Is this a feasible application of the technology?
I am unsure if you are asking if bar codes can be used in place of RFID for library systems, or if RFID can be used to replace bar codes. Generally speaking, RFID tags are used in libraries to increase inventory counting and management, and to automate processes. Deploying RFID applications while still using bar codes achieves neither of these goals.
For example, RFID can be used to allow self-checkout. A person presents a book to a reader at a kiosk. The system then updates the database to say this book has been checked out and can proceed through the door's security gates. The tag is interrogated at the door, but no alarm sounds. You can automate checkout with bar codes, but there is no meaningful security check at the door. There is no way to read the bar code on a book that was stuffed into a knapsack but not properly checked out.
RFID library systems are designed to complement a library's existing bar-code and/or Dewey Decimal Classification (DDC) system. The existing number or alphanumeric designation used to identify a book is stored in its RFID transponder's chip, or a permanent serial number in the chip is associated with the book's current designation. Reading the tag is similar to scanning the bar code, but one can read the tags on a stack of 20 books in a few seconds without opening the books, whereas it would require time to pick up each book and then scan the bar code. So the RFID transponder can function just like a bar code, with the additional benefit of faster and automated reads.
—Mark Roberti, Founder and Editor, RFID Journal