Power generation using independent dual organic rankine cycles from waste heat systems in diesel hydrotreating-hydrocracking and atmospheric distillation-naphtha hydrotreating-aromatics 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 para-xylene separation unit and an atmospheric distillation-Naphtha hydrotreating-aromatics plant;
• circulating a second heating fluid through 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 an aromatics refining system;
• circulating a third heating fluid through a third heating fluid circuit thermally coupled to a third plurality of heat sources of a third plurality of sub-units of the petrochemical refining system, the third plurality of sub-units comprising a hydrocracking-diesel hydrotreating system;
• generating electrical power through a first power generation system that comprises a first organic Rankine cycle (ORC), the first ORC comprising (i) a first working fluid that is thermally coupled to the first and second heating fluid circuits to heat the first working fluid with the first and second heating fluids, and (ii) a first expander configured to generate electrical power from the heated first working fluid;
• generating electrical power through a second power generation system that comprises a second ORC, the second ORC comprising (i) a second working fluid that is thermally coupled to the second heating fluid circuit to heat the second working fluid with the third heating fluid, and (ii) a second expander configured to generate electrical power from the heated second 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;
• 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;
• and
• actuating, with the control system, a third set of control valves to selectively thermally couple the third heating fluid circuit to at least a portion of the third 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 para-xylene separation unit and an atmospheric distillation-Naphtha hydrotreating-aromatics plant;
• identifying, in the geographic layout, 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 an aromatics refining system;
• identifying, in the geographic layout, a third heating fluid circuit thermally coupled to a third plurality of heat sources of a third plurality of sub-units of the petrochemical refining system, the third plurality of sub-units comprising a hydrocracking-diesel hydrotreating system;
• identifying, in a geographic layout, a first power generation system that comprises:
• a first organic Rankine cycle (ORC), the first ORC comprising (i) a first working fluid that is thermally coupled to the first and second heating fluid circuits to heat the first working fluid with the first and second heating fluids, and (ii) a first expander configured to generate electrical power from the heated first 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 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;
• identifying, in a geographic layout, a second power generation system that comprises:
• a second ORC, the second ORC comprising (i) a second working fluid that is thermally coupled to the second heating fluid circuit to heat the second working fluid with the third heating fluid, and (ii) a second expander configured to generate electrical power from the heated second working fluid;
• and
• a control system configured to actuate a third set of control valves to selectively thermally couple the second heating fluid circuit to at least a portion of the third 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.