Biofuels are not a new concept – indeed, Rudolf Diesel powered an engine with peanut oil at the World’s Fair in Paris in 1900. Brazil has a long history of biofuels, and their use has been particularly encouraged since the oil crisis of the ‘70s.
Biofuels derive energy from biological carbon fixation and are hence usually considered a renewable technology. There is a well developed biofuels industry in Brazil, and biofuels would appear to be obvious candidates for environmentally friendly CCHP trigeneration.
This section presents some of the issues relating to the use of sustainable biofuels for cogeneration in Rio de Janeiro. Liquid biofuels, and particularly sugarcane ethanol, are the most likely candidates for sustainable CCHP fuels in Rio. Because of this, we have focused on bioethanol. Other biofuels are available in Brazil, including biodiesel, sugarcane bagasse and forestry waste. In terms of sustainability, the same issues apply across the range of available biofuels:
- Are such fuels truly renewable, or has their production resulted in increased GHG emissions?
- Does the production of a specific biofuel result in unacceptable social and/or environmental costs?
Are Biofuels “Renewable”?
Because biofuels are created when crops fix carbon, they would appear at first glance to be a renewable energy source. However, not all biofuels are created equal – some require significant input of oil-derived chemicals in their production and processing and their cultivation may have required clearance of natural vegetation (including forests). Because of this, some biofuels are net generators of GHG. In the context of a low-carbon grid, it is essential that biofuels used for CCHP have a low carbon footprint.
Life-cycle-assessments (LCA) of biofuels show a wide range of net greenhouse gas savings compared to fossil fuels. For bioethanol, the highest GHG savings are recorded for sugarcane (70% to well over 100%) – the crop which is used to make Brazilian bioethanol. In addition, soy-derived biodiesel can provide significant GHG savings. However, under certain circumstances, Biofuels produce higher GHG emissions than fossil fuels – particularly when natural vegetation has been cleared to allow for their cultivation . This has been documented in Brazil in the case of soy-produced biodiesel .
Given that grid electricity in Rio is derived from almost 90% carbon-free sources, for biofuelled CCHP to contribute to climate change mitigation, biofuels used must provide a net GHG saving of 90% or better (as measured by life cycle assessment). The figure below shows some analyses of different biofuels.
Greenhouse Gas Savings of Biofuels Compared to Fossil Fuels. Taken from: Bringezu, S., Brien, M. O., & Howarth, R. W. (2009). Accessed online: Towards Sustainable Production and Use of Resources: Assessing Biofuels United Nations Environment Programme (PDF). Figure used by persmission.
Biofuels: Enviornmental & Ethical Issues
Even when biofuels help mitigate climate change by reducing GHG emissions, there are a range of wider social and environmental issues associated with their use. Biofuel production is at the heart of an intense debate that is being played out in the Brazilian countryside.
Concerns have been raised over the competition that biofuels pose to food production, and the consequent effect that this has upon food security and food prices. In particular, bioethanol production in Brazil has increased rapidly. Sugar cane production has tripled in the past 20 years, primarily to meet the rising demand for bioethanol . In the case of Brazil, increases in biofuel production would appear to have been achieved without displacing food production. However, there remain serious social and environmental concerns regarding the industrialised agricultural model of bioethanol production that is currently employed.
There are concerns regarding the infringements of the rights of sugarcane farm workers in Brazil . Indeed, there have been reports of widespread abuse of workers including contemporary slavery . The Brazilian government is addressing the issue of forced labour with the creation of the so-called lista suja, or ‘dirty list’. The ‘dirty list’ is updated every six months and consists of a register of names of employers (persons or legal entities) caught exploiting workers. The ‘dirty list’ is made public via the websites of the Ministry of Labour and the NGO Repórter Brasil. Addition to the list means that companies lose access to official means of obtaining credit, for example as provided by Brazil‘s National Development Bank .
Concern has also been raised that highly biodiverse areas with high environmental value (such as the Pantanal or the Cerrado) will be affected by sugar cane cultivation. These regions overlap with areas suitable for sugarcane expansion . The Brazilian government has responded to these concerns by setting up countrywide agro-ecological land use zoning (ZAE Cana) that restrict sugar cane growth in or near environmentally sensitive areas . Recent studies in the Cerrado region showed the expansion of sugar cane over some unprotected conservation areas – in spite of the large area already under cultivation that could be used for expansion .
