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Tiny Biodiesel Reactors

Posted by ryuzaki0 on from the tiny-power-plant dept.

Lee_in_KC writes "A professor of chemical engineering at Oregon State University developed a small reactor to directly convert vegetable oil to biodiesel. Goran Jovanovic reports his invention is approximately the size of a credit card. It pumps vegetable oil and alcohol through parallel channels to convert the oil into biodiesel almost instantly. Current mainstream methods to produce biodiesel take more than a day and also produces other byproducts which must be neutralized before disposal or use in other manufacturing processes."

7 of 369 comments (clear)

  1. better article by Quixote · · Score: 5, Informative
    You can find a much better article here.

    I'm not sure how feasible this is. Also, as per the longer article (above), it does not eliminate the need for NaOH; unless I'm reading it wrong.

    1. Re:better article by NitsujTPU · · Score: 5, Informative

      This is discussed in the article.

      NaOH is the catalyst used in the reaction.

      The microreactor under development by the university and the Oregon Nanoscience and Microtechnologies Institute eliminates the mixing, the standing time and maybe even the need for a catalyst.

    2. Re:better article by Hal_Porter · · Score: 5, Informative

      You can run diesel engines on unrefined rapeseed oil if you tweak them a bit

      http://en.wikipedia.org/wiki/Straight_vegetable_oi l
      In the UK drivers using SVO have been prosecuted for failure to pay duty to Customs and Excise.

      Biodiesel just means that you can run an umodified engine -

      from
      http://en.wikipedia.org/wiki/Biodiesel
      Sometimes even unrefined vegetable oil is incorrectly called "biodiesel". Unlike unrefined vegetable oil, biodiesel does not require fuel pre-heating and filtration due to issues with coagulation, and also require no or minimal modification to the fuel system.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    3. Re:better article by Gordonjcp · · Score: 5, Informative

      I've run a few cars on straight waste veg oil. You *do* have to pay fuel duty on it, but at a much lower rate than mineral diesel. You can run straight veg oil in pretty much all the PSA diesels (Peugeot / Renault / Citroën / some Volvo) if they have a Bosch fuel pump - the Lucas ones are more efficient but have tighter running clearances and the increased viscosity will damage them. I've had best results with the 2.5 turbodiesel as fitted to the Citroën CX and various trucks. The XUD-series engines work fairly well too.

      In general running pure veg oil is a pain in the arse because it's very hard to get the engine started. If you weren't going to switch off for more than a few minutes it would be just fine (which might be practical for generators).

  2. Re:Did I miss something, or..? by Doytch · · Score: 5, Informative

    Glycerin is not a problem in and of itself, it's the catalyst properties that are mixed in from the NaOH that end up creating useless glycerin that must be purified to be of use. Since this may eliminate the need for the catalyst, the glycerin can be used immediately without purification.

  3. What room temp IQ modded this troll? by Flying+pig · · Score: 5, Informative
    This is a joke, and somebody who doesn't know organic chemistry from his ass thought it was a troll. Dear idiot, the sodium hydroxide combines with the added alcohol to form sodium methoxide, which then reacts with the oil. The NaOH is not in fact a catalyst, it is an intermediate reaction component. And yes, it is corrosive.

    Don't they teach kids ANY organic chemistry nowadays? How are we to produce the next generation of recreational drug designers and home-made explosives producers that made the West what it is today?

    --
    Pining for the fjords
  4. Re:NaOH is a reactant not a catalyst by 0xC2 · · Score: 5, Informative

    You are half correct. The intended process is transesterification, which is direct (stepwise) substitution of the glycerol in fat with three molecules of alcohol (say for example ethanol). So one large triglyceride (a molecule of fat) is broken down to 3 fatty acid ethyl esters and one molecule of glycerin. This process is catalytic, and can be catalyzed by acid or base.

    (BTW, oil = liquid fat).

    The problematic side reaction is hydrolysis of the oil to fatty acids (i.e. saponification to soap), due to the presence of water in the crude oil. This side reaction is compounded by the difficulty of mixing the fat and alcohol during reaction (fat and alcohol not completely miscible), which reduces the efficiency of the catalytic transesterification, thereby increasing the extent of the unwanted side reaction (saponification to soap). Also crude oils contain fatty acids which could quickly neutralize a catalytic amount of sodium hydroxide (stopping the process).

    Therefore the conventional (batchwise) process is to treat the fat with excess sodium hydroxide in a non-catalytic initial step; whatever water is present is consumed in a conventional, non-catalytic saponification to sodium salts of fatty acids, glycerin, and excess sodium hydroxide. Any fatty acid is converted to its sodium salt. All of which are easily removed from the fat (oil). The resulting purified fat is suitable for the catalytic transesterification process to biodiesel.

    I'm a chemist, but haven't worked with these microreactors, so the following is guessing:

    A microprocessor can increase the efficiency of the desired transesterification by allowing intimate mixing of the alcohol and the fat, which is half the battle in this case. Also, a continuous processor can have advantages over batch processing in that the reaction conditions (pH, temp, etc.) can be dynamically controlled.

    My guess is that the fat (oil) would still require pre-treatment to remove water, fatty acids, and fine particles before entering the fuel cell.

    --
    Be heard || Be herd