There are disclosed a process for purifying ammonia which comprises
bringing crude ammonia into contact with a catalyst comprising manganese
oxide as an effective ingredient to remove oxygen and/or carbon dioxide
that are contained as impurities in the ammonia, and a process for
purifying ammonia which comprises bringing crude ammonia into contact with
a catalyst comprising manganese oxide as an effective ingredient, and
thereafter with a synthetic zeolite having a pore diameter in the range of
4 to 10 .ANG. to remove at least one impurity selected from the group
consisting of oxygen, carbon dioxide and moisture that are contained in
the crude ammonia. It is made possible by the above process to remove
impurities to an extremely low concentration from crude ammonia available
on the market for industrial use and crude ammonia from a gallium nitride
compound semi-conductor without decomposition of ammonia to generate
hydrogen.
