Sustainable biofuel refers to biofuels produced in ways that minimise environmental and social impacts while providing a renewable alternative to fossil fuels. Unlike conventional biofuels, which may compete with food production or contribute to deforestation, sustainable biofuels are derived from feedstocks and processes designed to reduce greenhouse gas emissions, protect biodiversity, and support long-term resource availability. Examples include fuels made from non-food crops, agricultural and forestry residues, algae, and waste materials. International initiatives such as the Roundtable on Sustainable Biomaterials have developed standards and certification schemes to assess sustainability across the biofuel supply chain. The concept is closely linked to broader debates on energy security, climate change mitigation, and the transition to low-carbon economies.
Sustainability standards
In 2008, the Roundtable for Sustainable Biofuels released its proposed standards for sustainable biofuels. This includes 12 principles:Roundtable for Sustainable Biofuels releases proposed standards for review Biomass Magazine, August 18, 2008. Retrieved December 24, 2008. "Biofuel production shall follow international treaties and national laws regarding such things as air quality, water resources, agricultural practices, labor conditions, and more. Biofuels projects shall be designed and operated in participatory processes that involve all relevant stakeholders in planning and monitoring. Biofuels shall significantly reduce greenhouse gas emissions as compared to fossil fuels. The principle seeks to establish a standard methodology for comparing greenhouse gases (GHG) benefits. Biofuel production shall not violate human rights or labor rights, and shall ensure decent work and the well-being of workers. Biofuel production shall contribute to the social and economic development of local, rural and indigenous peoples and communities. Biofuel production shall not impair food security. Biofuel production shall avoid negative impacts on biodiversity, ecosystems and areas of high conservation value. Biofuel production shall promote practices that improve soil health and minimize degradation. Surface and groundwater use will be optimized and contamination or depletion of water resources minimized. Air pollution shall be minimized along the supply chain. Biofuels shall be produced in the most cost-effective way, with a commitment to improve production efficiency and social and environmental performance in all stages of the biofuel value chain. Biofuel production shall not violate land rights".
Several countries and regions have introduced policies or adopted standards to promote sustainable biofuels production and use, most prominently the European Union and the United States. The 2009 EU Renewable Energy Directive, which requires 10 percent of transportation energy from renewable energy by 2020, is the most comprehensive mandatory sustainability standard in place as of 2010.
The EU Renewable Energy Directive requires that the lifecycle greenhouse gas emissions of biofuels consumed be at least 50 percent less than the equivalent emissions from gasoline or diesel by 2017 (and 35 percent less starting in 2011). Also, the feedstocks for biofuels "should not be harvested from lands with high biodiversity value, from carbon-rich or forested land, or from wetlands".REN21 (2010). Renewables 2010 Global Status Report p. 43.
As with the EU, the U.S. Renewable Fuel Standard (RFS) and the California Low Carbon Fuel Standard (LCFS) both require specific levels of lifecycle greenhouse gas reductions compared to equivalent fossil fuel consumption. The RFS requires that at least half of the biofuels production mandated by 2022 should reduce lifecycle emissions by 50 percent. The LCFS is a performance standard that calls for a minimum of 10 percent emissions reduction per unit of transport energy by 2020. Both the U.S. and California standards currently address only greenhouse gas emissions, but California plans to "expand its policy to address other sustainability issues associated with liquid biofuels in the future".
In 2009, Brazil also adopted new sustainability policies for sugarcane ethanol, including "zoning regulation of sugarcane expansion and social protocols".
Motivation Biofuels, in the form of liquid fuels derived from plant materials, are entering the market, driven by factors such as oil price spikes and the need for increased energy security. Many of these first-generation biofuels that are currently being supplied have been criticised for their adverse impacts on the natural environment, food security, and land use.
The challenge is to support second, third and fourth-generation biofuel development. Second-generation biofuels include new cellulosic technologies, with responsible policies and economic instruments to help ensure that biofuel commercialization is sustainable. Responsible commercialization of biofuels represents an opportunity to enhance sustainable economic prospects in Africa, Latin America and Asia.The Royal Society (January 2008). Sustainable biofuels: prospects and challenges, , p. 61.Gordon Quaiattini. Canada.com, April 25, 2008. Retrieved December 23, 2009.EPFL Energy Center (c2007). Roundtable on Sustainable Biofuels Retrieved December 23, 2009.
Biofuels have a limited ability to replace fossil fuels and should not be regarded as a 'silver bullet' to deal with transport emissions. They offer a prospect of increased market competition and oil price moderation. A healthy supply of alternative energy sources will help to combat gasoline price spikes and reduce dependency on fossil fuels, especially in the transport sector. Using transportation fuels more efficiently is also an integral part of a sustainable transport strategy.
