[HN Gopher] Touted as clean, 'blue' hydrogen may be worse than g...
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Touted as clean, 'blue' hydrogen may be worse than gas, coal
Author : geox
Score : 65 points
Date : 2021-08-12 20:50 UTC (2 hours ago)
(HTM) web link (onlinelibrary.wiley.com)
(TXT) w3m dump (onlinelibrary.wiley.com)
| letitbeirie wrote:
| Unless we figure out a way to reverse entropy, hydrogen is going
| be less efficient than any feedstock we make it out of.
|
| If/when we achieve direct solar separation at scale hydrogen
| might start to make sense for transportation/portable
| applications at least.
| boyadjian wrote:
| Decarbonized world does not exists. It's an invention of self-
| righteous/do-gooders/right-thinking people. Every human activity
| will generate CO2, it's inevitable
| Manuel_D wrote:
| Decarbonization can largely be achieved by replacing
| electricity production and fuels with carbon neutral processes.
| Nuclear power for power plants can do the former effectively
| anywhere where there is demand for power. The latter is
| trickier. Batteries work for things like cars, but don't have
| the energy density required for applications like transoceanic
| transportation. But that's where the prospect of hydrogen fuel
| comes into play. Industrial applications, like smelting, is
| another big application of fossil fuels that hydrogen can
| supplant.
| spfzero wrote:
| If generating electricity could be done carbon free via
| nuclear/solar/wind, and that electricity used to produce
| hydrogen via electrolysis, you'd have something for
| industrial/transportation uses.
| ancientworldnow wrote:
| Electricity production is only 20-40% of carbon generation
| (depending on what stat you're looking at and where). Nuclear
| power emits only a little less co2 than "clean" combined
| cycle nat gas when you account for the massive amount of
| concrete and energy for construction and decommissioning (aka
| lifetime emissions which is a stat rarely used for this
| reason).
|
| Dirty electricity production (coal primarily) also has an
| aerosol masking effect the latest IPCC report estimates to be
| 0.5-0.8C in cooling - an effect we lose when we switch to
| renewable (which we should do anyway as this bandaid will
| need to be ripped off eventually).
|
| The post you're replying to is exaggerating but a
| decarbonized economy will look nothing like what we have now.
| Manuel_D wrote:
| > Nuclear power emits only a little less co2 than "clean"
| combined cycle nat gas when you account for the massive
| amount of concrete and energy for construction and
| decommissioning (aka lifetime emissions which is a stat
| rarely used for this reason).
|
| This is far from correct. Yes, concrete production releases
| CO2, but that only happens once over the 50-80+ year
| lifetime of a nuclear power plant. Carbon emissions from
| nuclear are a fraction of fossil fuels [1]. They need to
| have a separate magnified section to meaningfully show them
| on the graph: https://www.carbonbrief.org/wp-
| content/uploads/2017/12/Scree...
|
| 1. https://www.carbonbrief.org/solar-wind-nuclear-
| amazingly-low...
|
| And as mentioned earlier, fuels and industrial processes
| are where hydrogen comes into play: nuclear can produce
| hydrogen without C02 emissions through thermal generation.
| derriz wrote:
| You're ignoring a parallel development - the
| electrification of transport, industry and home
| heating/cooking. These sources constitute the majority of
| the rest of the co2 emitted.
|
| In combination with decarbonizing electricity production,
| this provides a multiplier effect.
| salamandars wrote:
| Could hydrogen electrolysis be viable as grid or building level
| energy storage? Round trip efficiency is bad of course, but I
| (naively) wonder if it wouldn't have a lot of the downsides fuel
| cells have for vehicles?
|
| You could bury a huge volume of tanks beneath new buildings and
| store the gas at a lower pressure than we see in hydrogen car
| tanks - wouldn't that make the whole system simpler and more
| economical?
| lancemurdock wrote:
| or we could just go nuclear
| mullingitover wrote:
| Not or, _and_.
|
| The only way hydrogen even makes sense is if you build so much
| nuclear power that your baseline generation is peak electricity
| usage, and you use the extra generating capacity during low
| demand times to split water.
| dTal wrote:
| Hydrogen is a stupid fuel. There, I said it.
|
| It's hard to store. It leaks away. It has poor energy density by
| volume (and much of the energy simply goes to compress the damn
| stuff) - only 3x li-ion, for your trouble. It has a crappy round-
| trip efficiency - only 50% for water -> electrolysis -> fuel
| cell. It's just a shitty battery.
