The article is quick to point out the huge role of oil in the modern energy mix. It also fails to note that most of the energy ends up us waste heat. The so called "Primary energy fallacy". Other than that, it's a great read.
The article is quick to point out the huge role of oil in the modern energy mix. It also fails to note that most of the energy ends up us waste heat. The so called "Primary energy fallacy". Other than that, it's a great read.
To me (as someone who has worked on oil rigs, oil pipelines, oil refineries, and chemical plants), crude oil seems far more valuable as a material than as an energy source. It feels like a damned shame that we're still combusting so much of it for heat rather than reserving it for physical materials.
I understand the ways that economics are very important, and that the economics still currently favor burning a large fraction of the crude oil. But I also know that the right kinds of investments and a bit of luck can often change those economics, and that would be nice to see.
We can always make polymers and HydroCarbons in general from other sources if we have energy abundance. We literally can just capture the CO2 we emitted from burning fossil and make it plastics.
Of course this does not make sense in a world where we do not have enough energy to even keep datacenters open.
Edit: To clarify, I do not propose burning fossils to capture CO2 and make plastics. I am a Thermo Laws believer.
Methane >> carbon dioxide as a polyethylene/linear polymers feed stock. Double bonded oxygens are hella higher affinity than four loose hydrogens. Also as pointed out, even in a concentrated combustion effluent stack CO2 is low concentration at atmospheric pressure.
I don’t know about methane as an aromatic/hybridized ring building block. Anything is possible with chemical synthesis but is it energy feasible.
There’s always plant hydrocarbon feed stocks but I think using arable land to make plastics is dumb and also carbon intensive. (I do wear cotton clothing tho because you need to make trade offs).
Siemens has a collaboration with Porsche are piloting already eFuel production. Cost is super high (think like $10/liter). But thermodynamically feasible.
https://www.siemens-energy.com/global/en/home/press-releases...
That sounds like a hack from late-game Factorio: pollute enough that you can just pull iron filings right out of the air. Everyone wins! Except the meatbags who need to breathe the air …
Assuming the damn rain does not throw your iron down to the ground before it reaches its destination. But then again you have rivers as a plan B.
The problem with carbon capture from air is the low carbon concentration. Try to do the math for how much air you need to process to get even one barrel of oil worth of hydrocarbons from a DAC process.
The answer to this problem as it's currently being pursued is renewable carbon feedstocks. Growing things like canola on marginal land, harvesting it and turning it into biofuels and LCLFs (low carbon liquid fuels) using renewable solar/wind energy.
It's not a solved problem, though. Truly renewable carbon feedstocks have to source their carbon from the air, not the soil, which has to be continually measured. Land selection for carbon feedstock projects has to ensure it doesn't induce land-use change in other locations due to displacing other things like food production, etc. Otherwise the emissions and environmental harm from those downstream effects have to be included in the carbon positive/negative calculations for the project.
Remarkable amounts of carbon are available in waste streams, even if you exclude from the count plastics and other petrochemicals. Paper, cardboard, wood, natural fibers, carbon in sewage and waste food, and especially farm waste (parts of plants not otherwise consumed). Some of the latter is needed for soil conditioning, but most of that is from decay of roots, not stuff left at the surface.
All this can be extended by addition of hydrogen. Naively, if you process a carbohydrate into hydrocarbons, about half the carbon is lost as CO2. Adding hydrogen allows the oxygen to be carried off as water rather than CO2 (or, the CO2 to be converted to hydrocarbons and water in a second step.) Hydrogen currently comes from natural gas but that will have to change anyway, with the hydrogen being produced by (for example) electrolysis of water.
There is way more carbon in the ground as rocks than as oil. If you have plenty of energy, the difference is quite manageable.
Besides, as somebody already pointed out, there is that CO2 on the air that we actually want to get rid of. It's nothing compared to the rocks, and a little harder to get, but getting it first would improve things a lot.
The density of carbon in seawater is also higher much than it is in air. The relative concentration of bicarbonate in seawater is a few times lower than in air (as % by mass), but because water is nearly 1000x the density of air the true amount of bicarbonate there per volume is much higher.
The carbon isn’t valuable elementally as much as it is structurally and molecularly. I mean that as aromatic rings and other ready made building blocks that conveniently can be fractionally separated with pressure and temperature conditions in a column as a gross generalization. All of this is energy intensive but much less so than building up from three atom molecules with strong bonds. And much much less energy intensive than separating a trace % molecule from the atmosphere at low atmospheric pressure and translating that to complex molecules.