Selection Criteria for Biofuels
Although the use of biofuels to power CCHP in buildings would at first glance appear to be a way of achieving environmentally friendly status, the issue is complex and a range of issues should influence the selection of suitable biofuels.
The selected biofuel should cause a net reduction in GHG emissions. In the case of Rio de Janeiro, biofuels should have a net GHG saving of >90% compared with fossil fuels (as determined by life cycle assessment), due to the low-carbon nature of the electricity grid.
Biofuel should be produced in an environmentally sustainable way that does not negatively impact biodiversity. In addition, the biofuel should be produced in a way that does not infringe upon human rights – as a minimum standard biofuel should not be sourced from firms which are included on the lista suja. Suppliers of biofuel should be required to make a commitment to source fuel and feedstocks ethically.
Case Study: Sourcing Sustainable Biofuel
Air New Zealand has made a commitment to accelerate the development and commercialisation of sustainable new aviation fuels, while lessening the company’s exposure to oil price volatility and dependence on fossil fuels. The airline set three criteria for environmentally sustainable biofuels: social, technical and commercial. Test flights using such fuels have already taken place.
The biofuel must be environmentally sustainable and not compete with existing food resources. Secondly, the fuel must be a drop-in replacement for traditional jet fuel and technically be at least as good as the product used today. Finally, it should be cost competitive with existing fuel supplies and be readily available. The criteria for sourcing the jatropha oil used to make jet fuel required that the land was neither forest land nor virgin grassland within the previous two decades. The quality of the soil and climate is such that the land is not suitable for the vast majority of food crops. Furthermore, the farms are rain-fed and not mechanically irrigated .
- S. Bringezu, M. O. Brien, and R. W. Howarth, “Towards Sustainable Production and Use of Resources: Assessing Biofuels,” 2009.
- R. Zah and M. Gauch, “ÖKOBILANZ VON ENERGIEPRODUKTEN : BIOTREIBSTOFFEN Schlussbericht (EMPA),” 2007. [Online]. Available: http://www.news-ervice.admin.ch/NSBSubscriber/message/attachments/8514.pdf. [Accessed: 25-Sep-2012].
- Brazilian Sugarcane Industry Association, “Producing Food and Fuel,” sugarcane.org, 2012. [Online]. Available: http://sugarcane.org/sustainability/producing-food-and-fuel [Accessed: 25-Sep-2012].
- “Biofuels in Brazil: Alternative or Disaster?” [Online]. Available: http://www.youtube.com/watch?v=9eNn03PiTb8&feature=BFa&list=FLFXQKmejUaemgXA4DFDkt9A [Accessed: 25-Sep-2012].
- Nuffield Council on Bioethics, “Biofuels: Ethical Issues,” 2011. [Online]. Available: http://www.nuffieldbioethics.org/sites/default/files/Biofuels_ethical_issues_FULL REPORT_0.pdf [Accessed: 25-Sep-2012].
- “Brazil – Amnesty International Report 2008 | Amnesty International.” [Online]. Available: https://www.amnesty.org/en/region/brazil/report-2008 [Accessed: 25-Sep-2012].
- P. Costa, “Fighting forced labour: The example of Brazil,” 2009.
- M. M. C. Bustamante, J. Melillo, D. J. Connor, Y. Hardy, E. Lambin, H. Lotze-Campen, N. Ravindranath, T. Searchinger, J. Tschirley, and H. Watson, “What are the Final Land Limits?,” in Biofuels: Environmental Consequences and Interactions with Changing Land Use. Proceedings of the Scientific Committee on Problems of the Environment (SCOPE) International Biofuels Project Rapid Assessment, R. W. Howarth and S. Bringezu, Eds. 2008, pp. 271–291.
- “Air New Zealand Sustainable Biofuel Test Flight Update – Media Releases 2008 – Media Centre – About Us – Air New Zealand – United States Site.” [Online]. Available: http://www.airnewzealand.com/press-release-2008-sustainable-biofuel-test-flight-update [Accessed: 30-Sep-2012].