Just to be clear,please.

Is it ok for me to buy all my rail tickets at Beijing International Airport, showing my passport at the time? Can I then go straight to the trains (with passport and tickets) or do I need to queue in the station to go through an additional identity check and pick up additional tickets. Please excuse my question but I would clearly need to arrive at the stations perhaps 2 hrs before instead of the half-hour (30 minutes) that I was planning.

Thank you for your kind help.

Neil