Tag: circular

Basque Country Circular Economy 2030

A post on the ‘Low Carbon Future’ blog by IDOM caught my attention as it featured the below Sankey diagram. The post is a summary of an event held back in 2019 on the elaboration of a Circular Economy Strategy for the Basque Country” (“Foro de participación para la elaboración de la Estrategia de Economía Circular del País Vasco 2030”).

The diagram shows mass flows in mega tonnes (Mt) for the year 2016 within the autonomous community in the North of Spain. While the arrows are unicolored, stacked bars on the streams reveal their composition with contributions from metallic minerals, non-metallic minerals, fossil fuels, biomass and others.

Somehow I couldn’t get rid of the feeling that I had seen something similar before. And indeed a similar Sankey diagram for global flows is featured in this post from 2015 and – even more so – one for EU material flows in this followup post from 2018. They seem to have served as a template for the creation of a regional Basque version.

Circular Zinc Flows

While some were indulging in an extended spring cleaning (this year labeled ‘quarantine cleaning’) I decided to take on some of the hard disks sitting on my desk.

These circular zinc flow diagrams from 2011 survived the cleaning and are getting a new life here on the blog. They are more or less two versions of the same diagram, apparently with a Sankey diagram in mind.

The first is a top view and shows zinc flows in the economy (U.S. or world? … sorry, but I don’t have the accompanying text any more). Flows are in millions of tonnes (Mt) in 1996. The second one has the same numbers, but adds a 3D perspective…

Some tricky issues here: The ‘zinc in products’ stream of 8.1 Mt narrows down to zero, as the zinc sits in products, from where it later might be released into the cycle again. This does not help the attempt to draw them in a circle (to associate circularity of zinc flows). As a consequence the streams are not to scale (compare, for example the 0,8 Mt scrap feed flow right next to the 6,6 Mt flow for zinc from mines). The 3D perspective and the shadow effect don’t help in any way here…

Check out some more Sankey diagrams with the tag ‘circular’ and this post on radial Sankey diagrams.

European Copper Streams 2012

After all these colorful Sankey diagrams, here is something soothing for your eyes.

This b/w Sankey diagram shows European copper streams in 2012. It is taken from the 2017 dissertation by Simon Gloser-Chahoud of Technical University Clausthal in Germany with the woooh title ‘Quantitative Analyse der Kritikalität mineralischer und metallischer Rohstoffe unter Verwendung eines systemdynamischen Modell-Ansatzes’ (‘Quantitative analysis of the criticality of mineral and metallic raw materials using a system-dynamic model approach’ …thanks Google Translate!).

Flows are in kt. The dotted line references the geographical boundary of the EU-27 states. We can see that 1.100 kt copper concentrate was imported and 830 kt came from mines in Europe. Import and export of finished products containing copper is almost balanced. The overall addition of copper to the European stock (estimated at 90.000 kt) was at 3.200 kt. Copper in waste streams leaving this stock amounted to 2.500 kt, of which 1.750 kt were fed back into the copper production.

Europe JRC Critical Materials Report

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).

Global Plastics, Ellen MacArthur Foundation

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.

Cogeneration system Sankey diagram

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.

Australian Metal Flows

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).

Graedel REE wheel Sankey remake

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.