Shanghai Tongjie highlights energy recovery for mobile SWRO systems

Shanghai Tongjie says energy recovery can cut the power needs of containerized mobile seawater reverse osmosis systems in off-grid, emergency, and maritime deployments. The company says the technology can lower fuel use, shrink generator size, and improve the economics of temporary water production.

Why it matters: - Energy use is a major cost driver for mobile and emergency seawater reverse osmosis systems. - Lower specific energy consumption can reduce diesel fuel demand, generator size, and water production costs in off-grid camps, disaster zones, and maritime sites. - The savings can make temporary desalination more practical where grid power is unavailable or expensive.

What happened: - Shanghai Tongjie said integrating energy recovery devices into containerized mobile emergency SWRO systems reduces power consumption and changes lifecycle economics. - The company said the approach is relevant for decentralized, mobile, and emergency desalination deployments. - Shanghai Tongjie also offered project-specific CAPEX and OPEX comparisons based on site conditions.

The details: - Standard seawater reverse osmosis systems typically operate at 55 to 70 bar for feedwater with total dissolved solids of 35,000 to 40,000 mg/L. - Conventional systems without energy recovery can spend 50% to 70% of operating costs on electricity. - Energy recovery devices transfer mechanical energy from the brine stream back into incoming feedwater. - The company said this can cut high-pressure pump motor load by 40% to 50%. - Specific energy consumption can drop from about 6.5 to 8.0 kWh/m³ to 2.8 to 3.8 kWh/m³. - Single-pass SWRO systems typically recover 40% to 45% of feedwater, leaving 55% to 60% as pressurized brine. - That brine still exits at roughly 55 to 62 bar if not recovered. - Isobaric pressure exchangers can reach hydraulic energy transfer efficiency of up to 90% to 95%. - Centrifugal turbochargers can deliver hydraulic efficiencies of 65% to 80%. - The company said high-purity alumina ceramic rotors in modern isobaric devices can last more than 5 to 10 years when protected by 5-micron pre-filtration. - Shanghai Tongjie said its team evaluates established international brands and qualified domestic Chinese energy recovery units using site-specific temperature and salinity data.

Between the lines: - Energy recovery is most compelling where runtime is high and power is costly. - For units producing more than 100 m³/day or running 16 to 24 hours daily, the company said energy savings can offset added equipment cost in 18 to 36 months. - For smaller units under 50 to 100 m³/day, especially those running fewer than 1,000 hours per year, the added capital and complexity may not pay back as quickly. - In mobile systems, lower electrical load can also support smaller generator rentals or purchases and reduce transport weight. - The article positions the ERD, pump, and external power supply as one integrated system rather than separate components.

What's next: - Shanghai Tongjie is asking customers to provide target daily water volume, operating hours, local power cost or generator fuel price, and raw seawater TDS. - The company says it will use those inputs to model capital cost, specific energy consumption, and projected payback schedules. - Buyers weighing mobile desalination options can compare whether omitting energy recovery lowers upfront cost enough to outweigh higher operating expense.

The bottom line: - For mobile SWRO, energy recovery is not just a technical upgrade. It can be the main lever that determines whether a containerized desalination plant is affordable to run.