Passport validity for Beijing transit

Nilly, you will qualify for the 24 hour direct transit in Beijing as long as your passport is valid. You don't need to renew your passport for that, and there is no limit on the validity of passport for transiting in Beijing. But you may be required to apply for a free temporary stay permit at the immigration office when you arrive at the airport. Afterwards, you can leave the airport to visit the Great Wall and Temple of Heaven.