Beijing connection flight

Hi, I have to go to Australia and I have one flight ticket Brussel -Munich- Beijing and one Beijing-Guangzhou-Sydney, after 4h from arrival. I have checked baggage, so I will need to exit the transit zone as the flight tickets are from different airline companies. Do I need to apply for an entry permit or I must apply for a 72h free transit when I enter Beijing airport at the immigration office? The returning flights are pretty the same , only the stop is not Munich, but Frankfurt. I am an UE citizen, my country is included in those 51 which permit a 72 h free transit and I have a Australian Visa. Thank you