Market Analysis for Future Transportation Fuels

Richard H. Caro

Certified Automation Professional, International Society of Automation

Copyright 2022

Richard@Caro.us, Arlington, MA

Abstract

Public and private transportation vehicles mostly burn fossil fuels. Even
today’s electric vehicles are powered by electricity originating largely from electric
power plants that burn fossil fuels. Only a small percentage of electricity is
generated by solar, wind, hydroelectric, geothermal, or nuclear sources, all of
which do not depend upon combustion of fossil fuels. While battery-based
electrical vehicles are likely to expand rapidly, battery storage of electrical energy
may not be an optimal solution for the future of automotive power, and is certainly
not a solution for passenger and cargo aircraft. The evolution of fuels for powering
land and air transport vehicles is the purpose of this market analysis. The
conclusion of this study is that anhydrous ammonia manufactured with the use of
green hydrogen and green electricity will emerge to be the common fuel of the
future for all forms of transportation: land, sea, rail, and air.
Keywords: Automotive, aircraft, fuels, fossil, ammonia
 

Market Analysis for Future Transportation Fuels

Fuels Currently Used in Transportation Vehicles

The Oil and Gas industry dominate the production of the fuels used to power
automobiles, trucks, ships, and aircraft for transport of people, goods, and
commodities. While compressed natural gas and propane are used to power some
municipal buses, three forms of hydrocarbon fuels all distilled from crude oil
dominate: gasoline, kerosene/jet fuel, and diesel oil dominate ground and air
transportation. All such fossil-based fuels are burned in the vehicle to produce
power at varying degrees of efficiency, and all produce carbon dioxide (CO2) as a
byproduct of combustion and it is considered by most experts to be the greenhouse
gas most responsible for global warming.

It seems obvious that electric-powered vehicles (EV) are likely to replace
fossil-fueled vehicles, as recently required by the state of California by 2034. Even
so the power for battery-powered EVs generally comes from electric utilities that
still use combustion of fossil-based hydrocarbon fuels. Solar, wind, nuclear, hydro,
and geothermal sources (green electricity) still make up only a small, but modestly
increasing fraction of the electrical generation energy sources. Only the passenger
rail service, and to a lesser degree freight rail service, have developed a way to
directly power trains with electricity, but only over a small segment of the total US
rail service. Electrification of rail service is almost universal in Europe and Japan,
but not in the US due to the size of the US and the large capital investment
required to install electrical third-rails or catenary wiring. Even with electrified
trains, the source of electricity for rail use mostly comes from electric utilities that
burn fossil fuels. Interesting is that the common diesel-fueled locomotive for rail
transport actually has a number of electric motor traction engines with an on-board
diesel-fueled generator.

For most of the transportation sector, a way to store or create electrical
power in the moving vehicle itself must be found to allow random mobility of
vehicles. The most common electrical storage method has been use of rechargeable
batteries. The most common battery technology uses lithium/ion chemistry that is
known for its limited capacity, long re-charge times, and potential fire hazard due
to its flammable electrolyte. For automotive use, lithium/ion batteries are very
large, heavy, expensive, and flammable in some instances. Research continues to
develop solid-state batteries that promise higher capacity for the same weight,
faster re-charge cycle, more compact dimensions, and safer due to use of a nonflammable electrolyte. However, we are not there yet (2022).

Some use of fuel cells in which hydrogen is used to generate electricity and
power the vehicle is being used in some long-distance cargo vehicles, and in some
AGVs (Automated Guided Vehicles) used in warehouses and factories. There are a
few hydrogen/fuel cell powered automobiles being sold to test the market for such
architectures. Broad use of hydrogen fueled vehicles will depend upon the creation
of an all-new of a hydrogen distribution and dispensing network that currently does
not yet exist.

For passenger and freight aircraft electric power can only be used to rotate a
propeller, that is currently used in light aircraft, and was common prior to the jetage. It is unlikely to resume except for light aircraft and a few short-hop passenger
services. Longer distance aircraft will still require jet engines that burn nonhydrocarbon fuels such as hydrogen to avoid generation of greenhouse gasses.

More about Hydrogen

The fuel most publicized to replace hydrocarbons for both automotive and
aeronautic use is hydrogen. When hydrogen is burned with atmospheric oxygen,
only water vapor, some Nitrogen Oxide (NO), and heated nitrogen from the
atmosphere are produced in the exhaust. The environmental problem remains
however: where does all this hydrogen come from?

• Green Hydrogen – produced by the electrolysis of fresh (non-salt) water
using electricity produced by methods that do not release carbon dioxide to
the atmosphere (wind, solar, hydro, geothermal, or nuclear.)

• Grey Hydrogen – the most common method (95%) for production of
hydrogen using a steam reforming of natural gas (methane) that produces
greenhouse gas carbon dioxide (CO2) as a byproduct that is currently vented
to the atmosphere.

• Blue Hydrogen – produced from hydrocarbon sources like Grey Hydrogen,
but adding carbon capture to the process so that carbon dioxide is not
released to the atmosphere. The carbon dioxide may be injected into old oil
wells to recover oil that no longer flows freely, or to just store the carbon
dioxide in underground voids. There are some other carbon-capture
processes that are being developed that are intended to avoid atmospheric
venting of carbon dioxide.

