# US 11,298,672 B2 · Reactor heating to achieve minimum pressurization temperature

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- Number: US 11,298,672 B2
- Document ID: US11298672B2
- Status: Granted
- Kind: B2
- Application number: 16/996,999
- Filed: 2020-08-19
- Published: 2021-04-22
- Granted: 2022-04-12
- Earliest claimed: 2019-10-16
- Assignees: ExxonMobil Research and Engineering Company
- Applicants: ExxonMobil Research and Engineering Company
- Inventors: Thomas R. Kiliany, Jr.; Suriyanarayanan Rajagopalan
- Web page: https://patentgrep.com/patent/US11298672B2

## CPC

- B01J 19/0013: {Controlling the temperature of the process}
- B01J 8/0285: {Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062)}
- C10G 47/36: Controlling or regulating
- B01J 2208/00194: Tubes
- B01J 2208/00407: outside the reactor bed
- B01J 2208/00415: electric resistance heaters
- B01J 2208/00716: Means for reactor start-up
- C10G 2300/4031: Start up or shut down operations
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES

## Abstract

Systems and methods are provided for performing the initial heating phase for a thick wall reactor, such as a hydroprocessing reactor, by using heat tracing to heat the exterior walls of the reactor. Instead of attempting to initially heat the reactor by passing a low pressure heat transfer gas through the interior of the reactor, external heater(s) placed under the reactor insulation can be used to heat the exterior of the reactor. An example of a suitable external heater is a heat tracing blanket, where heat is provided by passing steam through pipes in contact with the external surface or by electrical heaters in contact with the external surface. This can allow for more rapid heating of the reactor, so that a target temperature can be achieved in a time of 5.0 hours or less.

## Claims

### Claim 1

A method for starting up a reactor, comprising:
heating a reactor wall of a reactor from an initial temperature of less than 70° C. to a first temperature of 95° C. or more by heating an external wall surface of the reactor wall using heat tracing, a pressure in the reactor being 2.0 MPa-g or less during the heating;
passing a pressurizing gas flow into the reactor to increase the pressure in the reactor by 0.5 MPa or more; and
passing a heated gas flow into the reactor to increase the temperature of the reactor wall by 50° C. or more relative to the first temperature.

### Claim 2 (depends on 1)

The method of claim 1, wherein at least a portion of the pressurizing gas flow comprises the heated gas flow.

### Claim 3 (depends on 1)

The method of claim 1, wherein the heat tracing comprises electrical heat tracing, steam heat tracing, or a combination thereof.

### Claim 4 (depends on 1)

The method of claim 1, wherein the heat tracing is inactive during the passing of the heated gas flow into the reactor.

### Claim 5 (depends on 1)

The method of claim 1, wherein a supplemental gas flow is passed into the reactor during the heating of the reactor wall using the heat tracing, the supplemental gas flow comprising a temperature greater than the initial temperature.

### Claim 6 (depends on 1)

The method of claim 1, wherein the external wall surface is heated to a second temperature that is greater than the first temperature by 10° C. to 50° C.

### Claim 7 (depends on 1)

The method of claim 1, wherein the reactor wall comprises a thickness of 2.5 cm or more.

### Claim 8 (depends on 1)

The method of claim 1, wherein the heating using the heat tracing is performed for 5 hours or less.

### Claim 9 (depends on 1)

The method of claim 1, wherein the reactor comprises a hydroprocessing reactor.

### Claim 10 (depends on 1)

The method of claim 1, wherein passing the pressurized gas flow into the reactor increases the pressure to 3.4 MPa-g or more, or wherein passing the heated gas flow into the reactor increases the temperature of the reactor wall to 250° C. or more, or a combination thereof.

### Claim 11 (depends on 1)

The method of claim 1, further comprising exposing a feedstock to a pressure of 2.0 MPa-g or more and a temperature of 250° C. or more in the presence of H2 in the reactor to form a hydroprocessed product.

### Claim 12 (depends on 1)

The method of claim 1, wherein the reactor wall comprises a reactor wall that has previously been exposed to a partial pressure of H2 at a temperature of 250° C. or more and a pressure of 2.0 MPa-g or more.

### Claim 13

A method for starting up a reactor, comprising:
heating a reactor wall of a reactor from an initial temperature of less than 70° C. to a first temperature of 95° C. to 160° C. by heating an external wall surface of the reactor wall using heat tracing, a pressure in the reactor being 2.0 MPa-g or less during the heating;
passing a pressurizing gas flow into the reactor to increase the pressure in the reactor to 2.5 MPa-g or more; and
passing a heated gas flow into the reactor to increase the temperature of the reactor wall from the first temperature to a temperature of 200° C. or more.

### Claim 14 (depends on 13)

The method of claim 13, wherein at least a portion of the pressurizing gas flow comprises the heated gas flow.

### Claim 15 (depends on 13)

The method of claim 13, wherein the heat tracing comprises electrical heat tracing, steam heat tracing, or a combination thereof.

### Claim 16 (depends on 13)

The method of claim 13, wherein the heat tracing is inactive during the passing of the heated gas flow into the reactor, or wherein a supplemental gas flow is passed into the reactor during the heating of the reactor wall using the heat tracing, the supplemental gas flow comprising a temperature greater than the initial temperature.

### Claim 17 (depends on 13)

The method of claim 13, wherein the external wall surface is heated to a second temperature that is greater than the first temperature by 10° C. to 50° C., and wherein the second temperature is 105° C. to 200° C.

### Claim 18 (depends on 13)

The method of claim 13, wherein the reactor wall comprises a thickness of 2.5 cm or more.

### Claim 19 (depends on 13)

The method of claim 13, wherein the heating using the heat tracing is performed for 5 hours or less.

### Claim 20 (depends on 13)

The method of claim 13, wherein the reactor comprises a hydroprocessing reactor, the method further comprising exposing a feedstock to a pressure of 2.0 MPa-g or more and a temperature of 250° C. or more in the presence of H2 in the reactor to form a hydroprocessed product.