Heavy oil catalytic unit (FDFCC) process technology operating procedures

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This device recycles raw material oil (vacuum residual oil, straight-run wax oil, deasphalted oil, etc.) from outside the device after being mixed by the raw material mixer (M-202), and then enters the raw oil buffer tank (D-202)； After the pressure is boosted by the raw oil pump (P-201/1, 2), it sequentially passes through the light diesel oil-raw oil heat exchanger (E-202/1, 2) and the oil slurry-raw oil heat exchanger (E-204/1, 2) to exchange heat and heat it up to about 265°C. After mixing from the refining oil mixer (M-201) in the fractionation section, it is divided into six paths and enters the lower part of the heavy oil riser reactor through the raw oil atomization nozzle. It contacts the high-temperature catalyst from the bottom catalyst of the heavy oil riser to complete the heating, vaporization and reaction of the raw material. The reacted oil and gas and the to-be-generated catalyst are rapidly separated at the outlet of the riser through three sets of rough cyclones. The gas enters three sets of single-stage cyclone separators in the heavy reverse settler through the riser. After further removing the carried catalyst fines, the reacted oil and gas leaves the heavy reverse settler and enters the main fractionation tower (C-201). The coked to-be-generated catalyst enters the heavy reverse stripping section through the heavy reverse rough spinning leg, where it contacts the stripping steam in countercurrent to strip the oil and gas carried in the catalyst. The stripped catalyst enters the upper part of the dense phase bed through the waiting slide valve and the waiting catalyst distributor. The storage capacity of the heavy reverse stripping section is adjusted by the waiting slide valve. The raw oil in the gasoline riser comes from the crude gasoline from the oil and gas separation tank (D-201) at the top of the main fractionator or the DCC gasoline and unqualified gasoline sent from outside the system. It is heat exchanged by the circulation-raw gasoline heat exchanger (E-220) at the top of the sub-fractionator, and is heated to about 100°C. Then it is divided into four channels through the crude gasoline atomization nozzle and enters the lower part of the steam reverse riser reactor. It contacts the high-temperature catalyst from the catalyst at the bottom of the gasoline riser to complete the heating, vaporization and reaction of the raw materials. The reacted oil gas and the to-be-generated catalyst are quickly separated by two sets of rough cyclones at the outlet of the steam reverse riser. The gases enter the two sets of single-stage cyclone separators in the steam desettler through the riser. After further removing the carried catalyst fines, the reacted oil and gas leave the steam desettler and enter the auxiliary fractionation tower (C-204). The carbon-deposited steam reaction to-be-generated catalyst enters the steam back stripping section through the steam reverse rough spinning leg, where it contacts the stripping steam in countercurrent to strip the oil and gas carried in the catalyst. The stripped catalyst passes through the steam-regeneration cycle inclined pipe, steam-regeneration slide valve, and steam-regeneration circulation riser. It is lifted by the supercharger (K-103/1, 2) and then enters the middle of the dense phase bed through the return pipe. The material level in the stripping section is adjusted by the steam reverse generation slide valve. The other path returns to the bottom of the heavy oil riser and is mixed with the heavy oil regeneration agent. The spent catalysts in heavy reaction and steam reaction both enter again and undergo partial combustion, burning most of the coke and all the hydrogen in the bed. Oxygen for burning is provided by secondary flue gas, primary main air, steam regeneration circulation pipe lifting air, etc. The semi-regenerated catalyst after primary charring passes through the semi-regeneration inclined tube and external heat collector and enters the middle part of the secondary regeneration bed for complete charring and regeneration. The secondary flue gas enters the middle of the primary bed through the riser. The second regeneration center is equipped with a semi-regeneration inclined tube catalyst distributor and an external heat collector return pipe overflow bucket. The second regeneration temperature is controlled by the heat taken from the external heat exchanger. The secondary high-temperature regenerated catalyst is divided into two paths. One path enters the bottom of the heavy-reverse riser through the regeneration