Keystone Pipeline

[arkirk]

I don't think we will ever move entirely away from burning hydrocarbons for vehicle fuel - it is simply superior in terms of energy density, refill/recharge time, and safety compared with batteries or alternative chemical fuels such as Hydrogen.

What will change, if we can move to sustainability, will be the source of that hydrocarbon.

Fossil fuels need to stay in the ground. But hydrocarbon fuels (and lubricants, plastics, etc.) can be made from CO₂ - with an input of energy.

The CO₂ in the air can be collected by plants; these can be burned to produce energy plus concentrated CO₂, and the concentrated CO₂ can be turned into hydrocarbons using either more solar power, or nuclear, or wind, or (most likely) a combination of all of these.

By using the solar, nuclear and wind power to make liquid hydrocarbon fuels, you eliminate the issue of storage - make gasoline when the sun shines, the grid demand is low, and/or the wind is blowing, and stockpile it to use at your leisure.

All of the technology to do this exists today. It just needs to become cheaper (which it slowly is) and/or for mineral oils to become more expensive (which they already would be if they were taxed to cover the externalities of climate change).

The bonds in CO2 are covalent. The bonds in H2O are ionic. Covalent bonds require much more energy to break than ionic ones. Chlorophyll + energy + CO2 results in replacement of the oxygen in the CO2 by protons. It is a slow, low temperature reaction and the Chlorophyll only catalyses the reaction. Inorganic breaking of this bond would require excessive energy inputs and would yield Carbon. I don't believe you can "burn" a completely oxidized compound..

Also collecting CO2 from an atmosphere that has some hundreds of ppm's of the compound would be extremely inefficient. Likewise capturing it from a combustion engine in more concentrated form would also involve energy intensive measures for compressing and storing it prior to whatever inorganic conversion method you might attempt. Just saying there might be better ways to store protons.

 

[bilby]

I don't think we will ever move entirely away from burning hydrocarbons for vehicle fuel - it is simply superior in terms of energy density, refill/recharge time, and safety compared with batteries or alternative chemical fuels such as Hydrogen.

What will change, if we can move to sustainability, will be the source of that hydrocarbon.

Fossil fuels need to stay in the ground. But hydrocarbon fuels (and lubricants, plastics, etc.) can be made from CO₂ - with an input of energy.

The CO₂ in the air can be collected by plants; these can be burned to produce energy plus concentrated CO₂, and the concentrated CO₂ can be turned into hydrocarbons using either more solar power, or nuclear, or wind, or (most likely) a combination of all of these.

By using the solar, nuclear and wind power to make liquid hydrocarbon fuels, you eliminate the issue of storage - make gasoline when the sun shines, the grid demand is low, and/or the wind is blowing, and stockpile it to use at your leisure.

All of the technology to do this exists today. It just needs to become cheaper (which it slowly is) and/or for mineral oils to become more expensive (which they already would be if they were taxed to cover the externalities of climate change).

The bonds in CO2 are covalent. The bonds in H2O are ionic. Covalent bonds require much more energy to break than ionic ones.

Yes, so?

Chlorophyll + energy + CO2 results in replacement of the oxygen in the CO2 by protons. It is a slow, low temperature reaction and the Chlorophyll only catalyses the reaction. Inorganic breaking of this bond would require excessive energy inputs and would yield Carbon.

Wait, what? 'protons' are Hydrogen. Plants add Hydrogen (from water) to CO₂ to produce carbohydrates (plus Oxygen), and they then either store the carbohydrates as sugars, or polymerise them into cellulose. You can oxidise this stuff back to Carbon (it is called 'charcoal burning' or 'charcoal production' and has been done for thousands of years; It does not require "require excessive energy inputs", in fact charcoal production generates excess energy), or you can oxidise it completely to CO₂ and H₂O (burning); or you can do those steps one at a time and use the charcoal as a fuel; But none of this is relevant in any way to my suggested process.

I don't believe you can "burn" a completely oxidized compound..

No, you can't; but if you read what I said, you would see that I wasn't suggesting that anyone would try to do so, so it doesn't matter that you can't.

