Did his son marry in Ireland? If so, the name of the townland where he lived at the time should be on the certificate. Of course, it's possible the son had moved away from his family's townland, but it would at least give you somewhere to focus your initial research.
If the certificate is not an Irish one, you're going to have a bit more of a hunt on your hands. There are no obvious clues in Griffiths Valuation which was carried out in Kilkenny in 1849/50 (Edward may not have been a head of household at that point, of course).
Do you know if your ancestors came from Kilkenny Town or county Kilkenny? You could check Slaters Directory for 1846 for the main Kilkenny towns at:
http://www.failteromhat.com/slaterl.php.
Slater published another directory ten years later. It's available in the National Library in Kildare Street, Dublin, but I don't know if it's online. Perhaps someone else can chip in with that info.
Unless you can pinpoint an urban street or a townland, you won't be able to take your research much further, I'm afraid.
All the best.
