This paper covers an energy optimization study conducted by Saudi Aramco to maximize energy efficiency and minimize GHG emissions via onion peeling method to analyze the system from outside to inside by segregating the system to three essential layers in Khurais hydrocarbon facility to achieve operational efficiency and environmental sustainability.
This paper is intended to:
Share the optimization strategy and how it can be replicated. Presents the results of this optimization study along with operating modes energy and emissions data and graphical representations. Highlights how this approach enhanced the overall facility operating efficiency.
The onion peeling approach allows to achieve maximum efficiency by conducting sensitivity analysis on each layer's parameters to achieve the optimum operating mode for minimizing power bill (i.e., maximizing power generation), minimizing scope 1 and 2 emissions, minimizing sales gas consumptions.
The aforementioned approach was done based on the following strategies:
Maximize power generation in facility whenever reaching the threshold that makes power generation better than importing from grids in term of GHG emissions and EI. Maximize waste heat recovery for power and steam generations. Minimize recycling in major energy consuming equipment in the facility. Maximize major energy consuming equipment efficiencies through load management optimizations. Follow operating levels concept rather than optimum mode concept by ranking all possible modes in hierarchy and challenge the system to achieve better operating level (i.e., lower level number)
Figure 1 Shows the model's layer and summary
Post-Implementation of the defined strategies and following operating level concept, several initiatives introduced to achieve lower operating levels with energy savings and GHG (scope 1 and 2) reductions realized.
Finally, this study concluded that to achieve better operational mode environmentally and economically, it is recommended to analyze the overall system from outside to inside as multiple layers, to capture opportunities in the system. Such an approach shall be followed after defining the needed strategies, depending on the facility's design, demand and operating conditions.