Configurations and related processing schemes of direct or indirect inter-plants (or both) heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect inter-plants (or both) heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of direct or indirect (or both) intra-plants and thermally coupled heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect (or both) intra-plants and thermally coupled heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

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.

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. 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.

Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of specific direct or indirect inter-plants integration for energy consumption reduction synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of specific direct or indirect inter-plants integration for energy consumption reduction for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of specific inter-plants and hybrid, intra- and inter-plants waste heat recovery schemes for thermal energy consumption reduction in integrated refining-petrochemical facilities synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of specific inter-plants and hybrid, intra- and inter-plants waste heat recovery schemes for thermal energy consumption reduction in integrated refining-petrochemical facilities synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of inter-plants and hybrid, intra- and inter-plants' direct or indirect heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of inter-plants and hybrid, intra- and inter-plants' direct or indirect heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of specific inter-plants and hybrid, intra- and inter-plants waste heat recovery schemes for thermal energy consumption reduction in integrated refining-petrochemical facilities synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of specific inter-plants and hybrid, intra- and inter-plants waste heat recovery schemes for thermal energy consumption reduction in integrated refining-petrochemical facilities synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.