# US 10,502,495 B2 · Systems for recovery and re-use of waste energy in crude oil refining facility and aromatics complex

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- Number: US 10,502,495 B2
- Document ID: US10502495B2
- Status: Granted
- Kind: B2
- Application number: 15/833,730
- Filed: 2017-12-06
- Published: 2018-04-05
- Granted: 2019-12-10
- Earliest claimed: 2015-08-24
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Mahmoud Bahy Mahmoud Noureldin; Hani Mohammed Al Saed
- Web page: https://patentgrep.com/patent/US10502495B2

## CPC

- F28D 7/0083: {with units having particular arrangement relative to a supplementary heat exchange medium, e.g. with interleaved units or with adjacent units arranged in common flow of supplementary heat exchange medium}
- B01D 3/007: {Energy recuperation; Heat pumps}
- B01D 3/32: Other features of fractionating columns {; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30}
- B01D 51/10: Conditioning the gas to be cleaned
- B01D 53/047: Pressure swing adsorption
- B01D 53/1462: {Removing mixtures of hydrogen sulfide and carbon dioxide}
- B01D 53/185: {Liquid distributors}
- B01D 53/343: {Heat recovery}
- B01D 53/48: Sulfur compounds
- B01D 53/8603: {Removing sulfur compounds}
- B01D 53/96: Regeneration, reactivation or recycling of reactants
- C01B 3/24: of hydrocarbons
- C01B 3/34: by reaction of hydrocarbons with gasifying agents
- C02F 1/586: {by removing ammoniacal nitrogen (for biological methods C02F3/00)}
- C07C 7/08: by extractive distillation
- C10G 33/06: with mechanical means, e.g. by filtration
- C10G 35/04: Catalytic reforming
- C10G 45/00: Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
- C10G 45/02: to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
- C10G 45/44: Hydrogenation of the aromatic hydrocarbons
- C10G 47/00: Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions (C10G15/00 takes precedence; destructive hydrogenation of non-melting solid carbonaceous or similar materials C10G1/06)
- C10G 65/00: Treatment of hydrocarbon oils by two or more hydrotreatment processes only
- C10G 65/12: including cracking steps and other hydrotreatment steps
- C10G 69/00: Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process (C10G67/00 takes precedence)
- C10K 3/04: reducing the carbon monoxide content {, e.g. water-gas shift [WGS]}
- C10L 3/101: {Removal of contaminants}
- C10L 3/103: {Sulfur containing contaminants}
- C10L 3/104: {Carbon dioxide}
- F01D 17/145: {by means of valves, e.g. for steam turbines (valves in general F16K)}
- F01K 3/185: {using waste heat from outside the plant (F02G5/00 takes precedence)}
- F01K 13/00: General layout or general methods of operation of complete plants
- F01K 13/02: Controlling, e.g. stopping or starting
- F01K 23/06: combustion heat from one cycle heating the fluid in another cycle
- F01K 23/064: {in combination with an industrial process, e.g. chemical, metallurgical}
- F01K 25/06: using mixtures of different fluids (plants using mixtures of steam and gas F01K21/04)
- F01K 25/08: using special vapours
- F01K 27/00: Plants for converting heat or fluid energy into mechanical energy, not otherwise provided for
- F01K 27/02: Plants modified to use their waste heat, other than that of exhaust, e.g. engine-friction heat
- F28F 9/26: Arrangements for connecting different sections of heat-exchange elements, e.g. of radiators (connecting different sections in water heaters F24H9/14 {, connecting headers with inlet or outlet fittings F28F9/0246})
- H02K 7/1823: {structurally associated with turbines or similar engines}
- B01D 2252/204: Amines
- C01B 2203/0227: containing a catalytic reforming step
- C01B 2203/0233: the reforming step being a steam reforming step
- C01B 2203/0283: containing a CO-shift step, i.e. a water gas shift step
- C01B 2203/043: Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
- C01B 2203/127: Catalytic desulfurisation
- C02F 2101/10: Inorganic compounds
- C02F 2101/101: {Sulfur compounds}
- C02F 2101/16: Nitrogen compounds, e.g. ammonia
- C02F 2103/18: from the purification of gaseous effluents
- C02F 2103/36: from the manufacture of organic compounds
- C10G 2300/202: Heteroatoms content, i.e. S, N, O, P
- C10G 2300/207: Acid gases, e.g. H2S, COS, SO2, HCN
- C10G 2300/4006: Temperature
- C10G 2300/4056: Retrofitting operations
- C10G 2400/04: Diesel oil
- C10G 2400/30: Aromatics
- C10L 2290/06: Heat exchange, direct or indirect
- C10L 2290/541: Absorption of impurities during preparation or upgrading of a fuel
- Y02P 20/129: Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
- Y02P 30/00: Technologies relating to oil refining and petrochemical industry
- F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- 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
- C10K: PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
- C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D)
- F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

