual improvement in energy efficiency. And if that isn't good enough, then we're done as a species.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#223

Post by [deleted] »

pure-awesome wrote: post #209
ThrustVectoring wrote: post #26

Earlier quoted context omitted.

>Where does the extra energy come from? It doesn't particularly matter. Centralized clean energy production is often significantly easier to solve than figuring out clean alternatives to gasoline use. Especially when the problem with clean alternatives to gasoline is political - it's hard for the US to ban ICE engines in China, but it's significantly easier to sell them carbon-neutral gasoline. >What is the efficienc…

> It doesn't particularly matter. Centralized clean energy production is often significantly easier to solve than figuring out clean alternatives to gasoline use. Especially when the problem with clean alternatives to gasoline is political - it's hard for the US to ban ICE engines in China, but it's significantly easier to sell them carbon-neutral gasoline. Oh! Is THIS why we're going about this roundabout process? I…

[deleted]

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#224

Post by dsfyu404ed »

whenchamenia wrote: post #145
etaioinshrdlu wrote: post #47

Earlier quoted context omitted.

You might find this youtube channel interesting: https://www.youtube.com/channel/UC2rzsm1Qi6N1X-wuOg_p0Ng/vid... He has run a gasoline engine on a whole slew of fuels, including some that may be surprising, such as isopropyl alcohol, various solvents, crude oil, and a 50% diesel gas mix. Gasoline engines can also run on pure propane, but the fuel pump, tank, and some other parts do need to be replaced. I guess the po…

Thats a low compression mower engine. Modern automobile engines are indeed quite sensitive to predetonation from slower ignition times offered by most alternatives without being designed for them.

>Modern automobile engines are indeed quite sensitive to predetonation from slower ignition times offered by most alternatives without being designed for them.

If by "design" you mean a different cam profile to drop the dynamic compression ratio then sure.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#225

Post by Mvandenbergh »

rayiner wrote: post #5

This is really, fundamentally important technology. Emissions reduction will not work: https://www.scientificamerican.com/article/nations-are-not-r... > The authors of the report stated in a press release that the kind of drastic, large-scale action the planet desperately needs has yet to be seen, even though global emissions have reached record levels at 53.5 billion metric tons in 2017, with no signs of peaking. >…

There's a pervasive solution bias in thinking about climate change and this is an example of it.

If reducing emissions won't work and we have to find a solution, then surely negative emissions is the answer?

The problem with that is that the fact that we need a solution does not mean that a solution exists and that eliminating solutions that definitely won't work doesn't mean that the remaining ones have to work.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#226

Post by dsfyu404ed »

exabrial wrote: post #211

Anyone explain how this works in regards to the laws of thermodynamics?

Use energy to assembly long complex molecules.

Rapidly oxidize said molecules releasing most of that energy.

Capture some of the energy released and turn it into mechanical power.

It's no different than any other carbon based energy source. The real question comes down to the efficiency and economics of each of the various steps.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#227

Post by IgorPartola »

neotek wrote: post #221
IgorPartola wrote: post #150

Earlier quoted context omitted.

It is the question. You need to break up the CO2 molecule and reconstitute it as gasoline. That will take more energy than the gasoline had initially. So you have a process where you take say solar energy and convert it into gasoline chemical bonds. Great, what is your efficiency of this process? Because if it is close to 100%, great. But chances are it is much closer to 0, at which point you’d be better off just usi…

>But chances are it is much closer to 0, at which point you’d be better off just using that electricity for something else. Unless your ultimate goal is not just to use energy efficiently, but to recapture carbon dioxide.

Solar panels take energy to produce, transport, and install. Mining the lithium needed to produce them is pretty harmful to the environment. Other parts of the process are pretty bad too. If your efficiency is too low, if you install a gigawatt power plant and produce a half gallon of gasoline a month, you will take way too long to get an emissions ROI. Just recapturing CO2 requires less energy than recapturing and reconstituting it as gasoline. Sure you can sell the gasoline and maybe make some $$ but will that actually in the end be a net negative for the atmospheric CO2? The answer will 100% depend on efficiency.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#228

Post by slfnflctd »

yongjik wrote: post #112
ajross wrote: post #105

Earlier quoted context omitted.

If there were realistic competitors for fossil fuels, we wouldn't be worrying about a climate crisis in the first place. Nothing is going to compete with pumping fuel out of the ground, and it never will. Any realistic scenario starts with some kind of regulation on carbon extraction and then worries about the economics of replacements. And technologies like this one that claim to be within a factor of two seem very…

But all these renewable energy sources are already competing with fossil fuels and sometimes even winning! And even with these sources you can't make synthetic gasoline economically viable. That leads to the question: if one can sell synthetic gasoline at profit, they must have a really cheap source of energy, in which case why go through the trouble of gasoline instead of selling the energy directly?

Imagine a remote military outpost-- the only supply chain access is limited & expensive.

Having vehicles that can go from empty to full in seconds by fuel you pulled out of the air yourself with solar panels last week could be much more valuable than using those same solar panels to charge an electric vehicle (or a battery bank and then later a vehicle).

Certain types of municipal or commercial fleets also have quick-refuel requirements. There are likely a few other limitations to current electrics that ICE engines don't have, as well.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#229

Post by bluGill »

Jedi72 wrote: post #218
nordsieck wrote: post #198

Earlier quoted context omitted.

> the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better. China is already leading the world in electric busses. They work great. Busses are such good vehicles for batteries, that for some routes it may even make sense to run them with super-capacitors, with chargers embedded in the road at stops. Trucks are always going to be a p…

A small percentage of vehicles by sheer number perhaps, but not by miles travelled. An average truck is working 50 hr weeks, plus commute time for the driver etc. As opposed to your average car which runs twice a day for 30 mins.

Still a small percentage. While the average car is 30 minutes twice a day, the small percentage of cars that are not average are still more than the trucks. People on vacation can drive all day. The average car is used for a dentist appoint in the middle of the day once in a while - this all adds up to a lot of cars on the road.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#230

Post by IgorPartola »

whiskers08xmt wrote: post #196
IgorPartola wrote: post #146

Earlier quoted context omitted.

I cannot see how you could take CO2 and make gasoline out of it using less energy than what the gasoline contains. At best, you will need to supply that energy via something like solar panels. Then it becomes a question of efficiency: how many Watts of gasoline can you produce per Watt of electricity you have? My guess is, not many.

It can still be competitive with things like tar-sand extraction, which takes more energy than you get out of the oil. It's only economically viable because energy in gasoline/oil form is more valuable than the energy content itself, due to it's ease of transfer. Air sequestration might be a viable fuel source in regions where import costs of fuel are high, but energy is cheap.

I did not know that! Thanks.

I am less concerned about economic efficiency and more about environmental efficiency. The process to set up carbon sequestration facilities will itself produce CO2. If you produce a paltry amount of gasoline because all your energy is going towards that conversion, it might take you years or decades to actually reduce atmospheric CO2.

Even more important is the fact that the gas you produce and sell will go right back into the air as CO2, further reducing your net impact. You would basically need to produce gasoline faster than people can use it. Do you think a private company can do this process and outpace the consumption of Asia and Africa? It’s a catch 22: either your process is so inefficient that you pollute more than you clean up, or it’s efficient enough that you just drop the prices of gasoline, putting CO2 right back into the air. Their option is that you produce so much gasoline that you cannot sell it fast enough. Ironically that will tank your profits.

I think doing something other than gasoline is the answer. Make fertilizer: it will help grow the ecosystem while not immediately winding up as CO2.

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