Detail:
- The powder referred to above is sodium borohydride (NaBH4).
- Each molecule of sodium borohydride contains 4 hydrogen atoms (4H).
- Two molecules of water (H2O) also contain four hydrogen atoms (2H2).
- Ultrapure water is water from which all interfering substances have been filtered out.
- Some of the required water comes from the fuel cell and is filtered.
- All of the basic substances and filtration installations needed are commercially available.
- One cubic metre of powder contains 9 MWh of energy.
Unpacking process
To make it pumpable, sodium borohydride, partially diluted with ultrapure water, is introduced into in a mixing chamber. Very lightly acidified ultrapure water is also introduced. Instead of acidification, a catalyst can also be utilised, depending on the requirements of use. When these ingredients meet, a natural exothermic reaction takes place, such that four hydrogen atoms split off from the sodium borohydride (NaBH4), and hydrogen gas (4H) and a sodium boron compound (NaB) remain.
In this reaction, so much energy is released that the water splits into hydrogen gas (4H per 2 molecules) and oxygen (2O per 2 molecules). The oxygen thus released then bonds with the sodium boron compound, yielding sodium metaborate (NaBO2) and hydrogen gas (4H). Thus, overall, four hydrogen atoms (4H) are released per molecule of sodium borohydride and 4 hydrogen atoms (4H) are released per 2 molecules of water, yielding a total of 8 hydrogen atoms (8H) and a reaction heat of 30MJ that is cooled to 90°C.
NaBH4 + 2H2O ——-> NaBO2 + H2O + 8H + 90°C of heat.
The hydrogen released has now become hydrogen gas and, with the help of a fuel cell for generating electricity, can be used as a direct energy source; in addition to the use of the heat from the reaction, the hydrogen can be converted into heat using a catalyst.
Packing process
The residual substances, consisting of sodium metaborate (borax) and water, are removed from the mixing chamber, after which a portion of the water is evaporated. The oxygen that is bonded to the sodium boron compound is removed and; in turn, hydrogen (4H) is again affixed to it, again yielding sodium borohydride (NaBH4), and the process repeats.
The hydrogen required for this is obtained by having the unpacking process take place two times simultaneously: the internal process and the external process. Both processes require sustainable electrical energy. Further, the unpacking process results in a yield of 8H.
The internal process yields 8H and in turn splits it into 2x 4H, i.e., 4H for the formation of the sodium borohydride (NaBH4) needed for the repetition of its own process and 4H for the creation of sodium borohydride (NaBH4) in the external process destined for market consumption. There, the 4H which has been bonded to the sodium boron compound through the splitting of the water is again converted into 8H (unpacking process).
Circular production of hydrogen
