Working systematically towards the test runs and start-up of the bioproduct mill

Preparations are currently being made on the construction site of Metsä Group’s bioproduct mill in Äänekoski for the test runs and start-up of the mill. As planned, test runs in the departments to be completed first will begin in the first quarter of 2017, and the entire mill will start up in the third quarter of 2017.

The various phases of the construction of the bioproduct mill have been planned and scheduled carefully, and any potential risks and the related measures have been identified and assessed. This ensures that the test runs in the departments, as well as the start-up of the mill, will run in a manner as controlled, systematic and smooth as possible.

The environmental effects have also been considered very carefully in each phase of the project.

“The equipment solutions are based on energy efficiency and clean technology. The main design criteria include a low level of wastewater, emissions in line with the permit limits for the existing pulp mill, and energy and resource efficiency in each phase of the process,” says Timo Merikallio, Project Director.

The environmental effects have also been considered very carefully in each phase of the project.

One example of this is the manufacture of sulphuric acid from the mill’s odorous gases to replace sulphuric acid bought from the market. In addition, gas produced from bark will replace around 50,000 tonnes of heavy fuel. During the construction phase, all recyclable waste has been recycled or used to produce energy at the Äänekoski integrated mill.

 

Wastewater treatment plant to be tested in April 2017

The wastewater treatment plant is one of the first departments to be inaugurated at the bioproduct mill. It is currently 85 per cent complete, and the installation of the equipment related to the final clarifier has been completed. The test run of the wastewater treatment plant will begin in April 2017. Its circuits will be tested and inspected first.

Its start-up phase will begin after the test runs in May 2017, when wastewater from the Äänekoski integrated mill will be directed to the process. The purpose of the start-up phase is to verify that the process works as planned. The start-up phase of the wastewater treatment plant will last for 2−4 weeks. After that, under normal conditions the plant will be able to process all the wastewater that is directed there.

The wastewater treatment plant is one of the first departments to be inaugurated at the bioproduct mill. The test run of the wastewater treatment plant will begin in April 2017. Photos: Metsä Group

During the start-up phase, wastewater can also be directed to the existing wastewater treatment plant, if necessary. In the event of interruptions, wastewater can also be directed to the safety basin in the same manner as at the wastewater treatment plant of the existing pulp mill.

The start-up phase of the wastewater treatment plant will last for 2−4 weeks.

The wastewater treatment plant at the bioproduct mill is based on a multistage biological treatment process and further chemical treatment. The multistage process improves the treatment result and reduces the plant’s sensitivity to interruptions.

“Modern treatment technology enables the bioproduct mill to operate in line with the permit limits for the existing integrated mill, even though the bioproduct mill will produce nearly triple the amount of pulp,” says Merikallio.

The emissions from the bioproduct mill will not affect the recreational or other use, or the ecological state, of the natural waterway downstream of the mill. At the end of February 2016, the Central Finland and North Savo ELY Centre approved the updated monitoring plan for the natural waterway downstream of the bioproduct mill. The related sampling programme has already been taken into use. The monitoring programme allows for careful monitoring of the state of the natural waterway before and after the inauguration of the bioproduct mill. If significant changes are detected in the samples, the mill is obligated to take corrective measures without delay.

More information:
Timo Merikallio, Project Director, Metsä Fibre Oy, tel. +358 50 5989 342
Johanna Harjukallio, Project Manager, Metsä Fibre Oy, tel. +358 40 3541 159

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