vent line problem

hi new here hope in the right place

i have a 97 flair 32 ft i have been having a problem when putting gas in it must run gas very slow and getting worst so i look into it and on the vent line there is a canister where vent goes into bottom and out the top of it problem is this is clogged so it made tank fill slow acting like no vent question is what is this canister so i can replace or can i do away with it any help would be great

thank you