Configurations and related processing schemes of inter-plants and hybrid, intra- and inter-plants' direct or indirect heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of inter-plants and hybrid, intra- and inter-plants' direct or indirect heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

## Claims

### Claim 1

A system comprising:
an aromatics complex of a crude oil refining facility, the aromatics complex configured to perform at least one oil refining process, the aromatics plant included in a plurality of oil refining plants of the crude oil refining facility, a plurality of streams at respective temperatures flowing between the plurality of oil refining plants, wherein the aromatics complex comprises a plurality of aromatics complex sub-units comprising an aromatics complex xylene products separation unit and a benzene extraction unit;
a first oil refining plant included in the plurality of oil refining plants, the first oil refining plant being different from the aromatics complex, wherein the plurality of oil refining plants comprise a sulfur recovery plant, a gas separation plant through which a gas separation plant stream comprising at least one of C2 to C4 flows, a hydrogen plant, a sour water stripper plant, an amine regeneration plant through which an acid gas regenerator bottoms stream comprising a weak amine salt flows, and a diesel hydro-treating plant;
a flow control system connected to the plurality of oil refining plants, the flow control system configured to:
flow an aromatics complex stream comprising a raffinate overheads column stream in the aromatics complex to a first heat exchanger of a heat exchanger system comprising one or more heat exchangers, and
flow a first stream from the first oil refining plant to the first heat exchanger; and
the heat exchanger system comprising:
the first heat exchanger configured to transfer heat between the aromatics complex stream and the first stream from the first oil refining plant.

### Claim 2 (depends on 1)

The system of claim 1, wherein the aromatics complex stream comprises a plurality of streams from one or more of the plurality of aromatics complex sub-units, and wherein the heat exchanger system is configured to directly heat the first stream from the first oil refining plant using the plurality of streams from the one or more of aromatics complex sub-units.

### Claim 3 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat an amine regenerator bottoms stream in the sulfur recovery plant using a first branch of the raffinate overheads column stream,
a second heat exchanger configured to heat a C3/C4 splitter bottoms stream in the gas separation plant using a second branch of the raffinate overheads column stream,
a third heat exchanger configured to heat a de-ethanizer bottoms stream in the gas separation plant using a third branch of the raffinate overheads column stream, and
wherein the flow control system is configured to:
flow the heated amine regenerator bottoms stream to the sulfur recovery plant, and
flow the heated C3/C4 splitter bottoms stream and the heated de-ethanizer bottoms stream to the gas separation plant.

### Claim 4 (depends on 3)

The system of claim 3, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are fluidically coupled to each other in parallel.

### Claim 5 (depends on 2)

The system of claim 2, wherein the heat exchanger system comprises:
the first heat exchanger configured to heat a raffinate splitter bottom stream in the aromatics complex using a low temperature shift (LTS) hydrogen plant stream in the hydrogen plant,
a second heat exchanger configured to heat a first branch of a sour water stripper bottom cold stream in the sour water stripper plant using a diesel hydro-treating stripper overhead stream in the diesel hydro-treating plant, and
a third heat exchanger configured to heat a second branch of the sour water stripper bottom cold stream using a diesel hydro-treating stripper bottom product stream in the diesel hydro-treating plant,
wherein the flow control system is configured to:
flow the heated raffinate splitter bottom stream to the benzene extraction unit, and
flow the heated first branch and the heated second branch of the sour water stripper bottom cold stream to the sour water stripper plant.

### Claim 6 (depends on 5)

The system of claim 5, wherein the second heat exchanger and the third heat exchanger are fluidically coupled to each other in parallel.

### Claim 7 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat a sour water stripper bottom cold stream in the sour water stripper plant using a first branch of the raffinate overheads column stream,
a second heat exchanger configured to heat a C3/C4 splitter bottoms stream in the gas separation plant using a second branch of the raffinate overheads column stream, and
a third heat exchanger configured to heat a de-ethanizer bottoms stream in the gas separation plant using a third branch of the raffinate overheads column stream,
wherein the flow control system is configured to:
flow the heated sour water stripper bottom cold stream to the sour water stripper plant, and
flow the heated C3/C4 splitter bottoms stream and the heated de-ethanizer bottoms stream to the gas separation plant.

