Power Station uses RO to minimise chemical and treatment costs
EP SHB Limited Power Station has purchased its latest Turn-Key water treatment plant from Culligan. A robust and efficient reverse osmosis system will be designed and commissioned over the next few months. The decision to buy Culligan’s solution resulted from a competitive tender to improve the efficiency of their de-mineralised water production process, critical for the production of super-heated steam responsible for power generation. Culligan was selected not only for the quality of their equipment, but for the design and technical knowledge they showed in proposing an effective long- term solution.
EP SHB Limited Power Station (EP SHB) in Stallingborough, near Grimsby is a 1,365 MW gas-fired power station. The power station generates electricity using combined cycle gas turbines. This ensures the exhaust heat generated is re-used through heat exchangers and a steam power plant. There are five gas turbines each served by heat recovery steam generators. Exhaust gases leave the turbines at 540oC and are used in heat recovery steam generators that create super-heated steam under high pressure. This in turn is used to drive the steam turbines for generating electricity efficiently.
Feed water quality is very important in the steam generation process. The raw water is drawn from a non-potable mains supply that needs to be treated before it can be used to generate steam. An in-house demineralised water system produces water to feed five high pressure steam boilers that produce the steam to drive the turbines.
“We need to operate efficiently and effectively, so water quality is high on our agenda to ensure we are producing demineralised water in large quantities continuously, minimising treatment costs and use of expensive chemicals,” said Rachel Laking, EP SHB’s Procurement Officer. “We selected Culligan as they have a good track record and they took time to understand our requirements in detail, tailoring a system that will operate well under a wide range of constraints.”
Culligan will be manufacturing and installing a skid mounted reverse osmosis (RO) system that has a relatively small footprint to couple up to EP SHB Limited’s existing demineralisation plant ensuring it runs optimally throughout the year. “We will be installing our IW EVO RO system that has tailored pre-treatment system and automatic flushing to extend the working life of the membranes in the reverse osmosis system. The system is designed to reduce high levels of incoming dissolved solids in the non-potable feed water, which are currently being fed to the chemical based de-mineralisation plant. Adding RO in front of the existing de-min system means, the site shall benefit on reducing hazardous chemicals usage by approximately 25 times,” said Moorthy Palanivelu, Culligan’s Projects Development Manager.
The system will be commissioned in Spring next year and is supported with a five-year membrane replacement programme and an annual service contract to ensure the reverse Osmosis operates efficiently throughout its life.