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A smart homogenization approach improving process knowledge and papermaking competitiveness

Final Report Summary - SHAKER (A smart homogenization approach improving process knowledge and papermaking competitiveness)

Efforts of the paper and board mills have already lead to a more closed water system, which, produce the accumulation of dissolved and colloidal material (DCM) in the water systems. At unexpected moments, there occur disturbances in the paper production process, like stickies explosions, anionic trash, scaling, corrosion, etc., that have unknown causes. The result hereof is that the produced paper is not within specifications and the paper machine has to be stopped to clean the whole system. The downtime caused by unstable wet-end systems is about between 8 and 30 hours, leading to a loss of EUR 24 to 9 000 k per stop. Therefore paper mills need to optimise and stabilise their wet end system with sustainable management principles if they want to remain competitive. This is especially important for small and medium-sized enterprises (SMEs) because of the need to compete in the same market with large mills that profit from the scale economy.

The objective of this project was to investigate the enhancement of sustainable management for stock (wood), energy (natural gas and green house effect) and water by stabilisation of the wet-end system of paper production based on a low cost sustainable concept. The scientific objective was to investigate, from an applied point of view, the source and behaviour of disturbing substances and the most important causes for sudden explosions of these disturbances within paper mills. The technical objective was to achieve further reduction of energy and natural gas (20%), water (20%), wood (5%) and chemical consumption (25%) combined with an improvement in runnability, flexibility, productivity, and product quality. The social and policy objectives were to decrease usage of natural resources and environmental effects (on nature and human), to improve or maintain employability at supplier SMEs and to improve working conditions (health, trachea and skin). Both supplier and end-user SMEs fulfil an important role within the European economy and therefore to the competitiveness compared to US, Far East and South America.

This project is the first step towards the commercialisation of the new concept. Therefore, the work started with a market research and the definition of proper routes for dissemination and exploitation of the results obtained during the project, WP7. This task was led by IUV. This task required strong collaboration and commitment between the SMEs, because marketing the new concept, in a new market (for IUV), is not easy, especially because papermakers were not familiar with the hyperboloid mixing in particular for in-mill applications. During the project it seems to be necessary to find other applications in the paper industry to make a bigger market potential and by that interest for the suppliers. Both in-mill water and pulp applications is a very serious market potential. The big advantage of the new mixing concept is that the device is sensor based and because of its vertical working low in energy consumption in comparisons with horizontal (high-speed) propellers.

The intention of the SHAKER concept is not to solve all the water related problems but to avoid them (preventive action). The cause of process instability is bad homogenisation of pulp and water within storage/dilution tanks. In dead zones of tanks, certain parts of (inner) tank walls, etc., long residence times occur and create an increase of e.g. anaerobic biological activity. This causes gradients of microorganisms, degradation products (VFAs) and will finally generate the mentioned problems. All have a dissolved and colloidal nature. Furthermore, there are some mill practices that may destabilise this dissolved and colloidal material existing very limited information to this respect.

The main innovations of the concept are:
- an integrated wet-end homogenisation concept dealing with the source of the disturbances;
- an optimal mixed (machine) chest towards a constant wet-end system;
- a concept, which is exploitable to other parts of the paper production process towards a chest-free papermaking;
- a system to stabilise paper making process and hence an improved product quality.

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