Yes, SUBLIMATIONS is a Scrabble word!

Letter values in Scrabble US: S 1, U 1, B 3, L 1, I 1, M 3, A 1, T 1, I 1, O 1, N 1, S 1.

Is it a valid word?

SUBLIMATIONS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(chemistry) a change directly from the solid to the gaseous state without becoming liquid
(psychology) modifying the natural expression of an impulse or instinct (especially a sexual one) to one that is socially acceptable