Abstract: The invention concerns a method for producing esters of a hydroxy acid and a C1-C8 alcohol. The invention is characterized by the fact that the esterification is carried out by reactive distillation on a heterogeneous catalyst. The invention makes it possible in particular to produce high purity lactic acid esters in high yields.

Abstract: A nozzle that consists of a pipe (4) with the end that extends into the treatment space surrounded by a hood (6) is employed to inject solids into a reaction space, a fluidized-bed combustion chamber for example, pneumatically. There are outlet bores (12) in the wall of the pipe (4) and below the lower edge of the hood (6). Inside the pipe (4) is an inner pipe (13) that is connected tight to pipe (14) above the outlet bores (12) and that creates in conjunction with the pipe (4) a space (14) for air to flow through. The air flowing through this intermediate space (14) and emerging from the outlet bores (12) ensures transverse intermixture of the solids inside the reaction space.