Catalan referendum, explained: What's behind the push to break from Spain?
http://edition.cnn.com/2017/09/27/europe/catalan-referendum-explained/index.html
In addition to economic difference, Cultural difference, especially linguistic difference, may boost motivation toward Independence. Similar case can be seen elsewhere in the world.
Though independence from a neighboring country will result in a lot of changes on social systems, I doubt it also happens in Catalan area. I think there would be no barrier between Catalona and Spain, because Spain is a member of EU and Catalan nation will also be.
