R Buitrago-Tello et al.
Original Article: Linerboard production and decarbonization
Supporting information may be found in the online version of this article. Key words: energy efficiency; carbon reductions; carbon cost; marginal abatement cost curve; CO 2 reduction measures
Introduction T he pulp and paper sector is an important contributor to carbon emissions, accounting for approximately 190 Mt of CO 2 in 2021. 1 As production is projected to increase by 2030, significant efforts must be made to break the dependency on fossil fuels and reduce energy demand. According to the International Energy Agency, the emission intensity of the sector must decrease by 4% annually from 2021 to 2030 to achieve zero CO 2 emissions. 1 Among the various products offered by the pulp and paper industry, linerboard has seen growing demand due to its use in lightweight packaging materials. The containerboard market was valued at over USD 160 billion in 2018, with expectations to reach USD 250 billion by 2025. 2 Linerboard, a critical component of corrugated cardboard packaging, is valued for being biodegradable, renewable, and recyclable, making it a sustainable material. 3 However, its sustainability depends on the energy efficiency of its production process, the sourcing of raw materials, and responsible forest management practices. A significant area of energy consumption in the manufacturing process is the paper machine drying section, which accounts for approximately 20% of the total energy used. 4 Implementing technologies to reduce the water content from 50% to 35% in paper webs entering the drying section could save 80 trillion BTU annually in the USA. 4 Another option to reduce energy demand in the drying section, particularly for linerboard production, is the adoption of condebelt technology. This technology replaces the conventional drying section with a drying rate 5–15 times higher than traditional steam drying, 5 and also reduces drying energy consumption by up to 20% while improving product quality. 6 Another critical area is the concentration of black liquor, the primary energy source in the kraft pulping process. Black liquor, which contains most of the pulping chemicals and dissolved wood solids, is concentrated to a high solids content before being burned in the recovery boiler. This concentration process occurs in a multiple-effect evaporator, which has a high steam demand. About 7% of the energy demand in US kraft mills (164 trillion BTU per year) is used for black liquor concentration. 7 Advanced membrane technologies for preconcentration of black liquor have shown
considerable promise, demonstrating potential steam savings of 20% to 30% through nanofiltration approaches. 8 Reducing carbon emissions in the power plant is also crucial. Steam production efficiency can be improved by incorporating high-power features into the recovery boiler (e.g., higher black liquor dry solids, air preheating, feedwater preheating, heat recovery from vent gases and flue gases). 9 High-efficiency recovery boilers can reduce carbon emissions by providing additional steam for power generation or by decreasing fossil fuel demand for steam production. 10 Modern recovery boilers can achieve thermal efficiencies above 80%, compared with 65% to 70% for older units, resulting in significant energy and emissions benefits. 11 Another carbon reduction strategy is the replacement of natural gas boilers with high-efficiency electric boilers. Electrifying boilers may increase greenhouse gas (GHG) emissions based on the current national grid mix. Future scenarios with a greater share of renewable energy in the grid could lead to overall reductions in GHG emissions. 12 The carbon intensity of the US electricity grid is projected to decrease by 50% to 70% compared with 2020 levels, making electrification increasingly advantageous for industrial decarbonization. 13 The potential of biofuels in lime kiln operations and the use of biomass for steam and power generation has also been explored as alternatives for decarbonizing linerboard production. 14 These measures have demonstrated the ability to achieve up to a 93.1% reduction in Scope 1 (direct) and Scope 2 (purchased energy-related) emissions. Further reductions can be achieved by enhancing energy efficiency in the manufacturing process. In this study, various strategies to reduce carbon emissions in a linerboard mill were evaluated, including technologies to improve energy efficiency in steam generation, black liquor concentration, and the paper machine dewatering and drying processes. Similar integrated approaches have been employed to evaluate biorefinery options and energy optimization in pulp and paper facilities, demonstrating the importance of system-level analysis for accurate technology assessment. 15,16 The novelty of this study lies in its comprehensive, integrated approach to evaluating multiple energy efficiency technologies for linerboard production through detailed process simulation combined with life cycle assessment and
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© 2025 The Author(s). Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. | Biofuels, Bioprod. Bioref . (2025); DOI: 10.1002/bbb.2790
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