Valmet to deliver a cooking plant pre-evaporator upgrade for Mercer Rosenthal in Germany
Valmet will deliver a Valmet Exergy Pre-evaporator for the Mercer Rosenthal mill in Germany. The solution increases the mill’s energy efficiency and brings savings in the feedwater treatment. The new system is planned to be taken into operation during the fourth quarter of 2025.
“We wanted to find a solution to improve the energy efficiency of our continuous cooking plant. By installing this pre-evaporation system, we can improve both energy and water efficiency. By more efficient steam consumption we can use more steam for electricity production in our existing steam turbine,” says Tobias Albert, Mill Manager for Mercer Rosenthal.
“We are pleased to continue our good cooperation with the Mercer Rosenthal mill. Valmet’s equipment has a low footprint, is delivered fully assembled to the site, and has an outstanding lifetime. This solution proves how a pulp mill’s sustainability can be improved with small investments,” says Bernhard Trunk, Senior Sales Manager, Central Europe, EMEA, Valmet.
Valmet delivers the main Exergy Pre-evaporation equipment, engineering, procurement, and installation. The equipment is planned to be connected to the production process during the mill’s annual shutdown in 2025.
“A partial stream of the hottest black liquor from the digester is directed to a falling film evaporator. The heating media for the falling film evaporator is medium-pressure steam, and the generated black liquor vapor is used to heat the digester. Since the medium-pressure steam condensate is no longer fed into the digester, it can be returned to the power plant at a high temperature. This, together with the higher dry solids content of the weak black liquor to the evaporation plant, creates the main savings effect,” continues Mercer Rosenthal’s Tobias Albert.
About Mercer
Mercer is one of the world’s largest producers of market pulp and a growing leader in the solid wood products space. The company has facilities in North America, Europe, and Australia. In 2023, the company’s total revenues were USD 2 billion. The Mercer Rosenthal mill produces about 360,000 tonnes of elemental and total chlorine-free Northern Bleached Softwood Kraft (NBSK) pulp per year, 400,000 MWh of renewable electricity, and about 5,000 tonnes of crude tall oil per year.
