How to access session hash by using session id?

In my rails application, I want to access the session hash by using session id. I tried the below.

 mysessionid=request.session_options[:id].to_s.strip ##"d80f7f8d71a1cba7fd11b4f76e571fc1"
 session_hash=session[mysessionid]

But it was not giving the session hash. Is there any way to access session hash?