inclined tube and contacts the feed oil to complete the heavy-reaction reaction-regeneration system catalyst cycle. The other route enters the bottom of the steam reverse riser through the steam reverse regeneration inclined pipe and contacts the recycled gasoline to complete the catalyst cycle of the steam reverse reaction-regeneration system. The existing external heat collector and steam-water forced circulation system are used to generate medium-pressure saturated steam, and the heated catalyst is cooled down and returned to the reactor. The deoxygenated water used in the external heat exchanger is supplied by the boiler water pump (P-1, 2, 7) and enters the external heat exchanger drum (D-119) for mixing, heat transfer and vapor-liquid separation of the steam-water mixture. The saturated steam generated by the external heat exchanger and the oil slurry steam generator is divided into two paths: One way goes to the existing CO boiler for superheating, and the other way goes to the newly added CO boiler for superheating. The two superheated steams are combined and then enter the medium-pressure steam pipe network of the entire plant. The burning air is supplied by the main fan (K-101/1) or the backup main fan (K-102/1, 2). The main fan outlet is divided into three main air streams: One share goes straight in again and again ； A stream of air is boosted by a supercharger (K-103/3) and used for secondary burning and fluidization by an external heat exchanger. ； The other stream is boosted by the supercharger (K-103/1, 2) and used as steam-regenerating catalyst boosting air. 1.1 In the main fractionation part, the reaction oil and gas from the heavy anti-settler enters the bottom of the fractionation tower, and contacts the circulating oil slurry in countercurrent through the herringbone baffle, washing the catalyst in the reaction oil and gas and desuperheating, so that the oil and gas enters the fractionation tower in a "saturated state" for fractionation. The oil and gas at the top of fractionation tower C201 flow out from the top into the hot water heat exchanger (E-215/1-6) at the top of the fractionation tower, the oil and gas dry air cooler (EC-201/1~12) at the top of the fractionation tower, and the oil and gas aftercooler (E-208/1~6) at the top of the fractionation tower are cooled to 40°C and enter the oil and gas separator (D-201) for gas-liquid separation. The rich gas ejected by D201 (temperature 40℃, pressure about ~0.265MPa (absolute)) enters the rich gas compressor (K-301) ； The crude gasoline from the bottom of D201 is pumped out by the crude gasoline pump (P-202/1,2). After being pressurized, part of it is sent to the top liquid separation tank of the auxiliary fractionation tower. ； All the way to the top of the main fractionating tower is used as cold reflux of the main fractionating tower. ； All the way as steam reverse riser feed. If needed during production, you can directly enter C-301 ； In the event of an accident, the unqualified gasoline line 604/2 can be directly connected to the device. The sulfur-containing sewage separated from the D-201 bottom water separation bag flows into the sulfur-containing sewage tank (D-208), and is sent to the sewage stripping device through the pump (P-209/1,2). The top circulation reflux is extracted from the 27th layer of the fractionation tower using a top circulation reflux pump (P-203/1,2). It is first used as the heat source of the depropanizer tower of the gas separation unit, then passes through E-201/1-4 to exchange heat with hot water, and finally enters EC-201/1-4. The temperature drops to 90°C and returns to the 30th layer of the fractionation tower. Light diesel oil is extracted from the oil collection tank of the 19# tray of the fractionation tower (the tray counting method is from bottom to top), and flows into the light diesel stripping tower (C-202). After steam stripping, it is extracted by the pump (P-204/1,2), and first enters the light diesel oil stripping tower (C-202). The oil-raw oil heat exchanger (E-202/1,2) exchanges heat, and then is sent to the reboiler at the bottom of the amine liquid regeneration tower for heat supply. After the temperature drops to about 120°C, it is then exchanged through the lean absorption oil-rich absorption oil heat exchanger (E-203/1,2). Among them, the diesel produced as a product of the unit is directly used as the raw material for diesel hydrogenation during thermal combination. ； When the heat is not combined, it will be cooled by the diesel cooler (E-210/1,2) before entering the tank area. All the way into the lean absorption oil cooler (E-210/1, 2), it is cooled to 40°C and then sent to the