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A Futures Market for Hydrogen .....
GJS, Hydrogen vs Ammonia, vs Methane

SECTION 1

Here’s why SpaceX uses Methane in Starship.

SpaceX’s new Starship and Super Heavy rocket uses the Raptor engine. Liquid Methane and Oxygen is the fuel of this engine. No other rockets have ever used Methane as rocket fuel. The Falcon 9 and Falcon heavy use kerosene (RP-1) as fuel. Moreover, for a long time, Hydrogen has been used in various rockets. But, SpaceX chose Methane for their Raptor.

So why does SpaceX use Methane?  GJS says, “Why they don’t use Methanol, Ethanol or Ammonia”?   Read on.

It’s because Methane (CH4) is cheap, a passive cooling system is enough to store Methane in liquid form, significantly denser than Hydrogen, storable for a more extended period, does not leak, does not require insulation on the fuel tank, and the rocket design is less complex compared to Hydrogen-powered rocket.

Let’s elaborate.

SpaceX has developed the Raptor. It’s a Methane powered full-flow staged combustion cycle engine. The Raptor engine is the first-ever in history, a full-flow staged combustion cycle engine ever flown on a rocket. No rocket engine that uses Methane has ever reached orbit except SpaceX rockets.

SpaceX’s Starship is a rapidly reusable Mars rocket. The Falcon rockets are not fully reusable. While the first stage of this rocket is reusable, the upper stage is not.

Another problem with Falcon 9 and Falcon Heavy rocket is it’s not rapidly reusable. After every flight, this rocket needs extensive refurbishment before SpaceX can use it again. The primary reason is the fuel of the Falcon rocket is Kerosene (RP-1). The burnt fuel leaves soot in the Merlin engine compartment, making it harder to reuse it without extensive cleaning.

Table of Contents

SpaceX’s Mars Plan:

As we mentioned earlier, Elon Musk wants to go to Mars. A spaceship will take more than 6 months to reach Mars from Earth. The round trip is 12 months. 

We know that the Mars atmosphere has CO2 and has frozen water in the ground. On Mars, we can create Methane (CH4) using these resources.

First, through electrolysis, we can split water (H2O) into Hydrogen (H2) and Oxygen (O2). 

2H2O = O2 + 2H2

Oxygen and Hydrogen will be collected in separate containers. Humans will use the Oxygen produced in this step.

On the next step, through a chemical process known as the Sabatier process, Carbon dioxide (CO2) and Hydrogen (H2) would create Methane (CH4).

CO2 + 4H2 = CH4 + 2H2O

The Methane (CH4) and water will be collected in separate containers. Starship will use Methane (CH4) and Oxygen (O2) as fuel. The Martians can drink water (H2O) produced in this step or use it to make Oxygen and Hydrogen.

Astronauts already use these steps to produce Oxygen from water and eliminate Carbon Dioxide at the International Space Station (ISS). As this process has been tested; therefore, we can also use it on Mars. The only difference is, ISS releases Methane (CH4) into outer space, while on Mars, we will collect it into containers as rocket fuel.

In the above-described process, we can make both Methane (CH4) and Hydrogen (H2). 

 

Kerosene (RP-1)

Methane

Hydrogen

Density

813 g/L

422 g/L

70 g/L

Oxidizer vs. Fuel Ratio

2.7 : 1

3.7 : 1

6 : 1

Efficiency

370s

459s

532s

Combustion Temp

3670 K

3550 K

3070 K

Boiling Point

490 K

111 K 

20 K

Combustion Byproducts

CO2, H2O, and black soot.

CO2 and H2O

H2O

Manufacturable on Mars

No

Yes

Yes

In rocketry, the efficiency of an engine is measured in specific impulse (ISP). 

A simplified comparison would be the MPG of our gasoline-powered vehicle. The higher the MPG of a car, the more mileage it can go on 1 gallon of gas, and the more efficient it is.

Now, let’s assume that we have 1lb of rocket fuel. It could be Kerosene (RP-1), Methane (CH4), or Hydrogen (H2).

ISP is measured in seconds. It’s the measurement for how many seconds the engine can push with 9.8 newtons of force with a fixed amount of fuel. The higher it can push with 9.8 newtons with the same amount of fuel, the higher the efficiency or ISP.

If we have one rocket engine with 100s ISP and another one with 150s ISP, then the second engine with 150s ISP is more efficient because it can do more work with the same amount of fuel.

From the above table, we can see that Hydrogen is efficient compared to Methane. However, Hydrogen has several issues.

SpaceX wants their rocket to be simple, cheap, and reliable. According to Elon Musk, “the best part is no part; the best process is no process.”

Though Hydrogen is efficient compared to other rocket propellants, it adds complexity to rocket engines and rocket design.

Hydrogen is a cryogenic fluid. It’s melting point is -259°C or -435°F, and its boiling point is -252°C or -423°F. Hydrogen needs to be stored in extremely cold temperatures to keep it in liquid form. Because of this, a hydrogen rocket needs insulation around tanks, thus increasing rocket weight, production complexity, and cost.

Furthermore, other problems arise because of the Hydrogen’s low boiling point. 

On a long trip to the Moon and Mars, the Hydrogen will boil off and evaporate. Moreover, during the earth’s re-entry of the Starship, the generated heat will cause a significant technical challenge to keep Hydrogen liquified in the fuel tank.

However, Methane does not have these problems. 

From GJS, Hydrogen embrittlement is a serious issue in common steel metallurgy that is required to hold 5,000 to 10,000 psi at low temperatures. When metal comes into contact with cryogenic Hydrogen, the metal becomes brittle. Therefore, a reusable rocket design that uses Hydrogen is very complex and challenging. Hydrogen engines need advanced metallurgy to prevent this embrittlement.

