Can an Iraqi passport holder obtain a 24-hour visa during a transit stop in the city of Guangzhou an

Taher, there is no such thing as 24-hour visa. If your flight itinerary is eligible for 24 hour visa free transit, you can enjoy your travel through China absolutely visa free. You have probably had in mind a temporary entry permit that allows you to exit the airport and make a short sightseeing of the city. If this is the case, you can always try to obtain such a permit upon your landing in Guangzhou.

You should have in mind that your layover in Guangzhou should be at least 8 - 10 hours long to be in a chance to be granted a permit. If you layover is shorter than that, you should not even try because you will be refused a permit for certain. If your layover is longer, you will approach 24/144 hour visa free transit immediately upon your landing where you will apply for a temporary entry permit by presenting your flight tickets and your accommodation booking confirmation if your layover is long and during the night hours. This application is free of any charge. When and if your permit is granted, you will cross the immigration and enjoy some time by exploring Guangzhou city on your own.

You should be aware that the issuing of the temporary entry permit is never a passenger's right, but more as a bonus that is offered on case by case basis. In any case, I wish you luck and pleasant journey.