Talk:Energy content of biofuel

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This discussion was copied from the Biofuel page. I have moved the article to a new page as indicated.--Alex 07:56, 17 July 2006 (UTC)

I like the energy chart....but leave out the chemical formulas! Also there are sig fig issues, what does ~ 14.15 mean??? and 8.53-16.15....1 sig fig is more than enough here. Looks like this page has fallen by the wayside, so maybe i'll come back and clean it up.... — Preceding unsigned comment added by (talk) 18:52, 20 October 2011 (UTC)

I just want to mention--natural gas is methane, so shouldn't have different entries for its properties without further clarification. — Preceding unsigned comment added by (talk) 02:15, 20 October 2016 (UTC)

The energy chart must go![edit]

The energy chart is way too big and now too comprehensive for this specific article, I think it should become its own article, something like "Energy source comparisons", "Fuel comparisons", etc (someone think of a name). We can broaden everything about the fuels such as there melting points, boiling points, efficiency of recycling, etc, and provide a comprehensive chart of all fuel/energy sources. --BerserkerBen 15:13, 26 April 2006 (UTC)

Awww (insert childish whining here), I was really getting into the modding of this chart. [I have since written maybe 60% of the info on this chart by now, and was hoping to get it finished before someone finally made some sort of inevitable suggestion/complaint.] I didn't start the chart, just inserted info that seemed relevant to the topic (like the column on CO2 gas-produced mass per fuel-used mass (something I haven't completed yet 'cause I haven't found a complete answer on the proportions and chemical compositions of the average sample of "Animal Waste", "Coal", "Petroleum" and average "Vegetable Oil"s (Soybean Oil makes maybe 40% of world production, but has poor energy content per fuel mass, and even worse energy content per CO2 gas-prod. mass (an idea for another column, but alas, there is only so much space on the average 1024x768 screen.)))) I also wanted to insert numbers where it says "Compression Dependant", and was thinking about using the average temperatures and pressures used in the industry of gas delivery (different for "Compressed Gas" and "Liquified Gas", by about 4 fold), but like I said, I didn't start the article, and don't want to offend it's projenitor by deleting, usurping, or otherwise "misplacing" large portions of data that he/she started (I only started working on this article in reverance of the questions that he/she started me to contemplating). But, if there is sufficient consensus among this Wikipedia community (the greatest and most inspiring I have yet to encounter since the Linux community (too bad Lostpedia [[1]] closed it's sources)), then I would be open to the idea of copying this chart as it is to either a page of it's own (like Comparison of Energy-Mediums OR Energy-Media)(fully linked to and from all pages that it references) AND/OR to the Energy development page AND/OR the Future energy development page. It should also be noted prior to data-transplantation, that the Fuel Cell and Battery Energy Storage sections (both of which I added in full) only relate to useable electrical energy output, they also "bleed" heat energy at a rate proportional to the rate at which elec. energy is extracted from them (Ampereage/Electric current). All other non-nuclear sources relate to their heat energy output which may be modulated either by use of a heat furnace AND/OR heat engine AND/OR internal combustion engine (a device which use heat to create pressure changes, without really using the heat itself). Their combustion really only has negative-side effects when you're not sure where to put the CO2 (now that we know to put carbon into plants, we're not sure which plants will consume carbon quikly, while storing solar energy densly into itself, for us to harvest back, without consuming more energy in the whole process, than we harvest back, compared to say, solar power). In direct response to your suggestion though BerserkerBen, I'm a tad sceptical of how adding the info of melting points, boiling points & efficiency of recycling, would be terribly helpful (only 'cause Diesel and certain Oils combust spontaneously under (rapid-)pressurisation). It might require a sub-chart like Comparison_of_BitTorrent_software page OR the Comparison_of_operating_systems page (I do apreciate the colour coding, anything to make the data more accessible, like the colourful charts and graphs of Television's (semi-)news. As hinted to above, an appropriate title to consider is "Comparison of Energy-Storage-Mediums" OR "Comparison of Energy-Media". All fuels mentioned in the chart are mere Energy Storage Mediums, as they (plants mainly) derived their energy from the Sun, and progressively over time were compressed underground by the gravity of the Earth. Thusly, solar, tidal, wind and geothermal power (heat engine from hot-mantle to cool-surface, OR cold-sea-bed to warm-surface) are the only sources of energy that seem sustainable (for at-least 1000 years) with current technologies. --Anonymous 07:15, 27 April 2006 (UTC)
Upon closer examination of various fuels, especially Vegetable oils as fuels, I concur with your assessment that listing the melting points and boiling points of fuels will be helpful as they can be used as indicators to fuel-reaction rates, thermal-energy outputs, phase-change pressure-differentials and perhaps some other key properties worth considering, especially when dealing with Internal combustion engines. As I understand them, ICEs function by using the pressure-change of cool petrol + air mix => hot CO2 + H2O + CO + NOx, a pressure shift of ~1000 factors (ie. the pressure in the piston chamber increases by a few thousand at the rate at which the fuel burns (reacts with air when sparked by spark-plug)). Recycling efficiency is also worth mentioning. --Anonymous 05:10, 01 May 2006 (UTC)

