Biodiesel

Back when gas prices peaked many people began to talk about the possibility of using biodiesel as a form of fuel.  At the COP15 conference there has been many mentions of biodiesel as a part of the renewable energy solution for the 21st century.   Being interested in biology and chemistry the idea of powering some of our cars using a carbon neutral source that we can grow every year really appeals to me.  I have only been a few side events where the specifics behind biodiesel have been mentioned.  This has spurred me to do a little bit of internet research and see what I can find.    I can tell you that this is an exciting technology that is currently under-utilized in the world.  But before I get in to that let me first give some background on biodiesel.

The word “Biodiesel” has been associated with many different products over the past three years.  Broadly speaking biodiesel is any fuel that can be produced from vegetable oils (such as soybeans) or animal fats.  It is renewable and it is clean burning.   It can be used in 2000 onwards diesel engines without any problems.   The most common form of biodiesel is B20.  That is 20% of biodiesel mixed with 80% normal gasoline.    Biodiesel has become more common in the US since 1998 when the Department of Energy (DOE) published its report talking about the benefits of using biodiesel.  Biodiesel is much more environmentally friendly than traditional fuel.  It is also relatively simple to create.

At the most basic level the reagents one uses when making biodiesel are simply triglycerides (fats like most of us can find around our mid sections) or vegetable oil.  For the purpose of this post I am going to use an example of making biodiesel from vegetable oil.   Please keep in mind that I don’t state a specific amount of any of the ingredients that one would need to do this process.  Also, I would not recommend that anyone tries to produce their own biodiesel unless they have some experience with chemistry.  In other words,  I am NOT responsible if you hurt yourself, your property, or others by attempting this.

  1. Start by cleaning out any impurities from the oil.  This can include dirt, food residue, or water.
  2. Next you titrate a sample of your oil to determine the free fatty acids.  This is done by measuring out a specific volume of oil.  From there you add an phenolphthalein (an indicator) then you proceed to slowly add your base (usually sodium hydroxide) until the solution turns very pale pink.  You then measure how much base you added to the solution.  After that you use the equation Molarity = Moles/Volume (L) solving for moles.  You then divide the number of moles by the volume of sample you added.  That number is your acid concentration.
  3. Once the acid concentration as been established you can then add your vegetable oil to a mixture of 3 times methanol (CH3OH) and sodium hydroxide (NaOH).  Run the reaction at about 60C and 20 PSI.  Let the reaction run for 15 to 20 minutes.
  4. The product is a mixture of soap, glycerin, alcohol, and water.  The glycerin is denser then the biodiesel.  So the first course of action is to separate the two layers.  This is most easily down by pipetting out and then discarding the lower layer of the product from the previous reaction.
  5. Next remove the excess water by using a technique called counter-flow washing.  Place a funnel with your biodiesel over a separation funnel with water.  From there slowly run the biodiesel through the water.
  6. When the wash is complete separate the bottom aqueous layer from the top layer.  Then check the pH of the bottom layer.  If it is basic repeat the wash.
  7. Once you have the product with the correct pH add about 5g of sodium sulfide to the biodiesel then shake and let it stand for 15 to 20 minutes.
  8. Now distill out the methanol from the product.
  9. The resulting product is your biodiesel.

Obviously, there are specific steps that one must take to produce biodiesel on a larger scale. However the chemistry remains about the same. The ease of this reaction makes one wonder why we have not seen a larger increase in biodiesel production.  The answer to that question is very complicated.  One reason it would require a massive amount of land or freshwater to grow enough plants to produce enough biodiesel to power all the vehicles in the US.  One has to take in consideration that this space must be used for other things such as food production and industry.   Also, history has shown us that “putting all our eggs in one basket” is not a very good idea.   Even with all the logistical problems ignored biodiesel faces tough completion from energy lobbyists who do not want the US to move away from using oil.

The biggest concern with moving towards the widespread adoption of biodiesel is the risk of not producing enough food because those crops have been converted to plants that can produce biodiesel.  That is where 2nd generation biodiesel comes in.  2nd generation biodiesel works much the same way as normal biodiesel only it uses the cellulose rich parts of the plants that we generally do not eat and cannot digest.  It works by pre-treating the plants with enzymes or steam to break about the bonds in cellulose and lignin.  After that the reaction takes place much like traditional biodiesel synthesis.  This biodiesel is just as environmentally friendly as the previous generation and it is much less stressful on the food supplies.

So how much should we rely on biodiesel in our energy portfolio?  Personally I think that we could to biodiesel to power at least 25% of our cars in the near future.  As more people begin to embrace the idea of biodiesel production will increase and prices will come down.  Biodiesel also has the advantage of not being subject to the price fluctuations that traditional gasoline has to go through.  I apologize for my long post.  However, this is something I feel very strongly about and I feel that I should share this information with everyone else.  If you take nothing else away from this post I would hope that you take away the idea that biodiesel is already here.  We just need to begin to utilize it.

Ben Roberts

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3 Responses

  1. It is fabulous to know that Alma students are witnessing the Copenhagen conference firsthand and will bring that experiential knowledge back to Alma!

    Question: Is anyone talking about industrial meat production and its ill effects on the earth?

    Best wishes to all of you. -Kate Blanchard (Religious Studies)

  2. In this year’s climate conference in Copenhagen, nations have between December 7 and December 18 to try and figure out the framework for a new climate change improvement. In my perspective, the conference has gone well so far, but has moved relatively slowly. Conferences that meet this often should be making much more headway. The conference should produce new guidelines to regulate emissions of the world’s biggest and dirtiest nations first. This specifically includes the United States given its volume of emissions.

    I would like to see the conference set a quota for the United States on a larger amount of renewable energy by 2015. We have the greatest technology, but for some reason we have a miniscule amount of renewable energy. We have immense amounts of area in the west that should be absolutely filled with windmills producing power for the greater half of the United States. I would also like the emissions to be cut drastically by that time. Again with the technology—why shouldn’t the country with the greatest technology have the least amount of emissions? Not caring about the environment has been proven to hurt it; this is not the 1920’s anymore, we need to become more conscious with the amount of emissions we are releasing. While on the subject of conscious, the subject of our natural resources should be touched on. We are running out. Peak oil is here, we are in desperate need to find a new source of energy—permanently. Coming away from the conference, the United States should have a good idea of how we are going to reduce the nation’s dependence on foreign oil. Not only would reducing our dependence on foreign oil improve the environment, but it would improve this dreadful economy. I would like to see the US walk away from Copenhagen with at least a well rounded idea of the direction we need to head for a new source of energy for our cars. Under developed countries that are still in the industrial stage of their development also need to be supplied with the proper funding and technology. Mexican president, Felipe Calderon promised that Mexico would supply their own funding as long as he had the aid of the newest technology to keep reducing the amount of emissions. More countries should take funding into their own hands, and not relying on other countries like Mexico. It is everyone’s planet, not just the citizens of well developed countries.

  3. And the best case scenario with biodiesel would be to make it from waste oils. Are there any implications of using biodiesel in the winter…or just with temperature fluctuations??

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