Recycling to save energy on paper production
Demand for fibres from previously non-forest sectors (such as the energy sector) has increased because of the shift towards a bio-based economy. This has impacted the paper and board industry and the prices of and demand for recycled fibre-based raw materials have started to increase. The pulp and paper industry needs to improve resource efficiency of current paper products with minimum environmental impact. Waste streams from recycling processes need to be regarded as a source of valuable components. The EU-funded project REFFIBRE (Tools for resource-efficient use of recycled fibre materials) worked to develop tools to design resource-efficient paper and paperboard production chains. Researchers optimised different material fractions to make savings of about 20 % for the same final product functionality. REFFIBRE developed methodologies, models and tools to show the possibilities that come with resource-efficient reuse and adding value along the value chain. Researchers linked together production design and process modelling tools to evaluate the environmental impact and technical feasibility of multi-product mill concepts. The team studied the effects of different fibre fractions and fillers on the properties of produced paper. They developed tools to find pulp combinations and paper compositions that reduce material or energy consumption without losing paper quality. Through models and experimental work, REFFIBRE showed that removing fillers and contaminated fines increased strength properties without affecting how the paper products looked. The researchers also showed that less energy was needed in paper production to remove water in wire and press sections. Team members used process models to optimise the quality and purity of the recycled pulps and developed indicator-based tools to optimise stock preparation systems in the future. They successfully produced side-stream plastic composites from rejects, de-inking sludge and fly ash in cooperation with two industrial partners. The researchers also minimised fibre rejects through improvements in the stock preparation systems and by installing novel equipment in two paper mills. These results will improve paper and paperboard value chains, helping industry and end users to decrease their overall waste production.
Keywords
Paper production, raw materials, waste streams, REFFIBRE, recycled fibre