Energies 2021 , 14 , 1161
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Table8. An overview of the best available technologies (BAT) for the pulp and paper sector based on the literature review.
Estimated Energy Saving
Estimated Emission Reduction
Typeof Technology
TRL
Description
Ref.
Process
Wood waste is used for gasification instead of combustion. The syngas is utilizing in a combined cycle gas turbine (CCGT). Energy recovery of waste biomass through a combined-heat-and-power (CHP) cycle. Use of the sludge from the water cycle to produce biogas in an anaerobic wastewater treatment plant, burning in the CHP to produce electricity. During production processing, such as pulp drying, and paper drying, a large amount of heat is lost. By recovering and reusing the waste heat, the energy efficiency will be improved, and emissions will be reduced. A recovery system such as recovery boiler closed hoods, and heat pumps can be used. An energy management system, such as steam, electricity, and gas consumption line monitoring, can improve energy flow control throughout the system and the measurement of energy efficiency. Frequent maintenance, especially on electrical equipment such as pumps, motors, fans, dryer systems, etc., can improve energy efficiency and reduce emissions. This technology, by using in mechanical pulping, reduces energy consumption. The technology makes modifications to the cell wall of the fiber and improves the strength of the fiber. Fungal and enzymatic are two common biological pre-treatment technologies for wood chips during mechanical pulping. The electricity use in mechanical pulping is converted into heat (2 tone steam production per ton of pulp), and heat can be recovered with a recovery boiler (up to 80% recovered as steam in TMP). Chemical pulp output from the digester can be washed by steam more than water, which has energy-saving potential. Part of the lignin (25–50%) is extracted from the black liquor by solving CO 2 and lowering the pH, which causes lignin to precipitate. Lignin is then purified. It can after be used as a quality fuel or a useful product for other industries. BLG is an emerging commercial technology capable of efficiently recovering energy from the black liquor’s organic content using a recovery boiler and gasification process. Ink particles can be removed in an earlier step before de-inking by separating long and short fibers (tested in the Andritz mill). Improving the screening and filtering in the recycling pulping process can save energy from 5 to 30%. Pulping with lower water content, reducing energy consumption to circulation, and pumping of pulp. Drying the sludge (using waste heat) can decrease water contact and increase the sludge calorific value. Replacing fossil fuels with this sludge reduces the emissions due to fossil fuel consumption.
Biomass gasification
8–9
[10,41–43]
Biomass CHP Biogas production from sludge
9
[44]
2%
9
3.5GJ/ton pulp or 1.07 GJ/ton paper
Energy Production
Wasteheat recovery
9%
9
[10,15,41,43]
Energy management
[15,44]
15%
9
Focus on maintenance
10%
9
[44]
Biological pre-treatment
1.8GJ/ton pulp
8–9
[10,42,43]
Mechanical pulping
Heat recovery
3.5GJ/ton pulp
[10]
8–9
Steam cycle washing
30–40% 7–8
[15,42,43]
Ligno Boost
[43]
Kraft pulping
Black liquor gasification
2GJ/ton pulp
[10,15,42,43]
10%
8–9
Recycled paper fractionation Efficient screening High consistency pulping
11–13%EL 40%Heat
[42]
[11,44]
15%
9
RCF Pulping
8%
9
[11,44]
[44]
Sludge dryer
5%
8–9
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