Method and apparatus for gas separation and synthesis

A process of operating a modified Stirling cycle machine wherein an internal working volume containing a gas has a flow path containing first and second spaces and a thermal regenerator disposed between the spaces, the first and second spaces being at different temperatures to expose the regenerator to a thermal gradient, the process also including cyclically reversing direction of flow of the gas along the flow path so that direction of flow alternates between opposite ends of the flow path, and cyclically varying pressure of the gas between upper and lower pressure limits within the working volume so that a phase relationship exists between the cyclic pressure variations and cyclic flow reversals relative to the thermal regenerator, the process being characterized by:

• (a) providing between the spaces an adsorbent bed containing adsorbent material to cooperate with the thermal regenerator to produce an adsorbent/regenerator combination,
• (b) introducing into the working volume a gas mixture containing a first component which is more readily adsorbed by the adsorbent material, and a second component which is less readily adsorbed by the adsorbent material,
• (c) simultaneously when coordinating the phase relationship between the cyclic pressure variations and the cyclic flow reversals relative to the regenerator combination, preferentially adsorbing and immobilising the first component on the combination bed by increased pressure when the gas flows in one direction, and preferentially desorbing the first component by decreasing the pressure when the flow direction is reversed,
• (d) removing from one end of the regenerator combination, a first gas fraction enriched in the first component, and removing from the opposite end of the regenerator combination a second gas fraction depleted in the first component,
• (e) achieving conversion between thermal energy and compression energy in the gas mixture.

An apparatus for separating first and second gas components from a gas mixture, the apparatus including:

• (a) a body having an internal working volume having first and second spaces, and a flow path interconnecting the first and second spaces,
• (b) an adsorbent bed and a thermal regenerator provided in the flow path, the bed containing an adsorbent material which is selectively more adsorbent of the first component than the second component, the thermal regenerator cooperating with the adsorbent bed to produce an adsorbent/regenerator combination to receive gas flow which passes along the flow path,
• (c) means to maintain the first and second spaces at different temperatures so as to expose the regenerator combination to a thermal gradient,
• (d) inlet means to admit the gas mixture into working volume, and outlet means to discharge gas from adjacent opposite ends of the adsorbent bed,
• (e) volume displacement means associated with the first and second spaces, and reciprocating means cooperating with the volume displacement means so as to reciprocate the volume displacement means within the body to produce cyclic variations in total pressure and cyclic reversals in direction of flow of the gas past the adsorbent bed, the reciprocating means determining a phase relationship between the cyclic variations of pressure in the gas and directions of flow of the gas,
• so that the gas flow along the flow path is subjected to cyclical reversals of temperature combined with cyclical reversals of pressure and direction of flow so that flow of a first gas fraction under reduced pressure past the adsorbent bed towards one space is enriched in the first more readily adsorbed component, while reverse flow of a second gas fraction under increased pressure past the adsorbent bed towards the opposite space is depleted in the first more readily adsorbed component.

An apparatus which resembles a modified Stirling cycle machine and is for separating a gas which is a mixture of at least first and second components, the apparatus including:

• (a) a body having an internal working volume having first and second spaces,
• (b) a flow path for gas interconnecting the first and second spaces,
• (c) a thermal regenerator and an adsorbent bed provided in the flow path between the first and second spaces, the adsorbent bed containing adsorbent material which cooperates with the thermal regenerator to produce an adsorbent/regenerator combination disposed between the first and second spaces, the adsorbent material having means for absorbing more readily the first component than the second component of the gas mixture,
• (d) means to maintain the first and second spaces at different temperatures so as to expose the adsorbent/regenerator combination to a thermal gradient,
• (e) first and second volume displacement means communicating with the first and second spaces respectively,
• (f) reciprocating means cooperating with the first and second volume displacement means so that the first and second volume displacement means reciprocate at the same frequency to produce cyclic variations in total pressure and in direction of flow of the gas, the reciprocating means determining phase angle between cyclic variations of pressure in the gas and flow direction of the gas over the adsorbent/regenerator combination, so as to subject the gas flow to cyclical reversals of pressure and direction flow, so that flow under decreased pressure of the first gas fraction past the regenerator combination towards one space is enriched in the first more readily adsorbed component, and flow under increased pressure of a second gas fraction past the regenerator combination towards the remaining space is depleted in the first more readily adsorbed component,
• (g) inlet means for admitting the gas mixture into the working volume,
• (h) outlet means for discharging gas fractions from opposite ends of the regenerator combination.