From Circular to Linear? Assessing the Environmental Performance of Steel and Plastic Kegs in the Brewing Industry

Abstract

Purpose: In the brewing industry, conventional steel kegs have seen competition from single-use (also referred to as one-way) plastic kegs increase due to their lower cost, lighter weight, and ease of use. This study aims to assess the environmental performance associated with these kegging solutions for the brewing industry. The results of this study can assist brewers that aim to lower their environmental impacts in making more sustainable choices. Methods: Life cycle assessment (LCA) was employed to evaluate and compare steel and plastic kegs from a cradle-to-grave perspective, including their production, use, and final waste treatment. The functional unit for the assessment was 1 liter of kegged beer. Different kegging solutions (30L) are compared, which include 1) a steel keg, 2) a plastic single-use keg, and 3) closed-loop plastic kegs scenarios, where the PET is recycled (in the Netherland and Sweden). Each of the kegging solutions is assumed to be transported between the brewery and bar, a distance of 100 km. While the plastic kegs are used only one time, the steel kegs are used up to 80 times, including cleaning and refilling. Results and discussion: Results suggest that both kegs are useful in certain situations. The steel keg was found to have lower GHG emissions and fossil resource depletion, while the plastic keg performed better for water depletion and metal depletion. A closed-loop PET recycling scenario was illustrated to significantly reduce the environmental impacts, primarily by recycling the PET. Furthermore, the lower weight of the plastic keg proved to be an important factor for the impact as well. The transportation distance from the brewery to the bar was found to be a sensitive assumption. From further analysis, it was found that if the transportation from the brewery is increased, the plastic keg may become a better option, with a break-even point of roughly 250 km. Conclusions: In conclusion, it was found that steel kegs were better for the local market, while plastic performed better outside the local market, which is especially important in a large country such as Sweden. Furthermore, the environmental performance of the single-use plastic kegs could improve through a closed-loop process similar to those available in other countries. The results can be useful in the brewing industry to provide insights of the environmental impacts of kegging solutions.

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12th International Conference on Life Cycle Assessment of Food 2020 (LCA Food 2020)
“Towards Sustainable Agri-Food Systems”
13-16 October 2020, Berlin, Germany – Virtual Format
1
Abstract code: ID 167
From Circular to Linear? Assessing the Environmental Performance of Steel
and Plastic Kegs in the Brewing Industry
Michael Martin1,2,*, Sjoerd Herlaar1
1IVL Swedish Environmental Research Institute, Life Cycle Management, Sustainable Society, Stockholm, Sweden
2KTH Royal Institute of Technology, Department of Sustainable Development, Environmental Science and Engineering
(SEED), Stockholm, Sweden
*Corresponding author. Tel.: +46-10-788-6681
E-mail address: michael.martin@ivl.se
Abstract
Purpose: In the brewing industry, conventional steel kegs have seen competition from single-use
(also referred to as one-way) plastic kegs increase due to their lower cost, lighter weight, and ease
of use. This study aims to assess the environmental performance associated with these kegging
solutions for the brewing industry. The results of this study can assist brewers that aim to lower
their environmental impacts in making more sustainable choices.
Methods: Life cycle assessment (LCA) was employed to evaluate and compare steel and plastic
kegs from a cradle-to-grave perspective, including their production, use, and final waste treatment.
The functional unit for the assessment was 1 liter of kegged beer. Different kegging solutions (30L)
are compared, which include 1) a steel keg, 2) a plastic single-use keg, and 3) closed-loop plastic
kegs scenarios, where the PET is recycled (in the Netherland and Sweden). Each of the kegging
solutions is assumed to be transported between the brewery and bar, a distance of 100 km. While
the plastic kegs are used only one time, the steel kegs are used up to 80 times, including cleaning
and refilling.
Results and discussion: Results suggest that both kegs are useful in certain situations. The steel
keg was found to have lower GHG emissions and fossil resource depletion, while the plastic keg
performed better for water depletion and metal depletion. A closed-loop PET recycling scenario was
illustrated to significantly reduce the environmental impacts, primarily by recycling the PET.
Furthermore, the lower weight of the plastic keg proved to be an important factor for the impact as
well. The transportation distance from the brewery to the bar was found to be a sensitive
assumption. From further analysis, it was found that if the transportation from the brewery is
increased, the plastic keg may become a better option, with a break-even point of roughly 250 km.
Conclusions: In conclusion, it was found that steel kegs were better for the local market, while
plastic performed better outside the local market, which is especially important in a large country
such as Sweden. Furthermore, the environmental performance of the single-use plastic kegs could
improve through a closed-loop process similar to those available in other countries. The results can
be useful in the brewing industry to provide insights of the environmental impacts of kegging
solutions.
Keywords: beer, LCA, keg, packaging, brewing
Introduction
The food and beverage sector has received significant focus in recent years to mitigate the negative

