We're planning to visit Beijing in May 2014 for 3 days.

Afterwards, we will also fly toNorth Korea for 5 days and return to China and spend there another 5 days. I wonder if i need double entry visa or not. Can it be requested by email/fax since i temporary live in Belgium. Also, if i come in person, Can i laso submit appication for espress service on Monday - and receive it on the same day?
Many thanks,
Lea