Life cycle assessment

Life Cycle Assessment demonstrates lower carbon footprint of
Specialty Papers vs. Plastic films

The European Specialty Paper Manufacturers Association PaperImpact, where Ahlstrom is an active member, commissioned a comparative cradle-to-gate LCA (Life Cycle Assessment) study to compare the environmental impacts of specialty papers to those of selected plastic films. The results of the study confirmed that release and label papers have a significantly lower carbon footprint compared to the typical plastic film alternatives. As an example, a typical plastic film release liner used as a carrier of self adhesive labels shows a 46% higher carbon footprint compared to the typical release paper.

In addition to carbon footprint, the assessment also considered environmental impacts in a number of other categories.  Most of them were clearly favorable to papers. The previous comparative impact assessment conducted by PaperImpact had indeed demonstrated that the European specialty paper industry had reduced carbon footprint by 13% in just two years and impacts in other categories between 12 and 20%. www.paperimpact.com 

What is an LCA study?

A Life Cycle Assessment (LCA) studies the environmental impact of a product starting from the extraction of raw materials – harvesting wood or drilling oil - all the way to the disposal of the product at the end of its life, including production of raw materials, manufacturing of products and transport. An LCA is the best evaluation of the environmental performance of products and their sustainability.

The principles, framework and guidance for conducting LCA’s are stated in ISO standards (ISO 14040, ISO 14044). There are four phases
 1) goal and scope – why and how the study is done
 2) inventory (LCI) – gathering the inputs and outputs
 3) impact assessment (LCIA)
 4) interpretation.
 
In an impact assessment, life cycle inventory results are assigned to a number of environmental impact categories: 

Impact category		Life cycle inventory data	Other name / Can cause
Global warming potential		CO2, CH4, GHG	Carbon footprint
Acidification		SO2, NOx	Acid rain
Photochemical oxidation		VOC, NOx	Summer smog
Eutrophication of water		COD, P, N	Growth of algae, harmful for aquatic life
Abiotic depletion		Raw material database data	Use of non-renewable natural resources
Land use		Raw material database data, m2	Use of land area
Primary energy use		MWh of electricity, GJ of steam	Total energy demand
Use of renewable energy		Biomass based fuels, MWh	Non-fossil primary energy demand
Use of non-renewable energy		Fossil based fuels, MWh	Fossil primary energy demand

The comparative LCA study between specialty papers and plastic films

Industry average data for specialty papers was compared to industry average data for PET (polyester) and LDPE (low density polyethylene) films. The boundaries were cradle-to-gate and the functional unit was 1000 m2. The LCA tool Simapro 7.1.8., ecoinvent version 2.1, was used for calculating the inventory and impact of paper. Trade association data (Plastics Europe) was used for the alternative materials. The study was performed by environmental consultants Angeline De Beaufort and Roland Hischier (Ecoinvent Centre) as well as Anna Maija Wessman, VP Sustainability at Ahlstrom on behalf of the commissioner, PaperImpact. To increase credibility, expert statements were asked from Rolf Frischknecht (ESU Services) and Phil McKeown (Unilever).

For paper, a worst case scenario (indicated as “alt” in the table below), where all sludge would be used for land spreading, or a scenario with no sludge (indicated as “ref” in the table below) were considered. For comparability between Ecoinvent datasets on the two materials, the official comparison used paper’s worst case scenario “alt” even though reality often falls in between the two scenarios.

The first case study examined typical release liners and compared a 30 um PET film to a 60 g/m2 specialty paper. The majority of impacts were clearly favorable for paper:

Impact category	PET film, relative to paper, ref/alt (paper is 100%)	Favorable to paper
Global warming potential	61% / 46%	++
Eutrophication	-26% / -45%	-
Acidification	21% / 10%	+
Photochemical oxidation	51% / 36%	+
Abiotic depletion	148% / 131%	+++
Primary renewable energy demand	-94% / -94 %	++
Primary non-renewable energy demand	145% / 126 %	+++
Primary total energy	15% / 10%	+
Land competition	-98% / -98 %	+/-

Similar pattern even if less diverging was discovered for the second case study comparing typical label substrates, a 50 um LDPE film to 70 g/m2 specialty paper (C1S): 

Impact category	LDPE film, relative to paper, ref/alt (paper is 100%)	Favorable to paper
Global warming potential	29% / 17 %	+
Eutrophication	-57% / -68 %	-
Acidification	8%/ -2 %	+/-
Photochemical oxidation	16% / 5%	+
Abiotic depletion	134% / 118%	++
Primary renewable energy demand	-93% / -93%	++
Primary non-renewable energy demand	140% / 122%	+++
Primary total energy	13% / 9%	+
Land competition	-98% / -98%	+/-

None of the materials score best in all environmental impact categories.

Specialty paper has clearly lower environmental impact than plastic film in terms of

• Global warming potential – LOWER CARBON FOOTPRINT
• Acidification – LESS ACID RAIN
• Photochemical oxidation – LESS SUMMER SMOG
• Abiotic depletion – PAPER IS COMING FROM A RENEWABLE RESOURCE
• Use of renewable primary energy – MODERN PULP MILLS ARE NET PRODUCERS OF ENERGY
• Use of total primary energy

Paper demands more land to grow the trees – BUT sustainably managed forests are the best carbon sink. Forests are not only a raw material for the paper sector but remain a vital amenity in our society. The results demonstrate in life cycle terms that paper is made from a renewable resource and uses renewable energy.

As eutrophication results were less favorable to papers, efforts must continue to further reduce not only the impact of the effluent water in pulp and paper mills, but also all other emissions over the life cycle.