The E.U. is Against the separation. The E.U. are the Globalist. They want a single State and not more States. They believe in consolidation of States, and NOT the other way around.
Catalan DOES NOT want to be part of the E.U. because of the migration that the E.U. loves and the tax increase for the migrants.
Catalans feel like they are losing their culture. The E.U. wants to flood them.
I’ve heard it said that the pro-independence parties actually supported the presence of the migrants for two reasons, basically-one the hope that in return, they’d vote for those parties, and two that they’d be wiling to learn Catalan instead of Spanish. you may be seeing what you want here, assuming that it’ll be like Brexit.