Synopsis: Focus on full sequestration and Abandon “blue hydrogen” landfill style capture and storage.
Researching the various ways of capturing carbon and storing it resulted in the conclusion that full sequestration of carbon is not only feasible, it is well proven, but can only when there is source of energy that does not itself create emissions.
Belief in the illusion of carbon sequestration using only energy from fossil fuels is belief in a form of perpetual motion. Yes, for those convinced that having found fossil fuels, it would be a complete waste to leave them in the ground, are desperate to believe anything that will allow continuing to use those fossil fuels.
The key to what works and what does not is considering that sequestration costs energy. Meeting the real cost of sequestration stops fossil fuels being cost competitive.
In the end, using fossil fuels to create “blue hydrogen” can’t both sequestrate all the emissions and then compete on price with green hydrogen, and e-fuels or fossil fuels cannot fund full capture and storage and then still compete on price with renewable energy. However, there are applications for E-Fuels where being price competitive is not necessary, and where E-Fuels can afford to be green. Plus, the same process used produce E-Fuels enables sustainable sequestration of carbon from CO2 to mitigate climate change.
All possible ways to capture and store carbon to reduce atmospheric CO2 can be divided into four categories, with the approach favoured by the fossil fuels industry being part of the least sustainable category, and what I refer to as “full sequestration” being proven in nature over billions of years, having produced all the fossil fuel in the world today, and also having transformed the Earth into the planet that sustains human life, .
This “full carbon sequestration”, or “direct air capturing carbon and recycling”, not only has been happening naturally for billions of years, it also now being scaled up as an industrial process at E-Fuel plants.
All fossil fuels were produced from carbon captured from CO2 in the air as shown be the green arrow. The carbon has been being separated from oxygen then becoming buried for billions of years. Without this carbon sequestration, there would be no fossil fuels, nor oxygen in the air.
The catch is carbon sequestration consumes energy. A lot of energy. In fact, sustainable sequestration requires more energy than can be obtained from the fuel produced.
The energy requirement why this “full sequestration” is inconvenient for the fossil fuel industries that earns profits from selling energy rather than using the energy to limit the industries emissions.
When either burning fossil fuels in at a power plant or producing “blue hydrogen”, carbon capture and storage is capturing a percentage of carbon emitted by the process and storing as landfill using the least energy possible. In both situations are attempts to limit emissions from processes that by their nature create emissions in order to produce energy or hydrogen.
At fossil fuel power plants, the more energy used in sequestration, the more fossil fuel that must burned with its own emissions to and more emissions that must be sequestrated. Then there is the ‘blue hydrogen’ challenge, but it is worth fist looking the production of E-Fuels.
The “recycle” part of the full sequestration process is always need as that is the production of the e-fuel. The limitation is that process that while the recycle process clearly works, it requires energy. Trying to drive the process from fossil fuels would be being stuck in a loop of the diagram above and trying to go round and round. The rules of thermodynamics mean that not only is it impossible to gain energy form such a loop, but other than at absolute zero there will always be losses, so there would be less energy every cycle. Even if there were zero losses, each cycle would have no energy left over for other uses.
So, E-Fuels are an example of synthetic full sequestration with oxygen being separated and returned to the air, as otherwise the result would not be a fuel that could be burned to produce energy. E-Fuels are also by their very nature made from renewable energy. Plus, E-Fuels are only viable when the carbon source is by air capture, which means E-Fuel production must pass every test to qualify as full sequestration. The production of E-Fuels is full synthetic sequestration, and then the production would lower global CO2 levels.
In contrast, “blue hydrogen” presents the worst possible scenario for sequestration. Firstly, relies on source capture because the steam reforming process is itself generating the emissions that must be captured, and source capture never capture 100% of emissions, and never itself be “net zero“. Even more significantly, fully sequestrating those emissions is not economically viable for blue hydrogen projects.
Then there is the prospect that genuinely carbon neutral green hydrogen projects, and even E-Fuel projects may, through the use bonus electricity, become not only carbon neutral but also less expensive than blue hydrogen, and as batteries improve, opportunities for hydrogen for energy are closing.
So why is anyone bothering with sub optimal carbon capture and storage and “blue hydrogen” projects?
- There is not enough renewable energy production to meet world requirements as of 2023.
- Fossil fuel companies see leaving fossil fuels in the ground as a tragic waste of potential profits and what they see as an invaluable resource.
Firstly, until the world has enough renewable energy, fossil fuels are needed to ensure many of the most valuable industries retain the valuations. This gives those who are dependent on fossil fuel revenues motivation to do whatever possible to delay the time when the world can produce enough renewable energy.
