Baking powder is a chemical and an edible additive. It is made of baking soda powder and other acidic materials, and is mainly used as a quick loosening agent for flour food.

Yeast is actually a fast-acting dry yeast. It is a new type of fine granular yeast strain with fast and efficient fermentation.

The main function of yeast improver is to use enzymes to improve the texture of dough, make the pastry texture more delicate and taste better, and to increase the bulkiness. Some enzymes also have the functions of whitening and assisting bulkiness.

So:

Baking powder can be used with improver.

Yeast can be used with improvers.

But yeast cannot be used with baking powder.