Method for treating a fluid, fluid discharge device for a fluid and associated system

Method, in particular for treating a fluid or fluid mixture, in particular a biogas mixture, comprising:

• (a) providing a first fluid adsorption storage which
• (a1) comprises at least one fluid with molecules of at least two different chemical substances, in particular a biogas mixture with methane molecules and carbon dioxide molecules, and
• (a2) comprises at least one first adsorbent to which at least some of the molecules of the fluid are adsorbed as adsorbates, while other molecules are not adsorbed as adsorptives, and wherein the adsorptivities of the molecules of the different chemical substances are different, in particular the methane has a lower adsorptivity with the adsorbent, which preferably comprises activated carbon, than the carbon dioxide,
• (a3) has at least one outlet valve and
• (a4) is under a storage pressure from a high-pressure range, in particular between 2 and 10 MPa,
• (b) providing a fluid discharge device comprising at least one supply line, at least one discharge line and at least one suction pump,
• (c) wherein, in a first separation mode, the following process steps (d), (e) and (f) with the sub-steps (f1) to (f3) are performed on or with the first fluid adsorption storage:
• (d) connecting the supply line of the fluid discharge device to the closed outlet valve of the first fluid adsorption storage;
• (e) opening the outlet valve of the first fluid adsorption storage and allowing the fluid to flow out of the first fluid adsorption storage through the opened outlet valve, in a first operating mode, in particular in a passive mode without suction pressure from the suction pump, until the storage pressure reaches a low-pressure range, in particular below 2 MPa, and/or as long as the outflowing fluid predominantly contains molecules of the chemical substance with the lower adsorptivity,
• (f) following the first operating mode, in particular following the passive mode, operating the fluid discharge device in a second operating mode, in particular in an active mode, with the following features:
• (f1) generation of a suction pressure at the open outlet valve of the first fluid adsorption storage by means of the at least one suction pump;
• (f2) desorbing or detaching adsorbates and/or molecules of the chemical substance with the higher adsorptivity that are still attached after the first operating mode, in particular after the passive mode, from the at least one adsorbent in the first fluid adsorption storage by means of the suction pressure of the suction pump, and
• (f3) removing these desorbed or detached adsorbates and adsorptives from the first fluid adsorption storage by means of the fluid discharge device, whereby the removed fluid now predominantly contains molecules of the chemical substance with the higher adsorptivity.