Process innovations drive efficiency and sustainability

Process innovations focus on improvements to pulp and fiber production processes. Lenzing is constantly working on resource efficiency, occupational safety, process stability, and quality. Ongoing developments in pulp production aim to enhance the biorefinery concept, thereby optimizing wood consumption. Another issue is the reduction of sulfur emissions through technological improvements and aftertreatment systems. These measures allow effective cleaning of the exhaust gases and compliance with (and surpassing) the emission regulations.

The foundation for sustainable innovations is the use of highly sophisticated production processes for pulp (including biorefinery products) and fibers (viscose/modal and lyocell). The lyocell technology platform has been expanded to the production of additional materials already, namely filament and direct-spun web. A number of new innovations have been developed in recent years that have significantly improved the lyocell process in terms of efficiency and quality but also in reducing energy and process chemical consumption, thereby improving the already sustainable lyocell process overall.

In terms of process improvement, R&D has developed an alternative technology to suspend dissolving wood or recycling pulp in solvent that requires not only fewer process steps and less energy but also yields better-quality spinning dope. As a consequence less filtration effort is needed that on the other hand reduces filter reject, creates less waste streams and improves the overall yield.

Another focus in recent years has been the development and manufacturing of new spinnerets, which are the hearts of every fiber production plant. These developments resulted in higher output per spinning end (reduction of specific energy demand), more stable spinning performance and thus improved fiber quality (less low grade fibers or cellulosic waste). Both improvements ultimately lowered greenhouse gas emissions. All these developments have already demonstrated their benefits in the expansion project in Heiligenkreuz, Austria as well as in the lyocell plant in Thailand.

R&D is also continuously working on online analytical methods to analyse various production streams in real time, a requirement for realizing digitalization and automatization and future benefits like online grading, fiber production optimization in terms of quality and energy consumption. One current focus is the development of technologies to more efficiently remove water from different process streams compared to the standard evaporation technologies, which are very energy-intensive. These technologies may again significantly help to further reduce energy consumption and thus the CO₂ footprint per ton of produced fibers.

In addition, projects are ongoing to also further reduce water and process chemical consumption. These activities are accompanied and supported by simulation and modeling. In the near future, Lenzing will significantly enhance its textile recycling activities – a very challenging task that not only includes the production of recycling pulp but also has to deal with the processability of recycling pulp in different fiber production processes. Success requires a holistic approach from pulp to fiber production to final applications in the textile and nonwovens. These activities may result not only in necessary modifications of the pulp production processes and the selection of feedstocks but also in adaptions or even new technologies in fiber production processes.  

A current focus is on boosting biorefinery integration at Lenzing’s pulp sites and therefore on increasing the usage of the raw material of wood. Several projects related to pulp production deal with the closure of loops (e.g. selective sulfur dioxide absorption, increased caustic soda recovery) and the reduction of wastewater (e.g. sulfate in pulp and viscose fiber production). Increasing energy efficiency and reducing carbon emissions are other topics of growing importance.

Activities in this field go beyond regular continuous improvements and seek innovative solutions to reach the ambitious goals set by Lenzing via its science-based targets (SBTs). In order to achieve maximum impact, pulp and fiber production are increasingly being assessed together to find interactions and synergies. A concrete example in this regard relates to reducing the energy consumption of evaporating aqueous systems by using membrane processes. These processes can be used for both pulp and fiber production, thereby demonstrating the Group’s holistic approach in process innovation.

EU BAT

All Lenzing sites in the EU, including one viscose plant, two lyocell plants, and two pulp plants, continuously met or exceeded the applicable EU BAT performance in 2022, which are set out in several EU best available technology reference documents. Compliance with EU BATs is the basis for the issuance and review of environmental and operating permits for the plants and is continuously monitored by the competent authorities in the EU Member States. Compliance monitorings, as well as requirements relating to management, monitoring program, reporting, etc., are also carried out in accordance with the EU BATs.

The EU BAT cannot be invoked outside the EU. All products produced in Lenzing production sites outside the EU, with the exception of one viscose plant in Indonesia, therefore have the EU Ecolabel for best-in-class performance. In 2022, the Lenzing production site in Thailand was successfully awarded the EU Ecolabel and became the latest facility in the Group to produce products with the EU Ecolabel certificate. In line with the sustainability target, the viscose site in Indonesia aims to achieve the EU Ecolabel in 2023 (targets 1 and 5).

Lenzing is also continuously working on improvements in other business areas. It is fully committed to the Supplier to Zero roadmap of the multi-stakeholder Zero Discharge of Hazardous Chemicals (ZDHC) initiative. All three viscose sites continued their biannual reporting to the ZDHC gateway in 2022. Progress has been made towards achieving the Aspirational Level as set in the sustainability target.

EU Ecolabel

The EU Ecolabel was established by the European Commission in 1992. It is an environmental quality label awarded to products and services that have a lower environmental and health impact than comparable goods throughout their entire lifetime. Products bearing the EU Ecolabel are therefore among the most environmentally friendly in the industry. Independent experts, scientists and NGOs devised the guidelines and criteria for awarding the EU Ecolabel in collaboration with the EU member states. The criteria are determined scientifically and consider the entire product life cycle. Regular revisions ensure that the criteria reflect new developments and that assessments remain current. For the Lenzing Group, this means that continuously stricter criteria have to be met in pulp and fiber production, both with regard to emissions released into the air and water as well as the handling of chemicals. The Lenzing Group can provide viscose, modal, and lyocell fibers with EU Ecolabel.