The delete Account option is hidden in the help section area of the facebook.
If you want to delete the account you can follow this link.
This Can also be found from facebook help section copied as under:
If you deactivate your account from the “Deactivate Account” section on the Account page, your profile and all information associated with it are immediately made inaccessible to other Facebook users. What this means is that you effectively disappear from the Facebook service. However, if you want to reactivate at some point, we do save your profile information (friends, photos, interests, etc.), and your account will look just the way it did when you deactivated if you decide to reactivate it. Many users deactivate their accounts for temporary reasons and expect their information to be there when they return to the service.
If you do not think you will use Facebook again and would like your account deleted, please keep in mind that you will not be able to reactivate your account or retrieve any of the content or information you have added. If you would like your account permanently deleted with no option for recovery, log in to your account and then submit your request by clicking here.
If you are currently unable to access your account, you will need to reset your password in order to log in. In order to do so, click the “Forgot your password?” link that appears above the field where you would normally enter your password. Once you’ve followed the instructions to reset your password and can log in, you can deactivate or delete your account using the steps outlined above. /help/?faq=13016