A method of drying hemp plants using a rotary drying system that dries the plants without damaging the cannabidiol in the plants.

An apparatus for drying material for an asphalt mixing facility includes a rotary kiln rotatably drivable about an axis of rotation, in which the material is dried, wherein the rotary kiln has a material inlet and a material outlet, a heating unit coupled to the rotary kiln for feeding heat to the rotary kiln, wherein the heating unit is designed with a burner which has a burner housing having a longitudinal axis, an air duct arranged at the burner housing for feeding air, a swirling element for swirling the air in the burner housing relative to the longitudinal axis, a hydrogen gas line connected to the burner for feeding hydrogen gas into the burner, wherein a hydrogen gas nozzle is connected to the hydrogen gas line for discharging the hydrogen gas, a burner head arranged at the burner housing for generating a burner flame.