12th International Conference on Life Cycle Assessment of Food 2020 (LCA Food 2020)
“Towards Sustainable Agri-Food Systems”
13-16 October 2020, Berlin, Germany – Virtual Format
2
environmental impacts. The brewing industry has also ramped up efforts to improve the
environmental performance of their operations and products, developing collaborative approaches
(BIER, 2015; EC, 2018). As Hallström et al. (2018) suggest, there may be significant potential to
improve, as the alcoholic beverage industry alone was found to represent between 3-11% of all dietary
GHG emissions in Sweden.
The literature available for improving brewing industry environmental impacts is limited, with most
studies focusing on country-wide consumption assessments or specific beers and packaging
(Hallström et al., 2018; Amienyo and Azapagic 2016; Cimini and Moresi 2016; Shin and Searcy 2018;
Niero et al. 2017). Packaging has been a crucial subject of inquiry in the field. As Niero et al. (2017)
suggest, the beverage packaging sector has been pioneers in sustainability, with the first life cycle-
based environmental impacts studies conducted on beverage containers. The business sector has also
highlighted the importance of packaging in promoting a transition towards a circular economy (CE),
see e.g., Ellen McCarthur Foundation (2015) and EC (2015).
Interestingly, the packaging landscape for beer has also changed in recent years in Sweden. In the
retail market, bottles have received increased competition from cans and for kegged beer, steel kegs
have seen increasing competition from plastic kegs (SBA, 2020). The craft brewing industry, which
often struggles with limited labor and capacity, has been keen to reduce costs and time for their
production and distribution processes while improving their sustainability. However, the shift toward
plastic kegs, often promoted as one-way’ solutions marks an important and shift to inquire, as it may
mark the transition from a circular system to a linear system. Additionally, there is very little scientific
inquiry on the environmental performance of these kegging solutions, necessitating support for more
informed decisions for the packaging of beer. The overall aim is to assess the environmental
performance associated with these kegging solutions to provide input to the craft brewing industry to
support their sustainable production efforts.
Material and methods
To assess the environmental performance of the steel and plastic kegging solutions, life cycle
assessment (LCA) was employed. The ReCiPe Midpoint (H) life cycle impact assessment (LCIA)
method was used. However, four of the available impact categories, namely greenhouse gas emissions
(GWP) and Material Depletion (Water, Fossil, and Metal) are outlined in this paper. All life cycle
inventory data for modeling the steel and plastic kegs and associated processes were obtained from
LCI databases such as Ecoinvent v. 3.5 (2018). The functional unit of this study is the transportation
of 1 liter of beer by keg. The system boundaries include all cradle-to-grave processes associated with
the different kegging solutions, i.e., production of the kegs, their transportation, use, and the final
disposal. The production of beer and all associated processes with serving are not included as it was
assumed to be similar in all kegging options and therefore excluded from the study.

12th International Conference on Life Cycle Assessment of Food 2020 (LCA Food 2020)
“Towards Sustainable Agri-Food Systems”
13-16 October 2020, Berlin, Germany – Virtual Format
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Figure 1: Depiction of the system boundaries of study. Dashed lines around the brewery and Retailer highlight
that internal processes are not included in the study.
For the assessment, it is assumed that the beer is produced and filled by a brewery in the Stockholm
area, and that the beer is shipped to an end-user (i.e. a bar), roughly 100 km away. Plastic kegs are
sourced from the Netherlands, while the steel kegs are sourced from Italy. The steel kegs, as illustrated
in Figure 1, recirculate (including washing) before entering the waste management system in Sweden
to be recycled. The kegs are assumed to recirculate 80 times based on findings in Cimini and Moresi
(2016). The plastic kegs are used only once and enter the waste management system in Sweden after
being emptied. All transportation for the kegs to Sweden, in addition to their transportation to the
waste handling and recycling systems, are assumed to be conducted by semi-truck. Transportation of
the kegs from the breweries to the bars, and back for the steel kegs, is assumed to be conducted by
light commercial vehicle. Two further scenarios are also included, where the PET of the plastic kegs
is also recycled using a similar system as OneCircle (2018), i.e., a closed-loop system. In these
scenarios, it is assumed that the kegs will be crushed, and the PET sorted and sent to the Netherlands
to be used for producing new kegs (denoted Plastic Keg Closed Loop-NL). Given that the same sorting
process can be done in Sweden, the Plastic Keg Closed Loop-SE scenario is also included to add the
sorting of recyclable PET, which is then sent to the Netherlands. All other sorted plastics are assumed
to be treated in municipal incineration plants in the Netherland and Sweden, respectively, with credits
for the energy recovery (i.e., electricity).
Results and Discussion
The results illustrate that the steel keg has significantly lower GHG emissions and fossil resource
depletion compared to the plastic keg. In contrast, the plastic keg has lower water and metal resource
use. Further analysis showed that the increased water resource depletion for the steel keg was
primarily due to cleaning the keg for reuse. The plastic keg illustrated more considerable fossil
resource use, arising from the manufacturing of the plastic components. Roughly 50% of the total
GHG emissions for the plastic kegs originate from the manufacturing of the kegs, with the remaining
50% a result of transportation and disposal, see Table 1. Furthermore, the overall life cycle impacts
of the plastic keg are illustrated to have a net positive effect on water depletion. This is due to the fact
that the Swedish energy mix has a considerable water footprint, and the benefits of energy recovery
from the incineration of the plastic keg may offset enough water use from the Swedish energy mix

