refilling vs renewal

refilling and renewal both are nouns.

Word	Noun	Adjective	Verb	Adverb
refilling	Yes	No	No	No
renewal	Yes	No	No	No

As nouns, refilling and renewal are synonyms defined as:

Other synonyms of refilling include replacement, replenishment.

refilling (noun)	renewal (noun)
filling again by supplying what has been used up	the conversion of wasteland into land suitable for use of habitation or cultivation
	the act of renewing
	filling again by supplying what has been used up