Exhaust gas treatment by thermal diffusion

A system, comprising:

• a combustion engine;
• and
• a thermal diffusion unit fluidly connected to the combustion engine via a flue line, the thermal diffusion unit comprising:
• a heating wall;
• a cooling wall;
• a plurality of thermal diffusion cells defined between the heating wall and the cooling wall;
• multiple heated passages formed through and fluidly connecting a first set of the thermal diffusion cells, wherein the heated passages are adjacent the heating wall;
• and
• multiple cooled passages formed through and fluidly connecting a second set of the thermal diffusion cells, wherein the cooled passages are adjacent the cooling wall;
• wherein at least one of the thermal diffusion cells in the first set is the same as at least one of the thermal diffusion cells in the second set;
• and
• wherein at least one of the thermal diffusion cells in the first set is separate from at least one of the thermal diffusion cells in the second set, such that a heated fluid flowing through the first set of thermal diffusion cells is separated from a cooled fluid flowing through the second set of thermal diffusion cells.

A method of reducing carbon from a combustion exhaust gas, the method comprising:

• thermally diffusing the combustion exhaust gas into a carbon rich gas and a carbon poor gas, wherein thermally diffusing comprises:
• heating a heating plate interfacing a first side of a diffusion sheet in a thermal diffusion unit;
• cooling a cooling plate interfacing an opposite side of the diffusion sheet;
• directing the combustion exhaust gas through the diffusion sheet, wherein the diffusion sheet comprises multiple thermal diffusion cells that are fluidly connected via a plurality of heated passages formed adjacent to the interfacing heating plate and via a plurality of cooled passaged formed adjacent to the interfacing cooling plate:
• wherein one of the carbon rich gas or the carbon poor gas of the combustion exhaust gas flows through the heated passages, and the other of the carbon rich gas or the carbon poor gas flows through the cooled passages;
• directing the carbon rich gas from an outlet of the diffusion sheet through a first flowline;
• and
• directing the carbon poor gas from the outlet of the diffusion sheet through a second flowline.