An associate of mine from the ethanol industry suggested Vaperma's membrane technology for methanol recovery on a small/medium scale. The linked video shows the ethanol purification application, but Vaperma is able to "tune" the membrane threads, so they could be made effective for methanol purification as well. With such a seemingly-simple design, scalability should be achievable. Check it out:

http://www.vaperma.com/_includ...mbrane_system_en.swf

http://www.vaperma.com/en/tech..._membrane_system.php

http://www.vaperma.com/en/tech...brane_technology.php