Hello Keith. Moles means molecules. There is one water molecule formed for each molecule of fatty acid alkylated. It is true that some water is produced during saponification of free acidity and it is also true that water is formed when mixing NaOH or KOH in an alcohol. But neither of these reactions are esterification or transesterification reactions.. It is considered that the transesterifiction reaction takes place in two or more steps, where the first step is the collapse of the glycerine-formed ester (the triglyceride etc) forming free glycerine and free acidity. Water is consumed in that step. In another step the new esters are formed where the equal amount of water is released. Conclusion: Some free water is good for the first step of the reaction. Does it make sense ? ----- Original Message ----- From: "Keith Addison" <[EMAIL PROTECTED]> To: <biofuel@sustainablelists.org> Sent: Sunday, April 18, 2010 7:27 PM Subject: Re: [Biofuel] Acid-base chemistry
> Hello Jan > > Thankyou! > >>The acid esterification produces water with 1M /M alkylated fatty acid. > > I have difficulty with moles. I do know how to figure it out, in > theory, but I'm not confident of the result. Would you mind writing > it as a formula equation, if that's the right term: > > A + B --> D + E > > Moles gives quantities though, which I'd like to know. Is it possible > to translate "1M /M alkylated fatty acid" into ml of water per litre > of oil or something similar? > >>The trans-esterification does not produce any water, > > We've had people saying it does, and others that it doesn't. It's > been said that some water is produced by the saponification of free > fatty acids, though it's very little, and someone else said some > water might be formed during the reaction that produces the methoxide: > > CH3OH + KOH ---> CH3OK + H2O > or > CH3OH + NaOH ---> CH3ONa + H2O > > Any comments? > >>but some water present >>(0,1%) is necessary to make the process run well. > > I didn't know that. Can you explain how it works? > > I did know that esterification will also perform some > transesterification if it has the chance, but it's slow. > > Thanks again Jan - all best to you > > Keith > > >>The acid esterification >>produces water with 1M /M alkylated fatty acid. This process will also >>perform trans-esterification assuming that there is some material to >>trans-esterify and that the operator in question lets the process >>continue. >> >>With best regards >>Jan W >>----- Original Message ----- >>From: "Keith Addison" <[EMAIL PROTECTED]> >>To: <biofuel@sustainablelists.org> >>Sent: Saturday, April 17, 2010 11:58 AM >>Subject: [Biofuel] Acid-base chemistry >> >> >>> Hello all >>> >>> A question... >>> >>> Even when everything is dry, including the oil, the >>> transesterification process itself produces some water, though not >>> very much. >>> >>> IIRC acid esterification also produces water, I think more water than >>> transesterification does, and via a different process. >>> >>> Does anybody know if that's correct, and what the chemical equations >> > are? With KOH and H2SO4. >>> >>> Thanks! >>> >>> All best >>> >> > Keith > > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (70,000 > messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
