How long does it take to get an express china visa in Thailand?

Hello! Could I come Wednesday and will it be done for sure by Saturday? I fly out Saturday at 6:00am.

Also I was wondering if I would qualify for the 72 hour free transit. This is my situation below:
I fly into Guanzhuo 8am Tuesday, leave the airport to pick up my stored luggage, catch a flight in Guanzhuo at 330pm Wednesday that is for America but has a 3hr layover in Beijing. I would not need to leave the airport in Beijing. Please let me know if I qualify for the 72 hours transit and how lon. It takes for an express entry permit in Thailand.