Cafe Sustainability: What can we do about paper cups?

This article is part 2 of our 3-part series on Café Sustainability. To read part 1, click here.

As we enter plastic free July, we’ve been thinking about ways to limit our plastic usage. While our previous research identified cups as being one of the smaller net environmental footprints on the environment (0.6% of total emissions on a CO2 equivalent basis) , we are still committed to finding ways of reducing our plastic footprint.

sustainability paper cup options

Hold up: what’s so bad about paper cups?

There’s been a lot of noise about this in the last couple of years, but it’s still worth clarifying what we’re dealing with here. Paper cups are generally paper wrapped internally with a polymer lining (i.e. plastic). The polymer is conventionally polyethylene, however ‘biodegradable/compostable’ cups typically use a poly (lactic acid) lining. The paper is typically non-recycled paper because of hygiene standards, though double-walled cups can (legally, at least!) contain recycled paper internally.

One of the reasons the cups can’t be recycled is because the plastic layers cannot be separated from the paper layer. Even if they could, polyethylene does not biodegrade and the materials are all sent to landfill.

What about ‘Biodegradable’ Cups?

The polymer lining in ‘biodegradable’ cups is usually Polylactic Acid (PLA). Polylactic acid degrades, in compostable conditions, primarily into carbon solids, CO2 and water. However, most PLA based polymers are sent to landfill and barely degrade. When it does, a significant proportion of degradation products is methane (between 15% and 50% of the non-condensable vapor phase). An abridged lifecycle analysis for polylactic acid-type cups was done at Seven Miles using publicly available data and some from academic journal articles (specifically: this one and this one), and is shown below. We used this lifecycle to determine whether we thought it was helpful or not to use for our cup ranges.

PLA lifecycle diagram

The bottom line from the PLA life cycle analysis, even with a composting process, still generate 0.32T of CO2, and 0.16T of methane/T of compost. One could capture the methane and then combust it (which improves the environmental footprint somewhat and your recover some energy). Also, one upshot of the composting process is that some of the carbon is sequestered into the compost, which can then be returned to farmland. However, it’s certainly not emission free.

Ultimately, both conventional (PE) and biodegradable (PLA) cups are damaging to the environment, and on balance may not be any better than each other.

A better solution for disposable cups

Beyond July, we are rolling out paper cups with a new technology through Detpak.

Detpak have integrated Smartplanet Technologies lining into paper cups. The film lining is a calcium carbonate-polyethylene mix. The lining is fully separable from paper at waste-disposal partner plants. The paper-based lining can then be fully recycled (up to seven times). The mineral-plastic film lining is the only waste then generated that is unrecyclable.

The major benefits of this technology include:

  • No major carbon emissions are produced from the cup itself (it can be 80% reused, and not ‘composted’)
  • The technology to separate and recycle the cup is well developed and on trial with Veolia and Suez – two major recyclers

See how the process works:

What else can we do?

Ideally, we’d eliminate all plastics in disposable items! At the very least, we are going to do our best to reduce it. So, for plastic free July, we are going to try several things in our own espresso bar:

  • BYO any cup – with extra July discounts to help change habits
  • Actively encourage customers to ‘dine in’ – our baristas will use their grace and tact to encourage people to sit and sip.
  • Say no to a takeaway lid – trying to eliminate plastic waste
  • Crazy cup competition – challenging customers to bring their most interesting ‘from home’ cup for takeaway coffee, with a reward given at the end of the month.

It’ll be interesting to see how repeat customers change their behaviours (or not) because of the above initiatives.

What do we hope comes from this?

We certainly hope to reduce our plastic usage in the long run. We also hope that the new technology being trialed in the new cups used in our espresso window will have a positive reduction in our plastic footprint.

We are also tackling other issues identified in our previous research. Our next challenge will be identifying how we can reduce energy wastage in espresso machines using smart timing technologies. Stay tuned!


This post is based on our recent Industry Forum: “Coffee & Sustainability”. For upcoming events, check out our events page

For more on the work of the Coffee Science & Education Centre, click here


 

Adam Carr
Coffee Science and Education Centre (CSEC) Ph.D, B.E. (Chemical Engineering) Adam has worked in research for over 8 years, with an overarching focus on high temperature water technology. He has worked in Australia at the University of New South Wales, and internationally at Cornell University, the Massachusetts Institute of Technology and Aerodyne Research Inc. The applications for his research have been diverse, including advanced particle production technologies, reaction engineering, sustainable fuels processing and novel extraction technologies. Once he discovered the application of his experience to the coffee industry, there was no going back! Adam returned to Australia in 2015 to pursue his interest in designing his own coffee technologies. He created the startup Highpresso PTY LTD to provide research consulting services to the coffee industry, and build new coffee technologies. His research led him to designing a new roasting system that prevented charring of the raw beans. Now at Seven Miles, Adam uses his skills and deep love of coffee to improve our understanding of coffee science and technology through our coffee science and research center. He designs experiments around testing the latest and greatest coffee gear available to the industry, and uses his connections to develop research projects centering around brewing better coffee.