transits in Beijing, can we use the 72 hour visa free transit?

Hi there, 7 of us are travelling to Bejing from Heathrow, staying 54 hours and then flying on to Thailand where we stay for 8 days, we then fly back to Bejing to get a connecting flight 6 hours later back to Heathrow, will we qualify for the 72 hour policy as we have to go back to Bejing a second time for our connecting flight?