Can I Apply for 72-hour Free Transit?

I fly into Guangzhou airport on the 24th of June and have a stop over for 16.5 hours before flying out to the UK/Europe on the 25th of June. I am travelling for a holiday and so do not have a Visa for the UK/Europe. I then fly back into Guangzhou airport on the 27th of July on my home and stay for 14.5 hours before flying home to Australia. Can I apply for a 72-hour Free Transit as I do not stay for over 24 hours for each of my stopovers? Or do I need to apply for a G type as I will be in China for a total of 31 hours?