PLANTS AND METHODS FOR OBTAINING MIDDLE-DISTILLATE PRODUCT AND LOW MOLECULAR WEIGHT OLEFINS FROM INITIAL HYDROCARBON RAW MATERIAL Russian patent published in 2013 - IPC C10G11/18 C10G50/00 C10G51/02 C10G51/06 

FIELD: oil and gas industry.

SUBSTANCE: method involves catalytic cracking of gasoil raw material in lift-reactor FCC zone by contact of the above gasoil raw material and the first catalyst at the temperature of 400°C to 600°C and average residence time in the above lift-reactor FCC zone in the range of 0.1 to 10 sec; as a result, lift-reactor FCC product is obtained, which contains cracked gasoil product and the first waste catalyst; separation of cracked gasoil product from the first waste catalyst; recovery of the first waste catalyst so that the first recovered catalyst is obtained; contact of intermediate raw material with the second catalyst in intermediate cracking reactor operating at the temperature of 482°C to 871°C and the pressure of atmospheric one to 345 kPa, with injection of steam if necessary; as a result, cracked intermediate product containing at least one low molecular weight olefin compound and the second waste catalyst; intermediate raw material contains raffinate C₄ flow; separation of the above cracked gasoil product into several flows of cracked gasoil product; and recirculation at least of some part of one or more flows of cracked gasoil product to lift-reactor zone.

EFFECT: increasing the yield of olefins.

8 cl, 2 dwg