Rockets require dense oxygen to burn. Near the edge of the atmosphere the air is not dense. Cooling the air increases the density. Cooling the air a lot will produce the dense oxygen required by a rocket.
Air also contains water vapor. Cooling the air will increase the density of this water vapor. Forming liquid water then ice. This water and ice will block air flow. Which will prevent a cooler from producing the oxygen required.
To prevent ice this cooler uses antifreeze. Methanol is sprayed (?) into the air being cooled. The methanol is then collected from the air and recycled. The collected liquid will contain water absorbed from the air. This prevents the ice and removes the water. Producing the dry, cold, and dense air for the rocket.
The innovation is using the methanol efficiently. The methanol introduced to the air absorbs water. This decreases it's antifreeze ability. This also increases the liquids volume. Where the oxygen is collected for the rocket the air is dense, low volume, and dry. This is where a low volume of pure methanol is required. From that point forward the air is less dense, warmer, and less dry. A larger volume of less effective antifreeze is required. By recycling the liquid and pumping the liquid forward they match the requirements with the liquid.
Rockets require dense oxygen to burn. Near the edge of the atmosphere the air is not dense. Cooling the air increases the density. Cooling the air a lot will produce the dense oxygen required by a rocket. Air also contains water vapor. Cooling the air will increase the density of this water vapor. Forming liquid water then ice. This water and ice will block air flow. Which will prevent a cooler from producing the oxygen required. To prevent ice this cooler uses antifreeze. Methanol is sprayed (?) into the air being cooled. The methanol is then collected from the air and recycled. The collected liquid will contain water absorbed from the air. This prevents the ice and removes the water. Producing the dry, cold, and dense air for the rocket. The innovation is using the methanol efficiently. The methanol introduced to the air absorbs water. This decreases it's antifreeze ability. This also increases the liquids volume. Where the oxygen is collected for the rocket the air is dense, low volume, and dry. This is where a low volume of pure methanol is required. From that point forward the air is less dense, warmer, and less dry. A larger volume of less effective antifreeze is required. By recycling the liquid and pumping the liquid forward they match the requirements with the liquid.
That's the best I can do YMMV :-) Cool stuff!