Let me set my idea out for you step by step:

Step one: Grow plants. Almost any plant will do, but lets take some trees as our example; They take CO₂ from the air, and produce cellulose (wood) and oxygen.
Step two: Burn the wood produced in step one in a 'biomass' power plant. You use oxygen from the air, plus cellulose, to make electricity and concentrated CO₂
Step three: Generate some more power - from solar panels, wind turbines, nuclear power plants, whatever - as long as it isn't burning fossil fuels.
Step four: Use the power from steps two and three, and the concentrated CO₂ from step two, plus some water, to make Hydrocarbons - CO₂ + H₂O + Energy -> CH_n + O₂
(Note that some of the current technologies allow better efficiency by using the sun to directly heat a catalyst in the presence of CO₂ and water - effectively allowing you to combine steps three and four and go directly from solar to hydrocarbons)

Depending on the exact details and the efficiencies of each step, you either end up with gasoline plus a surplus of electricity, which you can use for something else; Or gasoline plus a surplus of CO₂, which you can safely vent back to the atmosphere because that's where it came from in step 1. Whatever you do is as close as makes no difference to carbon neutral if you subsequently burn the hydrocarbons for fuel; If some is used to make plastics, the whole exercise is a net extractor of CO₂ from the air.

Also collecting CO2 from an atmosphere that has some hundreds of ppm's of the compound would be extremely inefficient.

Which is why I am proposing we leave that job to the trees - they are very good at it,

Likewise capturing it from a combustion engine in more concentrated form would also involve energy intensive measures for compressing and storing it prior to whatever inorganic conversion method you might attempt.

As long as the energy required for this step can come from a combination of the burning of the biomass at step two, and the carbon neutral source at step three, this is not important; The energy required to catch the CO₂ from the smokestack of the biomass plant is tiny compared to that required to make the CO₂ plus water into hydrocarbons.

Just saying there might be better ways to store protons.

Then feel free to present your 'better ways'

The technology to do the four steps above already exists; steps one, two and three are currently done on industrial scales, and the only reason step four is not, is that mineral oil is so cheap - both South Africa and the Third Reich used step four at industrial scale in the 20th century when embargoes and blockades cut off their supply of mineral oil.

No new technology is needed for my proposal; every part of the process has been proven to work at scale - although as far as I am aware nobody has yet combined all four steps at once above prototype scales.

 

[Derec]

The bonds in CO2 are covalent. The bonds in H2O are ionic.

Wrong. They are both covalent.
Covalent bonds require much more energy to break than ionic ones. Chlorophyll + energy + CO2 results in replacement of the oxygen in the CO2 by protons.

I don't believe you can "burn" a completely oxidized compound..

Unless you are a really bad cook (jokes about burning water).

 

[Derec]

I don't think we will ever move entirely away from burning hydrocarbons for vehicle fuel - it is simply superior in terms of energy density, refill/recharge time, and safety compared with batteries or alternative chemical fuels such as Hydrogen.

"Ever" is a very long time. In any case, I think we will move entirely away from internal combustion engines, and within decades. One possibility is using methanol (most hydrogen rich of liquid fuels) which is basically methane with one hydrogen replaced by a hydroxyl (OH) group which makes it polar (and thus liquid even at low molecular weight). Methanol can be used in fuel cell cars instead of straight hydrogen.

Fossil fuels need to stay in the ground.

All of them? Right now?

The CO₂ in the air can be collected by plants; these can be burned to produce energy plus concentrated CO₂, and the concentrated CO₂ can be turned into hydrocarbons using either more solar power, or nuclear, or wind, or (most likely) a combination of all of these.

Going through plants is quite cumbersome. Why not collect CO₂ from industries that already produce large amounts of it like cement or steel industries?

By using the solar, nuclear and wind power to make liquid hydrocarbon fuels, you eliminate the issue of storage - make gasoline when the sun shines, the grid demand is low, and/or the wind is blowing, and stockpile it to use at your leisure.

Again, using alcohols is preferable because they are liquid at lower molecular weights (and thus lower carbon/hydrogen ratios)

All of the technology to do this exists today. It just needs to become cheaper (which it slowly is) and/or for mineral oils to become more expensive (which they already would be if they were taxed to cover the externalities of climate change).

Whether something like this will win the future or steadily improving battery technology or elemental hydrogen remains to be seen. It will probably be some mixture of at least two of these.

 

[bilby]

"Ever" is a very long time.

Fair enough - 'in the foreseeable future' if you prefer

In any case, I think we will move entirely away from internal combustion engines, and within decades. One possibility is using methanol (most hydrogen rich of liquid fuels) which is basically methane with one hydrogen replaced by a hydroxyl (OH) group which makes it polar (and thus liquid even at low molecular weight). Methanol can be used in fuel cell cars instead of straight hydrogen.

