Muhaimin Iqbal
Author

Most Energy Efficient Green Hydrogen Production

Advanced Renewable

Tue , 23 Apr 2024 23:41 WIB

Apart from being clean energy, hydrogen is also have an abundant source throughout the world, namely water. The challenge is how to split this hydrogen from water with the lowest energy costs and a truly green process. So our research compares the five processes below and analyzes them in terms of energy requirements.

The most common and certainly technologically ready is the standard electrolysis of water to produce hydrogen and oxygen, the energy requirement is around 53 kWh for 1 kg of hydrogen. The second uses Solid Oxide Electrolyser Cells (SOEC), more energy efficient but still requires around 39 kWh.

For both methods, the energy required for the process is still higher than the energy content of hydrogen itself, 33 kWh/kg (LHV, Lower Heating Value). So these two methods are only feasible if there is excess electrical energy at low load times, so that instead of wasting electrical energy it can be stored in the form of hydrogen through these two methods.

A relatively new technique is the separation of H2 from water using sunlight with the help of Carbon Quantum Dots (CQDs) as a catalyst. From an energy perspective, it is not yet efficient because this process requires energy that is more or less the same as the energy stored in H2, namely 33 kWh/kg H2. However, because sunlight is free, this technique can be used to produce green hydrogen which is also feasible.

These last two methods are the most interesting, namely using carbon or charcoal to produce hydrogen in-situ and in-time, apart from being very energy efficient, only requiring 6.26 kWh per kg H2, it can also overcome the problem of very expensive hydrogen logistics.

Likewise, using CO2 and carbon as a medium to produce hydrogen, the energy requirements are the same as using carbon alone, 6.26 kWh per kg H2. The advantage of this last method is that it also utilizes carbon capture. And because H2 is produced using CO2 emission as production factor, we call the hydrogen we produce this way as Regenerative Hydrogen.

These last two methods are also as green as the previous three methods, because when we use biomass or charcoal as a medium for hydrogen production, the CO2 that comes out of the process is carbon neutral, it is offset by the CO2 that plants absorb for the photosynthesis process during their growth. Moreover, we don't release carbon neutral CO2 back into the air, but use it circularly to produce further hydrogen.

These two inventions will be presented at a prestigious energy forum in the world, namely the 10th International Conference on Renewable Energy Gas Technology (REGATEC 2024), in Lund, Sweden in mid-May. The two inventions that will be presented at this event by Advanced Renewable Organization (ARO) team are Regenerative Energy Roadmap and Low Cost Green Hydrogen Production.