Am I eligible?

Your itinerary is eligible for 144 hour visa free transit in wider Beijing area without any doubt.

Also, the use of 144 hour visa free transit is very easy. The first time you will mention it will be during your check-in in Seoul when you will declare that you will travel to Hong Kong via Beijing using 144 hour visa free transit. After a short check of your flight itinerary, you will be allowed to board the plane.

When you land in Beijing, you will first approach 144 hour visa free transit counter where you will declare the same thing and present your flight to Hong Kong. After a short check of your flight to Hong Kong, you will be granted a temporary entry permit and you will exit the airport to enjoy your stay. One detail here... It is highly advisable to have at least the first night accommodation booked in advance and to have your accommodation booking confirmation in hard copy. This is not necessary, but is advisable. Basically, this is it.