|
| The only thing it's got going for it is that it's a way of
| greenwashing fossil fuels.
| thescriptkiddie wrote:
| Any idea about the round trip efficiency for other synthetic
| fuels like methane or propane? It's probably awful but may be
| worth the increased density over hydrogen.
| abecedarius wrote:
| https://wimflyc.blogspot.com/2021/02/powerpaste-fuel-of-
| futu... sounds interesting.
| rootusrootus wrote:
| Or liquid fuels like gasoline or kerosene that don't just
| boil off if you don't keep them compressed. I'd like to see
| that analysis.
| dTal wrote:
| You can synthesize gasoline, for that matter. You can't
| really do much better than that for a liquid fuel. I'm
| surprised there's not more of a market for "green gasoline".
| It's not _that_ hard to make.
| cogman10 wrote:
| IIRC, wasn't the price point for a bio-gas (made from
| atmospheric CO2) something like $4/gallon?
| dTal wrote:
| If that's true then it's revolutionary. I'm sure that
| price point makes Americans clutch their pearls, but in
| Europe gas already costs a lot more than that.
| cogman10 wrote:
| This article [1] says the cost point is closer to $34 per
| gallon (back in 2009).
|
| [1] https://www.greentechmedia.com/articles/read/algae-
| biodiesel...
| trhway wrote:
| Musk/SpaceX is most probably working on efficient production
| of methane using water, CO2 and electricity for Mars
| refueling, and one can wonder whether it can get downstream-
| ed into the Earth economy giving Musk's energy related
| (solar/storage/etc.) business here.
| unpolloloco wrote:
| It's not a stupid fuel in cases where you need massive amounts
| of energy and can't spare the weight... Like rockets and...
| rockets
| cogman10 wrote:
| Maybe airplanes and boats?
| dTal wrote:
| Yes, I concede it's a good engineering solution there.
| Especially when you also need water!
| amluto wrote:
| If you're burning hydrogen to power a rocket, you don't get
| to keep the exhaust. If, on the other hand, you use
| hydrogen and oxygen to power a fuel cell, keep the water,
| and use the power output to power an ion thruster or
| similar device, I suspect you end up with worse overall
| results than simply using a rocket and carrying some water.
| Gwypaas wrote:
| Not even rockets. Lose too much from the low density leading
| to a larger structure and isolation required. Meaning worse
| performance than the pure numbers would imply. Not to mention
| cost of handling it.
|
| Case in point, SpaceX going larger rocket with less efficient
| kerosene first and now methane to increase efficiency and
| reduce soot, while still keeping everything simpler than
| hydrogen.
| unchocked wrote:
| Yet it's absolutely required for synthesizing hydrocarbons from
| CO2 so, there's that.
|
| I mean, pick any fuel you want, their utility as stores of
| energy are all based on hydrogen content. So we're going to
| kick the fossil habit and still have fuel of _any_ sort, we're
| going to have to learn to produce and utilize hydrogen at
| scale.
|
| Grey and blue hydrogen are transition fuels. They build a
| market for green hydrogen to fill. It's going to be a little
| messy along the way.
| Dylan16807 wrote:
| Using hydrogen as an ingredient is not at all the same as
| using it as a fuel.
|
| Plus you don't need hydrogen molecules to synthesize
| hydrocarbons, and when people say hydrogen they mean
| molecules.
| xyzzyz wrote:
| > I mean, pick any fuel you want, their utility as stores of
| energy are all based on hydrogen content.
|
| OK, I pick black coal. No hydrogen content. What do I win?
| j_walter wrote:
| Actually it does have hydrogen...
|
| https://en.wikipedia.org/wiki/Bituminous_coal >The carbon
| content of bituminous coal is around 45-86%;[1] the rest is
| composed of water, air, hydrogen, and sulfur, which have
| not been driven off from the macerals.
| joecool1029 wrote:
| >Actually it does have hydrogen...