Secondly, there is commitment to the belief that there just must be a way to extract value from fossil fuel reserves, or at least a way to justify the asset value of those reserves.
There are two different incentives for funding projects with the potential to find ongoing applications for fossil fuels. In addition to the obvious to goal of generating revenues, there is the goal of finding possibilities that allow maintaining continual high asset values for fossil fuel reserves. Neither company boards, upper management, or even governments with taxation revenue dependant or fuel companies been seen as profitable want to see a writing down of those potentially stranded assets.
Projects such a blue hydrogen have many barriers that avoid the reality check faced by technologies such as E-Fuels, and that may assist protect asset values while the barriers remain.
Every day the assets values can be protected, billions in profits continue to flow.
Background: Carbon sequestration.
Sequestration has been happening naturally for billions of years.
Natural sequestration that has not only managed to compensate all of the CO2 breathed out by every animal in the history of the Earth, and also kept global warming in check for billions of years, requires a lot of energy. Green energy. The main process is called photosynthesis and is solar powered. Plants combine solar energy, CO2 and water to produce O2 oxygen for the air and “fuel”.
In fact, this natural sequestration process leads to creating fossil fuels, and it is us digging up these fuels and burning them that is undoing all that work.
It turns out that this sequestration has not only prevented temperatures on Earth, but it was also responsible for transforming the planet into a place where life on land is possible and humans can live, which means undoing natural sequestration may not be advisable.
Why do were need sequestration beyond what happens naturally?
Burning fossil fuels is the exact reverse of full carbon sequestration. It is extracting the buried sequestrated carbon from the Earth and combining with oxygen from the air to produce energy, CO2, and usually some water. By reversing that natural process, we unlock energy received on Earth and locked away with sequestrated carbon over billions of years.
As we are not quite ready to stop A proposed alternative to stopping digging up the fuels and burning them is for humans to do own sequestration. The goal is to give natural sequestration to compensate for our burning of fossil fuels.
So how can humans now do our own sequestration?
The problem is the storage step, and as with most waste, there are two ways to deal with CO2 emissions:
- full sequestration: recycling’ by breaking down the CO2 to return oxygen to the air and restoring the original ingredients for potential reuse.
- Sustainable sequestration in like nature where oxygen is returned to the atmosphere.
- ‘landfill‘ sequestration: directly burying CO2 waste which is in some ways even more problematic to store than nuclear waste.
- Unsustainable sequestration that lowers atmospheric oxygen
The good news is that it is possible for humans to come to the aid of plants in provide additional “renewable” sequestration with recycling with oxygen separated and returned to the atmosphere and carbon stored underground.
We can do this recycling process synthetically geologically or biologically, but to consume CO2, you need to follow the example of plants and use ‘green’ energy that does not produce even more CO2 than is being consumed. Of course, as Porsche plans, you then use the synthetic eFuel, you are back to square one. While sequestration offsetting other emissions would require leaving the produce the synthetic fuel produced in the ground, the aim with biofuels carbon neutrality for the biofuel and not offsetting other emissions.
The bad news is that the recycling approach is impossible when using fossil fuels for energy, as in that case, burning fossil fuel as an energy source is producing more additional new CO2 than is being recycled. It is inherently like running on a treadmill but not being able to keep up.
Combining with oxygen with fossil fuels, also known as “combustion”, does produce energy, but can never produce more the energy that is required to again separate the oxygen from the fossil fuels as required for “recycling” and sustainable sequestration.
In theory, we could offset the emissions from burning fossil fuels with sufficient renewable energy powered “recycling” sequestrating as much CO2 as we emit by burning fossil fuels, but as in practice this requires being able to generate twice much renewable energy as we are obtained from burning fossil fuels.
Sequestration can work, but scaling trying to sequestration in combination with burning fossil fuels is like running on a treadmill: its ok as long as you don’t need to go anywhere. It can work for small scale project to allow boutique use of fossil e-Fuel projects, but the idea it can counter continued use of fossil fuels is an illusion designed to deceive.
Then we get to “blue hydrogen”, which is the plan to replace each unit of natural gas with hydrogen made from two units of natural gas, on the basis we can get so good at carbon capture and storage we can afford to capture twice the emissions. In the end, this can only work in very special small-scale cases for people won’t be prepared to pay 3x the price for energy, just so it can be energy for fossil fuels.
Carbon capture and storage may not mean what you would think.