Well I was thinking that things such as batteries would have columns (basically the chart becomes split into several charts) related to them such as efficiency of recycling (recharging), energy storage density (Wh/kg), energy production density (W/kg) energy volumes (wh/l) (w/l) etc. that kind of thing, really I too have added some to the chart and think that its has become big enough to be its own article with a little added introduction. --BerserkerBen 01:28, 28 April 2006 (UTC)

Sounds like they're all good ideas. In fact, {related to Recycling} now that I think about it, all fossil fuels and biofuels can also be recycled, if for example you carefully extracted pure CO2 from the atmosphere (or more easily from the power plant, or geosequestration rock-depositor) then mixed it with pure Hydrogen, subjected the mix to intense heat and pressure with various catalysts (like Vanadium, Nickel, Platinum, Palladium, Rhodium or Ruthenium for example), you should output first Methane then heavier, more complex compounds under higher pressures & lower temperatures (I understand this process to be Hydrogenation). Fossil fuel recycling is a very costly and time consuming process, made especially pointless as most of the hydrogen produced industrially comes from the De-Hydrogenation of fossil fuels in the first place. So the efficiency of recycling (recharging) fuels is definetly key to the sustainability of our developing energy-economy (how is the first world NOT part of the developing world, just a bit further along that's all :-]). {related to Energy density}You should notice however that 1 W.h = 1 Watt-hour = 60 (minutes) * 60 Watt.seconds = 3600 Joules = 3.6 kJoules. Joules is a much better form of measuring total work energy, especially because both batteries and fuel cells that are not functioning at peak efficiency will still release their total amount of energy, just more of it will be released as heat at lower efficiency levels (when not using combined heat + elec. efficiency calculations). So energy density relates to total energy density, not modulated by operating efficiency, working conditions, or thermal/electrical resistance/insulation. (related to energy production density) As 1 Watt = 1 Joule per second, 1 Watt per kg = 1 Joule per kilogram.second (1 W/kg = 1 J/kg.s). With batteries, these numbers are easy to input, but for fossil & biofuels and fuel cells, the rate at which energy can be extracted from the fuel, depends on the cumulative number-of, size and efficiency of the reactor(s) (or engine(s) be they heat engine(s) or ICE(s)). At which point, energy rates is an entirely new chart in of itself, where you're comparing biofuel reactors against fossil fuel reactors (or engines), fuel cells and batteries (and photovoltaics, solar heaters, geothermal plants, EM collectors, and all other methods of extracting energy from various energy-storage-mediums (those words again, remember: energy cannot be destroyed AND energy cannot be created, it can only be moved around and transformed from other forms, hopefully for our purposes (the greatest store-houses of energy are the earth and the sun, while energy wells of any form on the earth will always dry-up, the sun rarely fluctuates it's output by more than 0.15% every 10.87 years)). Note: the Sun outputs to the Earth 1366.35 W/m². That means that every 64 hours, the earth receives from the sun as much energy as the total amount of energy stored within all of the earth's fossil fuel deposits (~200 Myears old)(3.9 × 10^22 J (2003)). --Anonymous 05:10, 01 May 2006 (UTC)

Aaah CO2 recycling is the point to biofuels, as long has you grow new energy crops each year equal to or greater then the year before all CO2 produced by biofuels is negated by a equally size CO2 sink. Which is why I disagree about having CO2 values for biofuels. But anyways the move is underway!--BerserkerBen 11:12, 1 May 2006 (UTC)

