LIQUID HYDROGEN - Lox

  HYDROGEN GAS PRICES FOR FUEL CELLS AS PART OF A SUSTAINABLE CIRCULAR ECONOMY

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DO TRY THIS IN THE SCHOOL LAB - Maybe not for home experimentation, but it is easy to split water to prove that hydrogen and oxygen gases are the constituents.

To exist as a liquid, H2 must be cooled below hydrogen's critical point of 33 K. However, for hydrogen to be in a fully liquid state without boiling at atmospheric pressure, it needs to be cooled to 20.28 K (−423.17 °F; −252.87 °C). One common method of obtaining liquid hydrogen involves a compressor resembling a jet engine in both appearance and principle. Liquid hydrogen is typically used as a concentrated form of hydrogen storage.

As with any gas, storing it as liquid takes less space than storing it as a gas at normal temperature and pressure. However, the liquid density is very low compared to other common fuels.

Once liquefied, it can be maintained as a liquid in pressurized and thermally insulated containers.

AUSTRALIA'S H2 PLANS - Looking to corner the market in hydrogen production, the Southern Australian government appears to be positioning itself as a supplier to Asian, most likely targeting Japan as the frontrunner in fuel cell powered cars. Deserts and windy coastal regions could produce mountains of hydrogen from solar and wind farms. But that electrical energy could be used far more effectively to power a zero carbon grid, hence make Australia cleaner quicker than looking to profits overseas. On the other hand, at least they are looking to the future, no matter how misguided. At least the technology will advance. We are not sure the fabled hydrogen economy is the answer to a truly Circular Economy.

Liquid hydrogen is a common liquid rocket fuel for rocketry applications — both NASA and the United States Air Force operate a large number of liquid hydrogen tanks with an individual capacity up to 3.8 million liters (1 million U.S. gallons). In most rocket engines fueled by liquid hydrogen, it first cools the nozzle and other parts before being mixed with the oxidizer — usually liquid oxygen (LOX) — and burned to produce water with traces of ozone and hydrogen peroxide. Practical H2–O2 rocket engines run fuel-rich so that the exhaust contains some unburned hydrogen. This reduces combustion chamber and nozzle erosion. It also reduces the molecular weight of the exhaust, which can actually increase specific impulse, despite the incomplete combustion.

Liquid hydrogen can be used as the fuel for an internal combustion engine or fuel cell. Various submarines (Type 212 submarine, Type 214 submarine) and concept hydrogen vehicles have been built using this form of hydrogen (DeepC, BMW H2R). Due to its similarity, builders can sometimes modify and share equipment with systems designed for liquefied natural gas (LNG). However, because of the lower volumetric energy, the hydrogen volumes needed for combustion are large. Unless direct injection is used, a severe gas-displacement effect also hampers maximum breathing and increases pumping losses.

The product of its combustion with oxygen alone is water vapor (although if its combustion is with oxygen and nitrogen it can form toxic chemicals), which can be cooled with some of the liquid hydrogen. Since water is often considered harmless to the environment, an engine burning it can be considered "zero emissions". In aviation, however, water vapor emitted in the atmosphere contributes to global warming (to a lesser extent than CO2). Liquid hydrogen also has a much higher specific energy than gasoline, natural gas, or diesel.

The density of liquid hydrogen is only 70.99 g/L (at 20 K), a relative density of just 0.07. Although the specific energy is more than twice that of other fuels, this gives it a remarkably low volumetric energy density, many fold lower.

Liquid hydrogen requires cryogenic storage technology such as special thermally insulated containers and requires special handling common to all cryogenic fuels. This is similar to, but more severe than liquid oxygen. Even with thermally insulated containers it is difficult to keep such a low temperature, and the hydrogen will gradually leak away (typically at a rate of 1% per day). It also shares many of the same safety issues as other forms of hydrogen, as well as being cold enough to liquefy, or even solidify atmospheric oxygen, which can be an explosion hazard.

UTOPIAN

The allure of the hydrogen economy is plain, splitting plain ordinary water using electrolysis to obtain oxygen and hydrogen gas is like a dream come true, especially if we can generate free electricity using solar cells and wind turbines to split the water. Then the hydrogen is free right.

But is the electricity free? No, not really.

There is a cost, including the cost of manufacturing the solar panels or wind turbines and the transmission line installation and maintenance.

Where there is a cost, then we have to consider payback time and working life. If we can use most of the solar and wind energy directly to power vehicles, we make the best of the working life of our energy harvesting apparatus. And that means reduced greenhouse gases, so a reduced carbon footprint for the human race in an anthropogenic fight against climate change.

BACK TO BASICS - ELECTROLYSIS

A water molecule is formed by two elements: two positive Hydrogen ions and one negative Oxygen ion.

The water molecule is held together by the electromagnetic attraction between these ions. When electricity is introduced to water through two electrodes, a cathode (negative) and an anode (positive), these ions are attracted to the opposite charged electrode. Therefore the positively charged hydrogen ions will collect on the cathode and the negatively charged oxygen will collect on the anode.

When these ions come into contact with their respective electrodes they either gain or lose electrons depending on there ionic charge. (In this case the hydrogen gains electrons and the oxygen loses them) In doing so these ions balance their charges, and become real, electrically balanced, bona fide atoms (or in the case of the hydrogen, a molecule).

The reason this system isn't very efficient is because some of the electrical energy is converted into heat during the process.

HYDROGEN PRICES @ 2019

The biggest hurdle to hydrogen as an acceptable alternative fuel may be cost.

The average price for hydrogen fuel in California is about $16/kg — gasoline is sold by the gallon (volume) and hydrogen by the kilogram (weight). To put that in perspective, 1 gal of gasoline has about the same amount of energy as 1 kg of hydrogen.

