Russia Proposes to Obtain Hydrogen from Gas Wells
Russian scientists have developed a technology for obtaining hydrogen from natural gas directly in gas fields. To do this, water vapor, a catalyst, and oxygen must be injected into the well, which will ignite the natural gas. This is reported by the publication “Scientific Russia”.
This technology will help speed up the transition from fossil fuels to environmentally friendly hydrogen energy. Today, people receive about 80% of their energy by burning non-environmentally friendly oil and natural gas.
Although gas is considered “cleaner” than oil, carbon dioxide is still formed when it is burned. And when hydrogen is burned, only water vapor is released. However, this “green” energy source has not yet been widely used due to the difficulties with its production.
The approach proposed at the Skolkovo Institute of Science and Technology includes several stages. First, water vapor and a catalyst are injected into the well, which helps extract hydrogen from the components of natural gas.
Then air or pure oxygen is supplied there. Thanks to this, the gas ignites directly inside the formation. In the presence of water vapor and a catalyst, methane burns, turning into a mixture of carbon monoxide and hydrogen.
Although carbon dioxide is subsequently formed from carbon monoxide, it remains in the formation and does not enter the atmosphere. At the final stage, hydrogen is extracted from the well through a membrane that does not allow other reaction products to pass through. As a result, all the gases formed, except hydrogen, will remain permanently preserved underground. This helps reduce the “greenhouse effect”.
The technology was tested in reactors that create conditions identical to a real gas formation. To do this, the researchers loaded crushed rocks into the installation. Using pumps, they fed methane, water vapor, and a catalyst into it, and then oxygen. At the same time, the reactor maintained pressure typical of gas formations, eighty times higher than atmospheric pressure.
It turned out that the maximum amount of hydrogen (45% of all gases) is formed at a temperature of 800 °C and large volumes of water vapor. For maximum productivity, its amount should be four times greater than the volume of natural gas. At the same time, a temperature of 800°C is easily achieved during the combustion of natural gas, so it does not even have to be artificially maintained.
The composition of the rock also affects the yield of hydrogen. Thus, in experiments with an artificial porous medium made of aluminum oxide, the yield of hydrogen reached 55%. The higher efficiency in this case is explained by the fact that aluminum oxide is inert.
Natural rocks contain other, more active minerals. They can enter into side reactions with components of the gas mixture and affect the yield of hydrogen.
