tag:blogger.com,1999:blog-6537965748256551796.post5780090442124361763..comments2023-09-24T10:19:01.383+01:00Comments on John's Green Issues: Just how green are biofuels?Johnhttp://www.blogger.com/profile/14197399895034972279noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-6537965748256551796.post-31713097810889783422005-06-30T08:45:00.000+01:002005-06-30T08:45:00.000+01:00Interesting stuff, not because of the content butb...Interesting stuff, not because of the content but<br>because of the politics behind it. The content is interesting, and certainly the actual<br>carbon gains from bioethanol can be a suspect depending on the<br>system from which it is produced. One of the ways in which bioethanol<br>production makes any environmental sense is when it uses the wastes<br>from the existing sugar industry (molasses from the sugar refining process<br>and bagasse, the agricultural residue which is used to fuel the<br>distillation process). As for biodiesel from soya, soya oil is<br>essentially a waste product from extracting the protein from the bean<br>(the primiary reason for growing the crop, and a far more ecologically<br>sensible way of producing protein than beef, say), so convertion to<br>biodiesel is a way of adding value to the crop which also happens to<br>displace petroleum that would otherwise be burnt.<br><br>But in fact the logic in the article seems a bit muddled to me. One<br>assumption is that forests will grow where these crops are planted,<br>which is not always true, although perhaps he had Brazil in mind when<br>he wrote the piece and that was edited out. The other assumption is<br>that the world somehow does not demand these products (sugar, soya and<br>vegetable oil) and replanting forest would not displace some<br>wilderness value elsewhere in the world's agricultural landscape.<br><br>Besides, is forest regeneration is a realistic option, given all that<br>determines one particular course of action over another in modern<br>society. Its an idealistic option, for sure; everyone would like to see more forest<br>but without the economic arguement to make it happen it won't be<br>realised.<br><br>As with any criticism, it is no good shooting down an<br>option without offering a better alternative that<br>addresses the problem at hand, in this case liquid fuels for<br>transport. What are the alternatives? Often the hydrogen cell is<br>offered as the way forward, but realistically cars driven on H cells<br>are at least 10-20 years away so what are we going to do until then? H<br>cells have their own problems, too, that are waiting for technology to<br>solve - and where will the primary energy come from that will split<br>water to generate H2 and O2?<br><br>In my opinion, biofuels will only ever be a 'petroleum extender', allowing us to continue using our<br>diminishing petroleum resource more efficiently (since one gallon<br>will only contain 75% or 50% petroleum) while we get the long term<br>alternative operational.<br><br>Growing forests to sequester carbon is a pretty good option to remove<br>CO2 from the atmosphere, I agree, but unfortunately that is not the only issue at stake.<br>I think we need to grow more forests, but not at the expense of some of the few carbon reducing<br>options we have available.<br><br>We MUST make sure that we present the whole picture when we try and colour the opinions of others, and when it comes to the environmental health of the planet I cannot think of a more important cause to ensure we present all the facts accurately and leave politics out of it. Eh, Bush?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6537965748256551796.post-12569723987891401282005-07-02T16:02:00.000+01:002005-07-02T16:02:00.000+01:00Anonymous makes some good points. Waste products ...Anonymous makes some good points. Waste products such as molasses and spent edible oils are often cited as potential sources of biofuels; they can and should make a contribution (provided they do not displace demand to new agricultural production), but the quantities practically available are trivial compared with the scale needed for even a 1% contribution to petrol or diesel. Soya oil could make a much larger contribution but, at around 30% of the value from milled soybeans, it should not considered a waste product; demand for the oil is an important factor driving increased planting of the crop (the dominant product is, of course, the soya meal, most of which is used to feed cattle and poultry, not people directly - an environmentally destructive way of us getting our protein).<br><br>The technology for making some biofuels is efficient, particularly for sugar cane: in making bioethanol from sugar cane in Brazil the bagasse provides the fuel for the mill and distillery and there is little waste. Despite this, the emissions saving from using the ethanol to substitute petroleum is less than would be obtained from letting the same land go back to forest; still less for sugar beet and the oil crops.<br><br>But the most important point is that for biofuels to make a significant contribution to transport fuels, huge quantities of cane, beet, maize, soya or oilseed rape are needed. For example, the current global area of sugar cane (about 20 million hectares) would need to be more than doubled for bioethanol from cane juice to give just a 5% substitution of global emissions from fossil fuels used in transportation. Pro rata, biofuels from other sources would use even more land. So, huge areas of land would have to be converted to production of the extra crops needed with attendant massive releases of carbon; or land would be kept in agricultural production that could otherwise be returned to forest (which applies to almost all of the tropics and much of the temperate zones). <br><br>Of course carbon emissions are not the only thing that will determine how land is used; social issues, economics and political expediency will bear on what is done and when. But our thinking should not be circumscribed by current land use patterns. In almost all situations, more carbon is held on the ground in the pre-agricultural forest or grassland state than in crop production. Converting to arable land releases most of the carbon, converting back to forest or grassland claws carbon dioxide back, slowly, but generally faster than can be achieved by the substitution of fossil energy by biofuels. <br><br><br>Renton RighelatoAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6537965748256551796.post-76540114235307112392008-12-08T06:22:00.000+00:002008-12-08T06:22:00.000+00:00toshiba satellite 1110 battery with battery charge...<a href="http://www.batterylaptoppower.com/toshiba/satellite-1110.htm" rel="nofollow">toshiba satellite 1110 battery with battery charger and mouse</a><br> <a href="http://www.batterylaptoppower.com/toshiba/satellite-1115.htm" rel="nofollow">toshiba satellite 1115 battery with battery charger and mouse</a><br> <a href="http://www.batterylaptoppower.com/toshiba/pa3399u-1bas.htm" rel="nofollow">toshiba pa3399u-1bas battery with battery charger and mouse</a>Anonymousnoreply@blogger.com