2 gal beer in 5 gal keg

[MarsingRedneck]

Hi, I'm older know and don't drink as much beer as I use to. My batches now days are 2-2.5gals and I bottle in the Grolsch bottles. But I'm wondering, I have 5gal Corn Kegs sitting around. I usually brew Czech Pilsner. Could I naturally carbonate this small of an amount in my kegs and if so, how much corn sugar to prime with and could I use a small amount of CO2 to seal the keg and wait several weeks? If so how much? I do have a fridge I can put the keg in and set the temp to what ever It needs to be with my Inkbird temp controller.
Thanks

 

[bleme]

The problems you are going to run into here is there is so much headspace, it will be impossible to flush all the O2 using normal methods and if the headspace isn't pressurized, most of your natural CO2 will escape to the headspace. The only way I can see doing this is if you can transfer from your fermentor to the keg under pressure. You would need to fill the keg with sanitizer like Star San or Iodopher, purge the keg, then push it out with CO2. Then push your Pilsner in, preferably through the OUT post. Pressurize to about 12 psi, then leave at room temperature to carb.

Another option would be to carb in 2 liter bottles, then use a carb cap on the one you are pouring from to keep it carbonated.