is it possible to get 72 hour visa or a quick prearranged visa to catch my meeting next week?

Hey, the 72-hour visa free transit is only available for passengers who fly from country A to country B and have to transit in China for once. So if you plan to fly from Germany to China and then back to Germany, the policy is not suitable for you.
But a quick prearranged visa may be accessible. You can ask the sponsor of the conference help you apply for a visa on arrival. If it is approved, just let them pick you up when you arrive in the city.