reabsorption tower (C-303) as lean absorption oil. The rich absorption oil from the bottom of the reabsorption tower is heat-exchanged by E-203/1,2 to 100°C and then returned to the upper part of the 22nd layer of the fractionation tower. The first-stage reflux is extracted from the 15th floor of the tower by the pump (P-205/1,2) and used as the heat source for the stabilizing tower reboiler (E-304). It is cooled to 194°C, and then cooled to 190°C through the first-stage fractionation hot water heat exchanger (E-205) and returned to the 18th-layer tray of the tower. The recycled oil flows from the third layer of the tower to the recycled oil tank (D-203), and is pumped out by the recycled oil pump (P-260/1, 2), which is divided into three parts.: All the way back to the second tray of the fractionation tower as internal reflux ； All the way into D-202 as a raw material tank to replenish oil ； The other channel is mixed with raw oil and fed as a heavy reverse riser. In the event of an accident, the bottom of the refining tank can be pumped out directly into the inlet of the slurry pump. The circulating oil slurry is extracted from the bottom of the tower by the oil slurry pump (P-208/1, 2), and exchanges heat with the southern distillation bottom oil (E-206) and the raw material oil (E-204/1-4) in turn, and then enters the oil slurry steam generator (E-207/1, 2) to generate medium-pressure saturated steam. The temperature drops to 280°C and is divided into four paths.: Enter the upper part of the herringbone baffle of the main fractionating tower, the bottom of the main fractionating tower to control the bottom temperature, the herringbone tray of the auxiliary fractionating tower, and the bottom of the auxiliary fractionating tower. After the product oil slurry is extracted from the bottom of the fractionation tower, it is cooled to 90°C through the product oil slurry-hot water heat exchanger and cooling water tank (E-211) as the product discharge device. 1.2 Sub-fractionation part: The reacted oil and gas from the steam anti-settler enters the bottom of the sub-fractionating tower and comes into counter-current contact with a circulating oil slurry from the main fractionating tower. The catalyst in the reacted oil and gas is washed and desuperheated, so that the oil and gas enter the sub-fractionating tower in a "saturated state" for fractionation. The oil and gas at the top of the sub-fractionating tower flow out from the top of the tower and enter the oil-gas-hot water heat exchanger (E-218/1-4) at the top of the sub-fractionating tower and the oil-gas aftercooler (E-219/1-4) at the top of the sub-fractionating tower. After cooling to 40°C, they enter the oil-gas separator of the sub-fractionating tower for vapor-liquid separation. The rich gas ejected from the oil and gas fractionator of the sub-fractionating tower passes through the pressure control valve and enters the rich gas compressor (K-301) together with the rich gas from D-201. ； The modified gasoline coming out of the bottom is pumped out by the modified gasoline pump P-214/1, and after being pressurized, it is used as cold reflux in the sub-fractionating tower. ； The other way is sent to the top of the absorption tower as absorbent. The top circulation reflux of the secondary fractionation tower is extracted from the fourth layer of the fractionation tower (the tray counting method is from top to bottom), passes through the top circulation reflux pump P-213/1, 2 of the secondary fractionation tower, flows through E-220 and exchanges heat with the naphtha from the main fractionation tower, and then exchanges heat with the water heater E-221. The temperature drops to about 110°C and returns to the first layer of the secondary fractionation tower. After the light diesel oil in the auxiliary fractionation tower is extracted from the 14th layer, it flows to the 5th layer tray of the main fractionation tower. The oil in the middle section of the sub-fractionating tower is extracted from the 16th layer of the fractionation tower. It is boosted by the oil pumps P-212/1 and 2 in the middle section of the sub-fractionating tower and sent to the bottom of the desorption tower as a heat source for the reboiler. After exchanging heat with the hot water heat exchanger E-222 in the middle section of the sub-fractionating tower, it returns to the 15th layer of the sub-fractionating tower. The oil slurry at the bottom of the auxiliary fractionation tower flows to the bottom of the main fractionation tower. 