LCA of a newsprint paper machine: a case study of capital equipment

The environmental aspects of paper as a consumer good have been extensively studied. However, the paper machine has been mostly neglected in the literature. The purpose of this article is to present a LCA case study that explicitly focuses on the system of a newsprint paper machine and its environmental impacts and not on the system of the consumer good paper. The relevance of the paper machine as capital equipment is analyzed, and conclusions for the environmental improvement of paper machines are drawn based on identified hotspots. The article hereby answers the more general research questions of whether capital equipment has rightly been neglected in other studies regarding pulp and paper and which impact categories are important for analyzing the environmental burdens of a paper machine.

The study has been executed in collaboration with Voith Paper, an original equipment manufacturer. Hence, in distinction to literature-based studies, primary data on the paper machine was available resulting in a high overall data quality. Based on the ISO 14040 (2006) and 14044 (2006) standards, this article pursues a cradle-to-grave approach for the paper machine. It assesses the environmental impacts in the impact categories defined by the ReCiPe impact assessment methodology. Different types of energy generation are examined in a scenario analysis with combined heat and power generation (CHP) as the baseline case. For interpretation, a normalization and a sectoral analysis are performed.

The normalized results indicate fossil resource depletion and global warming as the most important impact categories. Global warming impacts are highly dependent on the energy processes and result to 432.7 kg CO2e per production of 1 t of paper for CHP and to 701.7 kg CO2e for EU25 grid mix. The sectoral analysis shows that the machinery's operations/use phase is clearly dominating most impact categories due to its long lifetime. An exception is the metal depletion, for which the materials and manufacturing processes are most important.

These findings prove that for most categories, the operations/use phase of the paper machine is the most important life cycle stage. In systems focusing on the consumer good paper, it is therefore sufficient to model the operation of the paper machine, whereas the manufacturing, transport, and end-of-life processes regarding the paper machine equipment can be neglected, unless metal depletion is important to the study.