A crucial step in advancing sustainability and environmental responsibility is to make sure energy is used optimally – making processes energy efficient protects both the environment and financial resources. Ensuring that processes can function as planned, without energy-intensive bottlenecks, is something we here at Altum Technologies dedicate our work to advancing.

Fouling negatively impacts energy efficiency. For example, in heat exchangers, it can increase energy consumption by approximately 10-15%, and in the worst cases, even up to 30-50%. As fouling decreases heat transfer efficiency and restricts flow of liquids, it is an essential issue to fix when trying to improve energy efficiency.

In honor of Energy Efficiency Day 2024, this blog post will discuss two real-life examples of improving energy efficiency with the help of our ultrasound service.

 Case 1: Preventing Fouling in Black Liquor Evaporators

A pulp mill had been experiencing issues with scaling in black liquor evaporators, mainly caused by calcium carbonate. The scale formed in this process is very hard in texture and difficult to remove, and drastically reduced both heat transfer and evaporation efficiency in the process.

Due to these scaling issues, it became difficult to maintain the process, especially for the intended four-month period during the winter. In the worst case, the process had to be stopped every month for a cleaning break. Due to fouling and increased energy consumption, the mill also needed to use additional energy sources, as burning the black liquor was not providing enough energy. This meant that the mill had to utilize fossil fuels to maintain production, which led to high CO2 emissions and extra costs.  

Altum’s multichannel ZPD (Zero Process Downtime) solution was installed on the inlet pipe to the evaporators to prevent scaling from happening. Before ultrasonic treatment, the temperature difference reached the set limit in approximately a month. However, with ultrasonic treatment, it remained constant, enabling stable, continuous operation for four months. Additionally, upon opening the evaporator after sonication, it was visibly cleaner.

By enabling the process to run continuously with unrestricted liquid flow and efficient heat transfer, the mill did not need to purchase any extra energy to maintain operations, translating to approximately 920 tons of less CO2e per year. Overall energy savings achieved by preventing fouling are estimated to be around 200 million MJ on an annual level.

Case 2: Preventing Fouling in Black Liquor Heater

One of our pulp and paper customers in Asia was dealing with fouling issues in their black liquor heater. This caused major issues in the whole production process, as scaling issues caused a decrease in production output and increase in production costs. The temperature of the black liquor after the heater needs to be at least 150 °C to maintain an efficient production process, however, this was difficult to maintain due to the decrease in heat transfer efficiency.

The amount of extra energy needed to run the process increased with fouling, as more and more steam needed to be fed into the pipe to maintain production efficiency. To solve these issues, Altum’s ZPD ultrasound solution was installed on the inlet pipe to the heater to prevent fouling.

By preventing fouling, a more stable flow and an overall 5% improvement of flow rate was achieved, in addition to temperature stability. Steam valve opening stayed below 80% during sonication for over 8 weeks, meaning no extra steam was required to maintain original production efficiency – without sonication the opening degree reached 100% in 4 weeks.

This led to energy savings of over 30 million MJ of make up energy per year, leading to CO2 savings of over 419 tons of CO2e annually.

Creating Energy Savings and Increasing Profit

With the help of Altum’s high-power ultrasound technology, companies have significantly enhanced both their sustainability and profitability. Energy efficiency is at the forefront of our work here at Altum, and we have proven results in lowering energy consumption. We’ll continue the work towards improved energy efficiency – will you join us?

Want to find out more about Altum’s solution for your process? Don’t hesitate to contact our experts for more information. You can also check out our references to see what else we’ve accomplished together with our customers.

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