This article was first published in聽
The laws of thermodynamics will never be repealed. You cannot get more energy out of a system than has been put in. Yet there are articles, videos and even patents that claim to have found the secret of running a car solely on water.聽The usual theme is to separate water into hydrogen and oxygen through the process of electrolysis, and then either burn the hydrogen, or introduce it into a fuel cell to generate a current that runs an electric motor.
A fuel cell is a device that produces electricity directly from a chemical reaction, in this case between hydrogen and oxygen. Basically, it鈥檚 the opposite of an electrolyzer that uses electricity to break water down into hydrogen and oxygen. Electrolysis, one of the first chemical reactions students ever learn in chemistry, dates back to the early 1800s and is a spin-off from Alessandro Volta鈥檚 invention of the battery. English chemist William Nicholson discovered that when the leads from Volta鈥檚 battery are placed in water, the water breaks down into hydrogen and oxygen. These gases can be seen bubbling up from the submerged ends of the wires.
Whether it is via direct combustion or by introduction into a fuel cell, hydrogen reacts with oxygen to produce water. This water, according to the arguments of 鈥渨ater-fuelled鈥� engine promoters, can then be electrolyzed to form hydrogen again, and the cycle can continue. So goes the theory. However, what is being proposed is pure folly, since energy has to be put in to break the water down in the first place. Where is that coming from? Furthermore, the energy obtained from the hydrogen cannot all be used to electrolyze water again because some of it has been used to power the car. There is no free lunch.
This is not to say that hydrogen cannot be used to run vehicles. It certainly can, and unlike gasoline, it can do so without producing carbon dioxide. At least without producing it directly. When hydrogen reacts with oxygen, the only product is water, which is why hydrogen is referred to as a 鈥渃lean鈥� fuel. But the hydrogen has to be produced somehow. By far the most common method is the reaction of steam with natural gas, which is mostly methane. The problem is that carbon dioxide is also produced along with hydrogen, which in this case is referred to as 鈥済rey hydrogen.鈥� If the carbon dioxide is captured without being released to the environment, then we have 鈥渂lue鈥� hydrogen. The ideal is 鈥済reen鈥� hydrogen, which is made without any carbon dioxide being produced at all. That can happen if hydrogen is produced by electrolysis, with the electricity coming from solar panels, windmills or nuclear power plants.
Hydrogen powered cars, buses and trucks do exist. Liquid hydrogen, which has to be maintained at a very low temperature, is produced by applying high pressure to hydrogen gas. It can be pumped into special, strong carbon fibre tanks in a vehicle, from where it flows into a fuel cell to generate the electricity to power the vehicle. Hydrogen cars are really electric cars, but instead of being supplied by a battery, the electricity is produced by the reaction of hydrogen with oxygen in a fuel cell. At this point, the cost of producing hydrogen is greater than the cost of producing gasoline or batteries, and there is the complication of handling a cryogenic fluid. Except in California, where a valiant effort is being made to promote hydrogen powered automobiles, there are too few hydrogen fill-up stations to make such cars practical.
But what if the problem of transporting and storing the hydrogen could be solved?
Electrolysis or reaction of methane with steam are not the only ways to manufacture hydrogen. Dropping a piece of sodium into water and having it skitter about, and then burst into flames, is a classic chemical demonstration. Sodium reacts with water to yield hydrogen along with sodium hydroxide. This reaction is extremely exothermic, meaning that it produces heat 鈥� enough to set the hydrogen ablaze. A very neat demo! Some other elements also react with water to produce hydrogen. Boron does this, but with much less vigour than sodium. In the early 2000s, Dr. Tareq Abu Hamed 鈥� who had trained as a chemical engineer first in Turkey, then at the Weizmann Institute in Israel, followed by a stint at the University of Minnesota 鈥� hatched the idea of producing hydrogen in a car as needed. This would solve the problem of storing hydrogen in a tank, a potentially dangerous situation, and would circumvent the need for costly hydrogen pipelines.
Boron reacts with water to form hydrogen and boron trioxide. Abu Hamed鈥檚 idea was to equip a car with a device that adds boron to water to produce hydrogen, meaning that only water and boron would be needed to run the car. Of course, the boron would be used up as it is converted to boron trioxide, but that could be, at least in theory, removed from the car and recycled into boron to be used again. Unfortunately, there is a fly in the ointment. It takes more energy to convert boron trioxide back into boron than can be derived from hydrogen. Conceivably, if that energy would come from solar power, such a car could be viable.
It seems, though, that the problems for this version of a water-fuelled car were too big to overcome, since we haven鈥檛 heard of any developments since 2006. However, we have heard about Abu Hamed. He is the recipient of the 2024 David and Betty Hamburg Award, the American Association for the Advancement of Science prize for 鈥淪cience Diplomacy.鈥�
Abu Hamed, a Palestinian who grew up in East Jerusalem, was recognized for using science to build relationships across the Middle East, particularly between Israelis and Palestinians. He is the executive director of the Arava Institute for Environmental Studies that brings together Palestinian, Israeli Arab, Jewish and foreign students to study environmental problems. With the global language of science being the unifying force, the students learn about each other鈥檚 cultures, religions and families. Although the war disrupted activities, the Arava Institute is back to fostering discussions and co-operation. It may be the only organization in the Middle East that has Palestinians and Israelis working together. They are still at war, but it is against climate change that threatens everyone in the Middle East and elsewhere equally.
