Power generation using independent triple organic rankine cycles from waste heat in integrated crude oil refining and aromatics facilities

Patent metadata

Field	Value
Publication number	US-9816759-B2
Application number	US-201615087503-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Aug 24, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A power generation system includes four heating fluid circuits thermally coupled to heat sources from sub-units of a petrochemical refining system. The sub-units include a hydrocracking plant, an aromatics plant, and a diesel hydro-treating plant. Subsets of the heat sources includes hydrocracking plant heat exchangers coupled to streams in the hydrocracking plant, aromatics plant heat exchangers coupled to streams in the aromatics plant, and diesel hydro-treating plant heat exchangers coupled to streams in the diesel hydro-treating plant. A power generation system includes three organic Rankine cycles, each including a working fluid that is thermally coupled to at least one heating fluid circuit 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;
a third heating fluid circuit thermally coupled to the plurality of sources from the plurality of sub-units of the petrochemical refining system;
a fourth heating fluid circuit thermally coupled to the plurality of sources from the plurality of sub-units of the petrochemical refining system, wherein the plurality of sub-units comprises a hydrocracking plant, an aromatics plant, and a diesel hydro-treating plant,
wherein a first subset of the plurality of heat sources comprises a plurality of aromatics plant heat exchangers coupled to streams in the aromatics plant,
wherein a second 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 third 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;

a first power generation system, a second power generation system, and a third power generation system comprising a first organic Rankine cycle (ORC), a second ORC and a third ORC, respectively,
the first ORC comprising (i) a first working fluid that is thermally coupled to the first heating fluid circuit and the second heating fluid circuit to heat the first working fluid, and (ii) a first expander configured to generate electrical power from the heated first working fluid,
the second ORC comprising (i) a second working fluid that is thermally coupled to the third heating fluid circuit to heat the second working fluid, and (ii) a second expander configured to generate electrical power from the heated second working fluid, and
the third ORC comprising (i) a third working fluid that is thermally coupled to the fourth heating fluid circuit, and (ii) a third expander configured to generate electrical power from the heated third 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, the second heating fluid circuit, the third heating fluid circuit and the fourth heating fluid circuit to at least a portion of the plurality of heat sources.

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

3. The system of claim 2 , wherein each of the first working fluid, the second working fluid or the third working fluid comprises isobutane.

4. The system of claim 1 , wherein the first heating fluid circuit, third heating fluid circuit and the fourth heating fluid circuit are fluidly connected to a first heating fluid tank, and wherein the second heating fluid circuit is fluidly connected to a second heating fluid tank.

5. The system of claim 1 , wherein the plurality of heat sources in the first heating fluid circuit are fluidly coupled in parallel, wherein the plurality of heat sources in the second heating fluid circuit are fluidly coupled in parallel, wherein the plurality of heat sources in the third heating fluid circuit are fluidly coupled in parallel, and wherein the plurality of heat sources in the fourth 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,
each aromatics plant heat exchanger comprises a respective stream circulated through the aromatics plant and a portion of the heating fluid, and
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.

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 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 first heating fluid circuit exchanges heat between a PX purification column bottom product stream in the para-xylene separation unit and a portion of the heating fluid,
a third aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a heavy Raffinate column splitter and a portion of the heating fluid,
a fourth aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a Raffinate splitter column overhead stream and a portion of the heating fluid,
a fifth 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,
a sixth aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a de-heptanizer column overhead stream in a xylene isomerization de-heptanizer in the aromatics plant and a portion of the heating fluid,
a seventh aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a benzene column overhead stream in an aromatics benzene extraction unit in the aromatics plant and a portion of the heating fluid,
an eighth aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between an extractive distillation column overhead stream in an aromatics complex extractive distillation column unit in the aromatics plant and a portion of the heating fluid, and
a ninth aromatics plant heat exchanger in the first heating fluid circuit exchanges heat between a Raffinate splitter overhead stream in an aromatics complex raffinate splitter in the aromatics plant 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 a PX purification column overhead stream in the aromatics plant and a portion of the heating fluid, and
a second aromatics plant heat exchanger in the second heating fluid circuit exchanges heat between a Raffinate column overhead stream in the aromatics plant and a portion of the heating fluid.

9. The system of claim 8 , wherein:
a first hydrocracking plant heat exchanger in third heating fluid circuit exchanges heat between a 2 nd stage reaction section feed stream to 2 nd stage cold high pressure separator in the hydrocracking plant and a portion of the heating fluid,
a second hydrocracking plant heat exchanger in third heating fluid circuit exchanges heat between a 1 st stage reaction section feed stream to 1 st stage cold high pressure separator in the hydrocracking plant and a portion of the heating fluid,
a third hydrocracking plant heat exchanger in third heating fluid circuit exchanges heat between a hydrocracking product stripper overhead stream in the hydrocracking plant and a portion of the heating fluid,
a fourth hydrocracking plant heat exchanger in the third heating fluid circuit exchanges heat between a hydrocracking main fractionator overhead stream

Assignees

• Saudi Arabian Oil Co

Inventors

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

Classifications

• C01B2203/0283

  containing a CO-shift step, i.e. a water gas shift step · CPC title

• C01B2203/043

  Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration · CPC title

• C01B2203/0227

  containing a catalytic reforming step · CPC title

• C01B3/34 Primary

  by reaction of hydrocarbons with gasifying agents · CPC title

• C01B2203/127

  Catalytic desulfurisation · CPC title