Performance of a Novel Compact Deoxygenation System Using Liquid Jet Compression: Comparative Analysis of Dynamic Simulations and Operational Data

Removing dissolved oxygen from water in the offshore industry is crucial for preventing corrosion, extending equipment lifetime, enhancing oil recovery processes, reducing fouling, and maintaining operational efficiency. Among the various technologies available for oxygen removal, closed-loop nitrogen stripping gas circulation in a two-stage mixer and separator configuration presents a competitive solution. This method is particularly advantageous for offshore applications where size and footprint are critical constraints. Over the years, research has been conducted to improve the efficiency and functionality of this process. One significant advancement has been the use of a liquid jet compressor in place of a conventional gas compressor in the deoxygenation stripping process. The objective of this study is to validate and qualify the technology by operating a complete demonstration plant, which includes both oxygen absorption and stripping gas regeneration processes. Operational data is analyzed and evaluated through comparison with dynamic process simulations. The demonstration system is designed for a capacity of 25 m3/h. Results include overall system parameters, controllability, control philosophy, pressures, temperatures, reactor performance, and deoxygenation efficiency. These are presented and compared with advanced dynamic process simulation outcomes. A comprehensive dynamic process simulation was developed to support the design of the deoxygenation process. Based on this, a full-scale physical demonstration system with a capacity of 25 m3/h was designed, fabricated, and subjected to several test campaigns. The resulting operational data has been analyzed, evaluated, and compared with the dynamic process simulation results. Results include overall system parameters, controllability, control philosophy, pressures, temperatures, reactor performance, and deoxygenation efficiency, all of which are presented and compared with advanced dynamic process simulations. The findings demonstrate that the process achieves dissolved oxygen levels below 10 parts per billion, even under challenging cold-water conditions in both freshwater and seawater. The liquid jet compressor has been proven to function effectively as both a compression and mixing device, achieving a mixing efficiency close to ideal equilibrium. Additionally, a critical variable is the system's turn-down capability and the ability to bypass the liquid jet compressor with a portion of the liquid flow while still maintaining sufficient stripping gas circulation. This functionality has been successfully demonstrated using the implemented control philosophy. The novelty of utilizing a liquid jet compressor to drive the stripping gas marks a step change in the design due to several reasons, which includes reduced impact of salt in the stripping gas stream, improved mixing and mass transfer, simplified control philosophy, avoidance of high-speed rotating equipment and further enabling of remote operation.