When the terminology “Carbon Capture and Storage” is used, unless otherwise clarified, what is being discussed is not the literal meaning of capturing and storing carbon, but rather only one specific process used by the fossil fuel industry. This is the approach of “point source capture” and then “landfill storage”, which is only of four possible alternatives for how capturing and storing carbon could attempted, with the four possibilities being:
- direct air capture
- direct air capture and recycle the materials.
- direct air capture and store as landfill.
- point source capture
- point source capture and recycle the materials.
- point source capture and store as landfill.
This use of the label “carbon capture and storage” to specifically mean only “point source carbon capture and storage as landfill” can help a perhaps intentionally confusing and well-funded marketing campaign, and it can lead to people mistakenly thinking results from the more successful “direct air capture” projects that extract CO2 from the air, or data on the natural processes that also provide “direct air capture ” and have been working for billions of years, also apply to the “point source capture” projects promoted by the fossil fuel companies but which have not yet proven to be successful in countering fossil fuel emissions.
Direct air capture.
Direct air capture simply means capturing CO2 from the air, with various methods for direct air capture described on the Wikipedia page, but there is little reason for capturing the CO2 from the air without then storing it, and there this page has some descriptions without the commercial bias that is very often present, and this page gives a useful perspective.
In contrast to “point source capture” which is basically trying to clean up instead of just leaving a mess, direct air capture is not necessarily focused on use of the least energy and cost while creating the appearance of achievement.
Direct air capture and recycle the materials: Full sequestration like nature.
This is extracting CO2 from the air, and restoring things to how they were before the CO2 was added to the air.
The limitation of the “recycle” process is that it requires at least the same amount of energy to put the O2 back in the air, as the energy obtained by burning fossil fuels or animals breathing or whatever took O2 from the air.
What is required is basically a process equivalent to photosynthesis as used in plants, which captures from the air CO2 which could have been converted into CO2 by combustion or fire, or by respiration (e.g. an animals breathing), and then restores the oxygen back into the air as O2 and embeds the carbon in molecules that prevent the carbon being able to simply escape back to the air.
Without this type of direct air capture occurring in nature, not only would over half a billion of years of animal breathing CO2 have created a greenhouse problem even before humans existed, but we never would have even had atmosphere with oxygen we humans need in the first place.
Direct air capture and recycle can work, even happens naturally, and could be assisted by humans.
The entire problem is not that there is no capture and storage of carbon happening, the problem is that natural process cannot keep up with not only 8 billion humans breathing, but a significant proportion of those human being responsible for the burning of fossil fuels, creating a much higher rate of CO2 needing to be sequestrated to maintain balance than ever before.
Initiatives include carbon-neutral fuels and generally all fall under one of the categories listed in this article:
Direct Air Carbon Capture and Sequestration: How It Works and How It Could Contribute to Climate-Change Mitigation
Direct air capture and store as landfill.
This is the process of extracting CO2 from the air and simply storing the CO2 somewhere.
The label “landfill” is my own label, but I feel it is adequately descriptive.
Obviously, the risk is the CO2 will simply find its way back into the atmosphere, but as an emergency measure it could play a useful role in mitigation strategies.
Plus, the process is not fully sustainable, as the O2 is not restored to the air. If this was done over the long-term, oxygen levels would fall as digging up fossil fuels burning them and then storing the ingredients with the oxygen in the ground is reversing the exact process that put the oxygen in the air in the first place, and humans are very sensitive to oxygen levels.
A danger is that this “stick the CO2 in the ground somewhere” approach could be misleadingly promoted as enabling continuing the burning of fossil fuels, which would effectively create a time bomb.
Sort of like sweeping the dust under a rug, there is a limit.
At least while plutonium-239 as the longest life nuclear waste has a half-life of 24,000 years, it does not last forever like CO2. Plus, the amount of nuclear waste produced for the same amount of energy is over thousands of times less than the amount of CO2 from burning fossil fuels.
Point source capture: Limiting the emissions that escape.
This could be seen as polluters cleaning up their own mess, if only they could meet the cost.
Point source capture is trying to capture emissions as they happen at the location where the emissions happen.
Clearly, this is not practical for point source capture at all cars, planes, boats or gas heaters and stoves at homes. What could be possible is point source capture at locations such as gas or coal power plants, cement factories, or blue hydrogen plants.
Interestingly, as shown in the photograph at the header of this page, there seem to be many fossil fuel structures where flames are permanently present, creating emissions with no clear benefit. Clearly, there is a long way to go before all emissions could be captured, capturing all emissions is very far away.
So what happens to emissions captured at the source?
Point source capture and recycle the materials.
The limitation of the “recycle” process is that it requires at least the same amount of energy to put the O2 back in the air, as the energy obtained by burning fossil fuels or animals breathing or whatever took O2 from the air.As stated above.