### Claim 8 (depends on 7)

The system of claim 7, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are coupled to each other in parallel.

### Claim 9 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat a sour water stripper bottom cold stream in the sour water stripper plant using a first branch of the raffinate overheads column stream, and
a second heat exchanger configured to heat an amine regenerator bottoms stream using a second branch of the raffinate overheads column stream,
wherein the flow control system is configured to:
flow the heated sour water stripper bottom cold stream to the sour water stripper plant, and
flow the heated amine regenerator bottoms stream to the sulfur recovery plant.

### Claim 10 (depends on 9)

The system of claim 9, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in parallel.

### Claim 11 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat the acid gas regenerator bottom stream in the amine regeneration plant using a first branch of the raffinate overheads column stream, and
a second heat exchanger configured to heat an amine regenerator bottoms stream using a second branch of the raffinate overheads column stream,
wherein the flow control system is configured to:
flow the heated acid gas regenerator bottom cold stream to the amine regeneration plant; and
flow the heated amine regenerator bottoms stream to the sulfur recovery plant.

### Claim 12 (depends on 11)

The system of claim 11, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in parallel.

### Claim 13 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat an acid gas regeneration bottom stream using a first branch of the raffinate overheads column stream, and
a second heat exchanger configured to heat a sour water stripper plant bottom stream using a second branch of the raffinate overheads column stream,
wherein the flow control system is configured to:
flow the heated acid gas regenerator bottom cold stream to the amine regeneration plant, and
flow the heated sour water stripper plant bottom stream to the sour water stripper plant.

### Claim 14 (depends on 13)

The system of claim 13, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in parallel.

### Claim 15 (depends on 2)

The system of claim 2, wherein the aromatics complex stream comprises the raffinate overheads column stream in the aromatics complex xylene products separation unit, and wherein, to directly heat the first stream, the heat exchanger system comprises:
the first heat exchanger configured to heat an acid gas regenerator bottom stream in the amine regeneration plant using a first branch of the raffinate overheads column stream,
a second heat exchanger configured to heat a sour water stripper plant bottom stream in the sour water stripper plant using a second branch of the raffinate overheads column stream, and
a third heat exchanger configured to heat an amine regenerator bottoms stream in the sulfur recovery plant using an extract column overhead stream in the aromatics complex,
wherein the flow control system is configured to:
flow the heated acid gas regenerator bottom cold stream to the amine regeneration plant,
flow the heated sour water stripper plant bottom stream to the sour water stripper plant, and
flow the heated amine regenerator bottoms stream to the sulfur recovery plant.

### Claim 16 (depends on 15)

The system of claim 15, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in parallel.

### Claim 17 (depends on 1)

The system of claim 1, further comprising a buffer fluid, wherein the heat exchanger system is configured to heat the first stream from the first oil refining plant indirectly through the buffer fluid using the aromatics complex stream.

### Claim 18 (depends on 17)

The system of claim 17, wherein the buffer fluid comprises at least one of oil or water.

### Claim 19 (depends on 17)

The system of claim 17, wherein, to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises:
the first heat exchanger configured to heat the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit,
wherein the flow control system is configured to flow the heated buffer fluid exiting the first heat exchanger to the sulfur recovery plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat an amine regenerator bottoms stream using the first branch of the heated buffer fluid,
wherein the flow control system is configured to:
split the buffer fluid exiting the second heat exchanger into a first branch and a second branch, and
flow the first branch of the heated buffer fluid to the gas separation plant,
wherein the heat exchanger system comprises a third heat exchanger configured to heat a de-ethanizer bottoms stream in the gas separation plant stream using the second branch of the heated buffer fluid,
wherein the flow control system is configured to flow the second branch of the heated buffer fluid to the gas separation plant, and
wherein the heat exchanger system comprises a fourth heat exchanger configured to heat a C3/C4 splitter bottoms stream in the benzene extraction unit using the third branch of the heated buffer fluid.

### Claim 20 (depends on 19)

The system of claim 19, wherein the flow control system is configured to:
flow the second branch and the third branch in parallel to the gas separation plant;
combine the second branch and the third branch exiting the third heat exchanger and the fourth heat exchanger, respectively, resulting in a combined buffer fluid stream; and
flow the combined buffer fluid stream to a buffer fluid tank.