Methane (CH4) does not create this embrittlement issue.

The density of Hydrogen is 70 g/L. In contrast, the density of Methane is 422 g/L. As a result, a Hydrogen rocket’s fuel tank needs to be significantly bigger than a Methane powered rocket. A big tank means a heavier rocket.

Therefore, a Methane powered rocket would be lighter compared to a Hydrogen rocket.

From GJS, Hydrogen is the smallest molecule on earth. The problem is that H2 is not really a molecule of dissimilar atoms but is considered a molecule of positive valence.  It leaks easily, primarily through the welded joints of the fuel tanks. Therefore, it needs extraordinary precision and cares to make the fuel tank leak proof.    Ammonia is difficult to seal but we can seal it with NPTF truncated threads and common Teflon sealing compounds.

Methane does not have this leak issue.

Hydrogen is also expensive compared to Methane (CH4).   From GJS, Today Green and locally built Hydrogen is $1.62 per Kilo if built with wind and solar. The bill for the hydrogen to launch the Artemis is now in the multiple millions to billions of dollars due to the delay of the leaky systems. There is no guarantee of successful launch at the Cape that is coming up this week.

As we can see, though Hydrogen is more efficient, it has many drawbacks.   From GJS, No it is not more efficient due to the drawbacks.

Therefore, SpaceX needs a rocket engine that does not have these issues. 

When they first started designing an engine, SpaceX did not want to take any risk of creating a completely new type of engine that no one developed. Therefore, they decided to use Kerosene (RP-1) for their Falcon family rockets. When they were successful with their Marlin engine, they started their R&D for the Methane powered Raptor.

In short, liquid Hydrogen needs extreme temperature control, leaks easily, less dense, thus requires a bigger fuel tank, expensive compared to Methane, not suitable for a reusable rocket and Mars mission, needs advanced metallurgy; hence, it increases rocket complexity and cost. 

Therefore, SpaceX made the right decision by not developing a Hydrogen rocket engine.

Interesting Findings:

How much does Elon Musk own of SpaceX?

SpaceX is a privately held company, and Elon Musk is the principal shareholder of SpaceX. During a recent FCC filing, SpaceX revealed that Elon Musk owns 54% of the company with 78% voting control in the SpaceX board.[1] Moreover, Elon Musk is the only person who owns more than 10% share of this company.

Can SpaceX or Elon Musk claim Mars?

In 2020, SpaceX’s Starlink started their service. Like every other product, a new Starlink customer has to sign a legal document. In that legal document, there is a term which states that:

“For Services provided on Mars, or in transit to Mars via Starship or other colonization spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities. Accordingly, Disputes will be settled through self-governing principles, established in good faith, at the time of Martian settlement.”

Therefore as you can see, if you want to get the Starlink internet, you have to declare, Mars is a free planet.

So, can SpaceX or Elon Musk claim Mars? 

Yes, SpaceX can claim Mars because according to a 2015 federal law 114-90, the US government allows a private entity to mine, own, possess, and sell a celestial body, even though the US does not claim it. Therefore, according to that federal law, Elon Musk and SpaceX can claim and mine Mars.

To learn more, please click here.

Bottom Line:

SpaceX made the right decision by abandoning Kerosene and Hydrogen and embracing Methane for their Starship. One day, this Starship would take humans to Mars.

Post navigation

GJS. Comments.

Why Hydrogen? My guess, This is just a guess….Some Scientific groups have implemented the Law of Hydrogen about 1962 when they made several mistakes in rocket fuel. Engineers had the perfect fuel which was Ammonia and LOX circa the X-15. There is no CO2 emission and low NOX emission. Technical papers are available.   

It was not long before NASA discovered the first mistake…pure oxygen in the manned capsule is a killer.  

They have finally made their final mistake in 2022. Hydrogen is difficult to work with and it is very expensive. What does it cost when they miss your last space launch.  

Back here on earth…..Better economics can be achieved with low cost solar and wind Ammonia…called Green Ammonia. Methane is fine for Mars…but on planet earth methane is the problem.  

There are several documents that support ammonia as the good rocket fuel and now very low cost since it is Green and Non Fossil built locally. 

Green Ammonia can be stored easily. Three hydrogens atoms are bonded to form a bonded dissimilar  nitrogen molecule producing 160 kilograms of hydrogen per ton of ammonia.  

Green Ammonia is not explosive. Green Play Ammonia is not corrosive to steel nor does it cause hydrogen embrittlement like hydrogen does to steel, Green Play Ammonia is .001 water which makes 17.48 % hydrogen. 

Just add a little water and keep it dilute from .005 to .001 water and you have a better rocket fuel and great way to store energy for years and years.    

Hydrogen must be used in Government Space Projects to support an Industry that has failed to solve the storage problem let alone the control problem.  

NASA is an industry within itself that has made a mistake. They keep pounding the hydrogen program out to the rest of the economy.  

It just won’t go to the top of the reliability curve. Somebody in Florida needs money now just like the Count Graf Zeppelin, Hindenburg in 1938.  

Hydrogen is a bomb. The leakiest molecule on the planet.  H2, Hydrogen is not an economic viable product found in storage or transport systems,  

The most unsafe choice for storage and transport is Hydrogen as H2, Build three H with one N and build it up as a true molecule.  It is non explosive and loaded with societal benefits. .  

Green Play Ammonia meets and exceeds expectations with it’s 100 year history of safest transport of concentrated energy with reusable storage batteries and bunkers.

Section 2 Click Here

 

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