Month: November 2012

Show it with Sankey Diagrams

Phosporus in the natural environment and the food chain has been a topic of several posts on my blog. So it didn’t come as a surprise to find yet another diagram on phoshphorus flows over at Nels’s MFA Diagram blog (one of the blogs I follow closely, see blogroll).

MFA diagrams have their focus on the nodes and the build-up of stocks. Sometimes they get a touch of Sankey diagram with the arrows having different magnitudes. The MFA diagram below is for phosphorous flows in China 2008 (original source: Min Qiao, Yuan-Ming Zheng, Yong-Guan Zhu, 2011. Material flow analysis of phosphorus through food consumption in two megacities in northern China). Values are in tonnes.


(click image to enlarge)

We can detect arrows with three different brush widths (my guess is 1px, 2px and 4 px), each standing for a value range into which the actual flow quantity falls. This may, however, bes somewhat misleading when having a quick glance at the diagram.

I quickly “translated” the above diagram to a Sankey diagram with flow values being actually to scale.


(click image to enlarge)

Here it is quite clear where the major phosphorus flows are located (from food production via urban consumption to sewage treatment plant and solid waste disposal: 2923 out of 5374 tons end up here). The other flows are comparatively small, with the phoshporous flow going directly to the aquatic system worth a mention. Two small flows in the center of the diagram are negligible, they are in fact so tiny in comparison to the major flows that they even don’t show up (or just as a hairline) here.

I have therefore added a minimum width of 1 px for small flows so that the annual 17 tons from urban consumption and the 1.9 tons from rural consumption to the solid waste disposal are at least visible (albeit not to scale with the other flows any more).


(click image to enlarge)

Final phosphorous sinks are solid waste disposal (landfill?) and the aquatic system.

Trigeneration Sankey

Via CarbonSignal blog comes the following post and Sankey diagram:

“Tri-generation, also known as combined cooling, heat and power (CCHP), is a combination of co-generation, known as combined heat and power (CHP) with an adsorption or absorption chiller to provide water chilling. More information of co-generation can be found here. The chilled water can then be used in refrigeration or air conditioning systems. The engine is connected to a generator which can supply electricity to the site or export electricity to the grid. Typically about 38% of the energy supplied as fuel to the engine is converted to electrical energy.

The rest of the energy leaves the engine as heat via the hot exhaust gases, the coolant system and the oil system. A large amount of the waste heat can be recovered through heat exchangers and can be used to supply all hot water to heat domestic hot water, supply heat to a HVAC system, or supply a chiller to provide all chilled water.

Alternatively the system can be designed to supply a mix of both hot and chilled water to match the site loads. The use of a heat recovery system and chiller can increase the efficiency to between 67- 85% depending on the mix of chilled and hot water required.”

Study on Computer Waste in Chile

This post on the MFA diagram blog directed me towards a study on computer waste in Chile. The Sankey diagrams featured are for CRT/LCD displays and laptop/desktop computers,

These are the flows of CRT (red) and LCD (blue) in 2010 and expected units in 2020

and the desktop (green) and laptop computers (dark blue) flows in 2010 and expected for 2020 (no. of units).

The full scientific paper can be found here.
(via MFA Diagram blog)