Options Biofuel development and use is a complex issue because there are many biofuel options which are available. Biofuels, such as ethanol and biodiesel, are currently produced from the products of conventional food crops such as the starch, sugar and oil feedstocks from crops that include wheat, maize, sugar cane, palm oil and oilseed rape. Some researchers fear that a major switch to biofuels from such crops would create a direct competition with their use for food and animal feed, and claim that in some parts of the world the economic consequences are already visible, other researchers look at the land available and the enormous areas of idle and abandoned land and claim that there is room for a large proportion of biofuel also from conventional crops.The Royal Society (2008). p. 2.
Second generation biofuels are now being produced from a much broader range of feedstocks including the cellulose in dedicated energy crops (perennial grasses such as switchgrass and Miscanthus giganteus), forestry materials, the co-products from food production, and domestic vegetable waste. Advances in the conversion processesCatherine Brahic. Hydrogen injection could boost biofuel production New Scientist, March 12, 2007. Retrieved December 23, 2009. will improve the sustainability of biofuels, through better efficiencies and reduced environmental impact of producing biofuels, from both existing food crops and from cellulosic sources.The Royal Society (2008). p. 2 & 11. One promising development in biobutanol production technology was discovered in the late summer of 2011—Tulane University's alternative fuel research scientists discovered a strain of Clostridium bacteria, called "TU-103", a key feature of the discovery is that the "TU-103" organism can convert nearly any form of cellulose into butanol, and is the only known strain of Clostridium-genus bacteria that can do so in the presence of oxygen. The university's researchers have stated that the source of the "TU-103" Clostridium bacteria strain was most likely from the solid waste from one of the plains zebra at New Orleans' Audubon Zoo.
In 2007, Ronald Oxburgh suggested in The Courier-Mail that production of biofuels could be either responsible or irresponsible and had several trade-offs: "Produced responsibly they are a sustainable energy source that need not divert any land from growing food nor damage the environment; they can also help solve the problems of the waste generated by Western society; and they can create jobs for the poor where previously were none. Produced irresponsibly, they at best offer no climate benefit and, at worst, have detrimental social and environmental consequences. In other words, biofuels are pretty much like any other product.Ron Oxburgh, "Fuelling hope for the future." The Courier-Mail, August 15, 2007. In 2008 the Nobel prize-winning chemist Paul J. Crutzen published findings that the release of nitrous oxide (N2O) emissions in the production of biofuels means that they contribute more to global warming than the fossil fuels they replace.
According to the Rocky Mountain Institute, sound biofuel production practices would not hamper food and fibre production, nor cause water or environmental problems, and would enhance soil fertility.Rocky Mountain Institute (2005). Winning the Oil Endgame p. 107. Retrieved December 23, 2009. The selection of land on which to grow the feedstocks is a critical component of the ability of biofuels to deliver sustainable solutions. A key consideration is the minimisation of biofuel competition for prime cropland.Growing Sustainable Biofuels: Common Sense on Biofuels, part 2 World Changing, March 12, 2008. Retrieved December 24, 2008.
Biofuels are different from fossil fuels in regard to carbon emissions being short term, but are similar to fossil fuels in that biofuels contribute to air pollution. Raw biofuels burned to generate steam for heat and power, produces airborne carbon particulates, carbon monoxide and nitrous oxides. The WHO estimates 3.7 million premature deaths worldwide in 2012 due to air pollution.
Ingredients
Sugarcane in Brazil
Brazil's production of ethanol fuel from sugarcane dates back to the 1970s, as a governmental response to the 1973 oil crisis. Brazil is considered the biofuel industry leader and the world's first sustainable biofuels economy. In 2010 the U.S. Environmental Protection Agency designated Brazilian sugarcane ethanol as an advanced biofuel due to EPA's estimated 61% reduction of total life cycle greenhouse gas emissions, including direct indirect land use change emissions. Brazil sugarcane ethanol fuel program success and sustainability is based on the most efficient agricultural technology for sugarcane cultivation in the world, See chapters Introduction (pp. 339–444) and Pillar I: Innovation (pp. 445–482) uses modern equipment and cheap sugar cane as feedstock, the residual cane-waste (bagasse) is used to process heat and power, which results in a very competitive price and also in a high energy balance (output energy/input energy), which varies from 8.3 for average conditions to 10.2 for best practice production.
A report commissioned by the United Nations, based on a detailed review of published research up to mid-2009 as well as the input of independent experts world-wide, found that ethanol from sugar cane as produced in Brazil "in some circumstances does better than just "zero emission". If grown and processed correctly, it has negative emission, pulling out of the atmosphere, rather than adding it. In contrast, the report found that U.S. use of maize for biofuel is less efficient, as sugarcane can lead to emissions reductions of between 70% and well over 100% when substituted for gasoline. Several other studies have shown that sugarcane-based ethanol reduces greenhouse gases by 86 to 90% if there is no significant land use change.