|
| Shitty coals like lignite and bituminous coal do. The
| real chad coal, anthracite, is up to 98% carbon.[1]
|
| [1]https://en.wikipedia.org/wiki/Anthracite
| dTal wrote:
| Sure, but when people say "hydrogen fuel" they usually mean
| pure H2. Trouble is, those carbon atoms everyone's so keen to
| get rid of are _damn_ useful, chemically speaking. I actually
| think there 's a lot more mileage in synthesizing
| hydrocarbons from biowaste. There's nothing inherently wrong
| with burning hydrocarbons - the problem is that we're lazily
| digging historical supplies out of the ground, instead of
| keeping the carbon cycle closed.
|
| Really, we should just put massive tax levies on fossil fuel
| extraction operations and call it a day. The market will sort
| the rest out.
| the_third_wave wrote:
| > There's nothing inherently wrong with burning
| hydrocarbons
|
| ...if and when you burn them with pure oxygen like done in
| rockets. Mostly they're burnt using using atmospheric
| oxygen though, leading to the production of nitrogen oxides
| (NOx) which come with their own problems [1]. It is
| possible to reduce the emission of these gases [2] at the
| cost of increased complexity and cost.
|
| [1] https://en.wikipedia.org/wiki/NOx#Health_and_environmen
| t_eff...
|
| [2] https://en.wikipedia.org/wiki/NOx#Regulation_and_emissi
| on_co...
| HWR_14 wrote:
| 50% round-trip efficiency and 3x the density of li-ion sounds
| pretty good, actually. Assuming your efficiency number is the
| entire cost of water -> compressed H2.
| dTal wrote:
| I'm not an expert in fuel cell efficiency, I'd read that
| number somewhere and a quick google confirms it:
| https://www.sciencedirect.com/topics/engineering/round-
| trip-...
|
| The energy density situation looks less attractive when you
| include the beefy 350-bar storage tanks, and the fuel cell
| itself. A battery just has two wires sticking out and that's
| it.
| jfim wrote:
| > A battery just has two wires sticking out and that's it.
|
| What about thermal management, the outer shell that can
| hold the battery cells and modules, and the battery
| management system?
| DaiPlusPlus wrote:
| Toyota's hydrogen tanks looked promising: 300mi range and 3
| minute refill time. It's disappointing it never went
| anywhere.
| neaanopri wrote:
| Combination of needing lots of infrastructure, and lack of
| political will.
|
| If US decided that instead of waiting for green tech to
| emerge, we would just simply stop burning fossil fuels and
| revert to an Amish standard of living until clean fuels are
| developed, we could have converted to Hydrogen already
| jxidjhdhdhdhfhf wrote:
| That or violent overthrow.
| behringer wrote:
| That's what's coming now.
| s5300 wrote:
| >It's disappointing it never went anywhere.
|
| There's probably a sound reason for that
| Tade0 wrote:
| It's 3 minutes assuming the fuelling station is at peak
| pressure - 700 bars. After the first fill up it needs
| several minutes to pressurize. Also such a facility costs
| at least $1mln and is unlikely to ever get much cheaper.
| AnimalMuppet wrote:
| > Also such a facility costs at least $1mln and is
| unlikely to ever get much cheaper.
|
| How much does a conventional gas station cost? I would
| expect several hundred thousand, at least.
| Retric wrote:
| A more relevant question is how much does a single gas
| pump or EV charging station cost. A gas station can
| easily have a dozen pumps for ~500k.
| cma wrote:
| Hydrogen tanks can also have multiple outlets (I get that
| they are more expensive than gas outlets, but the tank is
| presumably a large part of the hydrogen station cost).
| rootusrootus wrote:
| We really aren't that far from a plausible charging setup
| that can do 300 miles in 10 minutes. And that would be
| perfectly adequate. The infrastructure to support it would
| certainly be less difficult than trying to get hydrogen
| available everywhere.
| iainmerrick wrote:
| That's not adequate at all! The lines at gas stations
| would be massive. Charging via electric at home or in a
| parking spot seems a lot more convenient, even if it
| takes a few hours.
| shiftpgdn wrote:
| I feel like what a lot of people miss is that with an EV
| if you have a garage or dedicated parking spot you're
| leaving home with a "full tank" every single day. You
| only need to use a public charger if you're on a road
| trip.
| bbv-if wrote:
| That is the big 'if' for the majority of population in
| European cities. Pretty convenient for suburbs though.
| belorn wrote:
| Green hydrogen is the only realistic alternative to nuclear in
| areas which rely on wind power for renewable energy. Li-ion
| batteries can not economically create weeks long capacity of
| stored energy with a charge cycle of a few times a year. Wind
| does not have a day cycle as solar has.
