Transit visa (Jordanian in Korea)

Hello,
I am a Jordanian citizen studying in Korea, I want to visit Beijing for 3 days before i catch my second flight to Dubai. Do I need to apply for an entry permit? or can I get a free transit in the Airport? and in case I want to stay in Beijing for more than 3 days before my next flight to Dubai, is it possible to apply for an entry permit through mail, for the fact that I live in Pusan while the embassy is in Seoul (400 kilometers away from my place).

Thank you so much in advance for your help.