Power generation from waste heat in integrated crude oil hydrocracking and aromatics facilities

Patent metadata

Field	Value
Publication number	US-9803506-B2
Application number	US-201615087412-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Aug 24, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A power generation system includes two heating fluid circuits coupled to multiple heat sources from multiple sub-units of a petrochemical refining system. The sub-units include an integrated hydrocracking plant and aromatics plant. A first subset and a second subset of the heat sources includes diesel hydro-treating plant heat exchangers coupled to streams in the diesel hydro-treating plant and aromatics plant heat exchangers coupled to streams in the aromatics plant, respectively. A power generation system includes an organic Rankine cycle (ORC) including a working fluid that is thermally coupled to the two heating fluid circuits to heat the working fluid, and an expander to generate electrical power from the heated working fluid. The system includes a control system to activate a set of control valves to selectively thermally couple each heating fluid circuit to at least a portion of the heat sources.

First claim

What is claimed is:

1. A power generation system comprising:
a first heating fluid circuit thermally coupled to a plurality of heat sources from a plurality of sub-units of a petrochemical refining system;
a second heating fluid circuit thermally coupled to the plurality of heat sources from the plurality of sub-units of the petrochemical refining system, wherein the plurality of sub-units comprises a hydrocracking plant and an aromatics plant,
wherein a first subset of the plurality of heat sources comprises a plurality of hydrocracking plant heat exchangers coupled to streams in the hydrocracking plant, and
wherein a second subset of the plurality of heat sources comprises a plurality of aromatics plant heat exchangers coupled to streams in the aromatics plant;

a power generation system that comprises an organic Rankine cycle (ORC), the ORC comprising (i) a working fluid that is thermally coupled to the first heating fluid circuit and the second heating fluid circuit to heat the working fluid, and (ii) an expander configured to generate electrical power from the heated first working fluid; and
a control system configured to activate a set of control valves to selectively thermally couple each of the first heating fluid circuit and the second heating fluid circuit to at least a portion of the plurality of heat sources.

2. The system of claim 1 , wherein the working fluid is thermally coupled to the first heating fluid circuit in a pre-heater of the ORC and to the second heating fluid circuit in an evaporator of the ORC.

3. The system of claim 2 , wherein the working fluid comprises isobutane.

4. The system of claim 1 , wherein the first heating fluid circuit comprises a first heating fluid tank that is fluidly coupled to the first heating fluid circuit, and wherein the second heating fluid circuit comprises a second heating fluid tank that is fluidly coupled to the second heating fluid circuit.

5. The system of claim 1 , wherein the plurality of heat sources in the first heating fluid circuit are fluidly coupled in parallel, and wherein the plurality of heat sources in the second heating fluid circuit are fluidly coupled in parallel.

6. The system of claim 1 , wherein:
each hydrocracking plant heat exchanger comprises a respective stream circulated through the hydrocracking plant and a portion of the heating fluid, and
each aromatics plant heat exchanger comprises a respective stream circulated through the aromatics plant and a portion of the heating fluid.

7. The system of claim 6 , wherein:
the aromatics plant comprises a para-Xylene separation unit, and wherein a first aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a para-Xylene purification column overhead stream in the para-Xylene separation unit and a portion of the heating fluid,
the aromatics plant comprises a para-Xylene isomerization reactor, and wherein a second aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a Xylene isomerization reactor outlet stream in the para-Xylene isomerization reactor and a portion of the heating fluid,
the aromatics plant comprises a Xylene isomerization de-heptanizer, and wherein a third aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a Xylene isomerization de-heptanizer column overhead stream in the Xylene isomerization de-heptanizer and a portion of the heating fluid,
a fourth hydrocracking plant heat exchanger in the first heating fluid circuit exchanges heat between a 2 nd stage reaction section feed stream to 2 nd stage cold high pressure separator and a portion of the heating fluid, and
a fifth hydrocracking plant heat exchanger in the first heating fluid circuit exchanges heat between a hydrocracking main fractionator kerosene product and a portion of the heating fluid.

8. The system claim 7 , wherein:
a first aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between an extract column overhead stream in the para-Xylene separation unit and a portion of the heating fluid,
a second aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between a heavy Raffinate splitter column overhead stream in a Raffinate column splitter and a portion of the heating fluid,
a third aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between a para-Xylene purification column overhead stream in the para-Xylene separation unit and a portion of the heating fluid,
a fourth hydrocracking plant heat exchanger in the second heating fluid circuit exchanges heat between a hydrocracking main fractionator kerosene pumparound and a portion of the heating fluid, and
a fifth hydrocracking plant heat exchanger in the second heating fluid circuit exchanges heat between a hydrocracking main fractionator diesel product and a portion of the heating fluid.

9. The system of claim 8 , wherein:
a sixth hydrocracking plant heat exchanger in the first heating fluid circuit is connected in series with a sixth hydrocracking plant heat exchanger in the second heating fluid circuit, and
the sixth hydrocracking plant heat exchanger in the first heating fluid circuit and the sixth hydrocracking plant heat exchanger in the second heating fluid circuit exchange heat between a 1 st stage reaction section feed stream to 1 st stage cold high pressure separator and a portion of the heating fluid.

10. The system of claim 8 , wherein:
a seventh hydrocracking plant heat exchanger in the first heating fluid circuit is connected in series with a seventh hydrocracking plant heat exchanger in the second heating fluid circuit, and
the seventh hydrocracking plant heat exchanger in the first heating fluid circuit and the seventh hydrocracking plant heat exchanger in the second heating fluid circuit exchange heat between a hydrocracking product stripper overhead stream and a portion of the heating fluid.

11. The system of claim 8 , wherein:
an eighth hydrocracking plant heat exchanger in the first heating fluid circuit is connected in series with an eighth hydrocracking plant heat exchanger in the second heating fluid circuit, and
the eighth hydrocracking plant heat exchanger in the first heating fluid circuit and the eighth hydrocracking plant heat exchanger in the second heating fluid circuit exchange heat between a hydrocracking main fractionator overhead stream and a portion of the heating fluid.

12. The system of claim 1 , wherein the heating fluid circuit comprises water or oil.

13. The system of claim 1 , wherein the power generation system is on-site at the petrochemical refining system.

14. The system of claim 1 , wherein the power generation system is configured to generate about 58 MW of power.

15. A method of recovering heat energy generated by a petrochemical refining system, the method comprising:
identifying a geographic layout to arrange a plurality of sub-units of a petrochemical refining system, the geographic layout including a plurality of sub-unit locations at which the respective plurality of sub-units are to be positioned, wherein the plurality of sub-units comprises a hydrocracking plant and an aromatics plant;
identifying a first subset of the plurality of sub-units of the petrochemical refining system, the first subset including a plurality of hydrocracking plant heat exchangers coupled to streams in the hydrocracking plant and a plurality of aromatics plant heat exchangers coupled to streams in the aromatics plant, wherein heat energy is recoverable from the first subset to generate electrical power;
identifying, in th

Assignees

• Saudi Arabian Oil Co

Inventors

• Noureldin Mahmoud Bahy Mahmoud
• Al Saed Hani Mohammed
• Bunaiyan Ahmad Saleh

Classifications

• C10G47/00

  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) · CPC title

• C10G69/00

  Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process (C10G67/00 takes precedence) · CPC title

• F01K27/00

  Plants for converting heat or fluid energy into mechanical energy, not otherwise provided for · CPC title

• F01K3/00 Primary

  Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein (regenerating exhaust steam F01K19/00) · CPC title

• C10G2300/4006

  Temperature · CPC title