R Buitrago-Tello et al.
Original Article: Linerboard production and decarbonization
Figure 7 presents the carbon emissions for each alternative, assuming the electricity emission factor from the high-cost scenario over a 10 year period. Under these conditions, the membrane system showed the lowest carbon emissions, followed by the condebelt and MVR. In the electric boiler scenario, carbon emissions decreased significantly from 0.783 to 0.712 kg CO 2 -eq./kg product. Considering these emissions variations over time, the CAC was calculated based on total carbon reduction for each alternative over the 10 year period, using the same NPV methodology described previously (results in Table 4). In this context, carbon credits from electricity sold to the grid decreased, leading to a lower CAC for the high- efficiency recovery boiler. For electric boilers, instead of increasing carbon emissions, this alternative reduced them due to the lower impact of imported electricity. Similarly, the improvement in the national electric system reduced emissions from electricity demand, thereby lowering the CAC for other alternatives. The sensitivity analysis highlights that the industry can further reduce carbon emissions by replacing heat (steam) demand with electric energy, supported by the ongoing decarbonization of the US electric grid through an increased share of renewables (Table 4). Conclusions Improving steam generation and utilization technologies is essential for decarbonizing the pulp and paper industry. In linerboard production, reducing steam demand in critical areas such as black liquor concentration and the drying section can lead to significant reductions in total carbon emissions. For example, using GO nanofiltration membranes to preconcentrate black liquor, or installing a condebelt in the drying section can reduce total carbon emissions by nearly 15%. Enhancing steam generation in the recovery boiler can reduce carbon emissions further by approximately 10% through increased steam and power generation. However, to select the most suitable technology, it is necessary to balance potential carbon reduction with cost effectiveness. A MACC is an effective tool to identify alternatives that offer both carbon savings and cost benefits. For instance, using nylon felt in the press section, installing a shoe press, and preconcentrating black liquor with a mechanical vapor recompression (MVR) system significantly reduce operating costs, providing a return on investment. These technologies can achieve a maximum carbon reduction of 8%, with a cost of avoided carbon (CAC) ranging from −$67 to −$19 per ton, representing savings for the mill. In contrast, using a membrane system to concentrate black
14
© 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
Made with FlippingBook. PDF to flipbook with ease