Environmental effects of biodiesel

A number of environmental effects of biodiesel have emerged.

Greenhouse gas emissions

An often mentioned incentive for using biodiesel is its capacity to lower greenhouse gas emissions compared to those of fossil fuels. If this is true or not depends on many factors. Especially the effects from land use change have potential to cause even more emissions than what would be caused by using fossil fuels alone.cite journal | last = Fargione | first = Joseph | coauthors = Jason Hill, David Tilman, Stephen Polasky, Peter Hawthorne | date=2008-02-29 | title = Land Clearing and the Biofuel Carbon Debt | journal = Science | doi = 10.1126/science.1152747 | url = http://www.sciencemag.org/cgi/content/abstract/1152747 | format = fee required | accessdate =2008-04-29 | volume = 319 | pages = 1235 | pmid = 18258862 "Related news articles:"
*cite news |first=Deane |last=Morrison |title=Converting pristine lands to biofuel farms worsens global warming |url=http://www1.umn.edu/umnnews/Feature_Stories/Converting_pristine_lands.html |work=UMNnews |publisher=University of Minnesota |date=2008-02-07 |accessdate=2008-04-29
*cite press release | title = New Study Raises Major Questions on Biofuels | publisher = The Nature Conservancy in Minnesota | date =2008-02-07 | url =http://www.nature.org/wherewework/northamerica/states/minnesota/press/press3348.html | accessdate =2008-04-29]

Carbon dioxide is one of the major greenhouse gases. Although the burning of biodiesel produces carbon dioxide emissions similar to those from ordinary fossil fuels, the plant feedstock used in the production absorbs carbon dioxide from the atmosphere when it grows. Plants absorb carbon dioxide through a process known as photosynthesis which allows it to store energy from sunlight in the form of sugars and starches. After the biomass is converted into biodiesel and burnt as fuel the energy and carbon is released again. Some of that energy can be used to power an engine while the carbon dioxide is released back into the atmosphere.

When considering the total amount of greenhouse gas emissions it is therefore important to consider the whole production process and what indirect effects such production might cause. The effect on carbon dioxide emissions is highly dependent on production methods and the type of feedstock used. Calculating the carbon intensity of biofuels is a complex and inexact process, and is highly dependent on the assumptions made in the calculation. A calculation usually includes:

* Emissions from growing the feedstock (e.g. Petrochemicals used in fertilizers)
* Emissions from transporting the feedstock to the factory
* Emissions from processing the feedstock into biodieselOther factors can be very significant but are sometimes not considered. These include:
* Emissions from the change in land use of the area where the fuel feedstock is grown.
* Emissions from transportation of the biodiesel from the factory to its point of use
* The efficiency of the biodiesel compared with standard diesel
* The amount of Carbon Dioxide produced at the tail pipe. (Biodiesel can produce 4.7% more)
* The benefits due to the production of useful by-products, such as cattle feed or glycerine

If land use change is not considered and assuming todays production methods, biodiesel from rapeseed and sunflower oil produce 45%-65% lower greenhouse gas emissions than petrodiesel.cite web |url=http://www.defra.gov.uk/farm/crops/industrial/research/reports/nf0422.pdf | format=PDF 763 KB |title=Evaluation of the comparative energy, global warming and socio-economic costs and benefits of biodiesel |accessdate=2008-05-01 |last=Mortimer |first=N. D. |coauthors=P. Cormack, M. A. Elsayed, R. E. Horne |year=2003 |month=January |work=Sheffield Hallam University |publisher=UK Department for Environment, Food and Rural Affairs (DEFRA)

