- 1 'Types' of Hydrogen
- 2 Blue Hydrogen Briefing
- 3 Water Consumption
- 4 Falling Costs
- 5 Permeation Rates
- 6 Types of Hydrogen Storage Tanks
- 7 Conferences
- 8 Some Safety Discussions
- 9 Electrolysis of Sea Water
- 10 Worldwide Hydrogen Production
- 11 Worldwide Oxygen Production
- 12 US Hydrogen Demand
- 13 US Hydrogen Electricity Demand
- 14 Reduced GHG emissions
- 15 Save Buckets of Water
- 16 What's Not to Like about Renewable Hydrogen?
- 17 Summery
- 18 Abbreviations
'Types' of Hydrogen
Hydrogen itself is a colorless, odorless gas. It is the most abundant element in the universe and forms water when burned or combined with oxygen.
Hydrogen 'colors' disguises the impact GHG emissions have with hydrogen production from different manufacturing processes. The following 'definitions' are in use:
- Green - hydrogen made from renewable sources, essentially the electrolytical processes, using water and renewable energy such as wind and solar.
- Blue - gray hydrogen with carbon capture and sequestration processing added.
- Gray - hydrogen made from the methane in natural gas and other oil and gas products, mostly using Steam Methane Reforming.
- Brown - hydrogen made from coal mostly via Coal Gasification.
'Clean' hydrogen is an ambiguous phase meant to refer to any hydrogen production that has a net-zero or better GHG emissions 'footprint'.
Renewable hydrogen is made from renewable energy and water.
Fossil-fuel hydrogen or fossil-hydrogen is made from methane in natural gas and other oil and gas products.
Note until all manufacturing, storage and transportation industries and so on have been decarbonized all hydrogen production will have some carbon footprint.
Blue Hydrogen Briefing
A Blue Hydrogen Briefing by Tom Solomon of 350 New Mexico was presented to a meeting of the NMSEA on November 16, 2021. It is now available on YouTube. The talk itself starts at the 5:30 mark, with Q&A starting at minute 47.
Also the slide deck now includes a new slide on p18 with now a second scientific study warning about the climate impacts of producing hydrogen from methane.
Here's a heavily referenced article from EnergyPost.eu on research into how much water will be needed in the production of hydrogen through electrolysis (green hydrogen). Some quotes from the summary:
"Assuming the world is using over 70EJ of electrolytic hydrogen by 2050, the water consumption will be about 25 bcm. That is relatively small compared with the global figure of 2,800 bcm for agriculture (the largest consumer), 800 bcm for industrial uses, and 470 bcm for municipal uses."
"the numbers suggests that water consumption shouldn’t be a major barrier for scaling up renewable hydrogen"
The same article reports that methane reforming uses a similar amount of water per kg H2 as electrolysis! There are life-cycle comparisons included too for five hydrogen pathways, e.c. wind->electricity->hydrogen
But, it says, the water has to be desalinated for electrolysis to avoid degradation of the electrolysis cells. And then, that water costs including treatment would only cost 2% of a best case total renewable cost of $2-3/kg H2. Fossil fuel hydrogen today is available at $1.80/kg H2, some current renewable numbers are up to $5/kg H2. Under the Biden Admin I believe the DOE has a target to get costs down to $1/kg H2.
Here's more info on falling green hydrogen costs that are closing in on fossil-fuel hydrogen costs.
Here's more info from the WHA (World Hydrogen Association?) on industrial hydrogen uses worldwide: 25% petroleum refining, 55% ammonia (thence to fertilizer), 10% methanol and 10% other that includes fuel cells, glass, electronics, medical, food and metallurgical uses. This is important because if the Oil & Gas industry stops selling fuels and while the petroleum refining segment goes away, there's still a big market for renewable H2.
Permeation rates of hydrogen in various storage configurations has been reported. During some safety investigations, researchers reported the following leakage rates:
"Based on the data provided by the manufacturers, the hydrogen permeation rates of the hydrogen storage vessels of vehicle A and B were approximately 2.35 mL/min and 1.80 mL/min, respectively."
One presumes the volumetric measures corresponded to standard temperature and pressure conditions (STP).
Hydrogen tanks in trains, boats, planes and cars are made of carbon fiber and run around 10,000 psi their NWP (normal working pressure) but designed for 25,000 psi. Apparently there are at least Type III and Type IV hydrogen storage tanks in use.
Meanwhile, at NWP and ambient temperature, ISO 19881 requires that the steady-state permeability of Type IV hydrogen storage tanks in the system should be less than 6 Ncm3/h/L. (see "Review of the Hydrogen Permeability of the Liner Material of Type IV On-Board Hydrogen Storage Tank".
