Deep Seawater Intake Sohar Port

Abstract

This paper is the result of the first collaboration project between Delft University of Technology and Sohar University. The project team consisted of 6 core- members from both Sohar University and TU Delft along with 5 more students, together appointed to help find an answer for a problem stated by Sohar Industrial Port Company and Majis Industrial Services.
This paper proposes a deep seawater intake for the cooling water system of Sohar Industrial Port, Oman. In the region’s summers, surface water temperatures tend to rise to very high levels. Among other things, this results in inefficient cooling of the processes associated with the steel manufacturers, petrochemical plants, refineries and power plants present in the port. The proposed inlet subtracts water 4 km offshore at an average temperature of 24.9 ±C. Using this colderwater, the demand is expected to go downwith approx. 2% in the winter and 16% in the summer, saving system capacity and pumping costs. The 2,148 MW generated power at Sohar port is expected to increase efficiency by 0.72%. Furthermore, the coastal waters are vulnerable to algal blooms. These toxic algae can not be filtered out efficiently and lead to temporary closure of the desalination plants (mainly Reverse Osmosis) causing a threat to the drinking water supply in the entire north of Oman. This paper concludes however that there is not an (economically) feasible inlet location that is unaffected by the algal blooms. Other water characteristics such as turbidity and organic content are also expected not to show significant improvement at the proposed inlet location but more elaborate measurements should validate this.
A technical feasibility study was conducted to find the optimal system design. Multiple alternative materials being metals, alloys, HDPE and concrete have been investigated to serve as water conveyors to transport the water from the inlet to the shore. A possible design for the off-shore water inlet structure was made as well as a recommended design for the connection of the pipelines with the current facilities. Site selection, material selection, friction head loss calculations, pipeline sizing, concrete ballast weights, seabed pipeline stability and planning have been discussed in this report. Finally, a financial feasibility study has been conducted. A model was built and costs have been quantitatively estimated based on the technical design. Benefits have been quantified where possible and if not, were qualitatively described. It is concluded that it is not financially feasible to build a deep seawater intake for the entire port. Building a limited-scale variant, only providing RO and power plants, is a better solution but still unfeasible. Recommendation is done to scrutinise the processes within power plants and RO-plants further as their potential benefits are considerable.