This limitation means:
- Production of blue hydrogen, as explained below, becomes more expensive than green hydrogen and pointless if there is intent to recycle and store the recycled ‘ the emissions.
- For fossil fuel power plants to fully “recycle” emissions and restore O2 taken from the air in the generation of CO2, back into the air allowing storage of the carbon alone, would use up more than all of the energy before having any energy to then generate electrical power.
Applications that use fossil fuels an ingredient, but use clean emission free renewable sources for energy, could in theory capture emissions at the source, but generally, as with cement, there are better ways to reduce emissions.
So, recycle and store the carbon alone has no relevance for blue hydrogen, or for fossil fuel power plants, and is not in use in any significant way for any other current applications.
Point source capture and store as landfill: the classic “carbon capture and storage”.
As covered right at the start of this section, the words “Carbon Capture and Storage” have been somewhat appropriated by the fossil fuel industry to without other explanation be taken as meaning “point source carbon capture storage as CO2” which I describe as storage as landfill.
This indicates that to the fossil fuel industry, this is what it is all about. This is the great hope for a future.
But the future is neither zero emissions nor otherwise sustainable.
Point source capture means there are emissions, and it is never that 100% of emissions would be captured. Even if 100% of emissions were captured, it would still never be sustainable to store CO2. As well as the “landfill” limitations discussed previously, the fact that oxygen from the air is being stored with carbon means that eventually oxygen levels in the atmosphere would fall, and humans are very sensitive to oxygen levels.
There is a substantial list of projects as recorded on Wikipedia, but as noted:
According to the Global CCS Institute, in 2020 there was about 40 million tons CO2 per year capacity of CCS in operation and 50 million tons per year in development. In contrast, the world emits about 38 billion tonnes of CO2 every year, so CCS captured about one thousandth of the 2020 CO2 emissions.Carbon capture and storage: example projects.
Even the figure quested as captured is regards as questionable and is largely self-reported rather than independently verified, and there can be discrepancies between data from resource companies, and what is measured by independently. For example:
The company told regulators it expected to emit about 133,330 tonnes of CO2 each year on average — but its most recent data shows it is emitting more than half a million tonnes.Coalmines pollute much more than their operators predicted when they sought approval
Overall, gas and coal fired power plants are having trouble being cost competitive with renewables even without the added cost of trying to sequestrate emissions, and the focus of the fossil fuel industry has been moving towards “how can we become suppliers of clean fuel?”, with hydrogen being seen as the market with the greatest potential for a replacement revenue stream.
There has been a lot of hype about hydrogen, and much of that attention began with the idea that as most hydrogen is currently made from natural gas, all it would take would be an improvement to the process of producing natural gas from hydrogen and a rebranding as “blue hydrogen” to create a new future for fossil fuels.
Combustion powered sequestration: Can blue h2 or e-fuels work?
The maths problem: the reasons renewable energy is always required.
Imaging building a robot that can run, put on a treadmill linked to generator to generate power.
Physics and the laws of thermodynamics make it clear it would never be possible to generate more electricity than is needed to power the robot.
The same applies combusting of carbon and oxygen to make CO2 and energy, losing a significant percentage of the energy as heat, and then expecting just some of the remaining energy to be sufficient to free the oxygen from the CO2.
Yet that exactly process would be a large part of any process attempting to use fossil fuels to power sequestration.
Renewable full sequestration is based on using energy to process emissions in order to recycle the missions back to fuel and oxygen.
Just as if the robot is powered independently of the generator, then that system could work, although make little sense as more power is required to power the robot than comes out of the generator, sequestration powered by renewables offset the emissions from fossil fuels, although you need more renewable power for the sequestration than will be provided from fossil fuels producing the quantity of emissions sequestrated.
The only options without use of additional energy is to either only sequestrate a small fraction of the emissions, partially rather than fully sequestrate emissions, or partially sequestrate a fraction of the emissions.
The shortcut to partially sequestrate emissions is to bury the CO2 intact, burying the oxygen sourced from the air together with the carbon, and hoping it never escapes. I label this shortcut as ‘landfill sequestration’, with the ‘short cut’ resulting in the failure to return oxygen to the air or to store the carbon securely. We are surprisingly dependant on keeping oxygen at current levels.
Even plastic in landfill breaks down eventually, but the only way to breakdown the CO2 is to complete the sequestration process, and otherwise it outlasts nuclear waste.
Synthetic e-Fuels: Yes, it can work but only at a premium price.
