14 INDUSTRY NEWSANDRITZ


increase in brightness and removal of dirt specks. Higher efficiencies introduce another variable in the mix: lower quality (and therefore cheaper) raw materials can be used in order to achieve similar pulp characteristics. For example, the raw material mix considered for the 3-loop de-inking system consists of 20 per cent coloured letters, 40 per cent coloured wood-free magazines, and 40 per cent multi-print. The simplified system would need approximately 50 per cent white wood-free shavings for this purpose in addition to the multi-print raw material, which leads to considerably higher raw material costs. In contrast, the situation is quite


Table 2: Comparison of a 3-loop de-inking plant concept with a simplified system


3


a DIP plant producing 300 tons/ day (or 105,000 tons/year) for example, the investments costs calculated are 42 per cent lower for the simplified concept.


A clear difference is evident in


the efficiencies achieved, but in the opposite direction. Here, there are distinct advantages with the complex system, particularly the


different when the energy costs are compared. As the simplified system does not include some of the energy-intensive process stages, it uses 60 per cent less energy. Other costs, such as the cost of bleaching chemicals, also point to a clear advantage for the simplified system because some


Pulp Paper & Logistics


individual process stages are omitted. Even with these considerations, the DIP system with three loops (as illustrated in Figure 2) is less expensive overall. Although the simplified system has a clear cost advantage in several areas, the higher costs for the raw materials used in the simplified concept outweigh all of the other advantages. This becomes particularly noticeable over the life of the system, after the investment has been fully amortized, which is detailed in Table 3. It can be concluded that using the lowest quality raw material that is only just good enough for the desired end product does entail higher expenses for energy, chemicals, and also investment costs, but this is more than compensated by savings in raw material. More information from ANDRITZ


AG, Stattegger Strasse 18, 8045 Graz, Austria. Tel: 43 316 6902 2482. Fax: 43 316 6902 470. www. andritz.com


Table 3: Summary of costs July/August 2015


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36