Life Cycle Assessment Grass Paper
Research project at a glance
Departments and Instituts
01.06.2017 to 31.10.2017
One goal of bioeconomic research and consulting is to help ensure that existing fossil raw materials can be used more efficiently and substituted or supplemented with the highest possible proportion of renewable raw materials. The subject of the study on grass-based paper was the comparative life cycle assessment (according to ISO 14040) of the use of sulfate pulp, recycled pulp and grass-based pulp in the German paper industry. The LCA addressed the question of the extent to which the production of paper in Germany can be made more ecologically advantageous. After all, 22.6 million tons of paper products were produced in 2016.
To this end, an ecological comparison study had already been carried out externally in 2012. Now there were good reasons to significantly expand the analysis in 2017. Since the publication of the first study, the data situation regarding the value chain of pulp from wood had improved considerably. For example, higher quality and more precise data on raw material extraction and pulp production were now available for the South American region, from which a large proportion of German pulp imports originate.
With the support of databases, it was also possible to include detailed information on wood cultivation, processing and transport in the analysis. Thus, by including around 95% of the sulfate pulp used for paper production in Germany and its precursors, it was possible to model the value chain more precisely. For this purpose, the processes between the extraction of the raw materials required for pulp production and the delivery of the basic materials to the mill gate were selected as system boundaries. The impact assessment was carried out in the categories "energy use", "water consumption", "greenhouse effect/CO2 emissions" and "acidification".
Grass-based pulp performs significantly better than the wood-based sulfate pulp and waste paper pulp alternatives in terms of energy and water use, acidification potential and emissions balance. This is because a similarly large amount of feedstock (at least five tons per year per hectare) can be obtained compared to logging. Only eucalyptus promises a significantly higher yield per year and hectare. In addition, the transport route is crucial when assessing environmental performance. To use one ton of sulfate pulp in paper production, an average of 14,000 ton kilometers of pulp are moved in the form of logs, wood chips or already refined pulp. Thus, one result is that the amount of energy and emissions required to transport one ton of sulfate pulp is higher than the entire production process of two tons of recycled pulp or three tons of grass-based pulp.
In recent years, the use of water in the production of sulfate pulp has fallen sharply. Nevertheless, in the scenario on which this study is based, it is 32,000 liters per ton of sulfate pulp, 9,000 liters per ton of waste paper pulp and two liters per ton of grass-based pulp. Compared to the production of sulfate pulp and waste paper pulp, there was a clear overall environmental advantage for the grass-based pulp. For example, the production of grass-based pulp for the paper industry is six times more energy efficient than sulfate pulp, produces only 26% of the emissions, requires 16,000 times less water, and has an acidification potential that is 18 times lower.