MULTI-STEP PROCESS FOR POLYMERISATION OF OLEFINS Russian patent published in 2015 - IPC C08F10/00 C08F2/01 C08F2/34 

FIELD: chemistry.

SUBSTANCE: process is carried out in at least two series-connected gas-phase polymerisers. The first gas-phase reactor is a fluidised-bed reactor having a gas distribution system and a sump tube. The upper opening of the tube is aligned with the gas distribution system. The tube has a layer of polyolefin particles which move from the top to the bottom of the sump tube. The process comprises feeding a liquid into the sump tube in such an amount that upward flow of the liquid is induced in the layer of polyolefin particles above the tip for feeding a fluid medium, extracting polyolefin particles from the lower end of the sump tube and transferring the extracted polyolefin particles into a second gas-phase polymeriser. A process of polymerising olefins is also described.

EFFECT: preventing transfer of the reaction gas mixture from the first gas-phase reactor into the second, performing continuous gas-phase polymerisation with low operational costs.

9 cl, 2 dwg, 3 ex