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REDUCE CARBON FOOTPRINT WITH STAINLESS STEEL


The objective of this research is to analyze and compare the carbon footprint of returnable stainless steel (StS) kegs and one way plastic kegs.

BACKGROUND

The soft-drinks and alcoholic beverages account for the 0.9 and 0.6% of the so called Global Warming Potential (GWP) impact category of total products, respectively[1]. Thus, the beverage sector has started implementing strategies to reduce its impact on the global climate, as focused for instance by the Beverage Industry Environmental Roundtable on the basis of the sensitivity of the beer GWP to variations in material or process practice aspects (such as packaging material selection, distribution logistics, recycling rates, etc.) in either Europe or North America[2].

Despite its ancient tradition, the brewing industry is currently pushed to perform within the constraints of product quality, process safety, economic viability, and limited environmental damage.

The main environmental issues associated with brewing include material, water, and energy consumption, as well as waste production[3]. By referring to some European breweries, their corresponding specific consumption yields range from 8 to 12 kWh of electrical energy, from 100 to 200 MJ of thermal energy, and from 4 to 7 hl of water per hl of beer produced, respectively[4].

By means of surveys conducted by the Energy Technology Support Unit (ETSU) in the United Kingdom for a Kegging brewery[5], the energy use for specific brewery processes were identified. Indicated in Table 1, the vast majority of thermal energy is used in brewing operations, while electricity consumption is more evenly divided.

           Table 1. Estimated percentage energy use for various brewing processes[6]

Estimated percentage energy use for various brewing processes

Carbon footprint and LCA are used to systematically record and analyze the impact on the environment throughout the entire life cycle of a product or service. This involves an end-to-end analysis of the product or service. The LCA considers all raw materials, transports, production processes, usage and disposal of the product, whereas the carbon footprint at product level is a special application of the LCA methodology that specifically focuses on greenhouse gas emissions. ISO/TS 14067 specifies principles, requirements and guidelines for the quantification and communication of the carbon footprint of a product (CFP), based on International Standards on life cycle assessment (ISO 14040 and ISO 14044) for quantification and on environmental labels and declarations (ISO 14020, ISO 14024 and ISO 14025) for communication.

Working out the cost of a product in kilograms of CO2 is known as calculating its carbon footprint. This is a useful measure as it helps to have an idea of how the consumption patterns affect the amount of greenhouse gases in the atmosphere. As CO2 and other greenhouse gases contribute to climate change, choosing products with a low carbon footprint is one of the ways in which a consumer can make a difference.

Several studies have been carried out to verify the environmental impact generated through the brewing process. Nevertheless, recently the attention has been paid to analyze the environmental impact derived from the use of different packaging formats. For instance, there are environmental product declarations[7] that provide quantification and certification of the environmental performance of beers packed in disposable 33-cl glass bottles, 25-l steel kegs, or 20-l plastic drums, according to the Life Cycle Assessment (LCA) methodology[8].

Scientific papers comparing the LCA of returnable stainless steel kegs with one way glass bottles and aluminum cans have been also found in the literature[9],[10], as well as sustainability reports developed by companies such as Petainer[11] or Free Flow Wines[12],[13]. Nevertheless, the results obtained are contradictory among them because of the values assigned to the variables considered or the boundaries of the analyzed system.

 

AIM AND SCOPE

The objective of this section is to analyze and compare the carbon footprint of returnable stainless steel (StS) kegs and one way plastic kegs. The plastic one-way kegs considered are those made from PET with PP chimes, such as Unikeg, Petainer USD, Dolium or Polykeg T/BT.

The characteristics of the containers are summarized in Table 2.

Table 2. Composition of the product supplied in the containers

StS “Slim 237” keg [14] Plastic one-way kegs [15]
Capacity 20 l 20 l
Weight 5.8 kg (5.4 kg StS keg+ 0.4 kg StS spear)* 1.2 kg(0.97 kg PP chimes + 0.23 kg PET keg)*

*Only major components are considered.

The functional unit is represented by 1 keg, and the boundaries of the system include:

  • Phase 1: Creation of the keg;
  • Phase 2: Transportation of the keg from the manufacturing plant to the brewery;
  • Phase 3: Washing of the keg;
  • Phase 4: Transportation of the keg from the brewery to the consumption point;
  • Phase 5: Transportation of the keg from the consumption point to the brewery (for StS kegs) or to the disposal location (for one-way kegs).

