Talk:Biodiesel

Efficiency and economic arguments

User:SylviaStanley added the following to the article:

A 2005 study found that biodiesel production using soybeans required 27% more fossil energy than the biodiesel produced and 118% more energy using sunflowers.

This is a vital component to this section, but does not mesh will other studies I've seen, and it lacking some context/details provided in the full article (e.g., how/if the meal is accounted for).--E8 (talk) 22:40, 12 April 2011 (UTC)

Solar cells and algaculture

"... if the entire mass of a crop is utilized for energy production, the overall efficiency of this chain is currently about 1%. While this may compare unfavorably to solar cells combined with an electric drive train, biodiesel is less costly to deploy (solar cells cost approximately US$1,000 per square meter) and transport (electric vehicles require batteries which currently have a much lower energy density than liquid fuels)."

This statement falsely implies that all energy collected from solar cells must be used in conjunction with batteries, when, in fact, solar plants may instead be used exclusively for the electrolysis of water to produce hydrogen gas at 14~23 times the overall energy efficiency of biodesel. Similarly, there is no comparison with the characteristics of algaeic biohydrogen production, which has been estimated to require substantially less than biodiesel's surface area per joule.   — C M B J   06:27, 18 August 2011 (UTC)

Clarification on Carbon Emissions

I'm not 100% clear on the carbon-neutrality of Biodiesel. My understanding is that burning biodiesel releases CO2 like regular fossil fuels, but unlike fossil fuels, the carbon released is the same carbon that the plants used during photosynthesis. No new carbon is being released into the atmosphere, so it is essentially carbon-neutral. Can someone please clarify? -Fogelmatrix 16:01, 14 November 2011 (UTC) — Preceding unsigned comment added by Fogelmatrix (talk*contribs)

• That doesn't count the carbon released during shipping and production.Brakeu (talk) 00:24, 28 November 2011 (UTC)

• Methanol, which is a typically made from (non-renewable) natural gas, is used as a reactant in the biodiesel production process. There's also a carbon expense associated with the catalyst production, as well as process energy inputs. It should be noted that this topic is discussed in detail on the page and elsewhere, with sources. Biodiesel production has useful information as well.--E8 (talk) 02:03, 28 November 2011 (UTC)

Low Temperature Gelling

This section does not include mention of the cold soak filtration test astmd7501. it does not mention the fact that the biggest contributor to gel point temperature is the percentage of saturated fatty acids in the biodiesel. It does not mention urea clathration, a chemical process that lowers gel dramatically. It does not mention additives used to lower gel point.Rick36502 (talk) 05:51, 20 January 2012 (UTC)

• Good points all around. Clathrate compound could use the additional content is well. I see there is older research on the subject; has this technique been used at production scale or did it dead-end in the lab? (i.e., does it best fit the research section or elsewhere)--E8 (talk) 07:26, 20 January 2012 (UTC)

It appears to be in the patent application process. My research on the topic is posted at http://make-biodiesel.org/Biodiesel-Chemistry/urea-clathration.html Rick36502 (talk) 21:10, 20 January 2012 (UTC)

External Links

Please consider Small-scale Biodiesel Tutorial for the external links section. I have a conflict of interest and can not add it. It is a biodiesel tutorial website with more than 200 articles on hobby and farm biodiesel production. There was an objection about excessive advertisements, there are no advertisements on this webpage. For more detail see my Talk Page Rick36502 (talk) 23:15, 21 January 2012 (UTC)

After taking time to reading through some of Rick's website along with a number of others, I can say Rick's is my personal favorite in terms of completeness (citing sources, reasonably partial, etc) and activity (it's up-to-date). The two issues, as I see them are 1) this is a popular topic, and there are many biodiesel how-to, hobbyist, and research aggregating sites (DMOZ lists quite a few, and more exist), and 2) we have removed at least one other tutorial link from this page in the past due to factual errors on that site. Posting EL's here is an implicit endorsement. Given this issue, that the expertise of the authors has not been established and there is no peer review of this sites content is a barrier to posting.

Further, the EL links list is to remain "minimal" by policy, and the precedent on this page (along with other renewable energy pages which are subject to frequent link-spamming [1]) has been to move most links to DMOZ[2][3]. The DMOZ Biodiesel list is lengthy, so I have petitioned to add a subcategory there specifically for education/tutorial content. The EL list can then direct users to that shorter, more convenient list, and editors can avoiding having to play favorites.--E8 (talk) 23:12, 26 January 2012 (UTC)

Contamination by Water

This whole section with the possible exception of the bullet items is wrong. The citations supporting the section are not valid references.

For starters, water is soluble in biodiesel in trace quantities. it is not hygroscopic. LeChâtelier's Principle equalizing out the partial pressures of humid air and and the trace quantities of water dissolved in biodiesel will force water either into or out of the biodiesel as dictated by their relative partial pressures. Note that a long accepted method of removing water from biodiesel is to desiccate the air over it forcing the partial pressures to equalize, driving the water out of the biodiesel. hygroscopic implies water moving only in one direction, when it actually moves in both directions according to LeChâtelier's Principle.

The idea of monoglycerides acting as an emulsifier is an urban ledgend and has no scientific support, while soap and glycerin have both been proven to be real emulsifiers. At any rate, emulsifers have no bearing on dissolved water. Also note that the test for water is ASTM D2709. A centrifuge test for water and sediment. it does not test for dissolved water. Dissolved water is only an issue for blendstock, (what the standard was devised to test) because biodiesel can dissolve up to 1500 ppm of water while diesel can only dissolve 500ppm. A blend of biodiesel and diesel will only dissolve 500ppm, so it's possible to mix dry biodiesel and dry diesel, per the standards and get a wet blend that will fail a centrifuge test for water and sediment and blow out your IP.

The idea that there has been no way to test for water in biodiesel is wrong. The reaction of calcium hydride and water produces a mass of hydrogen gas that is directly related to the mass of water. this test is over a century old and has long been used to measure water in lubrication oils. In addition the karl fisher titration test for water has been around for a very long time as well. The conductivity of oil/biodiesel containing emulsified water has been known and used in automated production for years.

Water does not reduce the effeciency of the catalyst. It is a catalyst for hydrolysis. The more water the faster hydrolysis proceedes. The ffa produced by hydrolysis cataylised by water immeadiately consumes the caustics used as a catalyst for base transesterification by neutralising the ffa. In the worse case, it will consume all the caustic without making any biodiesel. 173.87.143.106 (talk) 04:26, 21 January 2012 (UTC)