There is an equally valid sustainable alternative to the battery: the use of a hydrogen combustion engine
Published by The team in News the 27/03/2023 at 16:55
Hydrogen thermal engine technology poses significant challenges to become the last link in the historical trajectory of combustion engines. Unlike the hydrogen fuel cell , the viability of hydrogen-burning propellants is uncertain. However, in regions that foresee the end of combustion engines, this type of engine could represent the last hope thanks to the use of alternative fuels . Before betting on the maturity of this technology, it is important to determine if it is worth it, given the challenges associated with storing and burning hydrogen.
It is necessary to clarify whether the advantages of this technology outweigh the disadvantages. The laws of physics are not favorable for catching, storing and burning hydrogen to produce thrust similar to that of today's engines. In other words, the question is whether the bet is worth it. However, it is important to remember that technologies considered dominant today have faced similar challenges in the past.
The consolidation of hydrogen-burning propellants is in a premature and dubious phase in terms of feasibility. However, with the use of alternative fuels, this type of engine may represent the last hope of the combustion engine in regions that have predicted its extinction. Pilots, in particular, are keen on this technology and advancements could offer them a viable alternative.
In summary, hydrogen combustion engine technology faces considerable challenges in becoming the final link in the historical trajectory of combustion engines. The question of whether the advantages outweigh the disadvantages is crucial. However, the use of alternative fuels could offer a viable alternative for regions that have foreseen the end of combustion engines. Pilots are particularly attached to this technology, and progress could offer them hope to continue using it in the future.
We'll look at the pros and cons of hydrogen combustion engine technology to assess its current state.
What is the hydrogen combustion engine?
Hydrogen combustion engines are not much different from conventional propellants . They share their characteristics and their nature, and their operation requires only minor modifications, such as adjustments to the injection, supply and lubrication systems. In other words, these engines are based on technology that has been around for over a century and a half.
The history of hydrogen combustion engines goes back to the beginnings of combustion mechanics. Indeed, from the beginning of the 19th century, the Frenchman François Isaac de Rivaz had tried (unsuccessfully) to operate an internal combustion engine with a mixture of oxygen and hydrogen as fuel. Since then, the technology has evolved, but it is still based on the same basic principles.
Despite their long history, hydrogen combustion engines have yet to reach their full potential. However, they are attracting growing interest as a clean and efficient alternative to traditional propellants. Many companies and governments are investing in research and development of this technology, which could play a key role in the transition to a greener and more sustainable economy.
What are hydrogen combustion vehicles?
Over the past twenty years, well-known car manufacturers have experimented and introduced engines of this type in passenger cars, while in the truck sector, experiments and successful conversions have been observed.
Toyota has been the most active in this area in recent years, using the Super Taikyu Series competition to slowly but surely explore this possibility. However, as with all tech bets, there are progress being made on some fronts, but also typical pitfalls of experimentation.
Thus, Toyota created three prototypes using the 1.6 liter engine of the iconic Toyota GR Yaris and adding hydrogen injection. They then developed a larger model, the Toyota Corolla Cross , and it looks like there will be more to come.
Not to be confused with fuel cell
Hydrogen fuel cell cars are different from hydrogen combustion cars , although they share some elements. Fuel cell cars have a stack that sits within the confines of electric powertrains, while hydrogen combustion cars have fuel tanks. In essence, fuel cell cars use hydrogen to generate electricity that powers the car's electric motor, while hydrogen combustion cars burn hydrogen to generate power that powers engine.
Currently, the fuel cell is more mature than the hydrogen combustion engine. The second generation of the Toyota Mirai has shown that fuel cell cars are poised for consistent commercialization due to the importance and industrial momentum they are receiving. The next generation of fuel cell cars is also aiming for a consistent commercial landing using the latest technologies.
The hydrogen combustion engine, on the other hand, develops in parallel with the battery and can take advantage of some of the common solutions targeted for hydrogen cars . However, it uses fuel tanks to generate power. Although the hydrogen combustion engine is in development, it is currently less mature than the fuel cell . Advances in both technologies could have a significant impact on the future of hydrogen cars.
Zero emission combustion (or almost)
This technology has the first advantage of being ecological and contributing to the decarbonization of transport, a crucial aspect in terms of sustainability and alternative mobility that cannot be compromised. Yet, to fully exploit its sustainable potential, hydrogen engines must meet two fundamental requirements.
First, like fuel cell models, they must be powered by clean hydrogen , that is, green hydrogen produced without emissions. This requirement is essential for the technology to be considered truly green and to contribute to the reduction of greenhouse gas emissions. Indeed, if the hydrogen consumed by hydrogen engines were produced from fossil energy sources, such as natural gas, coal or oil, it would not be possible to speak of decarbonization of transport .
Second, contrary to popular belief, these engines generate nitrogen oxides (NOx) during combustion, a major health pollutant that is closely associated with diesel engines. To avoid this, a catalytic treatment (SCR) method must be used, which can use hydrogen as a reducing agent. This would reduce NOx emissions to very low or even zero levels, which would significantly improve air quality in cities and reduce the health risks associated with polluting emissions.
