The development of a hydrogen economy would necessitate a huge increase in hydrogen demand. This necessitates scalable choices.
Hydrogen can be derived from nuclear power in two ways that are both scalable.
The first choice is to simply generate electricity from nuclear power, which can then be used to electrolyze water. It would be the same method as producing green hydrogen, except it would use nuclear power with a capacity factor of 90% instead of renewables with a capacity factor of 20% to 40%. As a result, the cost of hydrogen production falls.
However, the price is still prohibitively high. It is calculated to be cost-effective as compared to renewable energy. The main explanation for this is that electrolysis isn’t very effective. In most cases, the process uses around 20% of the power used to generate hydrogen through electrolysis. To put it another way, you only get 0.8 equivalent units of hydrogen back for every unit of electricity you put in.
Although this isn’t bad, there is a way to make hydrogen from nuclear power that is much less expensive. Methane, with its four hydrogen atoms, can be thermally decomposed to carbon and hydrogen instead of using electricity. Thermal decomposition of methane (TDM) or simply methane pyrolysis is a high-temperature process.
Methane pyrolysis occurs only at temperatures above 1100–1200 °C in the non-catalytic phase. This necessitates a significant amount of electricity. Catalysts, on the other hand, will lower the temperature requirement. Nickel catalysts have been shown to operate well at temperatures between 500 and 700 degrees Celsius, while iron catalysts have performed well at temperatures between 700 and 900 degrees Celsius.
There are two main factors that can make hydrogen output more cost effective than SMR. The first is that, although carbon is produced in this process, it is pure solid carbon, also known as black carbon.
Solid carbon is used in a wide range of applications, so collecting and using it will be much easier than capturing and sequestering carbon dioxide. One of the most exciting new applications is the potential for carbon black to be used to make carbon fiber, a valuable alternative to today’s toughest industrial products, basically as a free by-product.
The second reason is that these temperatures can be found in nuclear power plants, and even more so in advanced nuclear reactor technologies. Generation-IV nuclear technologies operate at far higher temperatures – between 500 and 1,000 degrees Celsius – and can thus supply heat directly to an industrial process rather than converting heat to energy and experiencing thermal efficiency losses in the process.
