Unless you edit all the cookies that you want to delete after 30 mins and set their expiry time accordingly, I don't think it is possible.
As far as I know, browser doesn't store the cookie creation time, so it is not possible to find when the cookie is created. We can only know whether the cookie is expired or not.
Not sure what is your purpose in deleting cookies every 30mins, but you can delete all cookies at once using this tool. Else, you can try using "Private Browsing" and start a new session after every 30 mins.
I am not aware of any such addon that is suitable for this requirement. In case you are interested in developing one for your self, you can monitor cookies (when they are created) and store the creation time and run though the list every 30 mins to delete old ones.