Biodiesel
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Biodiesel production from waste vegetable oil by barium hydroxide catalyzed transesterification with methanol
An introduction by Daniel Fernández Universidad Nacional de Colombia
Objective To provide a feasible alternative to commonly used NaOH and KOH catalysis in transesterification reactions To eliminate the need of a washing step in the production process To produce both a higher quality glycerin and a soap free biodiesel To eliminate the need of an esterification step in highly acidic used vegetable oils. To provide an heterogeneous catalyst which can be easily regenerated
Barium hydroxide – an ideal catalyst When one analyzes the chemistry of base catalyzed transesterification reactions it is obvious that any basic catalyst (brönsted base) will end up reacting with the free fatty acids present in the oil to form one or another type of ionic ester (i.e, soap). The advantage of barium hidroxide is that the esters formed by barium are highly insoluble in both biodiesel and glycerin and are easily regenerated to barium hydroxide or barium oxides by simple heating. The organic part of the molecule is simply oxidized in a combustion process. As a strong brönsted base, barium hydroxide monohydrate has been found to be highly active in tranesterification reactions [1,2]. When regenerated from its soaps, barium oxide can react with methanol to form alkoxides which are even more powerful brönsted bases and also insoluble. Hence, catalytic activity is increased with regeneration. (but there is always some loss of catalyst in filtration (< 1%)) It has been reported [1] that the reaction exhibts a lower activation energy when used in the presence of microwaves. Since soaps and the catalyst are both insoluble, it is expected that the biodiesel will be perfectly clean after filtration and will not need any further washing.
Experimentation A batch of pure methanol and WVO with a 2% free fatty acid content determined by titration was reacted with a 5% by weight amount of Ba(OH)2.H2O. The methanol-oil ratio was 1:6 and the total measured volume was 200mL. A Bottle of PETE was selected as reaction vessel for both high chemical resistance and ease of agitation, no heating was used.
Homebrewing implementation Since the catalyst has been proved to be effective in transesterification reactions, achieving all the objectives. It is clear that the chemical can be useful in homebrewing applications The catalyst could be implemented in a reactor setup like the one showed in the next slide.
Conclusions Barium hydroxide monohydrate can be implemented as a succesful heterogeneous renewable catalyst in the transesterification of waste vegetable oil (WVO) The amount of barium hydroxide needed for the reaction to proceed would be 5% by weight of feedstock. The reaction time expected for a reaction environment similar to the currently used by most homebrewers would be aproximatly twice the time needed for the reaction with NaOH or KOH (because of the difference in phases) The proposed reactor design would eliminate the need of : an additional washing step, the titration of the oil and the addition and preparation of an alcoholic KOH or NaOH solution. The proposed reactor design also provides the means to regenerate the catalyst
Literary sources Many literary sources were consulted for the making of the present slideshow, relevant sources are listed below [1] C. Mazzocchia, G. Modica, “FATTY ACID METHYL ESTERS SYNTHESIS FROM TRIGLYCERIDES OVER HETEROGENEOUS CATALYSTS IN PRESENCE OF MICROWAVES” , Chemistry, Materials and Chemical Engineering Department, Politecnico di Milano, P.zza L. da Vinci 32, 20133 Milano, Italy [2]Albis Ricardo Alberto, Parra Garrido Julián Andrés, Sánchez Castellanos Francisco J. “Transesterificación del aceite de palma con metanol por catálisis hetergonénea”, Universidad Nacional de Colombia, Revista Ingeniería e investigación Vol.25 No.2 Agosto de 2005. [3] A. Loupy. et al, The synthesis of esters under microwave irradiationusing drymedia conditions, Can. J. Chemistry, 71 (1993) 90
Finally !! Thank you for your time ! I hope you enjoyed the slideshow ! As you can see, this is just an introduction ! Much aditional experimental information is available. I just hope this gives you the enthusiasm you need to try the process !
An introduction by Daniel Fernández Universidad Nacional de Colombia
Objective To provide a feasible alternative to commonly used NaOH and KOH catalysis in transesterification reactions To eliminate the need of a washing step in the production process To produce both a higher quality glycerin and a soap free biodiesel To eliminate the need of an esterification step in highly acidic used vegetable oils. To provide an heterogeneous catalyst which can be easily regenerated
Barium hydroxide – an ideal catalyst When one analyzes the chemistry of base catalyzed transesterification reactions it is obvious that any basic catalyst (brönsted base) will end up reacting with the free fatty acids present in the oil to form one or another type of ionic ester (i.e, soap). The advantage of barium hidroxide is that the esters formed by barium are highly insoluble in both biodiesel and glycerin and are easily regenerated to barium hydroxide or barium oxides by simple heating. The organic part of the molecule is simply oxidized in a combustion process. As a strong brönsted base, barium hydroxide monohydrate has been found to be highly active in tranesterification reactions [1,2]. When regenerated from its soaps, barium oxide can react with methanol to form alkoxides which are even more powerful brönsted bases and also insoluble. Hence, catalytic activity is increased with regeneration. (but there is always some loss of catalyst in filtration (< 1%)) It has been reported [1] that the reaction exhibts a lower activation energy when used in the presence of microwaves. Since soaps and the catalyst are both insoluble, it is expected that the biodiesel will be perfectly clean after filtration and will not need any further washing.
Experimentation A batch of pure methanol and WVO with a 2% free fatty acid content determined by titration was reacted with a 5% by weight amount of Ba(OH)2.H2O. The methanol-oil ratio was 1:6 and the total measured volume was 200mL. A Bottle of PETE was selected as reaction vessel for both high chemical resistance and ease of agitation, no heating was used.
Homebrewing implementation Since the catalyst has been proved to be effective in transesterification reactions, achieving all the objectives. It is clear that the chemical can be useful in homebrewing applications The catalyst could be implemented in a reactor setup like the one showed in the next slide.
Conclusions Barium hydroxide monohydrate can be implemented as a succesful heterogeneous renewable catalyst in the transesterification of waste vegetable oil (WVO) The amount of barium hydroxide needed for the reaction to proceed would be 5% by weight of feedstock. The reaction time expected for a reaction environment similar to the currently used by most homebrewers would be aproximatly twice the time needed for the reaction with NaOH or KOH (because of the difference in phases) The proposed reactor design would eliminate the need of : an additional washing step, the titration of the oil and the addition and preparation of an alcoholic KOH or NaOH solution. The proposed reactor design also provides the means to regenerate the catalyst
Literary sources Many literary sources were consulted for the making of the present slideshow, relevant sources are listed below [1] C. Mazzocchia, G. Modica, “FATTY ACID METHYL ESTERS SYNTHESIS FROM TRIGLYCERIDES OVER HETEROGENEOUS CATALYSTS IN PRESENCE OF MICROWAVES” , Chemistry, Materials and Chemical Engineering Department, Politecnico di Milano, P.zza L. da Vinci 32, 20133 Milano, Italy [2]Albis Ricardo Alberto, Parra Garrido Julián Andrés, Sánchez Castellanos Francisco J. “Transesterificación del aceite de palma con metanol por catálisis hetergonénea”, Universidad Nacional de Colombia, Revista Ingeniería e investigación Vol.25 No.2 Agosto de 2005. [3] A. Loupy. et al, The synthesis of esters under microwave irradiationusing drymedia conditions, Can. J. Chemistry, 71 (1993) 90
Finally !! Thank you for your time ! I hope you enjoyed the slideshow ! As you can see, this is just an introduction ! Much aditional experimental information is available. I just hope this gives you the enthusiasm you need to try the process !
