Congrats on the triplets!

Each year, the Sustainability Forum of the Finnish Energy Industries presents an acknowledgement – the Climate Action of the Year Award – to an energy-industry company or organization that has carried out investments or development projects to mitigate climate change or has, through other actions, contributed to combating climate change. In 2016, Valmet’s long-time customer, Tampereen Sähkölaitos, won the public vote category and was among the best three in the main category.

“As a public utility company, our task is to serve society and local inhabitants. That’s why we value the public’s recognition even more than the award itself,” says Antti-Jussi Halminen, Vice President, Energy, Tampereen Sähkölaitos.

The year of 2015 was a year of investments for the company in energy efficiency and sustainability, as it invested in Valmet flue gas scrubbers at three of its power plants.

Saves 260 GWh of fuel energy annually

The new scrubbers recover energy in the flue gases that otherwise would escape into the atmosphere. They enable the company to produce more energy with the same amount of fuel, which increases efficiency. “We now save 260 gigawatt hours of fuel energy annually, which equals the amount needed to heat 15,000 single-family homes,” Halminen points out. “This reduces our CO₂ emissions permanently by up to 100,000 tons per year (10%) and has a major impact on air quality locally. We are committed to curbing climate change and saving our living environment.”

In addition to heat recovery, the new scrubbers do their original job of capturing flue gas sulfur and dust emissions.

The investment is part of the company’s energy turnaround from using fossil fuels to renewable fuels in its energy production.

Same family, different personalities

Through its air emission control technology, Valmet has played a major role in helping Tampereen Sähkölaitos reach its targets. Each of the three flue gas scrubbers has its own personality and features different technical solutions based on the power plant type and the fuel used.

The first flue gas scrubber was delivered to a 49.5 megawatt (MW) wood-chip-fired heating plant located in the Hervanta area of Tampere in connection with Valmet’s complete plant delivery in early 2015. The uniqueness of the scrubber lies in the condensate that is utilized to moisturize the combustion air and increase the heat recovery capacity. The cooled condensate is specifically used in the scrubber return water, reducing the final flue gas temperature to only 35°C so that about 15 MW of extra capacity can be recovered through the scrubber.

Hervanta heating plant, image: Tampereen Sähkölaitos

In the fall of 2015, Valmet commissioned a multi-stage scrubber system and related process equipment and facilities at the Naistenlahti 2 power plant, which has a heat capacity of 120 MW and an electrical capacity of 60 MW. Supplied and modernized by Valmet, the plant mainly uses wood and peat as fuel. The flue gases are cleaned with a combination of a pre-scrubber and a tube condenser. About 40 MW of extra capacity is recovered from the flue gases.

“We plan to replace the Naistenlahti 2 unit in the early 2020s with a new one, so the scrubber was dimensioned for our future needs,” Halminen adds.

Naistenlahti 2 power plant, image: Tampereen Sähkölaitos

The third Valmet flue gas scrubber is located at the brand-new Tammervoima combined heat and power (CHP) plant, which is fueled by municipal waste. The plant has a heat capacity of 40 MW and an electrical capacity of 12 MW. Its flue gas scrubber uses hotter water than the other two scrubbers to reach high electricity production and produce zero waste water. The scrubber adds 4–5 MW to the heat capacity.

Valmet’s automation controls all operations

Close and fruitful cooperation between Tampereen Sähkölaitos and Valmet goes back decades. The company’s plants utilize Valmet’s energy production technology extensively. All of its plants are operated with Valmet’s process automation and information management systems.