Goodbye hydrogen combustion engine

 Toyota bids farewell to hydrogen combustion and swaps it for a 22nd century prototype

Toyota has long been a leading innovator in the past decade for futuristic engine designs for sustainable alternative technologies to mitigate the climate crisis. While some automobile companies have increased their efforts to push the fully electric vehicle more broadly onto the market, others like Toyota have been spearheading hydrogen fuel developments. While Toyota has already had success with developing a hydrogen combustion engine, the company is now looking at refining their successful innovation to reach carbon neutrality goals. Following are the some of the important points:-

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Toyota has pulled out all the stops to remain competitive in the pursuit of carbon neutrality with the souped-up, hydrogen-powered GR Corolla they’ve got lined up to compete in the Super Taikyu Fuji Super TEC 24 Hours Race. In 2022, Toyota released their first racing car, the H2 Corolla, at the Japanese Super Taikyu Fuji 24h Race. The engine was fueled by zero-emission liquid hydrogen and was a success. Toyota has proved that they are leading the hydrogen revolution. The H2 Corolla took to the racing track again at this year’s Super Taikyu Fuji 24h Race event held in may.  Several new features make the engine one to watch on the track, including an extended cruising range created by a custom-shaped tank and enhanced durability of the liquid hydrogen pump. The model, tagged the #32 ORC ROOKIE GR Corolla H2 Concept, is fueled by liquid hydrogen, and Toyota will no doubt be hoping to gain insight from its track performance as there are still some bugs to be worked out the system.

Toyota currently has a broader initiative to reach zero carbon emissions by 2050. To do that, they appear to be banking strongly on their hydrogen developments. Toyota has been developing their hydrogen technology since 1992. In 2014, they introduced their fuel-cell technology to the world with their latest generation being launched in 2021. fuel-cell vehicles are predicted to be a valuable addition to the green portfolio of vehicle options, with Tesla even announcing their own hydrogen vehicle to be released as early as 2025. Hydrogen technology is one of the most futuristic innovations currently on the market. Liquid hydrogen offers several compelling benefits that make it an attractive option for an alternative fueling source for vehicles looking to go greener. One of its primary advantages is its high energy density, which means that it can store more energy in a smaller volume compared to traditional fuels. This characteristic is especially beneficial for applications requiring significant energy output, such as heavy-duty trucks and buses. 

The liquid hydrogen pump is the component that elevates the pressure of the liquid hydrogen fuel before it’s injected into the engine. This is something Toyota has put a lot of effort into improving in hopes of finishing the race without having to replace it. In the previous run of the Fuji Super TEC, Toyota went through three of these. When moving hydrogen from the tank to the engine, the pump uses a reciprocating motion in the piston action. This generates higher pressure than a standard pump, and the shaft and gears’ rotation action is smoother. However, in the previous engine, the load was uneven, and the parts wore out quickly. To get around this, Toyota included a dual-drive crankshaft mechanism. The adjusted application of torque translates into a more balanced boosting piston action, increasing durability significantly. In the 2023 edition of the Fuji 24 Hours Race, Toyota used three pumps, each with an average durability of eight hours. In 2024, they hope to have no replacements and achieve durability for the full 24 hours and beyond.

It is important to note that hydrogen as a fuel source is only as green as the energy source it is produced from. While pure hydrogen is not abundant or easy to capture, there are initiatives presently looking to source hydrogen in its pure form and not through other energy sources which could dampen its green potential. When hydrogen is used as a fuel, the only byproduct of its combustion is water vapour. This feature aligns perfectly with global efforts to combat climate change and reduce air pollution, particularly in urban areas where vehicle emissions are a major concern. Moreover, liquid hydrogen can be produced from a variety of renewable sources, allowing for a more sustainable and decentralized energy production model.

Toyota’s continued commitment to environmental sustainability is a model other automobile companies should look towards. “As we’ve said from the outset, the future will be shaped by acting with purpose and passion. Even while the engineers were saying it couldn’t be done, they’ve managed to develop the technology in an agile way while remaining competitive and keeping an eye on what’s going on around us,” says Toyota Chairman Akio Toyoda. Currently, Toyota has been partnering with Japanese manufactures Shinko Industries to build the fuel tanks for their hydrogen powered cars. “We saw for ourselves Toyota’s commitment to the future of Japan, being part of that was the biggest motivation to join the project.” recounts Keiji Kawano, Deputy General Manager of Shinko Plant Service regarding the H2 Corolla. Japan has consistently been a hub for futurist solutions. Additional projects they are developing are the Maglev trains and continued developments in AI technology as well as robotics and mobile health services.

Advantages of liquid hydrogen

There are two main advantages of liquid hydrogen over the compressed gas form normally used in FCEVs (hydrogen fuel cell electric vehicles:-

One of the properties of liquid hydrogen is that it’s more energy-dense than compressed gas, so it delivers about 50% more energy from the same volume.

Liquid hydrogen can be stored under normal pressure, meaning high-pressure storage tanks are not required.

Complications 

There are several significant problems with engines which run on liquid hydrogen, and unfortunately for motor companies looking in this direction over EVs, it's not going to be easy to solve. They have to keep liquid nitrogen extremely cold (below -253°C) so that it doesn’t vaporize.

Sealing the pump components is also an issue because sealed conditions are difficult to maintain under extremely cold temperatures.

Hydrogen fuel pumps wear out really quickly, and the system becomes inefficient. Oil lubricants are not an option because they would contaminate the fuel.

In comparison to electric vehicles, burning hydrogen is less efficient compared to the amount of electric power needed to charge a battery. The efficiency of hydrogen combustion is normally between 20% to 40%, whereas electric power sits at around 77%.

Large fuel tanks are needed for a hydrogen-combustion vehicle to have an acceptable range, even though liquid hydrogen is more energy-dense than gas form.

Despite evidence pointing to electric power as the way to go in the fight against carbon emissions, Toyota is still confident that the development of hydrogen engines will bear fruit.