Most fuel cell electric cars carry about 5 kg to 6 kg of hydrogen but go twice the distance of a modern internal combustion engine car with equivalent gas in the tank, which works out to a gasoline-per-gallon equivalent between $5 and $6.

Hydrogen fuel cell cars now average between 312 miles and 380 miles in range, according to the EPA. They will cost about $80 to refuel from empty (most drivers don’t let the tank run down to empty before they refuel, so end up refueling at a cost of $55 to $65).

That cost is currently being paid for by automakers, who provide lessees with prepaid cards for three years of fueling, up to $15,000. In California, which has the nation’s highest gas prices, filling up a conventional car with a large gas tank can cost $40 or more.

Kelley Blue Book estimates annual fuel costs for the Toyota Mirai, Honda Clarity Fuel Cell and Hyundai Nexo at $4,495, which is three to four times the cost of gas-powered alternatives.

“We recognize the automakers can’t keep paying for fuel, and we see the line of sight to get there, but it is a volume game and we need to hit a critical mass,” said Shane Stephens, principal and chief development officer at FirstElement Fuel, which runs 19 of the 39 hydrogen refueling stations in California and is developing 12 of the 25 additional stations for the state. His company’s near-term target is $10/kg, which would equate to roughly $4/gal of gas. 

Stephens is quoted as saying: “That is a good near-term acceptable number to hit in the next three to five years and get people off automaker-subsidized fuel.”

EUREKA - Hydrogen is the most abundant element in the universe. With the "green-energy" craze and talk of powering our future oil-free economy on hydrogen, it has received much attention in the last few decades. Learning about this potential fuel of the future is important and interesting, but not without snags, and these are for anyone to seek to overcome.

FOOL CELLS

Tesla co-founder and CEO Elon Musk has dismissed hydrogen fuel cells as “mind-bogglingly stupid,” and that is not the only negative thing he has had to say about the technology. He has called them “fool cells,” a “load of rubbish,” and told Tesla shareholders at an annual meeting years ago that “success is simply not possible.”

Musk found a surprising source of support in 2017, when Yoshikazu Tanaka, chief engineer in charge of the Mirai, told Reuters, “Elon Musk is right — it’s better to charge the electric car directly by plugging in.” But the Toyota executive added that hydrogen is a viable alternative to gasoline. Toyota chairman Takeshi Uchiyamada told Reuters at the same Tokyo auto show in 2017, “We don’t really see an adversary ‘zero-sum’ relationship between the EV (battery powered electric vehicle) and the hydrogen car. We’re not about to give up on hydrogen electric fuel-cell technology at all.”

The auto industry as a whole has not embraced Musk’s battery-or-bust vision of the future. A 2017 survey of 1,000 senior auto executives conducted by KPMG found they believe hydrogen fuel cells have a better long-term future than electric cars and will represent “the real breakthrough” (78 percent), with the auto executives citing the short refueling time of just a few minutes as a major advantage. Sixty-two percent told KPMG that infrastructure challenges will result in the battery-powered electric vehicle market’s undoing.

In California, debate continues over whether the subsidies offered by the state to jump-start the fuel cell market have paid back the investment as judged by the limited use of refueling stations and lack of profits. California is committed to the effort begun under former Governor Jerry Brown to fund renewable energy initiatives, which included a $900 million zero-emissions vehicles plan and funding for electric vehicle charging infrastructure, including 200 hydrogen stations by 2025.

INVENTION OF THE FUEL CELL

Sir William Grove invented the first fuel cell in 1839. Grove knew that water could be split into hydrogen and oxygen by sending an electric current through it (a process called electrolysis). He hypothesized that by reversing the procedure you could produce electricity and water. He created a primitive fuel cell and called it a gas voltaic battery. After experimenting with his new invention, Grove proved his hypothesis. Fifty years later, scientists Ludwig Mond and Charles Langer coined the term fuel cell while attempting to build a practical model to produce electricity.

The polymer exchange membrane fuel cell (PEMFC) is one of the most promising fuel cell technologies. This type of fuel cell will could end up powering cars, buses and maybe even your house. But most likely in combination with a battery.

ANIMATION - A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity.

The other electrochemical device that you may be familiar with is the battery. A battery has all of its chemicals stored inside, and it converts those chemicals into electricity too. This means that a battery eventually "goes flat" and you have to recharge it.

With a fuel cell, chemicals constantly flow into the cell so it never goes flat - as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals.

The problem with fuel cells is the storage technology. Batteries are the storage medium and supply all in one. Fuels cells need an external container to hold liquid hydrogen or hydrogen combined as a metal hydride to feed the unit that combines the gases to make electricity.

ANYTHING BUT OIL

In summary, until oil becomes more expensive, motorists will have little or no incentive to switch to battery or fuel-cell vehicles. We might stick with internal combustion engines, but power them with biofuels, except that we need the land to grow crops, and forest (fires) clearing for such use is causing global warming. Or it might turn out more efficient to build electric cars with onboard batteries that you charge up at home.

A-Z INDEX OF H2 POWERED FUEL CELL SHIPS

BOREAL SJO

FCS ALTERWASSER

HYSEAS III

NORLED

SAN FRANCISCO BAY

SANDIA & DNV-GL

SCANDLINES

VIKING LINE

LINKS & REFERENCES

https://www.cnbc.com/2019/02/21/musk-calls-hydrogen-fuel-cells-stupid-but-tech-may-threaten-tesla.html

https://www.cnbc.com/2019/02/26/how-toyota-is-helping-japan-create-a-hydrogen-fueled-society.html

https://www.ft.com/content/98080634-a1d6-11e7-8d56-98a09be71849

https://www.explainthatstuff.com/fuelcells.html

http://www.blue-growth.org

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