The results will provide the carbon footprint of using one StS keg and one plastic one-way keg. Then, the results will be extended considering the reusable character of SS kegs in order to represent the carbon footprint of both types of kegs versus the number of cycles or uses. With that purpose, Phases 1-5 will be considered for the plastic keg in every cycle (if appropriate), whereas in the case of StS kegs, only Phases 3-5 have to be considered after the first use.

 

THEORETICAL CALCULATION

The data considered in this analysis is based on reports previously published and developed by external consultants (the references are provided).

 

Phase 1. Creation of the keg

StS keg Plastic Keg
Raw Material 2.90 kgCO2/kg [16] 1.70 kgCO2/kg PP[17] / 3.00 kgCO2/kg PET[18]
Shaping 1.7 kgCO2/kg [19] 1.25 kgCO2/kg[20]
Weight (empty kegs; according to Table 2) 5.8 kg 0.97 kg PP 0.23 kg PET
kgCO2/keg 26.68 4.31

 

Phase 2. Transportation of the keg from the manufacturing plant to the brewery.

The distances will vary depending on each specific study case. In order to make the calculations, it will be considered that this transport stage will imply 5,000 km shipping by sea and 500 km by truck for both types of kegs.

StS Keg Plastic Keg
Shipping 2.98E-05 kgCO2/(km*kg)[21] 2.98E-05 kgCO2/(km*kg)[20]
5,000 km
Truck 1.84E-04 kgCO2/(km*kg)[22]
500 km
Weight (empty kegs; according to Table 2) 5.8 kg 1.2 kg
kgCO2/keg 1.40 0.29

 

Phase 3. Washing of the keg.

This phase is not necessary in the case of plastic one-way kegs due to the fact that they will not be reused.

SS Keg [23] Plastic Keg
Electricity 0.44548 kgCO2/kWh
- Steam generator - start up energy 0.5 kWh/keg
- Cleaning / filling machine 0.15 kWh/keg
- Steam generator machine 0.44 kWh/keg
Washing and sterilizing 0.293E-03 kgCO2/l
6.5 l/keg
Waste water 0.266E-03 kgCO2/l
6.5 l/keg
kgCO2/keg 0.49 -

 

Phase 4. Transportation of the keg from the brewery to the consumption point.

The distances will vary depending on each specific study case. In order to make the calculations, it will be considered that this transport stage will imply 1,000 km by truck for both types of kegs.

SS Keg Plastic Keg
Truck 1.84E-04 kgCO2/(km*kg) [24]
1,000 km
Weight (full kegs; according to Table 2) 25.8 kg 21.2 kg
kgCO2/keg 4.75 3.90

 

Phase 5. Transportation of the keg from the consumption point to the brewery (for StS kegs) or to the disposal location (for one-way kegs).

The distances will vary depending on each specific study case. In order to make the calculations, it will be considered that this transport stage will imply 1,000 km by truck for StS kegs, which have to return to the brewery, and 100 km for plastic kegs, which have to go to the disposal site.

SS Keg Plastic Keg
Truck 1.84E-04 kgCO2/(km*kg)[25]
1,000 100
Weight (empty kegs; according to Table 2) 5.8 kg 1.2 kg
kgCO2/keg 1.07 0.02

RESULTS

From the theoretical calculations developed, it is possible to obtain the carbon footprint of StS kegs and plastic kegs along the life cycle corresponding to one use.

Carbon footprint (kgCO2eq) related to the functional unit used once

Life cycle considering one single use Manufacturing (Phase 1) Washing (Phase 3) Transport (Phases 2, 4, 5)
StS keg 34.38 26.68 0.49 7.21
PET keg 8.52 4.31 0 4.21

Nevertheless, the refillable character of StS kegs makes their carbon footprint not to increase considering all the phases described for every use. Consequently, whereas phases 1-5 will be considered for the plastic keg in every cycle because of being one-way packages, in the case of StS kegs, only Phases 3-5 have to be considered after the first use.

Previous studies and experiences establish an average number of rotations of 60-80 before the disposal of the StS kegs, reaching even 120 cycles (4 rotations/year in 30 years)[26] and thus being an important factor to be considered before calculating the carbon footprint.

