Soy-fuel: the future of renewables?

Biodiesel has recently received a considerable amount of interest as a potential substitute for petroleum-based fuels. Green marketing efforts have constructed a rather idyllic picture around them pushing the idea that biodiesel could be the solution to un-renewable energy sources and ultimately “solve” climate change.

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In this post, I will attempt to deconstruct such arguments and explore different views on the future of biodiesel by a number of experts.

 Soy-fuel

Processed soybean oil, thanks to its high levels of acreage, is one of the leading biofuel in the world. The so called “soy-fuel” was first promoted by the United Soybean Board as a more environmentally-friendly and efficient alternative to conventional fuels. In fact, the soybean is a feasible choice: it is already grown across most of central and eastern America, from Minnesota all the way down to Texas and  and it requires less nutrients than most other crops. 

Nevertheless, scientists have proved that soy cropland could be much less efficient in terms of fuel production than canola, sunflower or palm oil. In fact, an acre of soy cropland can produce up to 250l of biodiesel, whereas the same area of sunflower and palm oil can respectively output 317 l and 2271 l.

Land-use change: what about planetary boundaries?

Will Steffen's paper on planetary boundaries include high levels of land-system change as a possible threat to human society. However, the boundary is strictly concerned with the lost of forests in favour of agricultural land and does not include savannah, grassland or tundra habitats loss.    

Agricultural expansion is the second biggest killer of endangered species and threat to biodiversity so choosing such an inefficient crop that would require an ever increasing amount land is essentially self-destructing in terms of conservation. 

Moreover, providing for worldwide increasing demand for energy with soy-fuel would take up so much land that it could not only compromise biodiversity, but also food security.

Biofuels are a great alternative to petroleum-based fuels, but it’s jut not feasible to grow crops on land.. but where else could we grow them?

That’s right! UNDER THE SEA!

Micro-algae could also considered as feedstock for producing biofuels as explained by Jonathan Trent at his Ted-Talk.

Jonathan believes that biodiesel from micro-algae will be able to compete with other fuels without having to compete over land with agricultural activities. The process of producing fuels through alga is quite simple: underwater containers are filled with urban waste water and some micro-algae, which are left to grow as they use nutrients in the water and energy from the sun.

There are a number of advantages that are associated with Jonathan’s innovative idea.  

1.     Micro-algae have the potential to produce up to 19,000 l of biofuel per acre – as opposed to 250 l by soybean- so are the most effective source of fuel known yet.

2.     Algae grown in this process can also be employed to produce cosmetics, fertilizers, animal feed and last but not least they can be eaten by humans.

3.     The manufactory plants used in the process will be able to support aquaculture of luxury products like muscles.

The down-side of using algae for fuel production is that they require high inputs of fertilizers. A study by Maria Barbosa proved that only to support algae in europe, production would require 25mn tons of nitrogen. 

Nevertheless, the high nutrients input would not lead to eutrophication issues as algae are grown in an enclosed environment from which nutrients would not escape to contaminate the surroundings.

If you want to find out more about algae biofuels tweet Algae Biofuels and for any questions comment below!