|
| What green hydrogen need to do is become economical, and to my
| knowledge it is even more expensive per w/h then nuclear is.
| ars wrote:
| Methane is a better fuel for that than hydrogen, you can make
| it from air plus energy (although not easily - there's not
| enough CO2 in the air for that). Or, more practically, coal
| and water and energy.
| Hermitian909 wrote:
| For context, I'm a software developer who works with a _lot_
| of battery researchers.
|
| My understanding from them is that while Li-ion batteries
| cannot create weeks long capacity, rust batteries may be able
| to in the future.
|
| Check out Form Energy[0] for an early version of this,
| they're claiming ~100 hours of storage right now and if
| they're right about the science and can manage the
| engineering it could grow past a month. These batteries are
| challenging to run, a bit like a mini-chemical plant, but
| they do actually seem plausible.
|
| (No personal association with the company, some of my
| coworkers know the founders though)
|
| [0] https://formenergy.com/
| the8472 wrote:
| "only realistic alternative" isn't quite right since it's one
| of several grid-scale storage options none of which have yet
| proven themselves to be economical.
| ipspam wrote:
| Am I correct in assuming that energy use, period, is the problem?
|
| I would love to see how many KWH per person on the entire planet
| are generated every year by legit clean sources.
|
| Solving global warming = destroying life as we know it.
| spfzero wrote:
| No, because pollution (CO2, etc.) is the problem. Energy use
| would be irrelevant if it did not harm the environment.
| dragonwriter wrote:
| > Am I correct in assuming that energy use, period, is the
| problem?
|
| No, greenhouse gas emissions are the problem.
| megaman821 wrote:
| No, the Earth reflects more waste energy back into space in a
| few minutes than we use all day. Nearly unlimited renewable
| energy is available with today's technology but there are
| political and economic problems to solve first before that can
| become a reality.
| dTal wrote:
| No, you aren't correct. Most energy, globally, is indeed
| generated in ways that are not environmentally friendly - but
| that's not an axiom. It's entirely possible to build a house
| with all the modern conveniences that's not even connected to
| the power grid. Solar packs a surprising punch - a panel 2.5m
| square, in full sunlight, can run a microwave.
| jacquesm wrote:
| You can't really compare hydrogen with gas and coal. Gas and goal
| are (fossil) fuels, hydrogen is _a battery_ , or more accurately,
| at best an energy storage medium. Yes, you can use it for
| rockets, but you first have to separate it out from water using
| the same energy that later oxidization will return.
| analog31 wrote:
| Right now the cheapest source of hydrogen is producing it from
| gas and coal. Using it as a portable storage medium for green
| energy is still the pot of gold at the end of the rainbow.
| jacquesm wrote:
| Yes, but then really coal and probably either oil or natural
| gas are the fuels. Hydrogen is then an intermediate product,
| a bit like running your electric car on electricity made with
| a coal or a gas plant. The real fuel is coal or gas, not
| hydrogen.
| xnx wrote:
| Sounds like the ethanol of hydrogen.
| Florin_Andrei wrote:
| > _The vast majority of hydrogen (96%) is generated from fossil
| fuels, particularly from steam methane reforming (SMR) of natural
| gas but also from coal gasification._
|
| That's the problem, right there. It's hard to make those
| processes clean.
|
| We need a different process for hydrogen. Or stick to 100%
| electric instead.
| justaguy88 wrote:
| Hopefully wind/solar electric
| Robotbeat wrote:
| Yeah, anything but green hydrogen is just a complicated way of
| keeping the status quo, fossil fuel oriented system in place.
| There might be a small benefit to global warming (not found in
| this paper), but it's using up a finite amount of capture space.
|
| I do think we can probably get a lot better at capturing methane
| leaks, though. It's low hanging fruit.
|
| ...and even green hydrogen is much less efficient for heating and
| propulsion than heat pumps and battery/direct-electric.
| Especially in the early days when we are still working to
| increase the energy payback of renewables, this is not helpful!
| We need high efficiency usage of electricity. Making hydrogen is
| something you shouldn't do unless there aren't alternatives.
