NOVELTY - Processing (M1) a gas, involves: directing process gas through adsorbent processing medium along one of radial axis and axial axis; rotating medium about rotation axis from first region to third region and directing heat transfer fluid; rotating adsorbent processing medium about rotation axis from third region to second region and directing purge fluid through adsorbent processing medium along one of radial/axial axis at second region; rotating adsorbent processing medium about rotation axis from second region to fourth region; and rotating adsorbent processing medium.    USE - For processing a gas (claimed) such as greenhouse gas including carbon dioxide.    ADVANTAGE - The method simplifies the purification steps, provides continuous purification with fewer components such as valves, and thereby reduces capital and operating costs of such LNG plants and results in a less expensive methane fuel.    DETAILED DESCRIPTION - Processing (M1) a gas, involves: at a first region, directing a process gas through an adsorbent processing medium along one of a radial axis and an axial axis; rotating the adsorbent processing medium about a rotation axis from the first region to a third region and directing a heat transfer fluid along the other of the radial axis and the axial axis to be in thermal contact with the adsorbent processing medium at the third region; rotating the adsorbent processing medium about the rotation axis from the third region to a second region and directing a purge fluid through the adsorbent processing medium along the one of the radial axis and the axial axis at the second region; rotating the adsorbent processing medium about the rotation axis from the second region to a fourth region and directing the heat transfer fluid along the radial axis and the axial axis to be in thermal contact with the adsorbent processing medium at the fourth region; and rotating the adsorbent processing medium about the rotation axis from the fourth region to the first. INDEPENDENT CLAIMS are included for the following:    (1) processing (M2) gas, involving: rotating an adsorbent-containing heat/mass transfer element about a rotation axis to sequentially expose a portion of the heat/mass transfer element to multiple processing regions; at one of the processing regions, directing a first fluid through the portion of the heat/mass transfer element in one of an axial direction and a radial direction while preventing the first fluid from passing through the portion of heat/mass transfer element in the other of the axial direction and the radial direction at one processing region; and at another of the processing regions, directing a second fluid through the portion of heat/mass transfer element in the other of the axial direction and the radial direction while preventing the second fluid from passing through the portion of the heat/mass transfer element in the one of the axial direction and the radial direction at the other processing region; and    (2) forming (M3) a heat and mass transfer apparatus, involving: connecting four elbow-shaped channels end-to-end to form a toroidal housing; positioning an adsorbent-containing heat/mass transfer element within the housing, the heat/mass transfer element including multiple radial flow paths oriented transverse to a rotation axis and multiple axial flow paths oriented transverse to the radial flow paths, the axial flow paths being in thermal communication with the radial flow paths, the axial flow paths being generally isolated from fluid communication with the radial flow paths at the heat/mass transfer element; and connecting the heat/mass transfer element to a driver to rotate the heat/mass transfer element about the rotation axis.