Those numbers won't work.
Power in needs to be >= Power out.
7.5V x 8A = 60W
36V x 2A = 72W
Then you need to look into DC/DC converters or Step-Up regulators or Boost regulators, different for same thing.
36V is an unusual output voltage, not too many commercial choices
http://www.mouser.com/Power/DC-DC-Converters/_/N-brvxe?P=1z0wdj3Z1yxt6q2