Stopping over for 19 hours at Beijing Airport

Generally speaking, you need to pay for the hourly lounge. But some airlines offer free lounge service for transit passengers if they hold a joint ticket. So you should check your ticket first to make sure whether it is a joint one. If yes, contact the airline to know whether they have such service. Otherwise you need to pay by yourself. There are luxury stores, cinema as well as book stores, you can kill time there easily.