Green Hydrogen an Environmentally Friendly Fuel for Shipping

3% of the world's greenhouse gas emissions come from the shipping industry. This greenhouse gas is emitted from the combustion of fossil fuels used by various types of vessels used to transport passengers and goods at sea. What are the possible alternatives to fossil fuels to combat climate change and global warming?

Green Hydrogen

Green hydrogen currently tops the list of researchers' favorites. The question is - what is green hydrogen or hydrogen fuel? The use of hydrogen as a renewable energy source instead of fossil fuels is called Green hydrogen uses.

It is called 'green' because conventional and widely used fossil fuels are more environmentally friendly than hydrogen fuels. Various harmful substances are found as a by-product of fossil fuels, but water is the only by-product of hydrogen fuel.

The use of hydrogen as a fuel is very diverse. It can be used in either liquid or gaseous form. There are as many systemic limitations in the preparation of fossil fuels as there are in the case of hydrogen fuels.

It is possible to make hydrogen fuel in multiple ways. Currently, about 80 million metric tons of hydrogen fuel are being produced in the world every year for use in industries such as oil refining, ammonia production, steel production, chemical products and fertilizer factories.

Green Hydrogen Production

By far the most common method of producing hydrogen fuel is steam methane reforming. In this method, the reaction of water vapor with methane at high temperatures produces mainly hydrogen and negligible amounts of carbon monoxide and carbon dioxide. This is the first step reaction.

An impeller used in its immediate next step reaction, water vapor, reacts with carbon monoxide to produce greater amounts of hydrogen and carbon dioxide. Finally, pure hydrogen is separated by purifying other wastes, including carbon dioxide.

In addition to methane, other hydrocarbons or fossil fuels, such as propane, gasoline, and coal, can be used to react with water vapor.

Using fossil fuels, this method produces 830 million metric tons of carbon dioxide per year in addition to hydrogen, which is equivalent to the total carbon dioxide emitted by the United Kingdom and Indonesia. The hydrogen obtained in this method is called gray hydrogen.

In the process of steam methane reforming, pure hydrogen is obtained by separating the carbon dioxide obtained along with the hydrogen, which is called blue hydrogen.

Hydrogen fuel can also be obtained through water analysis. By electrolysis of water, only oxygen is available as a by-product as well as hydrogen. In this method, the analysis of water is done by conducting electricity between an electrolyze.

If the source of this supplied electrical energy is renewable energy, then hydrogen without any pollutants is called green hydrogen. As renewable energy becomes more readily available over time (due to technological advancement and cost reduction), this approach is considered to be a promising production process.

Problems and Alternatives to Using Green Hydrogen

There are several alternatives to green hydrogen as a fuel for naval use. Energy from vegetable sources or animal waste can also be used as fuel for ships. However, as the use of this source of energy already exists in various other sectors, it will not be very effective for the shipping industry.

It can be used on ships by charging the battery with renewable energy, but there are limitations. Several luxury and cargo ships are too large. Some ships travel long distances by sea.

Charged batteries may not be the perfect solution for these large and long-distance ships. There will not be enough space on the ship to carry the batteries needed to run such a large ship or to travel such a long distance.

That means only hydrogen or any other synthetic fuel is left out. Compared to 1975, the demand for hydrogen fuel has now almost tripled. Almost the entire cost of this growing supply is being borne by various industries. Needless to say, most of this hydrogen produced comes from fossil fuels.

6% of natural gas and 2% of coal are being used directly to produce hydrogen. However, the supply of fuel from the hydrogen produced directly in the vessel (specially designed) could be met, as it would have been a completely zero-emission process.

It is possible to produce hydrogen without fossil fuels through electrochemical analysis of water but unfortunately, only 0.1% of the total hydrogen is being produced in this way.

There are multiple methods of using hydrogen fuel on ships. The easiest way is to use hydrogen as fuel in a combustion engine built inside the ship. But there is a problem - there is nitrogen gas in most parts of the air.

So the combustion of anything in the air produces various oxides of nitrogen which are responsible for the pollution of the environment. However, there is a solution. If there is a system to separate the nitrogen oxides produced by a post-combustion purification process, they will not mix directly with the air.

Hydrogen can be used directly in a fuel cell. This completely avoids the combustion of hydrogen, which eliminates the possibility of producing harmful gases.

Electricity is generated from hydrogen through chemical reactions inside the cell and water is the only by-product. However, the problem is that it requires a lot of fuel cells for which space on the ship is a huge problem.

Another option is steam-powered hydrogen electricity. A turbine is run using steam obtained from the combustion of hydrogen with 100% pure oxygen from which electricity is finally obtained.

The question is why green hydrogen is not widely used in the shipbuilding industry despite having such an excellent exception to fossil fuels. Why is the shipbuilding industry still dependent on fossil fuels?

The issue is a lot like the argument before that never-ending egg or chicken. Investors in the hydrogen fuel industry want to see exactly what is the value or demand for hydrogen fuel in the market?

Understanding the demand, they will determine if they will Green hydrogen investment heavily behind it. People in the shipbuilding industry, on the other hand, are wondering why I should move away from fossil fuels when there is not enough supply of these fuels.