The present invention relates to methods of separating one or more components from a feed composition, methods of desorbing one or more components from an absorbent fluid, as well as systems and apparatus that can carry out the methods. In one embodiment, the present invention provides a method of separating one or more components from a feed composition including contacting at least some of a first component of a feed composition including the first component with an absorbent fluid, to provide a contacted composition and a used absorbent fluid including at least some of the first component contacted with the absorbent fluid. In some embodiments the absorbent fluid can be an organosilicon fluid including an organosilicon including at least one of a hydroxy group, an ether group, an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, and a polyether group. In some embodiments, during the contacting the feed composition can be contacted to a first side of a membrane while the absorbent fluid is contacted to a second side of the membrane. In some embodiments, the membrane can be a silicone membrane.

A method for gas processing, in particular for processing biogas of a biogas plant in which in one method step a membrane process or a reactive process is executed, and in at least one further method step an adsorption and/or absorption process is executed.

The present invention relates to methods of separating one or more components from a feed composition, methods of desorbing one or more components from an absorbent fluid, as well as systems and apparatus that can carry out the methods. In one embodiment, the present invention provides a method of separating one or more components from a feed composition including contacting at least some of a first component of a feed composition including the first component with an absorbent fluid, to provide a contacted composition and a used absorbent fluid including at least some of the first component contacted with the absorbent fluid. In some embodiments the absorbent fluid can be an organosilicon fluid including an organosilicon including at least one of a hydroxy group, an ether group, an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, and a polyether group. In some embodiments, during the contacting the feed composition can be contacted to a first side of a membrane while the absorbent fluid is contacted to a second side of the membrane. In some embodiments, the membrane can be a silicone membrane.

A multi-stage process for recovering acid gas from natural gas having high acid gas contents utilizes two or more membrane absorption contactors arranged in series. The first membrane absorption contactor uses a physical solvent to remove a high volume of acid gas transferred across a membrane, and to reduce the acid gas content in the natural gas to a lower level that can be managed using chemical solvents. The second and, if needed, subsequent membrane absorption contactors can use a chemical solvent to remove acid gas transferred across the respective membranes and reduce the acid gas content in the natural gas to very low levels, if needed, depending on product specifications.

A multi-stage process for recovering acid gas from natural gas having high acid gas contents utilizes two or more membrane absorption contactors arranged in series. The first membrane absorption contactor uses a physical solvent to remove a high volume of acid gas transferred across a membrane, and to reduce the acid gas content in the natural gas to a lower level that can be managed using chemical solvents. The second and, if needed, subsequent membrane absorption contactors can use a chemical solvent to remove acid gas transferred across the respective membranes and reduce the acid gas content in the natural gas to very low levels, if needed, depending on product specifications.

A target chemical species, such as carbon dioxide, may be separated from a mixed gas by passing at least a portion of the mixed gas from a first chamber through a gas-selective membrane and into a second chamber, producing a concentrated gas. The concentrated gas has a higher concentration of the target chemical species than the mixed gas. At least a portion of the concentrated gas is passed through a diffusion-based membrane to a third chamber, where the third chamber includes an absorbent liquid in contact with one side of the diffusion-based membrane. The target chemical species is at least partially dissolved in the absorbent liquid and passed out of the system.

Processes for recovering hydrogen and hydrocarbons from a process stream are described. The processes incorporate a membrane separation unit to reject hydrogen preferentially from the net gas and recover the C.sub.3+ hydrocarbons from the hydrogen depleted retentate stream from the membrane unit using a retentate absorber. The invention eliminates the need for a large tail gas compressor package, while still achieving the target C.sub.3+ recovery of 85-90% or more with a smaller refrigeration package in the net gas section and membrane and retentate absorber equipment. It does not require any additional compressors, resulting in a significant reduction in plot space and power consumption.