*"Summary:" cite web |url=http://www.esru.strath.ac.uk/EandE/Web_sites/02-03/biofuels/why_lca.htm |title=Biodiesel Life Cycle Assessment |accessdate=2008-05-01 ] [] ] [] However, there is ongoing research to improve the efficiency of the production process. Biodiesel produced from used cooking oil or other waste fat could reduce CO₂ emissions by as much as 85%. As long as the feedstock is grown on existing cropland, land use change has little or no effect on greenhouse gas emissions. However, there is concern that increased feedstock production directly affect the rate of deforestation. Such clearcutting cause carbon stored in the forest, soil and peat layers to be released. The amount of greenhouse gas emissions from deforestation is so large that the benefits from lower emissions (caused by biodiesel use alone) would be negligible for hundreds of years. Biofuel produced from feedstocks such as palm oil could therefore cause much higher carbon dioxide emissions than ordinary fossil fuels.cite book |title=How the palm oil industry is cooking the climate |url=http://www.greenpeace.org/raw/content/international/press/reports/cooking-the-climate-full.pdf |format=PDF 10.48 MB
accessdate=2008-04-30 |year=2007 |month=November |publisher=Greenpeace International |quote=The main areas remaining for new extensive plantations are the large tracts of tropical peatlands – until recently virgin rainforest areas. Over 50% of new plantations are planned in these peatland areas ]

Deforestation

If deforestation, and monoculture farming techniques were used to grow biofuel crops, biodiesel may become a serious threat to the environment: [cite news |title=U.N. raises possible negative impact of biofuels on environment, food security |url=http://www.iht.com/articles/ap/2007/05/08/europe/EU-GEN-UN-Biofuels.php?page=1 |work=International Herald Tribune |date=2007-05-08 |accessdate=2008-04-30 ] [cite web |url=http://www.foe.co.uk/resource/briefings/palm_oil_biofuel_position.pdf |title=The use of palm oil for biofuel and as biomass for energy |date=2006-08-22 |accessdate=2008-04-30 |format=PDF 66 KB |work=Friends of the Earth ]
* Increasing the emission of climate change gases rather than helping curb them
* Damaging ecosystems and biodiversity
* Exacerbating social conflict

The demand for cheap oil from the tropical regions is of rising concern. In order to increase production, the amount of arable land is being expanded at the cost of tropical rainforest. Feedstock oils produced in Asia, South America and Africa are currently less expensive than those produced in Europe and North America suggesting that imports to these wealthier nations are likely to increase in the future.cite news |first=Michael |last=Grunwald |title=The Clean Energy Scam |url=http://www.time.com/time/magazine/article/0,9171,1725975-1,00.html |work=TIME |date=2008-03-25 |accessdate=2008-04-30 ]

In the Philippines and Indonesia forest clearing is already underway for the production of palm oil. Indigenous people are forced to move and their livelihood is destroyed when forest is cleared to make room for oil palm plantations.cite news |first=James |last=Painter |title=Losing land to palm oil in Kalimantan |url=http://news.bbc.co.uk/2/hi/asia-pacific/6927890.stm |work=BBC News |publisher=BBC |date=2007-08-03 |accessdate=2008-04-30 ] In some areas the use of pesticides for biofuel crops are disrupting clean water supplies,cite news |first=Jessica |last=Aldred |title=Biofuel demand leading to human rights abuses, report claims |url=http://www.guardian.co.uk/environment/2008/feb/11/biofuels.energy |work=guardian.co.uk |publisher= |date=2008-02-11 |accessdate=2008-04-29 ] and the loss of habitat caused by deforestation is threatening many species of unique plants and animals. One example is the already-shrinking populations of orangutans on the Indonesian islands of Borneo and Sumatra, which face extinction if deforestation continue at it's projected rate.cite book |last=Nellemann |first=Christian |coauthors=Lera Miles, Bjørn P. Kaltenborn, Melanie Virtue, Hugo Ahlenius |title=The last stand of the orangutan |url=http://www.unep.org/grasp/docs/2007Jan-LastStand-of-Orangutan-report.pdf |format=PDF 20.17 MB
accessdate=2008-04-30 |year=2007 | month=February |publisher=UNEP & UNESCO: GRASP |isbn=978-82-7701-043-5 |quote=State of emergency: illegal logging, fire and palm oil in indonesia's national parks ] [cite paper | author = Helen Buckland, Ed Matthew (ed.) | title = The Oil for Ape Scandal: How palm oil is threatening the orang-utan | version = Summary | publisher = Friends of the Earth Trust | date =2005-09-19 | url = http://www.foe.co.uk/resource/reports/oil_for_ape_summary.pdf | format =PDF 448 KB | accessdate=2007-01-02 ] [Citation | last1 = Ancrenaz | first1 = M. | last2 = Marshall | first2 = A. | last3 = Goossens | first3 = B. | last4 = van Schaik | first4 = C. | last5 = Sugardjito | first5 = J. | last6 = Gumal | first6 = M. | last7 = Wich | first7 = S. | year = 2007 | title = Pongo pygmaeus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. | url = http://www.iucnredlist.org/search/details.php/17975/all | accessdate = 2008-04-02 ] [Citation | last1 = Singleton | first1 = I. | last2 = Wich | first2 = S.A. | last3 = Griffiths | first3 = M. | year = 2007 | title = Pongo abelii. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. | url = http://www.iucnredlist.org/search/details.php/39780/all | accessdate = 2008-04-02 ]