|
| We don't need hydrogen for heat, for transport, or for storage
| (possible exception being seasonal storage once you've surpassed
| 95% clean electricity... no point in hydrogen storage if you're
| still only a 50% clean grid). Hydrogen trucks are more expensive
| (to buy and ESPECIALLY a to operate) and not necessarily any more
| range (possible exception if you use liquid hydrogen). We do use
| hydrogen industrially for all ammonia production and (believe it
| or not) all new iron ore reduction plants (DRI/HBI plants) in the
| US (they use syngas usually, a mix of hydrogen and CO, usually
| made from natural gas but it could be made almost entirely with
| hydrogen), so it's not like we won't find a use for the hydrogen
| we might produce from excess renewable power.
| shalmanese wrote:
| Well, also that green hydrogen is a drop in replacement for
| blue/grey hydrogen. The hard part is building all the
| infrastructure. If we can build the infrastructure on blue/grey
| and then gradually transition to green over time, it's an
| easier feat than waiting until we have economical green
| hydrogen before starting to build.
| vondur wrote:
| I would have hoped that the hydrogen needed for fuel would be
| produced by the electrolysis of water using solar/wind/nuclear.
| Anything else is kinda silly.
| iamgopal wrote:
| I think there is hope in to hydrogen that is produced as by
| product of carbon capture technology, especially green cement
| and lithium production via sea water.
| thescriptkiddie wrote:
| Is there a theoretical carbon capture technology with
| hydrogen as byproduct? It seems to me that if anything it
| would consume hydrogen.
| nanomonkey wrote:
| Gasification of woody biomass produces Carbon Monoxide,
| Hydrogen (a.k.a. syngas) and Biochar (Ash minerals and
| Carbon). If you bury the biochar then you are essentially
| reverse mining carbon. Biochar is stable in the soil for
| hundreds of years.
| dragonwriter wrote:
| > Is there a theoretical carbon capture technology with
| hydrogen as byproduct?
|
| Just from the elements involved, that seems possible, but
| only if the GHG you are capturing specifically is
| _methane_.
| Manuel_D wrote:
| Alternatively thermochecmical production [1] with thermal
| energy provided by nuclear. But yes, presently over 95% of
| hydrogen is produced through steam reformation which consists
| of knocking the hydrogen out of methane and producing C02 and
| hydrogen (CH4 + O2 -> C02 + 2H2).
|
| 1. https://en.wikipedia.org/wiki/Thermochemical_cycle
| wizzwizz4 wrote:
| That's "green hydrogen", and it does happen - but it's more
| expensive, because we already have the fossil infrastructure.
| ThinkBeat wrote:
| My ex wife worked at a large international airport. They
| converted their entire fleet of cars, trucks, into hydrogen.
|
| (Yes, it is inaccurate there were still some normal fossile fuel
| vehicle around).
|
| From her perspective it was great. No emissions at the airport.
|
| No waiting to charge the truck, filling it up was comparable to
| putting gas in the tank.
|
| The vehicle could run 24/7 as their old fossile fuel
| counterparts.
|
| I understand that the production of hydrogen may not be good at
| the moment, but I hope it changes.
|
| I would prefer to have a hydrogen car to a Li-ion battery, if and
| only if it became a majority platform.
|
| Every winter, tons of people want to go up to the mountains.
| Given it is in the middle of winter the weather can change and
| roads closed.
|
| Sometimes the wait can be several hours before the snow plows
| arrive and arrange slow column driving.
|
| It is easy for the snowplows or other rescue vehicle to provide
| diesel and petrol and in sone version of the future hydrogen.
|
| It is not easy to charge a lot of electrical cars. I an sure you
| can make trucks with huge batteries, but it will still take
| considerable time to charge them all, in if it is done in
| parallell. One truck charging 30 cars in 30 minutes or however
| long they will need to reach a level where they can run the heat
| at max and drive behind the plow.
|
| Until they figure all this out, I feel safest with a plug-in
| hybrid.
| meristohm wrote:
| While it doesn't make anyone rich, a culture/lifestyle shift
| towards doing more with our bodies, instead of converting other
| energy so that we have more free time (in which to convert even
| more resources), might enrich us in other metrics than money.
|
| What will it take for more people to meet their exercise needs
| without having to make time to exercise?
|
| Barring one or two funerals, I'm done with air travel, and long-
| distance travel in general; one small step for a man, and it
| could be giant if we agreed on regulation that limited the amount
| of fuel we collectively convert.
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