How long does it take to apply for a Visa in China? What is the requirement?

Robert, do you mean the free transit or a normal entry permit?
If it's the free transit permit, the processing only takes a few mimutes. You need to take your passport, confirmed onward ticket and entry permit for the next destination.
If you mean the normal entry permit, it generally takes seven working days to get. The required documents are difference based on different travel purposes.