An e-fuel is a fuel produced by sequestration, using renewable energy as an energy source. This process is very much like the robot in the previous section, in that the process uses one energy source to produce another energy source.
As the e-fuel is produced by sequestration in the current time as the fuel is required, in contrast with fossil fuels produced millions or even billions of years in the past, there i balance between the sequestration of CO2 to produce the E-fuel and emission from burning the E-Fuel.
Clearly, like the robot example, more energy will be needed to make the e-fuel than will be provided by the e-fuel, so energy for sequestration must come from renewable energy, or the process would be only one of converting fossil fuel into less fossil fuel with the same omissions overall as from the original fossil fuel.
So why turn renewable energy directly into E-Fuel that will produce less energy? It only makes sense for applications when there is a reason to pay considerably more to have energy as e-fuel instead of as electrical energy. There are applications where E-Fuels may justify that additional cost.
Applications where e-fuels may justify the price premium: Porsches and perhaps also planes?
When because horses stopped being viable for transport, it did not mean everyone stopped riding horses. Just as in societies where horses are no longer used for transport it became the wealthy who own horses, in the future it could be that some societies some of the wealthy will pay extra to keep internal combustion engines:
Not to put too fine a point on it, the Porsche 911 is not going to be easy to convert to battery power. There are lots of well-heeled 911 owners who want to be able to drive their 911 Turbos in the Alps forever and a day.
So what if the fuel costs €10 a liter? They have the money and are willing to spend it so they can thrill to the sound of that magnificent boxer engine mounted way back over the rear wheels.E-Fuels, Renewable Natural Gas, & Carbon Capture Are Deep Fakes
While this is about nostalgia rather than logic as it is possible to make an EV Porsche with even better performance than a 911, there are applications such as aviation for which it is suggested e-fuels become a need rather than just a wish. The problem of replacing avgas for long-haul airliners is yet to be solved. While there are those working on hydrogen solutions the space required by hydrogen fuel tanks presents a major challenge. It is expected that one day batteries will be available with sufficient energy, and while ultimately that will be the most cost-effective solution that day has not yet arrived. Although e-fuels are expensive, they could enable today’s airliners to fly almost carbon neutral.
E-fuels: 5x more reasons sequestration really clean energy if they need 5x more power from the grid?
It has already been discussed how fossil fuel energy cannot be used to produce E-Fuels, but what has not been covered is what about a partly green power grid, as in most cases is used to charge EVs today?
A frequent argument raised against EVs is that without a fully green source of electricity from a grid without the need for fossil fuels, then EVs are also not fully green. The calculation is that while even on today’s grid, EVs reduce emissions slightly ICEV vehicles, the full benefit of driving EVs will be realised only as the grid gets greener.
E-Fuels requires about 5x the electrical energy per km driven as an EV, and 5x the emissions from a ‘dirty grid’ would result more full cycle emissions using E-Fuels than just staying with fossil fuels.
The 5x more electrical energy comes from even the proponents of E-Fuels saying their aim is to reach 50% efficiency in producing the E-Fuel, no combustion engine having overall efficiently of 50%, and then allowing for losses and transport. Estimates range from 5x more electrical energy to 10x more energy, with 5x being the most optimistic.
However, if e-Fuels are produced from 100% renewables, then only lifecycle pollution would be the nitrous oxides by-products of combustion engines provided.
The bottom line is fuel for an e-Fuel vehicle will always be considerably more expensive for an EV but provided the bulk of miles/kilometres driven are EV kilometres, then E-Fuel vehicles can be a key part of a valid strategy to end emissions.
Any claimed E-Fuels that don’t use air capture, would be a scam and will only increase emissions.
Just as the e-fuels would be responsible for even more emissions than those from burning regular fossil fuels if the electricity to make e-fuels was generated using fossil fuels, use of direct capture CO2 would also disqualify the fuel as genuine e-fuel as it would then be part of a process to produce rather than sequestrate emissions.
The possible points for source capture would a fossil fuel power plant or a blue hydrogen plant.
E-Fuels require an excess of green energy over and above what is needed for local electricity, and any location currently using fossil fuel power plants should first apply green energy to replace powering the grid, as that does more to reduce emission than producing e-fuels. Even with that consideration aside, e-fuels require sequestration of CO2 to balance combustion emissions, and CO2 generated at the site cannot count as sequestration of CO2.
As for captured “blue” hydrogen emissions, that would be even more clearly a scam with the e-fuel being no more than “greenwashed” (or “blue-washed”?) with energy sourced from fossil fuels, as is the case with “blue hydrogen”, in order to re-label the energy as e-fuel.
