Transit Milan- Beijing international airport- Bangkok

We wil do a fligth from Milan to Bangkok, during GO TRIP there will be a stop in Beijing airport during 14h, then goes to Bangkok. And for BACK TRIP will be the same from Bangkok to Beijing airport with a transit of 19h and then Milan.
If we want (01 peruvian and 01 italian passport) want to visit Beijing city, is possible to get 24h visa-free transit in the same Beijing airport and get out the airport to visit the city twice (for each trip)?
What do we have to ask for?
Thanks