Definitely the SAS lounge. You can find all information you need here:
http://www.loungeguide.net/wiki/u/Br...usiness_Lounge
You even have a view on the Atomium

However, if it is not raining, consider going to the city. There is a direct train from the airport to the central station (only takes 15 to 20 minutes, costs around EUR 5 for a return ticket), which is located 5 minutes walk from the Grand Place, which is really worth seeing.

So if you arrive at 7:15, you will be in the city around 8, and, with your onward flight being at 11:30, you can walk around Grand Place, see Maenneken Piss, have a coffee, and take the 10:02 train back to the airport. Even the 10:16 will give you plenty of time.