12th International Conference on Life Cycle Assessment of Food 2020 (LCA Food 2020)
“Towards Sustainable Agri-Food Systems”
13-16 October 2020, Berlin, Germany – Virtual Format
4
for it to result in a positive effect. The closed-loop scenarios show that plastic reuse can significantly
lower three of the four impact categories featured in this LCA. The extra impacts deriving from
transport to a collection point, and transportation to a recycling plant are outweighed by the avoided
impact of using virgin material, see e.g. the lower impacts for the closed-loop impact. Similar findings
have been asserted in Eriksen et al. (2018) and Chilton et al. (2010) for recycling PET bottles.
Table 1 - Results per Impact Category, shown in respective impacts per liter of kegged beer.
Impact Category
Plastic Keg
Steel Keg
Plastic Keg-
Closed Loop NL
Plastic Keg-
Closed Loop SE
Water Depletion (m3)
-7.12E-06
8.68E-04
1.22E-04
2.34E-04
GHG Emissions
(kg CO2-eq)
3.00E-01
1.49E-01
9.91E-02
2.18E-01
Metal Depletion
(kg Fe-eq)
6.53E-03
4.06E-02
4.62E-03
4.77E-03
Fossil Depletion
(kg oil-eq)
1.02E-01
5.31E-02
3.80E-02
7.67E-02
Further analysis of the results suggests that the plastic keg becomes the better choice when the
transportation to the retailer (again assumed to be a bar) is more than 250 km away from the brewery
for the GHG emissions. This is slightly higher than results found in a study by Carbon Trust (2011)
which suggests the break-even point to be roughly 150 km. As such, it is important to note that in a
country such as Sweden, shipments outside of Stockholm, to larger cities in the south and north of
Sweden would be more beneficial to ship by plastic keg than steel kegs. This also provides insights
into packaging for the craft beer industry, which has been shown to be a large contributor to brewing
industry impacts (Shin and Searcy, 2018; Cimini and Moresi, 2016).
Conclusions
This study aimed to assess the environmental performance associated with steel and plastic kegging
solutions. It was found that steel kegs were better for the local market, while plastic performed better
outside the local market, which is especially important in a large country such as Sweden.
Furthermore, the results also highlight the potential for improving the performance of plastic kegs by
implementing local recycling strategies through a closed-loop process to recycle the PET similar to
those available in other countries. The kegging solutions were also found to be sensitive to the
transportation distance, with the plastic kegs to have lower GHG emissions if the distance from the
brewery to a bar is greater than 250 km from the brewery. As such, the results provide the brewing
industry with insights into the environmental impacts of kegging solutions to promote better decisions
and more sustainable production methods.
Acknowledgments
We would like to send our gratitude to the staff at OneCircle for their interest and help with data on
plastic kegs in addition to the Swedish breweries who have answered our questionnaire, have been
open with information about their processes and taking part in interviews. Furthermore, this study
was funded by the Swedish Environmental Protection Agency, Naturvårdsverket, through the project
“LinCS – Linking circularity metrics at product and society level,” without which this study could

12th International Conference on Life Cycle Assessment of Food 2020 (LCA Food 2020)
“Towards Sustainable Agri-Food Systems”
13-16 October 2020, Berlin, Germany – Virtual Format
5
not have been possible.
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