The problem with using alcohols as fuels is that they burn with a clear flame, which renders them more dangerous. Some racing cars run on Ethanol, but special precautions need to be taken by marshals and fire crews at tracks where such cars are running. The energy density is lower too; and you would need to replace all the current gasoline engines and infrastructure with Methanol (or Ethanol) infrastructure.

Fossil fuels need to stay in the ground.

All of them? Right now?

No; just as many as possible as soon as it is practical to do so.

The CO₂ in the air can be collected by plants; these can be burned to produce energy plus concentrated CO₂, and the concentrated CO₂ can be turned into hydrocarbons using either more solar power, or nuclear, or wind, or (most likely) a combination of all of these.

Going through plants is quite cumbersome. Why not collect CO₂ from industries that already produce large amounts of it like cement or steel industries?

No reason at all, other than that those sources are probably not sufficient for the volumes of hydrocarbons needed. I would envisage such sources (and even coal, oil and gas power plants) being used at least to begin with; but eventually you will need to use biomass.

By using the solar, nuclear and wind power to make liquid hydrocarbon fuels, you eliminate the issue of storage - make gasoline when the sun shines, the grid demand is low, and/or the wind is blowing, and stockpile it to use at your leisure.

Again, using alcohols is preferable because they are liquid at lower molecular weights (and thus lower carbon/hydrogen ratios)

This is only important if you are sourcing your Carbon from fossil sources. If it comes from the atmosphere (by a route that takes less than decades to complete the cycle), then it is irrelevant how much carbon is used. Hydrocarbons are better than light alcohols in that they can be used for lubricants and plastics manufacture as well as for fuel.

All of the technology to do this exists today. It just needs to become cheaper (which it slowly is) and/or for mineral oils to become more expensive (which they already would be if they were taxed to cover the externalities of climate change).

Whether something like this will win the future or steadily improving battery technology or elemental hydrogen remains to be seen. It will probably be some mixture of at least two of these.

Yeah, probably; The benefit with using this technique to make hydrocarbon fuel is that it requires no changes in infrastructure - this process can make fuels that are chemically identical to those already in use, so nobody needs to buy a new car, build a new service station, or modify their fuel supply chain infrastructure in order to implement it.

It might be a stop-gap on the road to fuel cell or battery-electric vehicles; but my guess is that this can result in Carbon-neutral transport more cheaply than those options; and if I am right, then those options will struggle to compete.

Obviously whether I am right depends on how cheaply this set of processes can be made to work, compared to other options; But with the advantage of using existing infrastructure and existing vehicles, I reckon it is the most likely way forward.

 

[Derec]

Fair enough - 'in the foreseeable future' if you prefer

Yet battery technology continues to improve. I doubt this "foreseeable future" is very long as there is no way of telling which technology will ultimately win out.

The problem with using alcohols as fuels is that they burn with a clear flame, which renders them more dangerous. Some racing cars run on Ethanol, but special precautions need to be taken by marshals and fire crews at tracks where such cars are running. The energy density is lower too; and you would need to replace all the current gasoline engines and infrastructure with Methanol (or Ethanol) infrastructure.

That is because they burn much cleaner than gasoline or diesel - and I am not talking about burning it directly anyway. If a clear flame is a safety concern an environmentally safe additive can be added to color the flame. Similar to we already do with colorless methane to make it stink so people can detect leaks.
Actually it's methanol that is used in racing, not ethanol. And lower energy density is more than compensated by the higher efficiency of a fuel cell electric vehicle compared to an ICE. And infrastructure will have to change over the next few decades anyway. What technology, or mix of technologies, will win out I cannot say however. I doubt it will be synthetic gasoline.

No; just as many as possible as soon as it is practical to do so.

Which means that we will still need to extract large volumes of oil for the foreseeable future. Which means we still need the Keystone XL pipeline.

No reason at all, other than that those sources are probably not sufficient for the volumes of hydrocarbons needed.

Worrying about reaching those limits is kind of silly when you are nowhere close to reaching them.

I would envisage such sources (and even coal, oil and gas power plants) being used at least to begin with; but eventually you will need to use biomass.

Or find a way to capture atmospheric CO₂ more efficiently than biomass.

This is only important if you are sourcing your Carbon from fossil sources. If it comes from the atmosphere (by a route that takes less than decades to complete the cycle), then it is irrelevant how much carbon is used.

It greatly reduces the efficiency of your process. To make a mole of gasoline you need an average of 7-8 moles of CO₂ vs. 1 mole for methanol. Furthermore you are talking about using biomass to generate CO₂ which you then need a great deal of energy to reduce back. How many hectares or arable land do you propose to use for this endeavor anyway?

