I have an application already running in Amazon EC2 instance with Apache and PHP installed. Now I'm trying to run another application in same instance with another apache installed. Is it possible to implement?
When you say "With another apache" you mean another version? Why can't you use the same version for both apps? Maybe what you need is just another application instace instead of a new apache instance.
Any way, as David said in the comments, you should check docker. It is the easiest way to get it done.
If it is too much, here you have a wiki page where they configure multiple apache instance. Hope it is usefull.