Water and wastewater treatment expert Envirogen Group has been awarded a £1m+ contract by Fortum Glasgow to demineralise water for the boilers at the new South Clyde Energy Centre (SCEC) in Glasgow. The EfW sector project will see two of Envirogen’s compact Eco MultiPro units, complemented by pre-treatment and polishing vessels, the group explains here.

The contract will provide the ultra-pure water quality required to generate 45 megawatts of low-carbon electricity (MWe) from non-recyclable residual waste, enough to power around 70,000 homes each year.

And by burning household waste to heat the boilers, the plant will divert up to 350,000 tonnes of household waste from landfill each year – the equivalent of around 380,000 households’ waste. This will help it meet the Scottish Government’s new landfill policy, banning the landfilling of biodegradable municipal waste from 31 December 2025.

Fortum selected the Envirogen system following the success of Eco MultiPro at other EfW energy operations, including Vital Energi’s Drakelow EfW plant near Burton-on-Trent, Staffordshire.

The complete Envirogen package includes Eco MultiPro based demineralised water system design, supply, installation, commissioning, training and extended warranty. Once commissioned the plant produces treated water of <0.2 microsiemens/cm and <20 ppb silica to 30 m³/hour flow rate, achieved by a flow of every unit of 15m³/o’clock.

Eco MultiPro is a skid-mounted RO-DI (reverse osmosis and electrodeionization) water treatment system that delivers high purity water, has low operating costs, uses no chemicals and has a compact design to save space.

Envirogen will deliver the units and pretreatment solution in the summer of next year, install the equipment in the fall of 2025 and commission it in January 2026.
Durable

Ilkka Toijala, Head of Fortum UK, said: “Envirogen worked with our technical team to develop a solution that provides a plant that can reliably deliver water in a time and cost efficient manner, in line with our sustainability objectives. This was aided by Envirogen’s long and proven track record in industrial water treatment.

“We evaluated the company’s other MultiPro solutions in the energy from waste space and concluded that Eco MultiPro would be the ideal water treatment technology for the South Clyde Energy Centre.”
Essential

Demineralised water is essential for the trouble-free operation of the boilers and turbines.
Simon Radford, Head of Sales, Envirogen Group said: “Steam turbines are highly susceptible to corrosion and scaling. Scale-forming ions and suspended solids from mains water can settle on turbine blades and in pipework, posing a risk of damage. The use of demineralised water is absolutely crucial. Despite the steam cycle being a closed system, modern boilers still require a constant supply of demineralised water to replace inevitable losses from steam leaks, blow-offs and other operational processes.”

The three-phase treatment of Eco MultiPro
Heating water is energy intensive and scale formation reduces efficiency. Envirogen’s answer to this is Eco MultiPro, with its three-stage membrane treatment process: reverse osmosis, gas transfer membranes and continuous electrodeionisation (CEDI). Together, these stages remove all scale-forming ions, ensuring optimum performance and low running costs.

High quality, no dangerous chemicals
Radford comments: “We worked closely with the plant’s designer, AFRY, from an early stage to develop a membrane-based solution that met the plant’s sustainability needs. The membranes enable Envirogen’s state-of-the-art MultiPro units to produce high-quality demineralised water without the need to use hazardous chemicals on site.

“Overall, the robust, reliable design addresses whole-life operating costs, both utilities and maintenance, over a 30-year design life.

Envirogen’s membranes are durable and long-lasting, providing significant cost savings through reduced replacement frequency. Furthermore, the RO-CEDI skid does not require chemical regeneration, instead requiring a small amount of electricity to renew the membranes. The entire demineralisation process has much lower operating costs compared to a conventional resin bed solution, particularly as it uses electricity generated on-site.