Process for extracting carbon dioxide from air or gas mixtures and obtaining carbon dioxide as a pure gas.
In the prior art, there are methods and devices with which carbon dioxide can be extracted from air or gas mixtures. What these methods have in common is that a high level of procedural effort and high energy inputs are required in order, on the one hand, to carry out a largely complete extraction of carbon dioxide and, on the other hand, to obtain the extracted carbon dioxide as a pure gas. A complete extraction is necessary, for example, if a biogas or sewage gas is to be purified in order to obtain pure methane. On the other hand, carbon dioxide can only be used economically if it is present in a purity of > 99% by volume. The state-of-the-art plant technologies are geared towards high volume throughputs and require a high initial investment and considerable maintenance costs. In addition, some of the processes are ecologically questionable (e.g. when using monetholamine or its derivatives) and cannot be carried out without product loss (e.g. methane slip). Therefore, in spite of a considerable need, these methods have not yet been widely used.
A process has been developed with which it is possible, by means of a biogenic substance dissolved in water, to completely extract carbon dioxide from any air / gas mixture in a highly effective manner and to bind it without pressure. The carbon dioxide bound in the aqueous acceptor medium can be selectively released again by means of an electrophoretic process, as a result of which it is obtained in pure form. The acceptor solution regenerated in this way can then be used for a renewed extraction of carbon dioxide. Thus, the process can be operated continuously, without product loss and ecologically harmless, and an air-/gas mixture that is free of carbon dioxide as well as a pure gas of carbon dioxide are obtained.