|
General comment ecoQuery: https://ecoquery.ecoinvent.org/3.11/cutoff/dataset/22808/documentation
This dataset has been extrapolated from the respective regional geographiy (RER). The dataset represents the production of kraft paper from chemical pulp produced in the kraft process. Kraft paper can be used for a number of flexible packaging applications such as paper sacks, wrapping papers and paper bags. When produced for paper sack applications, kraft paper is porous with high elasticity and high tear resistance, designed for packaging products with high demands for strength and durability. ;The dataset represents an average mix of white (bleached) and brown (unbleached) paper. The mix considered is a weighted average, based on the European production volumes for white and brown sack kraft paper. Recycled paper contributes less than 1% of the total fibres used for the manufacture of kraft paper.;The data was collected specifically for sack kraft paper but are representative for all kraft paper production. In many cases, other kraft paper grades are produced on the same paper machines as sack kraft paper, and would therefore have equivalent energy and water consumption profiles, emission profiles, etc. There would be small differences in some of the minor inputs for different kraft paper grades for other applications (e.g., quantity of wet strength and dry strength added), but overall the environmental profile would be comparable. ;Data in this model is from a study by CEPI Eurokraft and Eurosac conducted in 2022-2023. The dataset represents the production year 2021 and is average data calculated from several European Sack kraft paper mills. The majority of the mills in the study are integrated mills, but some "semi-integrated mills" were included. In the context of the study, semi-integrated mill means either an integrated mill that has been split into two companies (pulp production and paper production) where the pulp producer has not participated in the study, or a production site where paper is manufactured from a combination of both integrated pulp and market pulp.;The energy sources at integrated pulp and paper mills consist of external and internal fuels plus electricity from the grid. Both heat and electricity are produced from fuels. External fuels can be fossil or biobased. The internal fuels mainly consist of black liquor and bark from the wood input for pulp production. Black liquor is the by-product of the sulphate kraft pulping process. It contains almost all of the inorganic cooking chemicals along with the lignin and other organic matter separated from the wood during pulping in the digester. The initial concentration of weak black liquor is about 15% dry solids in water. It is concentrated to firing conditions between 65% and 85% dry solids concentration. It is then processed in the recovery boiler. The purpose of the recovery boiler is to recover the inorganic cooking chemicals and to make use of the energy in the organic portion of the black liquor. Source: Adams. T.N (editor) et al, "Kraft recovery boilers", 1997.;The following air emissions were reported in the study: CO2 (fossil and biogenic), CO (fossil), SO2, NOx, particles (all sizes). The listed air emissions are the most important emissions for the kraft paper production and cover all emissions at the mill, both from the cooking and recovering processes and combustion of fuels at different points at the plant. For a more complete air emission profile for sack kraft paper production, however, additional air emissions (beyond the ones listed above) were added for the combustion of the external fuels and internal using LCI datasets for combustion of different fuels as proxy. The air emissions were calculated based on the mix of the external and internal fuels in the study and more information about the fuel mix and the proxy is provided under "Extrapolations". No proxy was available for the combustion of black liquor, biological fibre slush, and tall oil. Emissions from these internal energy generation processes are therefore only reflected in the key emission factors provided by industry.
The process starts with the transports of wood and pulp to paper mill.
The activity includes transport of wood, purchased pulp and recycled paper (latter contributing less than 1% to the fibre input) to the paper mill, wood handling, chemical pulping, paper production (including any in-line paper coating), energy production on-site, internal wastewater treatment and infrastructure. Transport of other raw materials (process chemicals and additives) is not included. The activity ends with the paper leaving the factory gate. |