The density of hydrogen at STP (68 degF 1 atm) is 0.08376 kg/m3. A typical(?) hydrogen vehicle gets 70 miles/kg H2, so a 300 mile range requires a tank capacity of 4.28 kg. A 10,000 psi hydrogen tank will be about 200 liters or 3-4 times the volume of gasoline tanks typically found in ICE cars. So such a tank to meet the ISO standard will lose hydrogen when fully pressurize at:
6 Ncm3/h/L * 200 L * 30 (days/mon) * 24 (hr/day) = 864,000 cm3/month
At a (STP) density of 0.08376 kg/m3 and with 1,000,000 cm3/m3, losses are:
864,000 * 0.08376 / 1,000,000 kg/mo = 0.0724 kg/mo equivalent to 1.3% of a 5.6 kg charge.
The 2mL/min rate of the A and B vehicles above and a 200L tank, equates to about 2 mL/min * 60 /200 = 0.6 Ncm3/h/L or 10x lower than the standard demands, making their tanks lose only 0.13% of a charge per month.
The Toyota Mirai 2022 has a Type IV tank capacity of 5.6 kg H2 spread over three tanks running at a pressure of 70MPa (10,150 psi).
Types of Hydrogen Storage Tanks
The hydrogen storage tanks used for high-pressure gaseous hydrogen storage can be roughly divided into five types:
- Type I: metallic pressure vessel,
- Type II: metallic liner hoop wrapped with CFRP
- Type III: metallic liner fully wrapped with CFRP
- Type IV: polymer liner fully wrapped with CFRP
- Type V: has 20% less weight than type IV, is made of composites without a liner
Then there are metal hydride storage systems for hydrogen and others that can be considered/developed.
The World Hydrogen 2022 Summit & Exhibition, the leading global platform dedicated to hydrogen industry advancement is produced by the Sustainable Energy Council (SEC) in partnership with the Province of Zuid-Holland, the City of Rotterdam and the Port of Rotterdam, World Hydrogen 2022 is the place to meet with government and private sector leaders to showcase, discuss, collaborate and do business, driving the hydrogen industry forward.
Some Safety Discussions
https://blog.ballard.com/hydrogen-safety-myths on hydrogen safety
Electrolysis of Sea Water
"A step closer to sustainable energy from seawater" article from phys.org Aug 2018 talks about a catalyst that reduces the amount of chlorine you might get when using seawater in electrolysis. Presumably brine (saltwater) would have the same problem. Properly captured and separated/managed, chlorine has the potential to be used in other products (chemicals such as bleach).
From Wikipedia on Chlorine:
"In industry, elemental chlorine is usually produced by the electrolysis of sodium chloride dissolved in water. This method, the chloralkali process industrialized in 1892, now provides most industrial chlorine gas. Along with chlorine, the method yields hydrogen gas and sodium hydroxide, which is the most valuable product."
From the article "China set to drive global chlorine capacity by 2024"
"The global chlorine capacity is poised to see moderate growth over the next five years, potentially increasing from 87.69 million tons per annum (Mtpa) in 2019 to 92.13 Mtpa in 2024, registering total growth of 5%"
The chlor-alkali process is electrolysis of sodium chloride solutions (e.g. brine) to produce hydrogen, chlorine and sodium hydroxide (the alkali bit). Stoichiometrically, for every molecule of chlorine produced there is one molecule of hydrogen produced. So 87.69 Mtpa of 2019 chlorine (atomic weight 35.45) should produce 87.69/35.45 = 2.47 Mtpa of hydrogen. Does the US really need anymore chlorine?
Worldwide Hydrogen Production
Meanwhile, (from a Nov 2012 article) 2019 total world production of pure hydrogen is 75 million metric tonnes. The same article reports:
"Electrolysis of water at ambient temperatures requires 50-55 kWh per kilogram of hydrogen produced* (hence 60% and potentially 70% efficient with improved catalysts)."
The power to make the world's 75 million tonnes of pure hydrogen via electrolysis is therefore 75,000,000,000 kg * 55 kWh/kg = 4,125,000 GWh.
"As of the end of 2020, the United States had 97,275 megawatts (MW) of installed photovoltaic and concentrated solar power capacity combined."
If all the US installed solar power operated for 2000 hr/yr, it would generate 2000 * 97,275 MWh = 194,550 GWh. That in turn could then make 4.7% of the world's supply of hydrogen, insufficient for US purposes. At $1.8/kg H2, the corresponding annual gross income would be $75,000,000,000 * 0.047 *1.8 = $6.345 billion/yr.
