Total carbon footprint (TCF) of consumers: what role do plastics play?

Hello and welcome to this new blog post. Today we investigate the question of what impact plastic products have on our total carbon footprint. When one is confronted with the question of "do i use too much plastic products and harm the environment?", the short answer is no and here is why: 

Let us start with the following question: 

How much plastic do we use?

The answer was well researched by independent scientist Dr. Chris DeArmitt and he presented literature which shows that plastics (mainly PE, PP, PVC, and PET) only account for 1% by volume (0.4% by weight) of society’s material use. Ceramics (mainly concrete) represent 84%, natural materials like wood 9%, and metals 6%. Global plastics consumption is around 370 million metric tons per year, however this is still small compared  to the 90 billion metric tons of overall materials used [1]. In order to put things better into perspective, we can compare the overall amount of materials used to a watermelon and compare it to a blueberry, representing the yearly plastics consumption (Figure 1). 

Figure 1: Watermelon vs blueberry - comparing the overall material consumption to the plastics consumption (on a yearly basis) [1].

How much do plastic products contribute to my total carbon footprint?

The short answer is: not much - only 1.3 % according to the study conducted by Carbon Trust in 2009 [3].  The 1.3% are 13,7 tons CO2-equivalents per capita. Recreation and leisure activities represent 18% of the total consumer carbon footprint, followed by space heating with 14%. Figure 2 shows the complete overview of the total consumer carbon footprint.

Figure 2: The role of  plastic products in the total carbon footprint of consumers [3].

Conclusions

Combining the answers of the two aforementioned questions, we can conclude that focusing on replacing plastics, which only represent 1% by volume of all materials, is not the best way forward to protect our environment. Concrete and ceramics represent 80% of the materials and they are the biggest pile which we need to attack first. Also, improving space heating systems with modern heat pump systems can reduce the personal carbon footprint much more than trying to not use a plastic bag for shopping. Allover, plastics are part of the solution to protect the environment and not the problem. 

I wrote another post on how plastics protect our climate and environment by using them as insulating materials - here you can read the whole post. 

Thanks for reading and #findoutaboutplastics

Greetings, 

Herwig Juster 

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Literature:

[1] Materials and the Environment: Eco-informed Material Choice 1st Edition

[2] https://phantomplastics.com/why-is-plastic-bad-for-the-environment-get-the-facts-in-5-minutes/

[3] https://plasticseurope.org/wp-content/uploads/2021/10/201009-Denkstatt-Report.pdf

How To Turn Thermoplastics Carbon Neutral Or Even Carbon Negative? Here Is An Effective Way

Hello and welcome to a new blog post. Today we are going to discuss how to turn thermoplastics carbon negative in an effective way. 

In previous posts I presented to you the Global Warming Potential (GWP) of different plastics vs. their density as well as the GWP values of thermoplastics compared to their different thermal properties and transitions: Tg, heat capacity (Cp), short term temperature exposure (HDT) and long term temperature exposure (UL Yellow Card).

Among the materials and chemicals, thermoplastics have already a low GWP value. Gasses such as methane (CH4) have an estimated GWP of 27-30 over 100 years, and the average cement has a GWP of 600-800  kg CO2 eq / ton. Most thermoplastics are in the range of 2 -8 kg CO2 eq / ton. 

Is it possible to have carbon negative thermoplastics?

Yes, by using specific functional fillers which are able to lock in more carbon dioxide than they release in a later stage. In the following we discuss two filler examples: biochar and hemp. In general, after the pyrolysis of biomass, biochar is the lightweight black residue and it consists out of carbon and ashes.

Biochar

Seth Kane [2] and his team demonstrated that carbon-neutral composite materials can be produced by adding biochar. They evaluated  it over a cradle-to-gate life cycle assessment. Biochar was added as a filler in recycled HDPE (rHDPE), virgin HDPE, bio-based polylactic acid (PLA), and polyhydroxybutyrate (PHB).  In general, biochar fillers lock carbon in a stable form and this in a permanent way. Key results were that 40 w% biochar filler is sufficient for rHDPE to reach 0 kg CO2 equivalent. PLA requires 50 w% biochar filler to be considered 0 kg CO2 equivalent. And HDPE needs 52 w% to reach carbon neutrality (Figure 1). Furthermore they found out that biochar increases the tensile strength of rHDPE by 45%, and stiffness by 126%. Also the flexural storage modulus could be improved by 79% however all over the compound was more brittle. They concluded that adding biochar linearly reduced the GWP potential of the examined plastics by up to 3.3 kg CO2 equivalent per kg of material compound. 

Figure 1: Overview polymers with biochar filler to reach 0 kg CO2 eq. GWP

Hemp

In a similar situation we have hemp as a filler. It can be used with PP as base polymer in Automotive applications (door panels, seat backs paneling, bumpers, spoilers). Apart from cost and weight reduction, using hemp additives reduces the carbon footprint too. Industrial hemp additive manufacturer Heartland [4] demonstrated a carbon footprint reduction of virgin plastics by as much as 44%. 

Conclusions

Biochar and hemp used as fillers in thermoplastics are an effective way to reduce the carbon footprint. Together with recycling of thermoplastics (including fillers, and compounds) as well as other mitigation strategies such as bio-based plastics, usage of renewable energy in plastics manufacturing will reinforce the advantage of plastics over other so-called green materials in the long run. 

Greetings and #findoutaboutplastics

Herwig 

📚My Polymer Material Selection Book - Available Here

📊 Discover your Polymer Material Selection score by taking quick test here

🎥Join my YouTube channel community 

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Literature: 

[1] https://www.madeofair.com/

[2] https://www.sciencedirect.com/science/article/pii/S2666682022000226#sec0007

[3] https://www.sciencedirect.com/science/article/pii/S0959652620338956

[4] https://www.businesswire.com/news/home/20220124005281/en/Heartland-and-Ravago-Develop-Products-to-Reduce-the-Carbon-Footprint-of-Plastic

[5] https://www.researchgate.net/figure/Global-warming-potential-GWP-range-for-cementitious-Environmental-Product-Declarations_fig3_341943113

[6] https://www.findoutaboutplastics.com/2022/02/design-data-for-plastics-engineering.html