Pollution

In the United States, biodiesel is the only alternative fuel to have successfully completed the Health Effects Testing requirements (Tier I and Tier II) of the Clean Air Act (1990).

Biodiesel can reduce the direct tailpipe-emission of particulates, small particles of solid combustion products, on vehicles with particulate filters by as much as 20 percent compared with low-sulfur (< 50 ppm) diesel. Particulate emissions as the result of production are reduced by around 50 percent compared with fossil-sourced diesel. (Beer et al, 2004).Biodiesel has a higher cetane rating than petrodiesel, which can improve performance and clean up emissions compared to crude petro-diesel (with cetane lower than 40). Biodiesel contains fewer aromatic hydrocarbons: benzofluoranthene: 56% reduction; Benzopyrenes: 71% reduction.Fact|date=February 2007

If burned without additives, Biodiesel (B100) is estimated to produce about 10% more nitrogen oxide NO_x tailpipe-emissions than [http://www.epa.gov/SmartwayLogistics/growandgo/documents/factsheet-biodiesel.htm petrodiesel] . As biodiesel has a low sulfur content, NO_x emissions can be reduced through the use of catalytic converters to less than the NO_x emissions from conventional diesel engines. However, modern diesel engines already use exhaust aftertreatment and EGR to reduce NO_x emissions. These systems add complexity, increase costs, and reduce fuel economy (leading to higher CO₂ emissions). As a transportation fuel, biodiesel is in its infancy in terms of additives which are capable of improving energy density, resistance to gelling, and NO_x emissions. Debate continues over NO_x, particulates, smog, and greenhouse gas emissions from biodiesel and all other new transportation fuels, biofuels in particular. Ultimately, greater clarity on the fundamental distinctions between smog and other local pollution issues vs. greenhouse gas emissions will be essential for both well founded public policy as well as well informed consumer choices.

Biodegradation

A University of Idaho study compared biodegradation rates of biodiesel, neat vegetable oils, biodiesel and petroleum diesel blends, and neat 2-D diesel fuel. Using low concentrations of the product to be degraded (10 ppm) in nutrient and sewage sludge amended solutions, they demonstrated that biodiesel degraded at the same rate as a dextrose control and 5 times as quickly as petroleum diesel over a period of 28 days, and that biodiesel blends doubled the rate of petroleum diesel degradation through co-metabolism.cite web |url=http://www.uidaho.edu/bioenergy/BiodieselEd/publication/04.pdf |title=Biodegradability, BOD₅, COD and Toxicity of Biodiesel Fuels |date=2004-12-03 |accessdate=2008-04-30 |format=PDF 64 KB |work=National Biodiesel Education Program, University of Idaho ] The same study examined soil degradation using 10 000 ppm of biodiesel and petroleum diesel, and found biodiesel degraded at twice the rate of petroleum diesel in soil. In all cases, it was determined biodiesel also degraded more completely than petroleum diesel, which produced poorly degradable undetermined intermediates. Toxicity studies for the same project demonstrated no mortalities and few toxic effects on rats and rabbits with up to 5000 mg/kg of biodiesel. Petroleum diesel showed no mortalities at the same concentration either, however toxic effects such as hair loss and urinary discoloring were noted with concentrations of greater than 2000 mg/l in rabbits.

ee also

*Sustainable biofuel
*Biofuels#Current issues in biofuel production and use

References