reformer vs apparatus

reformer and apparatus both are nouns.

Word	Noun	Adjective	Verb	Adverb
reformer	Yes	No	No	No
apparatus	Yes	No	No	No

As nouns, apparatus is a hypernym of reformer; that is, apparatus is a word with a broader meaning than reformer:

reformer: an apparatus that reforms the molecular structure of hydrocarbons to produce richer fuel
apparatus: equipment designed to serve a specific function

Other hypernyms of reformer include setup.

reformer (noun)	apparatus (noun)
an apparatus that reforms the molecular structure of hydrocarbons to produce richer fuel	equipment designed to serve a specific function
a disputant who advocates reform	(anatomy) a group of body parts that work together to perform a given function