### Claim 21 (depends on 20)

The system of claim 20, wherein the first heat exchanger and the second heat exchanger are coupled to each other in series, wherein the third heat exchanger is fluidically coupled to the second heat exchanger in series, wherein the fourth heat exchanger is fluidically coupled to the second heat exchanger in series.

### Claim 22 (depends on 17)

The system of claim 17, wherein to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises:
the first heat exchanger configured to heat a first branch of the buffer fluid using a low temperature shift (LTS) converter stream in the hydrogen plant,
a second heat exchanger configured to heat a second branch of the buffer fluid using a diesel hydro-treating stripper overhead stream in the diesel hydro-treating plant, and
a third heat exchanger configured to heat a third branch of the buffer fluid using a diesel hydro-treating stripper bottom product stream in the diesel hydro-treating plant,
wherein the flow control system is configured to:
combine the heated first branch, the heated second branch and the heated third branch resulting in heated buffer fluid, and
flow the combined heated first branch, heated second branch and heated third branch to the sour water stripper plant,
wherein the heat exchanger system comprises a fourth heat exchanger configured to heat a sour water stripper bottom stream using the combined heated first branch, heated second branch and heated third branch,
wherein the flow control system is configured to flow the combined heated first branch, heated second branch and heated third branch exiting the fourth heat exchanger to a benzene extraction unit, and
wherein the heat exchanger system comprises a fifth heat exchanger configured to heat a raffinate column stream in the benzene extraction unit using the combined heated first branch, heated second branch and heated third branch received from the fourth heat exchanger.

### Claim 23 (depends on 22)

The system of claim 22, further comprising flowing the heated buffer fluid exiting the fifth heat exchanger to a buffer fluid tank.

### Claim 24 (depends on 22)

The system of claim 22, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are fluidically coupled to each other in parallel, wherein the fourth heat exchanger is fluidically coupled in parallel with a combination of the first heat exchanger, the second heat exchanger and the third heat exchanger, wherein the fifth heat exchanger is fluidically coupled to the fourth heat exchanger in series.

### Claim 25 (depends on 17)

The system of claim 17, wherein to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises the first heat exchanger configured to heat the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit,
wherein the flow control system is configured to flow the heated buffer fluid exiting the first heat exchanger to the sour water stripper plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat a sour water stripper bottom cold stream in the sour water stripper plant using the first branch of the heated buffer fluid received from the first heat exchanger,
wherein the flow control system is configured to:
split the heated buffer fluid received from the second heat exchanger into a first branch and a second branch, and
flow the first branch to the gas separation plant,
wherein the heat exchanger system comprises a third heat exchanger configured to heat a de-ethanizer bottoms stream in the gas separation plant using the first branch,
wherein the flow control system is configured to flow the second branch to the gas separation plant, and
wherein the heat exchanger system comprises a fourth heat exchanger configured to heat a C3/C4 splitter bottoms stream in the benzene extraction unit using the second branch.

### Claim 26 (depends on 25)

The system of claim 25, wherein the flow control system is configured to:
combine the first branch and the second branch exiting the third heat exchanger and the fourth heat exchanger, respectively, resulting in a combined buffer fluid stream; and
flow the combined buffer fluid stream to a buffer fluid tank.

### Claim 27 (depends on 25)

The system of claim 25, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in series, wherein the second heat exchanger and the third heat exchanger are fluidically coupled to each other in series, wherein the third heat exchanger and the fourth heat exchanger are coupled to each other in parallel, wherein the second heat exchanger is fluidically coupled to a combination of the third heat exchanger and the fourth heat exchanger in series.

### Claim 28 (depends on 17)

The system of claim 17, wherein, to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises the first heat exchanger configured to heat the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit,
wherein the flow control system is configured to:
split the heated buffer fluid exiting the first heat exchanger into a first branch and a second branch, and
flow the first branch to the sulfur recovery plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat an amine regenerator bottoms stream in the sulfur recovery plant using the first branch,
wherein the flow control system is configured to flow the second branch to the sour water stripper plant, and
wherein the heat exchanger system comprises a third heat exchanger configured to heat a sour water stripper bottom stream in the sulfur recovery plant using the second branch.

