Abstract: The invention relates to a method for the removal of lactide from polylactide and recovery of lactide from a lactide-containing gas by cooling the hot lactide-containing gas, wherein a polymer melt traveling through a nozzle forms thin threads the surface area of which is so large that in a normal-pressure or vacuum evaporator the lactide evaporates from the polymer rapidly into a hot carrier-gas flow and the polymer settles under gravity onto a collecting device. A hot lactide-containing gas is cooled rapidly to a temperature below 100° C., whereupon the lactide crystallizes from gas, forming lactide crystals, which are separated from the gas.

Abstract: The invention relates ro a method of converting hydrocarbons. According to the method, a gaseous or liquid hydrocarbon feed is passed into a circulating fluidized-bed reactor, wherein the feed is converted at a high temperatue under the influence of particulate matter kept in a fluidized state, and the converted hydrocarbon products are removed from the reactor in a gaseous phase. According to the invention, a circulating fluidized-bed reactor (1-3; 41-43) is used having an axially annular cross section and being equipped with a multiport cyclone (14,17; 52,63) for the separation of the particulate matter from the gas-phase reaction products. The reaction space comprises an intershell riser space (13; 50) formed between two concentrically located cylindrical and/or conical envelope surfaces. The separation of particulate matter from the gas-phase reaction products is performed by means of a multiport cyclone equipped with louvered vanes (14; 63).