Are E-Fuels a problem-solving bridge technology, or a stall tactic or fraud?
A better option than blue hydrogen?
E-Fuels can solve some problems.
From a full lifecycle emission point of view, e-fuels are a sound idea whilst blue hydrogen is not. The one downside is that while unlike blue hydrogen e-fuels made using full sequestration don’t increase global emissions, they move create local emissions from at the point of use. While those emissions are offset by emissions reductions are the point of production, that does not help if the use environment is particularly sensitive to local emissions. The reverse of blue or grey hydrogen, where global emissions are much higher but there are at least no emissions at the point of use.
That covered, e-fuels are a viable solution to some net zero-emission challenges.
There are videos suggesting “E-Fuels won’t work”. The problem with any statement that something “doesn’t work”, is such a statement requires a common understanding of it means for that thing to “work” and any such common understanding is very often missing.
E-Fuels clearly can “work” in the sense that they have been:
- Demonstrated to be able to be produced by sequestration emissions.
- Proven to be workable in unmodified internal combustion engines.
Yet, E-Fuels do not work if “work” is taken to mean:
- Provide a cost-effective alternative to EVs for applications where EVs have proven suitable.
- Could allow the internal combustion engine to remain the “mainstay of motoring”.
For consumer vehicles, there are still a few problems EVs do not yet solve:
- Long distance towing.
- Long range travel over sandy or some other difficult types of terrain.
- Long haul aircraft.
The limitation of EVs is due to the energy density of current batteries, and while historically hydrogen has been a contender for solving problems stemming from energy density, even hydrogen itself has always had energy density problems relative to conventional fossil fuels. Batteries for EVs have lifted energy density almost 10x since 2008, and effectively eliminated the gap to hydrogen, but there is still an energy density gap to fossil fuels which can be addressed by e-Fuels.
The primary use for e-Fuels is for applications such as long-haul aircraft where the additional energy density requirements make e-Fuels worth extra cost.
Secondly, there may be scenarios, including military uses, where connection to a grid is not possible and local solar or wind generation impractical.
Then thirdly, E-Fuels uniquely proved a way to provide carbon neutral fuel the trailed edge of existing vehicles as EVs become more mainstream. EV advocates and particularly religious environmentalists push for a full transition to EVs in a short timeframe, but there are so many vehicles out that last longer than most people would expect there than replacing all of them in less than around 30 years could produce far more manufacturing emissions than are saved by early retirement of working vehicles.
Bridge technology or stall tactic?
Many express concerns that the promise of E-Fuels will be used as excuse to create loopholes that allow the continued use of fossil fuels, and thus delay steps to mitigate climate change.
The problem is that many countries plan to ban the sale of internal combustion engine vehicles by a 2030, 2035 or 2040, and if E-Fuels can be carbon neutral, they provide an argument that such a ban is not required.
Currently the EU plans to continue to allow combustion engine vehicles provided these vehicles include mechanisms to prevent operation using fossil fuels. Critics point out that such mechanisms could be bypassed as there is no technical reason an engine that can be powered by E-Fuels cannot also be powered by fossil fuels.
In practice, the only real solution is to ensure E-Fuels cost less than fossil fuels, so there is no incentive to substitute fossil-fuels.
There is no way that by 2030, 2035 or 2040 production of E-Fuels is going to reach a level that could power all the world’s vehicles unless the vast majority of those vehicles continue to transition to EVs.
E-Fuels provide no reason for the average vehicle owner to choose an ICEV over an EV once EVs reach price-parity, which is an unstoppable trend as batteries continue to improve in cost-performance. Wrights law means EVs will take over as the mainstream, and E-Fuels will not stop this happening.
The E-Fuel reality check for all synthetic fuels including hydrogen.
On one hand the market and ability to distribute E-Fuels being already in place is a huge advantage over alternatives such as hydrogen.
But on the other hand, this exposes the reality that even with a ready market and distribution not being a barrier, there is no queue customers asking to buy e-fuels even if there is a price premium. Hydrogen for energy has even greater pricing problems, but the argument is that once the vehicles create a market and the distribution is solved then everyone would happily move to using hydrogen instead of the less expensive to buy and run electric vehicles.
Energy density comparisons (energy per unit volume).
For most applications, it is all about energy density. While hydrogen even its most energy dense but difficult to handle liquid form which must be kept below approximately 20.28 Kelvin (-252.87 degrees Celsius or -423.17 degrees Fahrenheit) has an energy density of only 2.3kW/litre, while “Petrol and diesel carry around 8.8 and 10 kWh/litre, respectively.“
However, in an EV such as the Toyota Mirai, hydrogen is stored as a high-pressure gas at 700 bar, the temperatures for liquid hydrogen become impractical in a car.
