You shouldn't try to recreate the session and then operate it, you should get the session via the security manager, using the thread the user was logged into, like so:
SecurityUtils.getSubject().logout();
If you somehow want to call logout from a different thread, you can use the SessionDAO interface, but you need to do extra configuration to have shiro use a SessionDAO as described here:
http://shiro.apache.org/session-management.html#SessionManagement-SessionStorage
When you have configured it correctly you can do stuff like:
DefaultSecurityManager securityManager = (DefaultSecurityManager) SecurityUtils.getSecurityManager();
DefaultSessionManager sessionManager = (DefaultSessionManager) securityManager.getSessionManager();
Collection<Session> activeSessions = sessionManager.getSessionDAO().getActiveSessions();
for (Session session: activeSessions){
if (sessionId.equals(session.getId()){
session.stop();
}
}