I have two questions regarding this issue.
In addition to Axiom Schema of Replacement, Which axioms do we need to deduce Axiom of Separation?
How to deduce Axiom of Separation from Axiom Schema of Replacement?
Axiom of Separation: $\forall w \forall x \exists y \forall z [z \in y \iff (z \in x \land \varphi(z, w, x ) )]$
Axiom Schema of Replacement:$\forall w \forall A [ (\forall x \in A \implies \exists ! y \varphi(x,y,w, A)) \implies (\exists B \forall x (x \in A \implies \exists y \in B \varphi(x,y,w, A)))]$