In sum, for hydrogen engine technology to be considered truly sustainable and contribute to the decarbonisation of transport, it must meet these two fundamental requirements. It is therefore crucial to develop sources of green hydrogen to power these engines, as well as to use catalytic treatment methods to reduce NOx emissions. If these conditions are met, hydrogen engines could play a key role in the transition to more sustainable and environmentally friendly mobility.
Efficiency: the great workhorse
Current hydrogen engines have a relatively low efficiency range, ranging from 25% to 35%, which is well below the 60% offered by the fuel cell. The latter is more efficient due to its lower operating temperature. To improve the performance of hydrogen vehicles, Toyota has developed a plan to further eliminate the combustion of hydrogen in the early stages of development of this technology. These stages relate to the size and location of the hydrogen tanks and the range the vehicle can provide.
It is difficult to obtain precise figures on the performance of these vehicles, as the technology is still in the experimental phase. However, it is known that the first prototypes of hydrogen combustion engines produced mediocre results, with a consumption of 50 liters per 100 kilometers. Toyota has, however, improved the performance of these vehicles with range increases hovering around 30% in the most recent prototypes.
In summary, although hydrogen powertrains have a relatively low performance range compared to fuel cells, Toyota is working on a plan to improve this technology. The first steps of this plan aim to further eliminate the combustion of hydrogen, which is related to vehicle range and the size and location of hydrogen tanks. Although precise figures are not yet available for this experimental technology, Toyota has made significant progress in improving the performance of its prototypes.
Dimensions and refueling
In the context of traditional propellers, the size of the motorization does not change much, but there are important differences when it comes to hydrogen. Indeed, hydrogen represents a major challenge in terms of integration, which makes its use difficult. However, Toyota has recently conducted experiments on the use of liquid hydrogen , which could represent a solution to this problem.
Until now, Toyota prototypes used hydrogen gas under high pressure, which required cylindrical tanks that were difficult to fit into vehicles. On the other hand, when the hydrogen is liquid, it is possible to design tanks that are more suitable for vehicles. This means that the use of liquid hydrogen could offer a viable solution for integrating hydrogen fuel cells into vehicles.
Ultimately, although the size of the powerplant varies little from traditional propellers , liquid hydrogen offers new perspectives for fuel cell vehicles. Toyota's recent experiments in the use of liquid hydrogen could offer a solution to the integration problems associated with the use of high-pressure gaseous hydrogen , paving the way for more efficient and environmentally friendly vehicles. the environment.
Toyota has managed to reduce hydrogen tank filling times to one and a half minutes thanks to its advances in hydrogen sports concepts. This could have a significant impact on refueling time, which would make the use of hydrogen more convenient for motorists. Unlike batteries, hydrogen in its liquid state does not require compliance with pressure standards. However, during official testing of the Corolla , Toyota experienced difficulty in maintaining the hydrogen at the required temperature, which resulted in losses due to gas evaporation once the tank temperature increased.
In order to be able to use hydrogen in its liquid state, it is necessary to set up a system to keep the gas at a low temperature and to minimize losses once it is ready to be burned. While this approach presents technical challenges, it also offers significant benefits, such as faster refueling times and greater convenience for hydrogen car drivers.
In sum, Toyota has made significant progress in reducing hydrogen tank filling times. Although there are temperature maintenance issues, the use of liquid hydrogen offers practical advantages that could accelerate the adoption of this technology in the automotive industry.
A great experience
Toyota chose to make the circuit its testing ground for its hydrogen thermal engine . Drivers, more than engineers, are in the best position to provide feedback on their experience with this type of engine. Automotive professionals find it difficult to perceive the differences between the operation of hydrogen combustion engines and conventional ones. However, they agree that the performance and acoustics of these engines are a real pleasure.
Although pilots appreciate the performance and acoustics of hydrogen thermal engines, their potential in the market for alternative zero-emission vehicles remains to be confirmed. Toyota claims to have already come 40% of the way to bringing cars with hydrogen combustion engines to market, but technical challenges remain. Nevertheless, Toyota is known for its passion for the automotive industry and its commitment to research.
Although automotive professionals have trouble perceiving the differences between hydrogen thermal engines and conventional engines, Toyota drivers have praised the performance and acoustics of these engines. However, their potential as alternative zero-emission vehicles has yet to be confirmed. Despite this, Toyota continues to commit to research and claims to have come 40% of the way to bringing cars with hydrogen combustion engines to market. Their passion for the automotive industry and commitment to innovation make them a company to watch closely.
Toyota uses the circuit as a proving ground for its hydrogen combustion engine, which is appreciated by drivers for its performance and acoustics. However, its potential as an alternative zero-emission vehicle needs to be confirmed. Toyota claims to have come 40% of the way to bringing cars with hydrogen combustion engines to market, but technical challenges remain. Despite this, Toyota is known for its passion for the automotive industry and its commitment to innovation, which makes it a company to watch closely in the field of alternative vehicles.
Toyota has chosen to make the circuit its testing ground for its hydrogen thermal engine, which is appreciated by drivers for its performance and acoustics. However, its potential as an alternative zero-emission vehicle needs to be confirmed. Toyota claims to be 40% of the way to bringing cars with hydrogen combustion engines to market, although technical challenges remain. Despite this, Toyota is known for its passion for the automotive industry and its commitment to research, making it a company to watch closely in the field of alternative vehicles.