The volumetric energy density of gaseous hydrogen at 700 bar is 42 kg/m³. Since 1 kg of hydrogen contains about 33.33 kWh of energy, the energy density of hydrogen at 700 bar in terms of kWh per litre would be (42/1000) * 33.33 = 1.4 kWh/L.
Then there are the tanks to consider. Not only are thick walls needed to contain the gas at this high pressure, but the tanks need to be cylinders which are far less space efficient in a vehicle than a rectangular prism would be, further reducing the practical energy density. of hydrogen in vehicles.
The hydrogen energy density still beats typical EV batteries in production in 2020 which 450Wh/litre, but EV batteries are expected to surpass the energy density of the Mirai before 2025, and as EVs are more efficient in using the energy onboard than hydrogen vehicles, as of 2023 several EVs similar in size to the Mirai already report superior range. Unlike hydrogen or fossil fuels where the chemistry is fixed and thus energy density cannot change, battery chemistries do change and improvements in energy density do happen.
However, there is a long way for batteries to go to every match fossil fuel for energy density, and the in-practice energy density of liquid fossil fuel vehicles is around 8x times of that of hydrogen vehicles. As of 2023 ICE vehicles with long range fuel tanks can have substantially greater range than any comparable EV or hydrogen vehicle.
While E-Fuels are already in use by all vehicles at Le Mans, Toyota has plans for a hydrogen powered internal combustion engine vehicle to be competitive with E-Fuel vehicles by 2026, but exactly why that achievement has significance is not really clear.
Specific energy (Energy per unit mass).
For are applications where the room required to store the fuel is less important than the weight of the fuel, and in these circumstances, hydrogen is unmatched. EV batteries have reached 0.5 kWh/kg, petrol and diesel around 12 kW/kg and hydrogen 33.3 kWh/kg.
So far, the only application I am aware of where that can make hydrogen the winner is in rocket fuel for space flight, where liquid hydrogen is viable due to there being no need for keep rockets in a fully fuelled state for any significant length of time.
What Is ‘Blue Hydrogen’ and why sequestration?
‘Blue’ Hydrogen from natural gas with partial landfill carbon sequestration.
Natural gas is predominantly CH4. One carbon atom and 4 hydrogen atoms.
Burning natural gas combines the carbon and hydrogen with oxygen, and results in one CO2 for every two 2H2O:
- CH4 +2O2 -> CO2 + 2H2O
Two water molecules for every one carbon dioxide molecule, from burning 14 parts by weight of carbon and 4 parts by weight of hydrogen, which means calculating heat of combustion reveals around half the energy comes from burning the carbon and the other half from burning the hydrogen. So, only half of the energy of natural gas can be gained from the hydrogen alone.
Around 95% of the hydrogen used commercially as of 2020 is sourced by extraction from fossil fuels with the majority being from natural gas by a process known as steam reforming.
Hydrogen produced by steam reforming is termed ‘grey hydrogen’ when the waste carbon monoxide is released to the atmosphere and ‘blue hydrogen’ when the carbon monoxide is (mostly) captured and stored geologically – see carbon capture and storage.Steam Reforming: Wikipedia.
Sequestration is to partially offset blue hydrogen production emissions.
Yes, unfortunately the carbon from the natural gas ends up as emissions rather than being captured directly, and it is not economically viable to ‘recycle’ the emissions and free the oxygen and store the carbon.
With the at least the same emissions and only around half the energy as could be obtained from the original natural gas, this makes ‘grey hydrogen’ a far more emissions intensive fuel than the original natural gas.
Why not blue hydrogen with source capture but recycle the emissions?
Blue hydrogen sequestration is forced to need sub-optimal source capture approach because the goal of the sequestration a modification of the emissions producing “grey hydrogen” production process.
But the biggest failure is the “landfill” storage rather than true full emissions sequestration. Unfortunately, that is also not able to be addressed.
As explained in “direct air capture and recycle“, the same amount energy is required to free the oxygen in order to return it to the air to the air as was generated by combustion. This happens to also be around the same amount of energy the hydrogen could provide as fuel, which means it would require all of the hydrogen to power freeing the oxygen from the emissions of the steam reforming, which would mean there was no hydrogen left. Another alternative would be to use renewable energy break up the emissions and free the oxygen, which would also be around the same amount or renewable energy needed to directly use the renewable energy to create the hydrogen using electrolysis!
Clearly, any potential cost saving from using “blue” rather than “green” hydrogen would be lost if the goal is to be fully sustainable and recycle the emissions instead of simply storing them.
