Can you carbonate in a 2L soda bottle?
Yes, absolutely. Just make sure the cap screws on tight.
A lot of homebrew supply store sell the Carbonator Cap that allows you to hook up a ball lock gas quick disconnect directly to the bottle...assuming you are talking about forced carbonation.
Cool I'm short about 5 bottles so I'm using a Pepsi bottle. Just gonna twist the cap on tight and duct tape it a bit. Cool thanks. Btw winter ale. Tested this morning. It's outstanding