Worldwide Oxygen Production
When electrolyzing water for hydrogen it of course produces pure oxygen at the same time. Wikipedia reports the industrial production of oxygen via a number of processes was 100 Mtpa in 2003. The economic impact of renewable hydrogen and it's cogenerated oxygen very much needs to take this into account.
At $10/kg, the US' 41 Mtpa H2 comes with 41 * 16/2 Mtpa O2 = 328 Mtpa O2 which would on the face of it be worth $3,280 Billion/yr.
US Hydrogen Demand
Meanwhile US demand for hydrogen is forecast to quadruple to 41 Mtpa by 2050 meaning it must be about 10 Mtpa now. From the above, US solar power could produce about 3.525 Mtpa H2 (with no solar power going into the grid). If NM could meet that demand, the state could enjoy that gross income of $6.345 billion/yr. For comparison 2016 NM state revenues were $5.462 billion/yr (Ballotpedia). But there are lots of buts: we should back out hydrogen from chlorine production from the calcs, for example
US Hydrogen Electricity Demand
But there's more, according to Tom Solomon's (350NM) projections, for 100% energy production from renewables the US will need an installed base of 4,545 GW (by 2036) Operating at 2000 hr/yr that's 9,090,000 GWh, To meet the 2050 US demand for hydrogen of 41 Mtpa at 55 kWh/kg H2 then would require:
41,000,000,000 kg * 55 kWh/kg / 1,000,000 kWh/GWh = 2,255,000 GWh.
(But by 2050 may be we could do better than 55 kWh/kg H2 and 2000 hr/yr is 5.5hr/day 365 days a year. See Unbound Solar)
Using a 2000 hr/yr operation, this would require increasing the installed renewable energy base by 1,127.5 GW an increase of 24.8% over Tom's 2036 number. At $1.8/kg (current fossil hydrogen prices), 41 Mtpa h2 is worth $73.8 Billion/yr.
Reduced GHG emissions
But there's more. At 7 kg CO2/kg H2 on average for steam methane reforming (SMR), converting to renewables saves 41 * 7 = 287 million tons/yr of CO2 emissions and an unknown amount of leaked potent methane emissions, for which there may be some estimates.
Save Buckets of Water
41 Mtpa H2 will consume 41 * 18/2 Mtpa water = 369 Mtpa water. The water consumption of fracking in the Permian basin is estimated to generate 32 million barrels of produced water per day in 2025 (SFNM). In a year with say 10% downtime, that's 10.5 billion barrels/yr. With 42 US gals/barrel and a US gallon weighs 8.33 lb that's:
10.5 x 42 x 8.33 billion lb /yr = 3,673 billion lb water/yr
and a metric tonne is 2204.6 lb, so the Permian Basin produced water is 1,666 Mtpa or 4 and half times the water consumption needed for US hydrogen production via electrolysis, if it shuts down all fracking in just the Permian basin!
What's Not to Like about Renewable Hydrogen?
So the next questions might be: how much of the US hydrogen business can NM enjoy if we overbuild solar and wind, and how much excess power could we generate, convert to hydrogen and sell to the industrial users, let alone for energy storage and transportation? Then compare that to just selling the power. Is it quicker and cheaper to ship H2 in trucks or pipelines than wait forever (10+years) to build transmission lines to ship out the energy? And where do we locate all this infrastructure and what will be actual costs of construction etc.?
We definitely would like to make renewable (green) hydrogen to back out gray (fossil fuel) hydrogen
- green hydrogen is not a problem as far as water usage is concerned
- green hydrogen save tons of water if it stops having to frack for more methane
- green hydrogen in transportation does not have a leakage (permeation) problem
- green hydrogen is big business when phasing out gray hydrogen (SMR)
- green hydrogen will cut GHG emissions a lot.
- the power requirements to meet hydrogen demand may be only as much a 1/4 of total needs.
- building out a green hydrogen business in NM could go along way to meeting our state budgetary needs
- technological improvements in efficiencies and such make this picture improve all around.
bcm = billion cubic metres
CFRP = Carbon fiber reinforced plastic.
EJ = exajoules (1 EJ is about 947.8 trillion BTUs, or 278 thousand GWh)
ICE = Internal Combustion Engines
MPa = megaPascals (1 MPa = 145.04 psi)
Ncm3/h/L = Normal cubic centimeters per hour per liter (of storage capacity)