The image below is a schematic flow diagram of a typical oil refinery that depicts the various unit processes and the flow of intermediate product streams that occurs between the inlet crude oil feedstock and the final end products.
In order to check-in into a hotel, the person must be 21 years old.  If the person is younger than 21, then a parent or guardian can  give permission for them to check-in. 1 person found this useful.
Generally, the minimum age to reserve a guestroom at Hyatt is 21 years old. However, this age may vary by hotel. Please check the specific policy of the hotel you plan to visit. A person of the minimum age requirement must be present for check in no matter who has made the reservation. I know that almost all of the hotels here in Ft. Lauderdale have this same policy.