Europe’s Joint Research Centre (JRC) has published a new report on ‘Critical Raw Materials and the Circular Economy’ in December 2017.

The report also builds on findings from a 2015 study by BIO by Deloitte, where a Raw Material System Analysis (MSA) Framework had been introduced that “investigates the flows and stocks of 28 raw materials from ‘cradle-to-grave’, that is, across the entire material life cycle from resource extraction to materials processing to manufacturing and fabrication to use and then to collection, processing, and disposal/recycling”. I had posted about this here.

Like in the 2015 study the authors present MSAs for a number of critical materials (CRMs) within the EU-28 boundaries and are depicting them as Sankey diagrams. The authors then expand into how scarcity and price may impact certain industrial sectors or products (Automative, Electronics, Batteries, etc.). Best practices are suggested for recovering critical materials.

Here is the MSA Sankey diagram for Germanium (from page 41 of the report):


All flows are in kilograms per the reference year 2012. We can see that roughly 80.000 kg of Germanium entered the EU in the year 2012, and 15.800 kg were made available on the secondary material market within the EU.

For the individual industrial sectors, another type of figure is presented. This breakdown of how much of the CRMs is used in a specific sector gives a better understanding of the dependency on certain CRMs.

This Sankey diagram (from page 39 of the report) for the Electrical and Electronical Equipment sector shows, for example, that 87% of the Germanium (ge) entering the EU are used in the EEE sector, making it the largest consuming sector of Germanium. The remaining 13% are used in other sectors:

Crossing the information from the MSA Sankey diagams that show availability of a CRM, and the information from the Sankey diagram showing demands per sector gives a good understanding on why some materials are considered critical for industries, and measures for recovering more of them from tailings or waste are meaningful.

Source: Mathieux, F., Ardente, F., Bobba, S., Nuss, P., Blengini, G., Alves Dias, P., Blagoeva, D., Torres De Matos, C., Wittmer, D., Pavel, C., Hamor, T., Saveyn, H., Gawlik, B., Orveillon, G., Huygens, D., Garbarino, E., Tzimas, E., Bouraoui, F. and Solar, S., Critical Raw Materials and the Circular Economy – Background report. JRC Science-for-policy report, EUR 28832 EN, Publications Office of the European Union, Luxembourg, 2017, ISBN 978-92-79-74282-8 doi:10.2760/378123 JRC108710.

Access JRC report here (PDF).

This week the global plastics flows topic made the news and social media with the publication of the EU Plastics Strategy and Chancellor Philip Hammond presenting the United Kingdom’s plan for tackling plastic waste.

Ellen MacArthur Foundation has long been active in research and awareness building in this field. It aims at supporting a transition to a circular economy. The foundation tweeting under @circulareconomy contributed this Sankey diagram. It is from a 2016 report they produced together with the World Economic Forum and McKinsey.

The Sankey diagram shows indeed, that “today, plastic packaging material flows are largely linear”. This beautifully crafted diagram had already caught my attention back in 2016 when I first saw it.

However, I had this subtle feeling that something was wrong here. Not regarding the content or the data … but rather that something wasn’t OK in the Sankey diagram, Just my gut feeling. Now, seeing the Sankey diagram again in the above tweet this week, I finally sat to quickly do a remake of this Sankey diagram. Here it is:

I stuck to the original layout and design as closely as possible, using the same color codes and even the white all caps font. While transfering the numbers (all percentage values, so no issue there), it immediately became clear to me what caused my irritation. Can you identify it yourself by comparing the two pics?

Won’t give it away now and wait for your comments. Will post the answers to this small ‘spot-the-difference contest’ here next week.

[Edit 24 Jan] Blog reader ‘First!’ was the first to comment and point out that the 2% recycling flow does not seem to be to scale (i.e too wide / overemphasized) in the Sankey diagram published by Ellen MacArthur Foundation, and possibly the same issue with the two arrows representing 14% each.

Just another quick Sankey diagram before the weekend. This beautifully crafted black&white diagram is from a scientific article ‘Exergy assessment of a cogeneration system with micro-turbine and absorption chiller’ by Martínez Reyes et.al. published in Proceedings of COBEM 2005 (18th International Congress of Mechanical Engineering).

This is for a cogeneration system with a 30 kWe gas micro-turbine and a 35 kWt absorption chiller. Flows are in kW with a scale of 1 cm = 100 kW in the original size. Good handling of the loop flow.

The Australasian Institute of Mining and Metallurgy (AusIMM) is an association of the minerals industry. In this AusIMM Bulletin article titled ‘From Waste to Wealth’ they talk about metal recovery and recycling in Australia.

This Sankey diagram (actually two Sankey diagrams) from the article visualizes metal flows in Australia in 2012/2013 based on data from Golev & Corder (2014).

The smaller yellow diagram section on the left actually just shows mining activities in Australia and the fact that the largest portion of mining output (ores) are exported. Only 7.5 Mt are processed within Australia. This Sankey arrow is then blown up and corresponds to the yellow input stream into the second diagram [a similar solution to decouple diagrams with different scales was presented in yesterday’s post].

