As nouns the difference between emission and permeate
is that
emission is that which is emitted or sent out; issue while
permeate is a watery by-product of milk production.
As a verb permeate is
to pass through the pores or interstices of; to penetrate and pass through without causing rupture or displacement; -- applied especially to fluids which pass through substances of loose texture; as, water permeates sand.