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

Patent metadata

Field	Value
Publication number	US-9803508-B2
Application number	US-201615087606-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 diesel hydro-treating 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

The invention 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 diesel hydro-treating plant and an aromatics plant,
wherein a first subset of the plurality of heat sources comprises a plurality of diesel hydro-treating plant heat exchangers coupled to streams in the diesel hydro-treating plant,
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 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 1 , 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
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 are fluidly coupled in parallel.

6. The system of claim 1 , wherein:
each diesel hydro-treating plant heat exchanger comprises a respective stream circulated through the diesel hydro-treating 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 1 , wherein:
the aromatics plant comprises a para-Xylene separation plant, and wherein a first aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a purification column overhead stream and a portion of the heating fluid,
the aromatics plant comprises a 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 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 stream and a portion of the heating fluid,
a fourth diesel hydro-treating plant heat exchanger in the first heating fluid circuit exchanges heat between a hydrotreater light product outlet and a portion of the heating fluid,
a fifth diesel hydro-treating plant heat exchanger in the first heating fluid circuit exchanges heat between a diesel stripper tower overhead stream and a portion of the heating fluid, and
a sixth diesel hydro-treating plant heat exchanger in the first heating fluid circuit exchanges heat between a diesel stripper bottom product stream and a portion of the heating fluid.

8. The system of claim 7 , wherein:
a first aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between an extract column overhead stream and a portion of the heating fluid,
a second aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between a Raffinate column overhead stream and a portion of the heating fluid,
a third aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between a heavy Raffinate column splitter overhead stream and a portion of the heating fluid, and
a fourth diesel hydro-treating plant heat exchanger in the second heating fluid circuit exchanges heat between a diesel stripper tower bottom product stream and a portion of the heating fluid.

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

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

11. The system of claim 1 , wherein the power generation system is configured to generate about 40 MW of power.

12. 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 diesel hydro-treating 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 diesel hydro-treating plant heat exchangers coupled to streams in the diesel hydro-treating 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 the geographic layout, a second subset of the plurality of sub-unit locations, the second subset including sub-unit locations at which the respective sub-units in the first subset are to be positioned;
identifying a power generation system to recover heat energy from the sub-units in the first subset, the power generation system comprising:
a first heating fluid circuit and a second heating fluid circuit, each heating fluid circuit fluidly connected to the sub-units in the first subset;
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 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; and

identifying, in the geographic layout, a power generation system location to position the power generation system, wherein a heat energy recovery efficiency at the power generation system location is greater than a heat energy recovery efficiency at other locations in the geographic layout.

13. The method of claim 12 , further comprising constructing the petrochemical refining system according to the geographic layout by positioning the plurality of sub-units at the plurality of sub-unit locations, positioning the power generation system at the power generation system location, interconnecting the plurality of sub-units with each other such that the interconnected plurality of sub-units are configured to refine petrochemicals, and interconnecting the power generation system with the sub-units in the first subset such that the power generation system is configured to recover heat energy from the sub-units in the first subset

Assignees

• Saudi Arabian Oil Co

Inventors

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

Classifications

• F01K27/00

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

• F01K23/06 Primary

  combustion heat from one cycle heating the fluid in another cycle · CPC title

• C10G2300/1096

  Aromatics or polyaromatics · CPC title

• C10G7/12

  Controlling or regulating · CPC title

• C10G45/72

  Controlling or regulating · CPC title