1.3 Absorption Stable Part The rich gas from the oil and gas separators at the top of the main and auxiliary fractionation towers enters the first section of the pneumatic compressor for compression, and is then cooled to 40°C by the pneumatic compressor intercooler, and then enters the pneumatic compressor intermediate gas-liquid cooler for gas and liquid separation. When it reaches 40℃, it enters the oil and gas separator (D309) to separate the compressed rich gas and condensed oil. The separated rich gas enters the second stage of the air compressor, and the outlet pressure of the second stage is 1.6MPa (absolute). After the rich gas at the outlet of the second section of the air compressor merges with the top gas of the desorption tower and the wash water, it is cooled by the compressed rich air air cooler (EC-301/1,2), mixed with the bottom oil of the absorption tower, cooled to 40°C by the aftercooler at the outlet of the air compressor (E-305/1-4), and then enters the oil and gas separator (D-301) for three-phase separation of gas, liquid and water. The rich gas from D-301 enters the lower part of the absorption tower, and the modified gasoline and supplementary absorbent as the absorption medium are flown to the 52nd and 56th layers of the absorption tower respectively, where they come into counter-current contact with the gas. The heat released during the absorption process is taken away by the two intermediate recirculation stages. One of the intermediate reflux flows from the 36th layer tray into the absorption tower 1st reflux pump (P-302/1, 2). After being boosted, it is cooled by the absorption 1st intermediate oil cooler (E-306) and then returns to the 37th layer tray of the absorption tower. ； The second middle reflux is extracted from the bottom of the upper section of the absorption tower. It is boosted by the second middle reflux pump (P-303, P-302/2) of the absorption tower and then enters the oil cooler (E-307) of the second middle section of the absorption tower. After cooling, it returns to the upper part of the lower section of the absorption tower. The bottom oil of the absorption tower is boosted by pump P-309/1, 2 and mixed with the rich gas from the compressed rich gas air cooler and then enters the compressed rich gas aftercooler. The lean gas at the top of the absorption tower enters the bottom of the reabsorption tower (C-303), where it contacts the lean absorption oil in countercurrent and absorbs the gasoline components in the lean gas. The pressure at the top of the tower is (1.3~1.4)MPa (absolute), and the temperature is 45°C. The dry gas at the top of the tower is divided into two paths: One road enters the gas system of the entire plant after being purified by the double removal system, and the other road directly enters the gas system in the event of an accident. D-301 bottom condensate oil is pressurized by pumps P-301/1, 2, and directly enters the upper part of desorption tower C-302. The temperature at the top of the tower is 40°C, and the pressure at the top is 1.5MPa (absolute). The overhead gas from the desorption tower is mixed with the compressed rich gas before reaching E-305/1-4. There is a middle extraction section in the middle of the desorption tower, which is heated by stabilized gasoline through the intermediate reboiler E-301 of the desorption tower and then returned to the desorption tower. C-302 deethanized gasoline at the bottom of the tower is pumped out from the stabilizing tower feed pump (P-310/1, 2), and is heated to about 141°C through the stabilizing tower feed heat exchanger (E-303/1, 2) before entering the stabilizing tower (C-304). The stable tower top pressure is 1.15MPa (absolute), the tower bottom temperature is 178°C, and the bottom reboiler E-304 is heated by the main fractionation tower No. 1. Light components below C4 are distilled from the top of C-304. After being condensed and cooled to 40°C by the stabilizing tower top evaporation air cooler (EC-303/1-4), they enter the stabilizing tower top reflux tank (D-302). After the liquefied gas is pressurized with a stable tower top reflux pump (P-305/1, 2), part of it is used as cold reflux, and the other part enters the double deodorization system and the deodorization system and then enters the gas sub-device. The stabilized gasoline at the bottom of the tower undergoes heat exchange through the stabilizing tower feed heat exchanger (E-303/1, 2), the desorption tower intermediate reboiler (E-301), and the stabilized gasoline-demineralized water heat exchanger (E-311/1, 2), and then stabilized After the gasoline cooler (E-309/1, 2) is cooled to 40°C, it is divided into two channels. One channel is driven into the top of tower C-301 with pump P-304/1, 2 as a supplementary absorbent, and the other channel is directly sent to the product refining unit for sweetening.