There needs to be more appreciation for the laws of thermodynamics when discussing technology. Everything is not a 1-dimensional reduced abstraction.
The #1 rule of HN that must never be violated: software developers are the smartest people on earth, and literally every field could benefit from their definitely not stunningly overconfident and reductionist contributions. I dread threads about engineering subjects I get paid to be competent in because I can't handle the tsunami of neckbeard opinions that I'm about to see.
> there is that CO2 on the air that we actually want to get rid of
For this reason I have long been slightly baffled that development of compostable/biodegradable bio-based plastics is such a priority in materials research. Sure, it's interesting in the very long run, but for the foreseeable future, converting atmospheric CO2 (via plants as an initial step) into a long lived, inert material that can just be buried after an initial use seems like a benefit.
> It also fails to note that most of the energy ends up us waste heat.
I've heard the statistic that 40% of the total oil pumped out of the ground just to transporting oil. We use almost half just to move it to and fro before even using it.
Is this accurate?
This can't be accurate.
Let's say a barrel of oil travels 15,000 km from Saudi Arabia to Texas, gets refined, gets shipped another 10,000 km to Europe, then the last 1,000 km overland by truck.
This reasonably well sourced Reddit post [0] says big oil tankers burn 0.1% of their fuel per 1,000 km, smaller ones a bit more. Say 0.2% on aggregate, that's 5% for the whole journey, 10% because the ship is empty half the time.
From the same source, a truck burns about 3% per 1,000 km. This seems too high: for a 40,000 kg loaded truck that's less than 1 kmpl or 2.5 mpg. But let's believe it, double it for empty journeys, and we still only get 16%.
I used very conservative estimates here: surely most oil doesn't travel anywhere near that far.
Alternative thought experiment: look at the traffic on the highway. If this were true, even neglecting oil burnt for heating or electricity or aviation, you'd expect 40% of the vehicles to be tanker trucks.
[0] https://www.reddit.com/r/explainlikeimfive/comments/2jozd7/e...
> you'd expect 40% of the vehicles to be tanker trucks.
I’d expect tanker trucks to carry far more fuel than the typical vehicle.
> Say 0.2% on aggregate, that's 5% for the whole journey, 10% because the ship is empty half the time.
Fuel saves from slow steaming and being empty are massive.
> If this were true, even neglecting oil burnt for heating or electricity or aviation, you'd expect 40% of the vehicles to be tanker trucks.
The US has a lot of domestic pipelines [1], and a lot of the remainder is done by train [2] because trains are the most efficient way to transport bulk goods over extremely long distances.
[1] https://www.bts.gov/geography/geospatial-portal/us-petroleum...
[2] https://www.aar.org/wp-content/uploads/2018/07/AAR-US-Rail-C...
I suspect this is confusion between the statistic that 40% of global shipping traffic is transportation of fossil fuels.
https://qz.com/2113243/forty-percent-of-all-shipping-cargo-c...
Say a tanker truck has a roughly 300 gallon fuel tank and a 10,000 gallon payload tank (per google). Thats roughly 3% loss to cross a lot of the US, which is by no means insignificant but assuming ships are not any worse and the pipeline to the ship is minimal, around a manageable 6% loss.
Trucks need a lot more infrastructure in a lot more places than ships, though. I guess that's not often factored in.
I also don’t have a source, but I have heard that 15% of global energy is dedicated to handling petroleum (extracting, transporting, refining) which feels like a plausible number.
I very much doubt that number. Maybe it was referring to 40% of the price of oil for consumers comes from the stages after pumping?
This doesn't math out to me just based on what I know of energy consumption numbers.
Sounds really dubious to me. Tankers and pipelines are really efficient.
I would not believe it at all without source.
Maybe someone got confused by "transportation" altogether being major consumer?
It must be way higher if you really got into it
i.e. A friend that works on rigs is flown to and from rigs from anywhere on earth every month, then choppers out to the rig and back. Same for everyone that works on the rigs.
The helicopter fuel is a drop in the oil ocean. You can just check this but checking how much oil that rig produces per month. How many flights the helicopter does every month and the amount of oil needed for it. It’s gonna be a drop in the bucket. Otherwise it would not be profitable to drill for oil.
And? Given how much typical oil rig produces this would not be a serious part of its production.
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