Laravel customized session.lifetime at user level

I am overwriting session.timeout value in one of the middleware (for Laravel web app) but it doesn't seem to be affecting in terms of timing out a session. Though if I debug it shows value I have overwritten.

Config::set('session.lifetime', 1440);

default value is as following:

'lifetime' => 15,

Website that I am working on has very short session lifetime for most of the users but for selected users I want to provide extended session lifetime.

via Chebli Mohamed