Blue hydrogen as an interim solution?
In additions to the source capture caveat that not all emissions are captured, the caveats on landfill storage also apply: it is not sustainable over the long term.
However, blue hydrogen not being sustainable over the long term, would not prevent blue hydrogen having role as a transition fuel.
Even if emissions are only slightly reduced over emissions from grey hydrogen, until there is sufficient green hydrogen to meet demand for hydrogen, then there is some justification for blue hydrogen.
This justification does not extend to use of blue hydrogen for energy. One barrier to blue hydrogen as a transition fuel is that while emissions relative to natural gas are relocated to reforming plant, total emissions for the same energy increase. It seems the main reason the gas providers are happy to push blue hydrogen, is it has the potential into increase sales of natural gas.
Using grey hydrogen for energy results in more emissions per unit of energy than using natural gas, as the steam reforming process consumes part of the energy from the gas and there is no reduction in total emissions. However, use of grey hydrogen for energy does relocate where the missions occur and move emissions from the location needing the energy to the location of the steam reforming.
Even if blue hydrogen ever does successfully demonstrate a reduction in emissions over grey hydrogen, it would not create a significant change, and blue hydrogen is a long from proving any reduction in emissions over using natural gas for energy directly.
The main proposition for blue hydrogen as a transition fuel seems to focus on blue hydrogen providing a stop gap for green hydrogen, or a backup supply for green hydrogen in some future “hydrogen economy”.
Another problem is that it is far from certain such a “hydrogen economy” will ever exist.
Blue hydrogen means more emissions than burning natural gas.
Double the natural gas required, which is good for the natural gas business.
It is easy to see the appeal of the blue hydrogen to natural gas companies. Twice the natural gas is required to supply customers with the same energy. Customers will be paying more, but in theory they will now get “clean” energy”.
Provided other clean energy sources are not less expensive, then there is huge profit potential.
But unless emissions per unit gas are halved, emissions increase.
Gas mining results in leakage emissions, which are typically methane and can be regarded worse than CO2 emissions, and this doubles if twice the natural gas is mined. Then there is the carbon from the natural gas used for energy which ends up as CO2 or carbon monoxide (CO) with steam reforming and must be sequestrated, and again there is twice carbon for the same energy as there would be if just burning natural gas for energy.
Gas projects without use as ‘blue hydrogen’ target 80% sequestration, so if for example, 90% of the emissions were sequestrated in a blue hydrogen project were sequestrated, then it could be an even greater success than a successful gas sequestration project. However, no project is even close to 50% reduction required even ignoring the leakage emissions to be on par with just using natural gas.
Fortescue Metals Group boss Andrew Forrest has criticised “failed” carbon capture and storage technology and said the general population is entitled to feel sceptical about its use.
As the Morrison government moves to award carbon credits to fossil fuel projects that promise to capture and store carbon dioxide, the mining billionaire has told a podcast such projects had failed “19 out of 20 times”.Andrew Forrest criticises use of carbon capture and storage saying it fails ‘19 out of 20 times’
Considering how much is not captured, ?
There are already demonstrations of carbon capture and storage, with impressive sounding numbers as to the amount of carbon captured, and the environmental benefit of all that captured carbon.
However, it is essential to look beyond merely how much has been captured, and also consider how much has been emitted and not captured. Some project with impressive sounding numbers on capture, have emissions that are so excessive they more than eradicate any benefits from the capture.
It turns out that for some projects, even the capture itself may produce more emissions than what has been captured, with the capture and storage process resulting as many emissions as are captured.
The point is, while CO2 may indeed be captured, PR releases stating how much is captured rarely reveal the true story. The truth is all
The studies show, So Far, Capture and Storage For Blue Hydrogen Fails.
This is already well documented, even by me in the ‘blue hydrogen‘ section of the exploration “Hydrogen: Facts vs Myths“, and in the “Blue Hydrogen. The greatest fossil fuel scam in history?” video by “Just have a think”. Then there are studies of the effectiveness, or perhaps more accurately the ineffectiveness, of ‘Blue Hydrogen’ projects, as described in this video.
I may add more links, but the revelation that so far, ‘blue hydrogen’ results in more emissions than simply burning natural gas, is not new. Nor is it news that since more natural gas is consumed by shipping ‘blue hydrogen’ to consumers than just shipping natural gas, natural gas suppliers are very enthusiastic the opportunity.
- 2023 June 2nd : Updated and restructured text, fixed dated links and added synopsis.
- 2022 Feb 20th : Initial draft version to provide linkable content for another author.