CO2 reduction and energy efficiency at Zellstoff Pöls AG

Project description:

From 2011 to 2018, Zellstoff Pöls AG has undertaken comprehensive measures to reduce emissions of fossil CO2 and to increase overall energy efficiency. One of the most significant projects was to ensure efficient use of the waste heat flow from the process, by supplying it to a district heating network. An 18 km supply line provides industrial plants, public facilities and private households with heat energy from Pöls.

A further increase in energy efficiency was accomplished with the installation of two flue gas coolers in the recovery boiler. The thermal energy of the flue gas heats up the feedwater, which results in a significant reduction of steam. A new system of heat exchangers in the recovery boiler enabled the use of another heat flow,
which led to an additional reduction in steam consumption.

By commissioning a tall oil plant, it was possible to further process tall soap resulting from the processing into crude tall oil. This substance can be used as a substitute for fuel oil.
Due to its special properties, tall oil is also in great demand in the chemical and cosmetic indus-tries.

By using an additional waste heat stream from the pulp mill, the temperature in the paper production water cycle increases, which brings considerable advantages.
A further significant energy efficiency measure is the ability to recover the heat in the exhaust air extracted from the paper machine.

Project purpose:

Our projects during the past year have had the overall objective of reducing fossil CO2 emissions and continually increasing energy efficiency in the mill. Linked to this is a decrease of primary energy demand and the economical usage of available energy sources (steam, elec-tricity).

Project evaluation:

The consistent implementation of Zellstoff Pöls AG’s energy efficiency strategy has led to savings in CO2 emissions of approximately 160,000 tonnes per year.

 

Siegfried Gruber

Head of Project Engineering Zellstoff Pöls AG

Increasing the benefit from our main raw material, wood, by pushing the mill’s energy efficiency and generating new products, was one of the main goals, alongside mill optimisation, over the last 10 years.

In 2011 Zellstoff Pöls AG invested in a new district heating system for the whole of the Murtal valley in Austria’s federal state of Styria. Today 120 GWh of heat per year is delivered to more than 15,000 households in the region, through an 18 km pipe system. This project was only possible due to excellent relationships between industry, communities and several project partners. Above all, the environment is the winner, as no additional and valuable wood is burnt for heating purposes.

 

Main features:

CO2 Emissions saved (tCO2): 16,000 tonnes per year

Investment: €60 million investment in CO2 reduction projects (2011-2018)

Partnerships:  Zellstoff Pöls AG, Bioenergie Wärmeservice GmbH