### Claim 29 (depends on 28)

The system of claim 28, wherein the flow control system is configured to:
flow the first branch and the second branch in parallel to the sour water stripper plant;
combine the first branch and the second branch exiting the second heat exchanger and the third heat exchanger, respectively, resulting in a combined buffer fluid stream; and
flow the combined buffer fluid stream to a buffer fluid tank.

### Claim 30 (depends on 28)

The system of claim 28, wherein the second heat exchanger and the third heat exchanger are fluidically coupled to each other in parallel, and wherein the first heat exchanger and a combination of the second heat exchanger and the third heat exchanger are fluidically coupled to each other in series.

### Claim 31 (depends on 17)

The system of claim 17, wherein, to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises the first heat exchanger configured to heat the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit,
wherein the flow control system is configured to flow the heated buffer fluid exiting the first heat exchanger to the sulfur recovery plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat an amine regenerator bottoms stream in the sulfur recovery plant using the heated buffer fluid received from the first heat exchanger,
wherein the flow control system is configured to flow the heated buffer fluid exiting the second heat exchanger to the amine regeneration plant,
wherein the heat exchanger system comprises a third heat exchanger configured to heat an acid gas regenerator bottom stream in the amine regeneration plant using the heated buffer fluid received from the second heat exchanger.

### Claim 32 (depends on 31)

The system of claim 31, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are coupled to each other in series, and wherein the flow control system is configured to flow the buffer fluid stream exiting the third heat exchanger to a buffer fluid tank.

### Claim 33 (depends on 17)

The system of claim 17, wherein, to indirectly heat the first stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises the first heat exchanger configured to heat the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit,
wherein the flow control system is configured to flow the heated buffer fluid exiting the first heat exchanger to the sour water stripper plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat a sour water stripper plant bottom stream in the sour water stripper plant using the heated buffer fluid received from the first heat exchanger,
wherein the flow control system is configured to flow the heated buffer fluid exiting the second heat exchanger to the amine regeneration plant, and
wherein the heat exchanger system comprises a third heat exchanger configured to heat an acid gas regenerator bottom cold stream in the amine regeneration plant using the second branch of the heated buffer fluid received from the second heat exchanger.

### Claim 34 (depends on 33)

The system of claim 33, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are coupled to each other in series, and wherein the flow control system is configured to flow the buffer fluid stream exiting the third heat exchanger to a buffer fluid tank.

### Claim 35 (depends on 17)

The system of claim 17, wherein, to indirectly heat the stream from the first oil refining plant through the buffer fluid, the heat exchanger system comprises:
the first heat exchanger configured to heat a first branch of the buffer fluid using a raffinate overheads column stream in the aromatics complex xylene products separation unit, and
a fourth heat exchanger configured to heat a second branch of the buffer fluid using an extract column overhead stream in the aromatics complex,
wherein the flow control system is configured to flow the first branch of the heated buffer fluid exiting the first heat exchanger to the sour water stripper plant,
wherein the heat exchanger system comprises a second heat exchanger configured to heat a sour water stripper bottom stream in the sour water stripper plant using the first branch of the heated buffer fluid received from the first heat exchanger,
wherein the flow control system is configured to flow the heated buffer fluid exiting the second heat exchanger to the amine regeneration plant,
wherein the heat exchanger system comprises a third heat exchanger configured to heat an acid gas regenerator section stripper bottom stream using the heated buffer fluid received from the second heat exchanger,
wherein the flow control system is configured to flow the second branch of the heated buffer fluid exiting the fourth heat exchanger to the sulfur recovery plant, and
wherein the heat exchanger system comprises a fifth heat exchanger configured to heat an amine regenerator bottoms stream in the sulfur recovery plant using the second branch of the heated buffer fluid received from the fourth heat exchanger.

### Claim 36 (depends on 35)

The system of claim 35, wherein the flow control system is configured to:
combine the first branch exiting the third heat exchanger and the second branch exiting the fifth heat exchanger resulting in a combined buffer fluid stream; and
flow the combined buffer fluid stream to a buffer fluid tank.

### Claim 37 (depends on 35)

The system of claim 35, wherein the first heat exchanger and the fourth heat exchanger are fluidically coupled to each other in parallel, wherein the first heat exchanger and the second heat exchanger are fluidically coupled to each other in series, wherein the second heat exchanger and the third heat exchanger are fluidically coupled to each other in series, wherein the fifth heat exchanger and the fourth heat exchanger are fluidically coupled to each other in series.