Power generation from waste heat in integrated aromatics, crude distillation, and naphtha block facilities

Patent metadata

Field	Value
Publication number	US-9803513-B2
Application number	US-201615087512-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

Optimizing power generation from waste heat in large industrial facilities such as petroleum refineries by utilizing a subset of all available hot source streams selected based, in part, on considerations for example, capital cost, ease of operation, economics of scale power generation, a number of ORC machines to be operated, operating conditions of each ORC machine, combinations of them, or other considerations are described. Recognizing that several subsets of hot sources can be identified from among the available hot sources in a large petroleum refinery, subsets of hot sources that are optimized to provide waste heat to one or more ORC machines for power generation are also described. Further, recognizing that the utilization of waste heat from all available hot sources in a mega-site such as a petroleum refinery and aromatics complex is not necessarily or not always the best option, hot source units in petroleum refineries from which waste heat can be consolidated to power the one or more ORC machines are identified.

First claim

What is claimed is:

1. A power generation system, comprising:
a first heating fluid circuit thermally coupled to a first plurality of heat sources from a first plurality of sub-units of a petrochemical refining system, the first plurality of sub-units comprising a Naphtha hydrotreating, atmospheric distillation, and aromatics refining system;
a second heating fluid circuit thermally coupled to a second plurality of heat sources from a second plurality of sub-units of the petrochemical refining system, the second plurality of sub-units comprising a para-xylene separation system;
a power generation sub-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 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 actuate a first set of control valves to selectively thermally couple the first heating fluid circuit to at least a portion of the first plurality of heat sources, and the control system is configured to actuate a second set of control valves to selectively thermally couple the second heating fluid circuit to at least a portion of the second plurality of heat sources.

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

3. The power generation system of claim 2 , wherein the first heating fluid circuit comprises a first heating fluid tank that is fluidly coupled to the first and second heating fluid circuits, and the first heating fluid tank is fluidly coupled with the pre-heating heat exchanger of the ORC.

4. The power generation system of claim 1 , wherein the working fluid comprises isobutane.

5. The power generation system of claim 1 , wherein the first or second heating fluid circuits comprises water or oil.

6. The power generation system of claim 1 , wherein the ORC further comprises:
a condenser fluidly coupled to a condenser fluid source to cool the working fluid; and
a pump to circulate the working fluid through the ORC.

7. The power generation system of claim 1 , wherein
a first sub-set of the first plurality of heat sources comprises three para-xylene separation unit heat sources, comprising:
a first para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to a raw para-xylene stream circulated through an air cooler to a storage tank, and is fluidly coupled to the first heating fluid circuit;
a second para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to a para-xylene purification stream circulated through an air cooler to a para-xylene purification reflux drum, and is fluidly coupled to the first heating fluid circuit; and
a third para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to a C9+ ARO stream circulated through an air cooler to a C9+ ARO storage, and is fluidly coupled to the first heating fluid circuit;

a second sub-set of the first plurality of heat sources comprises two para-xylene separation-xylene isomerization reaction and separation unit heat sources, comprising:
a first para-xylene separation-xylene isomerization reaction and separation unit heat source comprising a heat exchanger that is fluidly coupled to a Xylene isomerization reactor outlet stream before a separator drum, and is fluidly coupled to the first heating fluid circuit; and
a second para-xylene separation-xylene isomerization reaction and separation unit heat source comprises a heat exchanger that is fluidly coupled to a de-heptanizer column overhead stream, and is fluidly coupled to the first heating fluid circuit;

a third sub-set of the first plurality of heat sources comprises a naphtha hydrotreating plant reaction section heat source, comprising a heat exchanger fluidly coupled to a hydrotreater/reactor product outlet and fluidly coupled to a separator, and is fluidly coupled to the first heating fluid circuit; and
a fourth sub-set of the first plurality of heat sources comprises an atmospheric distillation plant heat source, comprising a heat exchanger fluidly coupled to an atmospheric crude tower overhead stream, and is fluidly coupled to the first heating fluid circuit.

8. The power generation system of claim 7 , wherein a first sub-set of the second plurality of heat sources comprises three para-xylene separation unit heat sources, comprising:
a first para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to an extract column overhead stream, and is fluidly coupled to the second heating fluid circuit;
a second para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to a Raffinate column overhead stream, and is fluidly coupled to the second heating fluid circuit; and
a third para-xylene separation unit heat source comprising a heat exchanger that is fluidly coupled to a heavy Raffinate splitter column overhead stream, and is fluidly coupled to the second heating fluid circuit.

9. A method of recovering heat energy generated by a petrochemical refining system, the method comprising:
circulating a first heating fluid through a first heating fluid circuit thermally coupled to a first plurality of heat sources from a first plurality of sub-units of a petrochemical refining system, the first plurality of sub-units comprising a Naphtha hydrotreating, atmospheric distillation, and aromatics refining system;
circulating a second heating fluid through a second heating fluid circuit thermally coupled to a second plurality of heat sources of a second plurality of sub-units of the petrochemical refining system, the second plurality of sub-units comprising a para-xylene separation system;
generating electrical power through 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 and second heating fluid circuits to heat the working fluid with the first and second heating fluids, and (ii) an expander configured to generate electrical power from the heated first working fluid;
actuating, with a control system, a first set of control valves to selectively thermally couple the first heating fluid circuit to at least a portion of the first plurality of heat sources to heat the first heating fluid with the first plurality of heat sources; and
actuating, with the control system, a second set of control valves to selectively thermally couple the second heating fluid circuit to at least a portion of the second plurality of heat sources to heat the second heating fluid with the second plurality of heat sources.

10. The method of claim 9 , wherein the working fluid is thermally coupled to the first heating fluid circuit in a pre-heating heat exchanger of the ORC, and the working fluid is thermally coupled to the second heating fluid circuit in an evaporator of the ORC, and an outlet of the pre-heating heat exchanger of the ORC is fluidly coupled to the evaporator of the ORC.

11. The method of claim 10 , wherein the first heating fluid circuit comprises a first heating fluid tank that is fluidly coupled to the first and second heating fluid circuits, and the first heating fluid tank is fluidly coupled with the pre-heating heat exchanger of the ORC.

12. The method of claim 9 , whe

Assignees

• Saudi Arabian Oil Co

Inventors

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

Classifications

• F01K25/14 Primary

  using industrial or other waste gases · CPC title

• F01K27/00

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

• F01K13/006

  Auxiliaries or details not otherwise provided for · CPC title

• C10G45/02

  to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing · 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