I agree that the chart would be better in it's own article. --Salix alba (talk) 11:00, 24 May 2006 (UTC)


I understand the reason for the comparative data, but why are Uranium and Nuclear Fusion included under 'fossil fuels'? - IstvanWolf 14:12, 2 November 2006 (UTC)

While Deuterium is stable, Tritium has a half-life of 12.32 years (formed by billion year old Cosmic rays of stars just recently interacting with atmospheric gases) & Uranium-235 (the primary neutron source of all fission reactors) has a half-life of 7.038 × 108 years. All of these isotopes are artifacts of the natural nuclear fusion of stellar activity, or are fossils (if you will) of the continuing formation of this planet by the particle radiation of the universe. The other fossil fuels are more recent in their formation, but are also formed by the natural decay rates of the compounds of our planet, star(s) & the comet(s) that sped up the process(es). - 07:55, 18 December 2006 (UTC)

GWP per MJ?[edit]

For me the interesting point about the table is the CO2 column. It could be of interest to many to know a) what is the CO2 per MJ (i.e. one column divided by another) and b) the "equivalent" CO2 per MJ taking into account the range of other products such as NOx. The key point is to be able to distinguish biofuels on the basis that, lets say, the Global Warming Potential of one type of biofuel is high because of the non-CO2 products. Beyond that, its not such a big deal where the table sits. - mildly_odd 23:08, 7 November 2006 (UTC)

Is anyone able to contribute here or point to another page with similar content?
I did my best to satisfy your request for more data on the listed fuels vs. CO2 (feel free to insert some more data, and I'll do the rest (bearing in mind that the 3 oils listed I only inserted as those are both high volume per farmland, and have low melting points so that they shouldn't clog up fuel injectors or solidify in the fuel tank)). I regret however that I am unable to specify energy content per CO, NOx, sulfate or particulate levels as those outputs depend almost exclusively on specific fuel brands, refinement configurations and combustion profile (temperature, oxygen purity, electrostatic density, RPMs, burn efficiency, etcetera ad infinitum). That is why I settled for CO2 assuming perfect burn profile in pure oxygen, and leave individuals to measure the rest, as these other gases are much more harmful than plain old CO2, especially the particulates that embed carbon-nano-loop-structures within the brain cells of those who breath them in, including children who develop life-long neurological symptoms. - 07:55, 18 December 2006 (UTC)
When I inserted more data into the table, I added a link to another, similar table in the Row Title for Energy density (it contains some interesting listings, some of which I was planning to insert myself, which it looks like I'll have to now since they left out some essential dependencies, such as the charge decay rate of storage media like batteries and hydro-dams). - 07:55, 18 December 2006 (UTC)

Cetane numbers[edit]

What are the sources for the cetane numbers? The cetane number for various biofuels, especially palm oil, appear a bit high! Lkleinjans 11:14, 1 June 2007 (UTC)

New Intro[edit]

Added a new intro. I like the chart, think it is very useful hope my intro is of use. I think it will explain it to the avg. personRaysofenergy (talk) 20:11, 6 May 2008 (UTC)


This isn't mentioned, can't add it as I don't have all specifics. According to one source it's 20,95 MJ/kg (see ) which would be in line with the statement that it's 50% the energy value of natural gas (see ), however, other sources give lower numbers ie 5 to 12 MJ/kg, ... see (talk)= —Preceding undated comment added 09:02, 17 July 2012 (UTC)

Algae in "Yield of Common Crops" table[edit]

First, algae is not a "common crop" associated with biofuel production. I know of nowhere that I can buy 10,000 gallons of algal fuel.

Second, the figure of 10,000 gallons per acre, which appear preposterous on its face, is unreferenced.

Third, the figure of 10,000 gallons per acre seems to be based on prognostications about the distant future potential of algal biodiesel production from (biased) sites like, and does not represent actual production, which, economically speaking, is close to zero. Even then, it is littered with caveats — ifs, ands, and buts — about scaling up small-scale research, etc. This table is not a "future potential, maybe in 15 years" table, it is a "common crops" table. Algae have no place in it until algae cultivation for fuel becomes common. — Preceding unsigned comment added by (talk) 15:36, 2 August 2013 (UTC)

External links modified[edit]

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