Carbon footprint considering the returnable or non-returnable character of the kegs

Number of rotations/uses kgCO2eq/SSkeg kgCO2eq/Plastic keg*
1 34.38 8.52
2 40.69 17.04
3 46.99 25.56
4 53.29 34.08
5 59.60 42.59
6 65.90 51.11
7 72.20 59.63
8 78.51 68.15
9 84.81 76.67
10 91.11 85.19
11 97.42 93.71
12 103.72 102.23
13 110.02 110.75
14 116.33 119.26
15 122.63 127.78
16 128.94 136.30
17 135.24 144.82
18 141.54 153.34
19 147.85 161.86
20 154.15 170.38
30 217.19 255.57
40 280.22 340.76
50 343.26 425.94
60 406.29 511.13
70 469.33 596.32
80 532.37 681.51
90 595.40 766.70
100 658.44 851.89
110 721.47 937.08
120 784.51 1022.27

* One-way kegs do not rotate, so the carbon footprint increases linearly with the number of uses required, which corresponds with the number of kegs required.

 
Carbon footprint considering the returnable or non-returnable character of the kegs.

 

CONCLUSIONS

The decision of choosing between plastic and StS kegs is sometimes affected by the environmental awareness of the packing industry.

Despite the fact that the manufacturing, washing and transport of StS kegs result in higher GHG emissions that those associated to plastic kegs, it is important not to forget the refillable character of StS kegs. This implies that there is no need of StS keg manufacturing after every use, which reduces their carbon footprint when the entire life cycle is analyzed.

Even considering that StS kegs require washing processes and returnable logistics, the carbon footprint of these phases is nothing when compared to the whole process of creation and transport that every use of plastic kegs requires.

As it can be observed from the results obtained, StS kegs show a lower carbon footprint than one-way plastic kegs after 12 uses, which can be achieved in 3-4 years on average. From that moment on, every use of a StS keg will entail the reduction of harmful substances to the environment.

These facts make the choice of THIELMANN containers the most sustainable solution for your business.

 



[1] http://ec.europa.eu/environment/ipp/pdf/eipro_report.pdf
[2] http://media.wix.com/ugd/49d7a0_70726e8dc94c456caf8a10771fc31625.pdf
[3] Cimini & Moresi, 2015. Carbon footprint of a pale lager packed in different formats: assessment and sensitivity analysis based on transparent data. J. Clean. Prod.
[4] Olajire, 2012. The brewing industry and environmental challenges. J. Clean. Prod.
[5] Sorrell, 2000. Barriers to Energy Efficiency in the UK Brewing Sector. Science and Technology Policy Research (SPRU), University of Sussex.
[6] Olajire, 2012. The brewing industry and environmental challenges. J. Clean. Prod.
[7] EPD® Carlsberg® and Tuborg® Beer. Reg. no S-EP-00264; no S-P-00311; no. S-P-00314. Available at: http://www.environdec.com
[8] ISO, 2006. Environmental Management – Life Cycle Assessment – Principle and Framework.
[9] Cimini & Moresi, 2015. Carbon footprint of a pale lager packed in different formats: assessment and sensitivity analysis based on transparent data. J. Clean. Prod.
[10] Cordella et al., 2008. LCA of an Italian lager beer. LCA Case Studies.
[11] http://www.petainerkeg.com/uploads/files/petainer_keg_supply_chain_white_paper.pdf
[12] http://freeflowwines.com/wp-content/uploads/free-flow_project-report.pdf
[13] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf
[14] http://kegs.thielmann.com/kegs/slim-keg/
[15] http://www.unikeg.com/uploads/files/UniKeg%20Brochure%202016_DEF-spread.pdf
[16] http://www.aceroplatea.es/docs/ISSF_Stainless_Steel_and_CO2.pdf (annex A)
[17] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf (Page 8)
[18] http://pacinst.org/publication/bottled-water-and-energy-a-fact-sheet/
[19] http://www.sciencedirect.com/science/article/pii/S0959652615007933 (Table 1)
[20] http://www.semplastik.com.tr/pdf/envcomppol.pdf
[21] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf (Page 9)
[22] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf (Page 9)
[23] http://www.coolworldconsulting.co.uk/download/i/mark_dl/u/4012885470/4626332214/CF%20Kernel%20Pale%20Ale.pdf
[24] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf (Page 9)
[25] http://freeflowwines.com/wp-content/uploads/free-flow_spring-2013-report.pdf (Page 9)
[26] Brewery and Beverage Industry, 2014. Envases fiables; Kegs de acero inoxidable como embalaje sostenible.

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