Lowering water levels, rising uncertainty

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.¹ 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 2022’s record-breaking summer heatwaves.²

But water scarcity is not an issue confined to the Rhine alone. According to the German Environment Agency (UBA), the nation’s ongoing phase-out of coal power and lignite mining could see the Spree’s water levels drop by up to 75% during the warm summer months.³ This is due to water being required 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 these massive projects can take years, and these shortages are already becoming acute. This is to say nothing of the intense heat Europe experienced this year, its second record temperature summer in a row, which further underlines that German industry needs to start putting plans in place to mitigate potential disruption.⁴ 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. It is then used for integral processes including reactor and alkylation unit cooling, as well as cracking – the process in which 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, and 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.

References

¹ https://www.reuters.com/business/environment/germany-introduces-national-water-strategy-climate-change-forces-action-2023-03 15/#:~:text=Germany%20is%20a%20water%2Drich,many%20parts%20of%20the%20country.
² https://news.sky.com/story/europe-is-facing-drought-with-more-groundwater-being-lost-than-replaced-by-rain-12915078.
³ https://www.umweltbundesamt.de/en/press/pressinformation/spree-faces-increased-water-shortage-after-coal.
⁴ https://climate.copernicus.eu/summer-2023-hottest-record.

This article was originally published in the January 2024 issue of Hydrocarbon Engineering magazine. To read the full article, sign in or register for a free subscription.

Written by Andreas Essmann, Aggreko Europe, Germany.

Read the article online at: https://www.hydrocarbonengineering.com/refining/24012024/lowering-water-levels-rising-uncertainty/