Utilization of Low-Grade Waste Heat by Capitalizing ORC to Maximize Hydrocarbon Yield and Reduce CO2 Emissions in Upstream Crude Processing

Abstract Efficiency enhancements and energy conservation in existing operational facilities have become increasingly essential undertakings in the pursuit of optimization and decarbonization. This paper aims to shed light on how to use low-grade waste heat to improve the process, increase stable condensate production, reduce power consumption, and reduce the CO2 footprint in the gas processing train of a crude oil production facility using the Organic Rankine Cycle (ORC) system. In the Gas Oil Separation Plant (GOSP), the gases separated from high-pressure production traps and low-pressure production traps are compressed and cooled by fin-fan coolers. The compressor's discharge heat serves as a low-grade waste heat source. The proposed approach is to utilize this low-grade waste heat for the benefit of process improvement by employing the Organic Rankine Cycle (ORC) system instead of releasing this waste heat into the ambient through air-cooled fin-fan coolers. Currently, the compressor discharge gases are cooled down to 145°F by using air coolers; however, with the ORC, the compressor discharge gases will be cooled down to the process requirement of 80 to 90°F The cooling of the compressor discharge gas to 80 to 90°F by using the ORC system will help in condensing the heavier hydrocarbons upfront, resulting in an increase in condensate production, removing the moisture from the gas by condensing before entering into TEG system and reducing the volume of the gases to be processed in the subsequent steps. The lower gas temperature for the LP and HP compressor suction will result in less heat from compression, hence lowering the power requirement of the compressors. Practically, we can eliminate after cooler operation on a compressor train and generate additional power from ORC. The refrigeration system's condensing load will also be reduced due to low temperatures. The power generated by ORC will be connected to a local electrical grid to operate auxiliary equipment, which will offset some of the energy power imported from the grid. This study provides an extensive overview of gas train systems and how the ORC system can be effectively used. Traditionally, the ORC system has been utilized merely to generate power; however, this study focuses on the technological benefits of improving the process, optimizing power utilization, increasing production, and minimizing CO2 emissions in an operating facility. This study aims to illustrate the advantages and potential improvements that can be achieved by applying the ORC system. The opportunities for implementing the technology are enormous, as it has the potential to deliver annual value creations in increased product recovery and electricity savings.