In the metal production process there are losses, and material is being exported and imported. The annual increase to the Australian ‘in use stocks’ (i.e. metals being used infrastructure, buildings and products) is 12 Mt, possible only thanks to 7 Mt metals imports. Some 7 Mt of metals are also released annually from ‘in use stocks’.

The dotted lines signal that there are possible routes, but either outside the scope of the Australian market or no reliable data is available (new scrap from the manufacturing step being fed back to the smelting).

In this post on rare earths I have recently featured an alluvial diagram depicting rare earths use from a presentation by T.E.Graedel (Yale). That same presentation also lead me to another article by X. Du & T.E. Graedel titled ‘Uncovering the Global Life Cycles of the Rare Earths Elements’ (open access) that has a number of circular flow diagrams I would call “REE wheels”.

The article describes how quantitative data on rare earths is available for mining and processing, but “very little quantitative information is available concerning the subsequent life cycle stages”. Also, data is mostly available for the overall REE production, but not individually for every single rare earth element. They therefore aim to estimate and approximate the quantities for ten REEs, based on sources from China and Japan.

Here is the REE wheel for Yttrium (element Y) from the article:

The diagram can be read from 7 o’clock to 5 o’clock in a clockwise direction. The processing steps are “Mi” (mining), “S” (separation), “F”(fabrication), “Ma” (manufacturing), “U” (use) and “W” (waste management), thus showing the flow of the rare earth element through the economic cycle.

I did a Sankey diagram version of the above Yttrium REE wheel to have the arrow magnitude representing the quantities. Flows are in Gigagrams (million metric tons) per year.

Due to the fact that the arrows connect horizontally and vertically to the node (and do not run diagonally like in the original) my remake looks less “circular” somehow… in fact it resembles more one of those retro indoor AM/FM loop antennas you would hook to your HiFi. So I am not fully satisfied with the outcome. Would it be better if the nodes were tilted 45°?

What’s nice is that the extraction of ore (17.4 Gg) can be directly compared to the 2.9 Gg Yttrium release to the environment. I switched ore input and tailings output at the mining node to have them side-by-side.

Comments and improvement suggestions welcomed.

I had previously reported on Sankey diagrams being used in articles on circular economy (earlier this year in January and back in 2013). Researchers in the field of MFA, circular economy and urban mining apparently love to use them…

Here is another one from an article by Willi Haas et.al. published a few weeks ago (How Circular is the Global Economy?: An Assessment of Material Flows, Waste Production, and Recycling in the European Union and the World in 2005; DOI: 10.1111/jiec.12244).


Open Access @ Journal of Industrial Ecology, via Green Manufacturing blog

The answer to the question raised in the title is answered visually: Not very circular!

The above Sankey diagram is for “all societal material flows globally”, world mass flows moved by mankind. 62 gigatonnes (Gt) of material processed, out of which 58 Gt are newly extracted, and only 4 Gt recycled. “From such a system-wide metabolic perspective, the degree of circularity of the global economy measured as the share of actually recycled materials in total processed materials appears to be very low, at 6%.”

Fossil fuels (yellow) are converted to energy, most biomass (green) ends up as gaseous emissions or solid waste. Construction materials are in orange and metals in blue and these add to stocks of buildings, infrastructures, and other goods with a lifetime longer than a year. The two red arrows are for industrial minerals and “waste rock” (would that be tailings from mining?). Note: The legend is cut off in the screengrab above (please check the original article, page 6).

Interesting article, make sure you read it (open access). It also features a second similar Sankey diagram for Europe (EU-27). Beautiful and intelligent use of a Sankey diagram.

Yesterday it became known that the European Commission would shelve their circular economy package of waste, recycling and incineration laws for now, in favour of an even more ambitious legislation to be presented by end-2015 (read here or here).

That led me to browse tweets using the hashtag #circulareconomy, and I ended up unearthing two nice Sankey diagrams…

The first one is by WRAP UK, showing the EU-27 material flows estimated in 2020. This is not for a specific type of material, but all material.

Flows are in million tonnes, with the 2020 values in blue, and the current (2010) figures in brackets below for comparison. There are three nodes: ‘Direct Material Input’, ‘Domestic Material Consumption’ and ‘Waste’. Unfortunately the size of the node icons is too large, and the flows are difficult to see. But still, this is a nice idea!

The main message is that in comparison to 2010, Europe could have 350 million tonnes of recycled material in 2020. Check out these Sankey diagrams by WRAP UK that basically convey the same messsage, but are less infographic.

Another Sankey diagram I found when browsing through the tweets was this one below. The title of the diagram is “How circular is th UK?”.

I found it in a blog post ‘Designing Out Waste Consortium’ by Ramon Arratia on Interface’s Cut The Fluff blog on sustainability, but it is originally from this Green Alliance blog post by Julie Hill.

No values shown along the flows in this Sankey diagram, but neatly shaped circular flows. The question raised in the title is answered prominently with the message that 19% of the material in the UK is led in a loop (pink flow).

Austrian technical consulting firm pro-wel offers process engineering services to its customers. Their website features two Sankey diagrams, one of which is a rare circular one with curved arrows (see others).

I also like the technical frame around the diagram, a must have in engineering and architecture.