Police say David Alun Lewis lived with his parents in Ystrad Mynach, but would sometimes visit Cardiff and stay at the Huggard Centre.
His parents have paid tribute to him:
This is so sad. We love David so much and our lives will never be the same again.
We can’t believe such a thing has happened to our son.
The last known sighting of Mr Lewis was around 7.45pm on Wednesday walking along Penarth Road near the Big Yellow Storage opposite a BMW garage.
Police are still appealing for witnesses, and say they want to speak to anyone who was near the Taff Embankment between 7.45pm and 11.45pm on Wednesday.
More top news
Rain and drizzle will clear eastern counties this evening. Remaining mild with breaks in the cloud by dawn.
A leading vet charity warns that you could end up with a stressed, lonely or even aggressive pet if you don't care for it properly.
From pensioners to first-time buyers to public sector workers, a rundown of how today's Autumn Statement and Spending Review affect you.