US 11,439,969 B2 · Accelerated cooling process for reactors

Abstract

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, wherein the reactor includes a quench gas distribution system. The process comprises shutting off hydrocarbon feed to the reactor, stripping hydrocarbons from the catalyst, and cooling the reactor to a first threshold reactor temperature in the range of from 375-425° F. (190-218° C.). At least a portion of circulating gaseous medium flowing to the reactor is then routed through a temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.). Once cooled, mixing the cooled gas with the circulating gaseous medium flowing to the reactor. Continuing steps routing and cooling until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.). The reactor can then be purged with N2 gas, followed by introducing water into the reactor via the quench gas distribution system. The catalyst can then be safely removed from the reactor.

Claims17

Dependent claims

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, wherein the reactor includes a quench gas distribution system, the process comprising:

a) shutting off hydrocarbon feed to the reactor;
b) stripping hydrocarbons from the catalyst;
c) cooling the reactor to a first threshold reactor temperature in the range of from 375-425° F. (190-218° C.);
d) routing at least a portion of circulating gaseous medium flowing to the reactor through at least one temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.);
e) mixing the gas cooled in d) with the circulating gaseous medium flowing to the reactor;
f) continuing steps d) and e) until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.);
g) after step f), purging the reactor with N2 gas;
h) after step g), and when the reactor is at the second threshold reactor temperature, introducing water into the reactor via the quench gas distribution system;
and
i) dumping a catalyst slurry from the reactor, the catalyst slurry comprising the catalyst and the water.

7 more elements

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, the process comprising:

a) shutting off hydrocarbon feed to the reactor;
b) stripping hydrocarbons from the catalyst at a temperature above the final reactor operating temperature;
c) cooling the reactor with H2 gas at a controlled reactor cooling rate, wherein the reactor includes a quench gas distribution system, and during step c) at least a portion of the H2 gas is introduced into the reactor via the quench gas distribution system and the reactor is cooled to a temperature in the range of from 375-425° F.;
d) routing at least a portion of circulating gaseous medium flowing to the reactor through at least one temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.);
e) mixing the gas cooled in d) with the circulating gaseous medium flowing to the reactor;
f) continuing steps d) and e) until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.);
g) circulating N2 gas through the reactor during at least one pressure/depressure cycle of the reactor;
h) after step g), introducing water into the reactor via the quench gas distribution system;
i) when the reactor is flooded with the water, dumping a catalyst slurry from the reactor, wherein the dumped catalyst slurry comprises the catalyst and the water;
j) separating the water from the dumped catalyst slurry to provide separated water;
k) optionally, recycling at least a portion of the separated water to the reactor;
l) after step i), vacuuming residual catalyst from the reactor;
m) after step l), assessing the patency of a plurality of quench apertures of the quench gas distribution system;
and
n) washing at least one internal component of the reactor with pressurized water, wherein:
the controlled cooling rate during step c) is not more than 25° F. per 15 minute interval, and
the water introduced into the reactor during step h) has a temperature not less than 50° F. and a chloride content not more than 50 ppm.

14 more elements

Dependencies are inferred from the claim text.

Accelerated cooling process for reactors

Life of this patent

Accelerated cooling process for reactors

Life of this patent

Abstract

Claims17