Russian scientists develop filtering membranes to remove impurities from natural gas

Researchers from Mendeleev Russian Chemical Technology University and Lobachevsky University have developed filtering membranes for removing impurities from natural gas. The new technology has the potential to be a real breakthrough in natural gas purification. Filtering membranes based on polymer ionic liquids have a high degree of selectivity, which makes them more efficient than traditional purification methods.

The main impurity that natural gas contains is CO2. The more impurities, the less energy can be obtained from the combustion of fuel, the more damage is done to the gas equipment. The technology developed by Russian chemists is based on the unique ability of ionic liquids to selectively dissolve CO2 in large quantities. The impurity is captured and removed more thoroughly in comparison with other purification options.

The problem is that it is impossible to make a membrane - a film or a hollow fibre - from a liquid. However, polymer ionic liquids not only can interact selectively with carbon dioxide, they can also become the basis for such materials being developed by our scientists.

"A composite membrane is a commercially available substrate onto which a synthesised polymer is applied. To produce membranes with a selective layer, we dissolve the polymer in a solvent and then apply it to the substrate in a thin layer. We can see its shine with the naked eye. It is this layer that separates the gases. To assess the morphology of the membranes and the thickness of the selective layer, we use scanning electron microscopy," said Ksenia Otvagina,  junior researcher at the Laboratory of Electronic Purity Substance Production Technologies of the UNN Research Institute for Chemistry.

"The resulting membranes are tested on a specially designed membrane test bench. It contains a membrane module into which the membrane is loaded. Then, using the thermostat, the temperature is programmed in a narrow range from 10 to 50 degrees Celsius," explained Dmitry Zarubin, junior researcher at the Engineering Chemistry Research Laboratory of the UNN Research Institute for Chemistry.

The membranes that scientists have developed largely mimic the processes that take place in nature, for example, blood filtration in the kidneys or gas exchange in the lungs. Such membranes can also be used to separate substances in liquid and gaseous media.

The membranes will improve the efficiency of natural gas combustion and reduce the wear and tear of the equipment that runs on natural gas.