We also are in rural central Ohio and we get our liquid nitrogen from a source
that I never would have thought of. It seems that liquid nitrogen is part of
the farm experience if you happen to breed cattle the modern way. Liquid
nitrogen is used to store bull semen. So we get our liquid nitrogen from the
Northern Ohio Breeder's Association (NOBA for short). Their 800 number is
800-289-6622.
Our rep comes by once a month and charges $25 for the visit and $25 for each 30
liter dewar he fills. This is considerably cheaper than Air Products, Inc.
which delivers liquid nitrogen along with compressed gases to our Chemistry
Dept.
An added benefit of NOBA is a monthly color postcard showing the back end of a
cow (accompanied by her "vital statistics") which would be quite titillating if
I happened to be of the bovine persuasion.