Hydrocarbons are better than light alcohols in that they can be used for lubricants and plastics manufacture as well as for fuel.

Those applications use so little crude oil and natural gas will be sufficient to meet those needs with no problems for at lest a century.

Yeah, probably; The benefit with using this technique to make hydrocarbon fuel is that it requires no changes in infrastructure - this process can make fuels that are chemically identical to those already in use, so nobody needs to buy a new car, build a new service station, or modify their fuel supply chain infrastructure in order to implement it.

We are talking about a change that will take decades. People naturally replace their cars and fueling stations their equipment anyway.

It might be a stop-gap on the road to fuel cell or battery-electric vehicles; but my guess is that this can result in Carbon-neutral transport more cheaply than those options; and if I am right, then those options will struggle to compete.

If you can make it cheaper than regular oil it might be a stopgap. If you could use waste biomass (rather than having to devote precious arable land) and use a process more efficient than what you envision (something like thermal depolymerization, basically running how oil is produced naturally at warp speed) it might be a viable part of the mix.

 

[arkirk]

Wrong. They are both covalent.
Covalent bonds require much more energy to break than ionic ones. Chlorophyll + energy + CO2 results in replacement of the oxygen in the CO2 by protons.

I don't believe you can "burn" a completely oxidized compound..

Unless you are a really bad cook (jokes about burning water).

Derec: Water molecules are Hydrogen ion associated with Hydroxyl ion or HOH. These bonds are easily broken either chemically or by electrolysis. On the other hand, hydrocarbons that typically come out of the ground are covalent bonds which are resistant to electrolysis. Ionic bonds still require energy to break but usually this accomplished by the simple addition of something like a salt to an electroysis unit to increase the rate of ionization. Creating stored energy always takes energy.
There's no free lunch energy. That seems so hard for people to understand.

 

[Derec]

Derec: Water molecules are Hydrogen ion associated with Hydroxyl ion or HOH.

Wrong. Just wrong. Please look it up. Water is a covalently bonded polar molecule. What you are probably misremembering is the fact that a very small fraction of water molecules (~1 in 10 million molecules) self-ionizes into OH^- and H₃O⁺ ions (free protons cannot exist in aqueous solutions) which is why even pure water has some electrical conductivity.
What water has is a relatively strong bond between individual (and covalently bonded) water molecules called the hydrogen bond. That allows water, with the low low molecular weight of 18 to be liquid at standard temperature and pressure.

These bonds are easily broken either chemically or by electrolysis.

It actually takes quite a bit of energy to break the covalent bonds in water (464 kJ/mol). Certainly more than the O=O and H-H bonds which is why you get net energy by burning hydrogen (or running it through a fuel cell).

On the other hand, hydrocarbons that typically come out of the ground are covalent bonds which are resistant to electrolysis.

They are resistent to electrolysis because they are not polar. But the bonds holding hydrocarbons together are weaker than bonds in water and carbon dioxide which is why you get net energy by burning hydrocarbons.

Ionic bonds still require energy to break but usually this accomplished by the simple addition of something like a salt to an electroysis unit to increase the rate of ionization.

Salts are examples of ionic bonds. Water isn't.

Creating stored energy always takes energy.

No shit Sherlock! Chemical energy exists in the form of weaker bonds compared to bonds of compounds created when this chemical energy is released.

There's no free lunch energy. That seems so hard for people to understand.

Nobody said that there was. That still doesn't make water ionic though.

 

[bilby]

Pure water has a pH of 7.

This means that the concentration of ions is 10^-7 mol/litre; a mole of water is 18ml; so there are about 56mol of water per litre of which 0.00000001 mol is ionic. So water is one part ionic to five hundred million parts covalent.

You are both right; but Derec is five hundred million times more right than arkirk.

 

[OLDMAN]

Yeah, this is nothing compared to coal fired electric plants in China and the US. There are plenty of rivers that could be damned. If you want to solve the problem of co2 from autos, you have to pass a law requiring all autos to be electric, by say 2045? That's a number I just pulled out of my ass by the way.

Most every damable river is already dammed--and dams are far from green when it comes to the ecology of the river and sometimes the ocean beyond. (Species like trout that spawn in fresh water but live in the ocean.)

Not in Canada, not even close. But that would require a North American grid system and we all now that Canada is a foreign country that Obama doesn't trust or consider worthy of help.