Energy From Biomass: Can it Help in Climate Change Mitigation?

E-01 Sustainable Biomass for Energy and Industrial Raw Materials: Biomass Potentials

Source: David J. Moorhead, University of Georgia, Bugwood.org
Source: David J. Moorhead, University of Georgia, Bugwood.org

There are many terms and implications associated with woody biomass production and its potential as an energy source. Viktor Bruckman from the Commission for Interdisciplinary Ecologial Studies at the Austrian Academy of Sciences suggested the main question is: how can we extract energy in such a way that we can ultimately mitigate climate change? In other words, how can we produce energy from biomass in the most sustainable way possible?

Bruckman then introduced his research topic: biochar and its application in forestry. Biochar is produced from biomass that is converted by pyrolysis, which leaves a char containing upwards of 70 % carbon. In extracting the energy from the biomass (i.e: for bio-fuels), this high carbon co-product, when re-introduced into the ecosystem, can act as a carbon sink. The carbon content of biochar can influence soil respiration and is typically used as a soil amendment.

One of the challenges with using biochar on the land base is the risk of creating a source of pollution, which can happen as a result of contaminated woody feedstock. Other potential drawbacks include the difficulties in applying biochar to the land. Weather events, such as wind and especially heavy rainfall, can cause it to erode away before it has time to be incorporated into the soil. Manually incorporating the biochar into the soil is likely impractical. But after a few months, once the char begins to penetrate the soil column, this factor becomes unimportant.

The field trial began with a direct application of biochar to the forest floor.  A relatively acidic site (soil pH 3-4), the biochar application induced a sudden change in soil conditions, causing an initial dieback of some of the ground vegetation. However, the recession was short-lived and certain plants were able to reestablish.  A time-lapse video was created to capture this regeneration.

While the study found that soil respiration was not improved with the application, and in fact might have inhibited it, these were only short-term results. Therefore the fate of the carbon, which is essentially one of the most important attributes to biochar. is still uncertain. However, Bruckman asserted, the opportunity to extract a sustainable energy from biomass, while recycling the carbon back into the soil cycle, can assist in mitigating climate change.

From the use of biochar in Austria, to some innovative approaches from Tokyo Japan, Toru Terada introduced the “satoyama” and its potential as a sustainable source for biomass. A satoyama (“sato”- village, “yama” – forest) is a forest that occurs in an urban setting. There are a number of people that take on the responsibility of managing these “forests.” One such group, called the Coppice Club, is a volunteer-based group consisting of mainly retirees, joined by some forest professionals and other volunteers to maintain these forests. Due to their close proximity to the urban interface, and with informed forest management, it’s quite practical to consider the satoyama as an ideal resource for biomass.

Javier Arevalo closed the session with his research in Sierra Leone and Burkina Faso. In Sierra Leone, there are farmers that produce charcoal to improve their livelihoods. While there are laws that limit charcoal production, farmers are finding charcoal production far more lucrative than working their fields. This is worrisome due to the fact that food security is at risk. After all, less farmers mean less crops. And with less crops comes less food production.

Meanwhile, in the West African country of Burkina Faso, charcoal is banned. Therefore the main source of heat for cooking food is wood. Arevalo stated that 15-30% of firewood comes from managed forests, while the remainder comes from those that sell privately, a product that is likely unsustainably-sourced wood.

The presenters offered a wide range of views on the potential of biomass-sourced energy. Ultimately, the need for renewable and sustainable sources of energy reverberates throughout the globe. While wood can serve this purpose, the challenges and benefits of its use can differ depending on the country’s socio-economical and ecological values.

Written by: Nichola Gilbert

blog comments powered by Disqus