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

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.

A method of recovering heat energy generated by a petrochemical refining system, the method comprising:

• identifying, in a geographic layout, 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;
• identifying, in the geographic layout, 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 comprises a para-xylene separation unit system;
• identifying, in the geographic layout, a power generation system, comprising:
• 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 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;
• 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.