Pure exact structures and the pure derived category of a scheme

Abstract Let $\mathcal{C}$ be closed symmetric monoidal Grothendieck category. We define the pure derived category with respect to the monoidal structure via a relative injective model category structure on the categoryC( $\mathcal{C}$ ) of unbounded chain complexes in $\mathcal{C}$ . We use λ-Purity techniques to get this. As application we define the stalkwise pure derived category of the category of quasi–coherent sheaves on a quasi-separated scheme. We also give a different approach by using the category of flat quasi–coherent sheaves.