Talk:Biodiesel/to do
- Note the amount of land required to produce a reasonable quantity of Biodiesel. Total world oil consumption is ~4*10e12 kg/yr. Using Soya yielding 1000kg/ha, this would require ~4*10e7 sq km of land to be devoted to Biodiesel production. (Stats taken from http://en.wikipedia.org/wiki/World_energy_resources_and_consumption) This is 4 times the surface area of the US. It should be made clear to the non-scientific reader that this is impractical in terms of available fertile land. 'We can eat, or we can have biodiesel, but we can't do both.'
- Also I believe the scientific name of chinese tallow has changed to Triadica Sebifera, from Sapium Sebiferum. Using the old name in google results in outdated links.
- Whilst extensive, this article totally ignores the strength of opposition from prominent scientists, environmentalists and journalists such as George Monbiot who warn of the potential threat of the mass production of biodiesel crops. May I suggest you expand or produce a new section outlining some of the major arguments against such as the displacement of communities and (often biodiverse) forest to grow biodiesel crops, the draining of wetland and subsequent release of Co2 from dried out peat bogs, the environmental problems of any monoculture such as pesticide build-up or nutrient depletion, and most strikingly of all the loss of space for food production. A useful resource might be: http://www.monbiot.com/archives/2005/12/06/worse-than-fossil-fuel/
- Biofuels Deemed a Greenhouse Threat (ELISABETH ROSENTHAL, New York Times, Feb 8, 2008) claims that two new studies show that the damage to forests and such makes it so that, all told, biofuels use more carbon than regular fuels.
- Expand production cost discussion. currently more expensive, that could reduce with economies of scale, focused production, innovation, and use of better crops.
- Adjust notation of many volumetric amounts. IE, "230,000 million US Gallons" is simply 230 billion US Gallons. Problems like this exist all throughout the article.
- Check the figures on the yield 95,000 litres oil/ha per year from an algae farm. There are no such farms in existence. One company GreenFuel is currently proving the concept at the Redhawk power station in Arizona. Check an article: Biofuel made from power plant CO2 http://www.newscientisttech.com/channel/tech/mg19225725.600-biofuel-made-from-power-plant-cosub2sub.html They estimate that a farm of between 8 - 16 square kilometers (8000 - 16000 ha) will yield 150 million litres of biodiesel plus 190 million litres of ethanol per year. Total fuel 21,250 - 42,500 litres per year. I have done some calculations that make me feel that even these values may be a bit optimistic. The 21,250 value is getting close to the limits discussed in: http://www.upei.ca/~physics/p261/Content/Sources_Conversion/Photo-_synthesis/photo-_synthesis.htm ; "At least eight photons are required to store one molecule of CO2 which means 1665 kJ of light energy are required to store 477 kJ in the plant. Max efficiency is 28.6 %. Only light in the range 400-700 nm can be used. This amounts to 43% of total solar incident radiation." Thus before other considerations the limit is 12.23%. They go on to take into account other factors like energy lost in respiration and set a limit of 6.6% in crops. In practice crop farming yields are very much lower than 6.6% in agreement with your table.
- "Green Diesel" should not redirect here, but to "Vegetable oil refining".
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