Building Water Resilience in Southern Europe Refinery

Water resilience is more crucial than ever, especially for industries that rely heavily on water for their operations. This case study explores how our Client, a global energy company, tackled the challenge of improving water management at their oil refinery in Southern Europe. By implementing innovative solutions, they not only met regulatory requirements but also enhanced their overall water efficiency and resilience. Read on to discover the key strategies and outcomes of this project, and how it can serve as a model for other industries facing similar challenges.

Global Outlook, Local Needs

Founded in Europe more than 70 years ago, the Client is a publicly traded global power company with a diverse portfolio that includes oil, gas, hydrocarbon refineries, and renewable energy sources like marine, solar, wave, and wind. With such a broad spectrum of operations, the Client has varied water needs. They recently assessed one of their refineries water management system to enhance efficiency and reuse. The goal was two-fold:

To meet new regulatory requirements limiting suspended solids in treated effluent discharge.
To fully operationalize improvements previously implemented in the water supply and effluent systems, minimizing the water footprint of the site and increasing the water resiliency as well.

To address these needs, the Client turned to our water experts.

The Challenge

The refinery's water and wastewater treatment systems were developed incrementally, without a unified plan. As Carlo Zaffaroni, Global Industrial Water & Wastewater Subject Matter Expert and Engineering Division Director at WSP in Italy, explained, there was no single overriding plan. Instead, plans ran in parallel for both the preparation of primary water (used in their processes) and the treatment of wastewater (dirtied after use in production).

The refinery also experienced significant fluctuations in wastewater amounts between dry periods and heavy rain. Past improvements had been installed to correct the variance, but we were tasked with making a final rationalization of the entire system. Even more concerning, all the refinery’s water comes from a single surface water channel. "A single source means there’s no redundancy nor resiliency," says Carlo. "There’s no slack if permissions change."

Our Holistic Approach

We understand water technologies, water balances, and mass & energy balances. We have comprehensive experience with different types of industrial water needs, such as cooling, steam production, manufacturing processes, potable water, etc., and how each process generates different types of wastewaters requiring specific cleaning processes before its release into the environment.

Water is not simply water. Water consists of H₂O, salts, solids, organics and various other substances. We performed mass and energy balances to understand what happens to whatever else is inside the water at each step of treatment.

In the case of the site, the refinery had already started to reuse some of their treated wastewater. Specifically, they used the effluent of the wastewater treatment as makeup water for the cooling tower. Since the cooling tower evaporates water to remove heat from its process, it doesn’t require the very highest quality water. However, they experienced some operational issues when it came to suspended solids in the wastewater.

System discharge reduced

190 m³/h

Improved water recovery rate

66%

Our plan took the wastewater from the existing biological system and installed disc filters to deliver water totally free of solids. Then we sent part of the filtered water to the cooling tower. Another part went to a new reverse osmosis system (together with a part of primary water) for reuse. The blend of waters was an improvement, keeping the salinity of the effluent at acceptable levels and minimizing clogs in the system.

Reusing water in this manner decreases the amount of water that the refinery takes from the primary channel. As a result, there is automatically more resiliency in the system and extra capacity to treat wastewater during periods of heavy rain. Storm water comes in large amounts, but it is much more diluted. There is less pollution to remove, but given the amount, it cannot go to the biological system. Since it is not so dirty, it can go to a lighter treatment.

Our team members fulfilled several roles across the scope of the project. We conducted field activities and inspections along with concentrated desktop activity to calculate the mass balances. Team members produced drawings, piping and instrumentation diagrams, technical specifications and engineering sketches. We also interacted with vendors to produce the exact definitions of the required items to be installed, so the client could send tenders with the correct technical specifications for disk filters, storm water polishers, membrane plants, and everything else required.

The Results

Part of our mandate was to adjust and fine-tune previous attempts at improvement. We took a holistic approach to eliminate the over-treatment of wastewater, saving the refinery time and energy, reducing its carbon footprint. Even though some steps are still pending or nearing completion, we are already seeing significant benefits from our approach:

The quality of water replenishing the cooling towers and fire-fighting circuit has improved, with lower solids content minimizing the potential for clogs.
The salt drain will allow the concentrate of the new RO to be safely discharged.
The recovery rate of exiting water is being gradually improved from its current 23% up to 66%.
System discharge is being reduced by approximately 190 m³/h.
The use of lime in primary treatment was removed, reducing the production of sludge and lowering the CO₂ emissions.

Our solution integrates both pre-planned interventions, such as a desalination unit, and necessary improvements to meet the new Best Available Techniques (BAT) requirements, such as disc filters. This comprehensive treatment process significantly reduces water consumption and enhances the refinery’s water resilience. During dry weather, the new arrangement ensures a fully compliant BAT chain, producing treated water that is safe for discharge.

Widening Ripples

Climate change can cause both water scarcity and excess simultaneously. With our assistance, the refinery is reducing its dependencies, decreasing its costs, and improving the whole area’s access to water. Additionally, the new treatment plan for heavy storm water means that discharge following severe weather events will be cleaner, with the refinery removing more pollutants than before.

Improving water resilience for the Client’s refinery also has a broader societal benefit. In times of water scarcity, when the flow in the primary channel is low, the refinery will require less uptake. It will reuse its own wastewater instead, which builds water resilience for the community as well as the company.

Water needs vary significantly across different industries and sectors. The requirements of a refinery, for example, are distinct from those of the pharmaceutical or food and beverage industries. Understanding these differences is crucial for applying the most appropriate water technologies. By leveraging the latest advancements in water treatment, we ensure that our solutions are both effective and sustainable.

Key Takeaways

Water is not simply water, it is H₂O, salt, solids, organics and various other substances.
Climate change can cause both flooding and drought in the same area, often occurring close together.
Industries relying on a single source of primary water lack redundancy and resilience during periods of both excess and scarcity.
Reusing wastewater reduces the amount drawn from the primary sources, thereby increasing system resilience.
Effective wastewater treatment and reuse lower the company’s emissions and carbon footprint.
Reusing wastewater also enhances water resilience for the local community by reducing industrial demand.