Economics of Grey or Blue hydrogen production strongly depends upon the price
of natural gas, the availability and price of green electricity, and the cost of
disposal of carbon dioxide. In mid-2022, where green electricity and fresh water is
available, green hydrogen can be produced for less than the cost of grey hydrogen.
However green electricity (solar) is often available with significant investment in
dessert areas where fresh water is not generally available, or in coastal areas (wind)
where the water has high salt content. Fortunately, green electricity from hydro
water power provides plenty of fresh water for electrolysis to produce green
hydrogen. Many nuclear generation sites also have access to fresh water for reactor
cooling as well, but nuclear power has fallen on disfavor, and for this study is
being deprecated. Perhaps electrolysis of salt water will prove to be economically
feasible as well using desalinization methods, but it is not yet developed. Perhaps
new geothermal processes will produce green electricity in locations where fresh
water is plentiful and where wind and solar are less feasible, but this too is
speculative.

Problems with distributing hydrogen.

Hydrogen gas cannot be transported in mild steel piping like natural gas. The
hydrogen molecule can permeate steel piping causing embrittlement and
potentially failure and leakage of the hydrogen. This means that hydrogen is NOT
a safe substitute for natural gas since specialized materials are required for its safe
pipeline distribution. Pressurized hydrogen gas can safely be stored or transported
in tanks or pipelines made of carbon fiber, 316 or 304 stainless steel.
Storage of hydrogen as a liquid appears infeasible since it would require
intense refrigeration to the liquid hydrogen boiling point -273oF. However,
advances in materials for hydrogen absorption and adsorption are being developed
that may enable such methods to safely transport hydrogen as an adsorbed gas in a
solid storage medium. The vehicle would then be required to carry the solid filled
adsorbent, the hydrogen, and the container plus any heating mechanism required to
de-adsorb the hydrogen. This too is speculative.

Finally, another approach to transport hydrogen is to change the chemical
composition from hydrogen to another non-carbon containing chemical that is
easily reacted to release hydrogen. There are two such chemicals: anhydrous
ammonia (NH3), and hydrazine (N2H4). Each of these molecules, hydrogen,
anhydrous ammonia, and hydrazine can be directly used in fuel cells to generate
electricity with only water and nitrogen as byproducts. Which one to be used in the
future requires an economic and logistical appraisal as follows:

• Hydrogen – under pressure, hydrogen may be stored in non-metallic tanks or
may be stored as a hydrate of a solid. Storage as a hydrate is a process called
adsorption and is under development. So far there are no conclusive results.
This also assumes that the adsorbed hydrogen will not become a hazard
worse than today’s gasoline tanks in case of an automobile collision. If the
hydrogen is stored as a compressed gas, the fuel tanks must be strong
enough to protect it in case of an accident because any released hydrogen
would be highly flammable.
• Anhydrous Ammonia – can be contained under moderate pressure in
lightweight steel tanks. In case of fuel tank rupture in an accident, the
released ammonia gas, being lighter than air, would rapidly dissipate and is
generally not flammable although it is highly toxic and an extreme irritant.
• Hydrazine – is only liquid above 28 degrees F (-2 deg. C), therefore must be
contained in steel tanks that can be heated. In case of fuel tank rupture in an
accident, hydrazine is highly flammable and would present a serious
explosive hazard.

Conclusion: Hydrazine is too hazardous for automotive use. Compressed hydrogen
presents several unanswered questions for fuel tank materials and weight and
presents a hazardous condition in case of accident. Anhydrous Ammonia seems to
be a less hazardous and more economic fuel of the future for automotive use.

More about Anhydrous Ammonia

Anhydrous ammonia can be considered as a safe way to transport and store
hydrogen. Anhydrous ammonia is easily converted to release hydrogen in the
presence of a Nickle catalyst such as in a solid oxide fuel cell. For jet aircraft use,
anhydrous ammonia can be heated with recirculated exhaust gases and passed
through a catalyst converting it to hydrogen for combustion in the jet engine with
heated nitrogen and water vapor as exhaust gases.
Anhydrous ammonia has been in mass production for many years as
fertilizer for many crops. The anhydrous ammonia is typically applied to the soil
before planting a crop in order to replenish the nitrogen that was used to grow the
previous harvest. This application has created a very large market for anhydrous
ammonia that is safely transported by truck or rail in lightly pressurized steel tanks.
However, most of today’s anhydrous ammonia is produced by a process that uses
hydrogen and steam to reform natural gas, but carbon dioxide is a byproduct. It
will take new plants to produce green anhydrous ammonia starting with green
hydrogen and nitrogen from the atmosphere (3 H2 + N2 –> 2 NH3) that uses ferric
oxide as a catalyst.

Conclusion

Now we have identified the fuel of the future: anhydrous ammonia for solid
oxide fuel cells in electric automobiles, buses, trucks, trains, and ships; it will also
power jet aircraft by decomposition with heat and catalyst to generate hydrogen
which is the combustion fuel.