Patent WO-2011144198-A4 (WO)
Inventor: DIETRICH KARL-WERNER
IPC: C01B3/00
Filed: 2011-04-19
Abstract: With hydrogen as a secondary energy carrier, renewable energies are stored together with the natural gas and transported by means of the gas network. Renewable energies are more quickly available in the form of hydrogen than in the form of electricity, because new high-voltage lines do not have to be constructed. In addition, renewable energies are thus able to act as a base-load energy source. The present invention relates to the conversion of, for example, wind electricity or solar electricity into hydrogen and the introduction of said hydrogen into natural gas. Together with the natural gas, the hydrogen is stored in the natural gas field and/or transported in the natural gas network to the consumption point. Because of the physical and combustion-related differences between hydrogen and natural gas, such mixtures cannot be used in the event of an unsteady mixture ratio, such as occurs in the nature of renewable energies, without continually measuring the hydrogen content. Thus, for example, the hydrogen content must be determined immediately before combustion and the metering of the gas mixture must be adapted to the calorific value of the gas mixture. This is a measure that is required practically at every consumption point and that must be supported both technically and legally. Technically, because the gas meter measures not only volume but also the hydrogen content, for example by means of the density, and legally, because the fluctuating calorific value of a fluctuating hydrogen/natural gas mixture must be considered in the law of weights and measures. Because the processing of a fluctuating gas mixture according to the invention requires careful market preparation, it can be advantageous to accumulate the hydrogen in the natural gas field for some time while still unmixed natural gas is extracted and delivered. For this purpose, the hydrogen is introduced into the natural gas field and, as soon as hydrogen can be detected in the extracted natural gas, the hydrogen is separated from the natural gas and returned to the natural gas field. Said method variant is suitable especially where the natural gas can be separated from the gaseous hydrogen anyway as a liquefied gas. Hydrogen is returned to the field and natural gas is transported and delivered as a liquefied gas. Hydrogen from renewable energies thus can also be used advantageously to extract natural gas by displacing the natural gas in the natural gas field. By separating the hydrogen from the extracted natural gas and returning the hydrogen over a long period of time, the amount of recoverable natural gas of a field can also be increased depending on the geological structure. Natural gas, which has nearly triple the calorific value of hydrogen at the same gas volume, is flushed out of the field by the light hydrogen. Regardless of the method variant selected, the entire natural gas logistics are available to the renewable energies in the form of hydrogen at the end of the natural gas extraction. Renewable energies gradually replace the energy carrier natural gas in the field, the gas network, or in general in transport and at the load in order to then follow the natural gas. Natural gas becomes a renewable raw material - wind farms and solar farms become gas fields.