Thai travel to China

Hello. Im Thai, working as a cabin crew in Qatar. I'd like to go to China as a tourist. I want to buy a tour from Thailand and will depart as a group from Thailand. The tour will provide and manage the visa for other people. However, i cannot leave the passport in Thailand as i need it for my duty.
I'd like to ask if it's possible to ask for it from the embassy in doha, what documents i require and how long the process will be.
Thank you very much.