again. Alternatively, fuel cells with optimized structures can be directly fed with high concentration methanol solutions or even pure methanol. Water drag The water in the anodic loop is lost because of the anodic reaction, but mostly because of the associated water drag: every proton formed at the anode drags a number of water molecules to the cathode. Depending on temperature and membrane type, this number can be between 2 and 6. Ancillary units A direct methanol fuel cell is usually part of a larger system including all the ancillary units that permit its operation. Compared to most other types of fuel cells, the ancillary system of DMFCs is relatively complex. The main reasons for its complexity are: providing water along with methanol would make the fuel supply more cumbersome, so water has to be recycled in a loop; CO2 has to be removed from the solution flow exiting the fuel cell; water in the anodic loop is slowly consumed by reaction and drag; it is necessary to recover water from the cathodic side to maintain steady operation. See also References Further reading Merhoff, Henry and Helbig, Peter. Development and Fielding of a Direct Methanol Fuel Cell; ITEA Journal, March 2010 External links Fuel Cell News Today. An internet portal of news and articles of fuel cell developments 12th Small Fuel Cells. Annual conference on portable fuel cell technology developments Fuel cells Methanol