Systems and methods for injection of feedstock are included. In one embodiment, a system includes a solid fuel injector. The solid fuel injector includes a solid fuel passage, a first gas passage, and a second gas passage. The solid fuel passage is configured to inject a solid fuel through a fuel outlet in a fuel direction. The first gas passage is configured to inject a first gas through a first gas outlet in a first gas direction. The second gas passage is configured to inject a second gas through a second gas outlet in a second gas direction. The first gas direction is oriented at a first angle relative to the fuel direction. The second gas direction is oriented at a second angle relative to the fuel direction, and the first and second angles are different from one another.