Solar hydrogen economy: what is it?
Solar or bio means that the hydrogen is generated from renewable energy sources. Biomass, like wind power or solar energy, is ultimately solar energy in it's various forms. With biomass are usually meant plants that are produced by the farmer in agriculture. This means that the solar hydrogen economy gets its hydrogen 100% from the living natural cycle. For example, no carbon is released that has not previously been absorbed from the atmosphere by the plants. Biomass has a very special meaning, since the use of biomass enables a real quantitative solution of the energy supply.In addition, there is the possibility of capturing and storing the CO2 released from the biomass when generating the hydrogen in a concentrated form, or of directing it for further use. This would even remove CO2 from the atmosphere. And this removal of CO2 from the atmosphere is already necessary today. It is not enough to operate "CO2-neutrally" in the future, but we have long since reached a level that makes it necessary for mankind to have the option of recovering CO2 and to make use of it. The production of biochar can also play an important role here.
The hydrogen economy not only means that hydrogen is used for transport and storage, but that hydrogen is the main energy carrier. This would mean that the electricity grid, which we have previously considered to be a kind of livelihood for our society, would be superfluous, since every house is supplied with hydrogen and generates its own electricity and heat from this on site with fuel cells. This is much more economical because it makes the entire electricity infrastructure superfluous. At this point you can already see that there must be "losers" in this upheaval process. The question is how much power these potential losers have to influence our opinion formation today and to influence future developments in their favor.
Another important point is that the use of bio-hydrogen is actually about hydrogen (H2). Not about methane or gas mixtures. This is important as it is the basis for using the gas. The hydrogen is not simply burned, but converted in the fuel cells by direct conversion of H2 and 02 to water ("cold combustion"), and electrical power and heat are released in the process. Hydrogen ions migrate through a membrane and then combine directly with the oxygen ions.
The technology for producing this pure hydrogen from biomass is in principle very old. For example, coal has been gasified to produce town gas since the middle of the 19th century. What is new, however, is the much better technology that is available to us today. After the production of synthesis gas by means of the steam reformer, a second processing step follows: the shift reactor ensures that at the end of the process chain only H2 and CO2 remain, which are then separated from one another. In this way you get pure H2 as an energy carrier.