Petrochemical’s adaptive measures for lowering river levels

Online Editor

Lowering river levels, rising uncertainty – what can the petrochemical industry do? Andreas Eßmann explores how plants and refineries reliant on waterways for cooling processes can adapt to these new circumstances.

In March 2023, Germany’s cabinet made history. Responding to weeks of high temperatures and low rainfall, it agreed on the country’s first national water strategy, prioritising conservation. This was unsurprising, as water levels for rivers such as the Rhine – a vital commercial artery for the nation – have plummeted in recent years, with cargo ships unable to use it during the 2022’s record-breaking summer heatwaves.

But water scarcity is not an issue confined to the Rhine alone. According to the Germany Environment Agency (UBA), the nation’s ongoing phase-out of coal power and lignite mining could see water levels in Berlin’s main river, the Spree, drop by up to 75% during the summer months. This is, in part, owing to the use of water to fill abandoned coal mines, and groundwater pumped to help extract these fossil fuels no longer being used.

UBA’s President Dirk Messner is already warning of potentially severe scarcity issues across Brandenburg, Berlin and Saxony if existing dams and water reservoirs are not upgraded. However, construction on projects like these can take years, and water shortages across Germany are already acute. This is to say nothing of the intense heat Europe experienced this summer, which further underlines the fact that German industry needs to start putting plans in place to mitigate potential disruption. After all, any further scarcity will impact all levels of society and shift the country’s industrial policy even further, so standing still is not an option.

Petrochemical Problems

Widescale droughts pose particular problems for petrochemical plants, as they are commonly situated on a riverbank or coastal region and use an open-loop system in which water is taken from the adjacent body then used for integral processes such as reactor and alkylation unit cooling, as well as cracking – where heavy hydrocarbon molecules are broken up into lighter molecules – and catalytic reforming, where refinery naphthas are distilled from crude oil into high-octane liquid products.

Water is also used to cool and liquify hydrocarbons, as well as in refluxing – the running of gas vapours from the top of distillation columns through a cooler to condense it for further use in plant systems. Given its versatility and crucial role in a plant’s day-to-day operations, a consistent supply is vital, so the traditional method of harnessing river water and dispersing cooled wastewater has continued unchallenged as the standard in petrochemical refining.

Adapting to the new normal

Yet with the concerning news about Germany’s declining river levels, this strategy may no longer be fit-for-purpose. Put simply, the plant cannot be cooled by water that is no longer there, so more unplanned downtime and disruptive events may ensue. The newly introduced nationwide water conservation strategy must also be accounted for, as it could be a sign of things to come for industries that intensively use water.

Faced with this wider scarcity threat and tightening regulations, facility stakeholders need to be aware of what could become the new normal, and consider how they may need to adapt site processes accordingly. Alternatives to open loop systems, including closed and semi-open circuits, should therefore be explored if the petrochemical industry is to mitigate any potential disruption.

Closed and Semi-Open Loop Systems

What sets the semi-open circuit system design apart from traditional open-loop models is its greater emphasis on water conservation. In a semi-open design, up to 98% of water used on-site is conserved, with the only losses coming from cooling towers economically and efficiently releasing heat through steam. Consequently, issues relating to falling river levels may no longer be as pressing, as consumption can be drastically reduced during potential droughts.

Closed-loop circuits appeal in a similar way, as they are exactly that – closed. They recirculate a fixed volume of water through on-site cooling towers to ensure no loss of resources, using chillers to maintain the fluid’s temperature after it passes through the demanding plant environment. Although this approach allows for even greater conservation, the additional equipment it requires may lead to increased energy consumption.

Considering the power pricing volatility of the past few years, plant stakeholders may be left in a position where opting for more sustainable practices may come with considerable financial downsides. With all industries under pressure to do more with less, specifying energy-efficient solutions is therefore a must for plants adopting either strategies involving closed or semi-open loop systems.

Living in a Modular World

Alongside these twin cost and green pressures, plant stakeholders also need to account for the weather’s inherent unpredictability. Indeed, although there is a consensus among scientists that this summer’s heatwaves will become more likely due to climate change, these wider trends may not be reflected in the day-to-day weather patterns.

Even if the bigger picture points to gradually shallower rivers, this continued unpredictability may make it harder for facility and plant managers to present a business case for permanent equipment. This is understandable – German industry is under more pressure than ever to decarbonise while remaining competitive at home and abroad, and capex budgets can only stretch so far.

Instead, what is required is a dynamic, modular approach to equipment procurement. By adopting hire strategies for key cooling tower, chiller and generator solutions, plants can be more responsive to both legislative and weather-based developments, with the provision of these technologies scaled up and down depending on site need. This is much harder to achieve with a permanent installation, which may quickly become under- or over-specified for site demand as the situation changes, or even non-compliant following updated environmental regulations.

Efficiency Needn’t Hamper Sustainability

To best manage these sometimes-conflicting pressures, it is vital that decision makers review their supply chain and engage outside expertise where appropriate. Integrating sustainable, efficient temporary solutions into ongoing operations and contingency plans is a key first step. However, proactive and pre-emptive planning will be required if this is to be truly effective.

Suppliers capable of providing the latest equipment have a considerable role to play in these efforts and must adapt their portfolios accordingly. Aggreko, for example, introduced its Greener Upgrades initiative in 2021 to help the petrochemical industry make small switches to equipment procurement strategies, resulting in big differences to overall NOx, particulate matter and CO2 emissions, and fuel consumption.

This includes the provision of new technologies such as Stage V generators, battery energy storage solutions (BESS) and the use of alternative fuels such as hydrotreated vegetable oil (HVO). Using these solutions to power key conservation technologies, including cooling tower and chiller equipment, can help plant and facility managers reduce energy and water usage while remaining in accordance with environmental legislation.

Finding Assurances in Uncertainty

Throughout all these changes, business continuity must remain paramount. However, established water usage practices are rapidly changing in response to climate uncertainty, placing process up-time at risk. To mitigate business upheaval, plant stakeholders should consider leveraging supplier expertise to manage conflicting demands and the additional skillsets required to operate and maintain new equipment.

As part of this, facility managers should expect services that were once considered extra – for example, on-site installation and remote maintenance – to be included as standard when working with suppliers. For instance, the implementation of new cooling tower, chiller and generator technologies can result in site upheaval if carried out improperly. Similarly, suppliers adopting a fit-and-forget, non-monitoring approach to such vital site equipment can leave petrochemical plants exposed in a challenging business landscape.

This is clearly unacceptable and has driven Aggreko’s efforts to ensure responsive support and monitoring services. Being able to remotely and quickly pick up any breakdowns or outages that may impair refinery performance and provide swift on-site support is a must in the increasingly under-pressure petrochemical industry, where unplanned downtime can be extremely costly. Bearing this in mind, site decision makers should also consider the size and scale of any potential supplier’s depot network before integrating them into their business contingency and continuity plans.

Alleviating Concerns

In conclusion, the pressure to do more with less continues to affect all German industries, especially with climate change creating instability on a national, continental and global level. However, given plunging water levels on the Rhine, Spree and other rivers, and the sector’s traditional reliance on H2O for site processes, German petrochemical plants are more vulnerable than most.

Yet with permanent equipment potentially proving too expensive and unsuitable to manage the changeable weather, new approaches are needed. With costs being so closely monitored, hire options can instead provide petrochemical sites with the dynamism they need to maintain yields and site productivities, even while conserving water. Decision makers should therefore reach out to appropriate suppliers and begin putting steps in place to adapt to what could be a fundamental change in the way plants and refineries operate.

Andreas Eßmann is sector expert for petrochemicals at Aggreko Europe.