Those are hard to identify from a picture. The first one looks like ponytail palm (Beaucarnea recurvata), which is not a palm, weirdly enough. The second of course is a palm but can't tell the genus from the picture. You could probably look it up in The Encyclopedia of Cultivated Palms by Riffle, Craft and Zona. It's a great book if you like palms. I actually have a copy at home but am not going to spend the time to look it up - you should be able to find it in a library. Palms with blue leaves are relatively uncommon so it shouldn't take too long to pin it down.
If you are in Minas Gerais then I would go to UFV in Vicosa and find someone who works on ornamentals or plant taxonomy. I know a couple of professors there who could probably point you in the right direction if you go there often. Good luck!