Natural gas liquid fractionation plant waste heat conversion to simultaneous power and potable water using organic Rankine cycle and modified multi-effect-distillation systems

Patent metadata

Field	Value
Publication number	US-10690407-B2
Application number	US-201715842434-A
Country	US
Kind code	B2
Filing date	Dec 14, 2017
Priority date	Aug 8, 2017
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

Certain aspects of natural gas liquid fractionation plant waste heat conversion to simultaneous power and potable water using organic Rankine cycle and modified multi-effect distillation systems can be implemented as a system that includes two heating fluid circuits thermally coupled to two sets of heat sources of a NGL fractionation plant. The system includes a power generation system that comprises an organic Rankine cycle (ORC), which includes (i) a working fluid that is thermally coupled to the first heating fluid circuit to heat the working fluid, and (ii) a first expander configured to generate electrical power from the heated working fluid. The system includes a MED system thermally coupled to the second heating fluid circuit and configured to produce potable water using at least a portion of heat from the second heating fluid circuit. A control system actuates control valves to selectively thermally couple the heating fluid circuit to a portion of the heat sources of the NGL fractionation plant.

First claim

What is claimed is:

1. A system, comprising:
a first heating fluid circuit thermally coupled to a first plurality of heat sources of a natural gas liquid (NGL) fractionation plant, the first plurality of heat sources comprising:
a first portion of sub-units of the NGL fractionation plant that comprises an ethane system;
a second plurality of sub-units of the NGL fractionation plant that comprises a propane system;
a third portion of sub-units of the NGL fractionation plant that comprises a butane system;
a fourth portion of sub-units of the NGL fractionation plant that comprises a pentane system;
a fifth portion of sub-units of the NGL fractionation plant that comprises a natural gasoline system; and
a sixth portion of sub-units of the NGL fractionation plant that comprises a solvent regeneration system;

a second heating fluid circuit thermally coupled to at least one second heat source of the NGL fractionation 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 in an evaporator of the ORC to heat the working fluid, and (ii) a first expander configured to generate electrical power from the heated working fluid;
a multi-effect-distillation (MED) system that comprises one or more trains thermally coupled to the second heating fluid circuit and configured to produce potable water using at least a portion of heat from the second heating fluid circuit; and
a flow control system that comprises a first set of control valves to selectively thermally couple a heating fluid of the first heating fluid circuit to at least a portion of the first plurality of heat sources of the NGL fractionation plant, the flow control system further comprising a second set of control valves to selectively thermally couple a heating fluid of the second heating fluid circuit to the at least one second heat source of the NGL fractionation plant.

2. The system of claim 1 , wherein the MED system comprises a plurality of trains thermally coupled to the second heating fluid circuit.

3. The system of claim 2 , wherein the plurality of trains comprise three trains, a first train comprising six effects, a second train comprising four effects, and a third train comprising two effects.

4. The system of claim 1 , further comprising a heating fluid tank that is fluidly coupled to the evaporator of the ORC.

5. The system of claim 1 , wherein the system further comprises one or more conduits containing the working fluid and the working fluid comprises isobutane.

6. The system of claim 1 , wherein the first and second heating fluid circuits further comprise one or more pipes containing water or oil.

7. The system of claim 1 , further comprising:
a condenser fluidly coupled to the expander and to a condenser fluid source to cool the working fluid; and
a pump to circulate the working fluid through the ORC.

8. The system of claim 1 , wherein the first portion of sub-units of the NGL fractionation plant comprises at least two ethane system heat sources, comprising:
a first ethane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a deethanizer refrigeration compressor; and
a second ethane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of an ethane dryer.

9. The system of claim 1 , wherein the second portion of sub-units of the NGL fractionation plant comprises at least five propane system heat sources, comprising:
a first propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a propane dehydrator;
a second propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a depropanizer overhead stream;
a third propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a propane vapor recovery compressor stream;
a fourth propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a propane refrigeration compressor stream; and
a fifth propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a propane main compressor stream.

10. The system of claim 1 , wherein the third portion of sub-units of the NGL fractionation plant comprises at least four butane system heat sources, comprising:
a first butane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a butane dehydrator;
a second butane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a debutanizer overhead stream;
a third butane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a debutanizer bottoms; and
a fourth butane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a butane refrigeration compressor stream.

11. The system of claim 1 , wherein the fourth portion of sub-units of the NGL fractionation plant comprises at least one pentane system heat source, comprising:
a first pentane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a depentanizer overhead stream.

12. The system of claim 1 , wherein the fifth portion of sub-units of the NGL fractionation plant comprises at least three natural gasoline system heat sources, comprising:
a first natural gasoline system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a natural gasoline decolorizing section pre-flash drum overhead stream; and
a second natural gasoline system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a natural gasoline decolorizer overhead stream; and
a third natural gasoline system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a Reid vapor pressure control column overhead stream.

13. The system of claim 1 , wherein the sixth portion of sub-units of the NGL fractionation plant comprises at least two solvent regeneration system heat sources, comprising:
a first solvent regeneration system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of an ADIP regeneration section overhead stream; and
a second solvent regeneration system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of an ADIP regeneration section bottoms.

14. The system of claim 1 , wherein the at least one second heat source comprises at least one propane system heat source that comprises a heat exchanger that is thermally coupled to an outlet stream of a depropanizer overhead stream.

15. A method of recovering heat energy generated by a natural gas liquid (NGL) fractionation plant, the method comprising:
circulating a first heating fluid through a first heating fluid circuit thermally coupled to a first plurality of heat sources of a natural gas liquid (NGL) fractionation plant, the first plurality of heat sources comprising:
a first portion of sub-units of the NGL fractionation plant that comprises an ethane system;
a second plurality of sub-units of the NGL fractionation plant that comprises a propane system;
a third portion of sub-units of the NGL fractionation plant that comprises a butane system;
a fourth portion of sub-units of the NGL fractionation plant that comprises a pentane system;
a fifth portion of sub-units of

Assignees

• Saudi Arabian Oil Co

Inventors

• Noureldin Mahmoud Bahy Mahmoud
• Kamel Akram Hamed Mohamed

Classifications

• B01D1/0058 Primary

  Use of waste energy from other processes or sources, e.g. combustion gas (for water treatment C02F1/16) · CPC title

• F01K23/064

  in combination with an industrial process, e.g. chemical, metallurgical · CPC title

• B01D1/2896

  Control, regulation · CPC title

• F01K27/02

  Plants modified to use their waste heat, other than that of exhaust, e.g. engine-friction heat · CPC title

• F01K25/08

  using special vapours · CPC title