One of the claims in the patent I linked to above states: >A heat exchanger as claimed in claim 93, wherein the antifreeze injector comprises a plurality of in

One of the claims in the patent I linked to above states: >A heat exchanger as claimed in claim 93, wherein the antifreeze injector comprises a plurality of injection portions and is arranged to inject a more concentrated antifreeze at a first injection portion in a first region of air flow and a more water-diluted antifreeze at a second injection portion which is more upstream than the first injection portion at a second region of air flow that is warmer than the first region. So I think they have system than repeatedly injects and collects the methanol and methanol/water mixture, re-injecting it each time upstream of the previous injection point.