Why do I lay lot of farts during pawan mukt aasan I perform. My other companions usually don't have that much.

Pawan Mukt aasan .... Pawan means.. Air, Mukt means free , aasan means posture.. AIR FREEING POSTURE. So the aasan is doing its job !! Freeing the trapped air is the object which you are accomplishing. Either your companions are not doing it right or they are a little bit discrete about it.