Energies 2021 , 14 , 1161
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paper (53%), paper and board for packaging (41%), and special types of paper such as sanitary and beverage labels (6%) [9]. Based on the Austropapier data from 2017, Figure 2 prepares a general description of the pulp and paper sector’s material flow and sectoral production activities.
Figure2. Material flow in the Austrian pulp and paper sector in the year 2017 [9], illustration inspired by CEPI (Confederation of European Paper Industries) [24]. 2.2.2. Energy Use and Emission Impacts of Paper Production As mentioned in the previous sections (Sections 2.1.1–2.1.3), paper production is an energy-intensive process and requires energy input in the form of heat and electricity. Heat is typically consumed as high-pressure steam in turbo generators to produce electricity. The heat is then extracted to medium and low-pressure steam for utilization in production processing, such as wood chipping, pulp production, heating of cooking liquor in chemical pulping, evaporating water from the pulp, and paper sheet in the dryer section, etc. [15]. In Austria, the paper sector is the largest industrial final energy consumer, with a consumption of 23%, which corresponded to 20 TWh of the total industrial final energy consumption in 2017. This amount of final energy is consumed for steam generation in the drying and separation processes (73.5%), industrial furnaces (3.1%), electric motors (20.1%), and space heating (2.5%) [26]. In total, the sector utilized 4.532 TWh electricity and 11.3 TWh steam as useful en- ergy [9] for the production of pulp and paper. About 75% of this energy is used in papermaking processes (67% in the drying section [15]), 10% in chemical pulping, and 4% in mechanical pulping processes [27]. However, the Austrian P&P sector is equipped with local heat and power generators, especially in integrated paper mills and chemical pulping mills. The biofuel obtained from chemical pulping, mainly black liquor, and bark and wood wastes are used in the cogeneration plants (CHP) and generate the main part of the electricity demand, approximately 2.856 TWh, corresponding to 63% of the total
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