PAPERmaking! Vol11 Nr2 2025

R Buitrago-Tello et al.

Original Article: Linerboard production and decarbonization

Figure 3. Hotspot analysis for carbon emissions of different technologies to improve the steam generation/demand in the production of linerboard.

electricity demand required to operate the boilers, leading to a net increase in emissions of 57.2%. It was expected that the US electric system would incorporate renewable energies, reducing the carbon emissions associated with the electricity demanded by the mill. The graphene oxide membrane system offered significant steam savings by preconcentrating weak black liquor from 15% to 30% solids, resulting in a 30% reduction in carbon emissions by avoiding natural gas combustion in the boiler. However, these reductions were partially offset by the increased electricity demand required to pump the liquor through the membranes, the loss of pulping chemicals due to the membrane’s partial selectivity to inorganics (as detailed in Supporting Information, Table S4), and the decrease in on-site electricity generation caused by reduced steam flow to the turbines. Increasing the number of membranes from four to five did not yield further carbon emission reductions. Chemical recovery was enhanced by adding a fifth membrane. The electricity demand increased, offsetting the chemical recovery’s benefits in carbon emissions. The net carbon reduction for a four-membrane system was 14.7%, and the five-membrane system was 14.2%.

Similar to the membrane system, the MVR technology reduced the steam demand required to concentrate the white liquor, leading to an 18.5% reduction in carbon emissions by avoiding natural gas combustion in the boiler. However, these savings were partially offset by the increased electricity demand for the fan that compresses the water vapor, as well as the reduced on-site electricity generation due to lower steam flow. As a result, the net carbon reduction achieved by the MVR system was 8%. In the paper machine, the implementation of nylon felt and a shoe press increases the web solids from 50% to 61% and 50 to 54%, respectively. This increase in web solids reduced the steam demand in the drying section, thereby lowering the natural gas demand in the boiler. However, the decrease in steam demand also led to reduced on-site electricity generation, which in turn increased Scope 2 emissions. As a result, the net carbon reductions were 8% for the nylon felt and 5% for the shoe press. In the case of the condebelt, this alternative offered higher savings in steam demand in comparison with the nylon felt and shoe press. The reduction in the steam provided to the turbine for electricity generation was also offset by the electricity savings that this alternative offered, resulting in a net carbon reduction of 14.6%.

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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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