generally we take yield as weight of biodiesel / weight of oil is it correct ?
if so if no reaction take place we get yield as 100%. To avoid this we have to ensure that obtained product is biodiesel. it is impossible for a research student to measure all property to conform it. what are the main property that should measure conform it.
is there any other method to find out the yield, how realistic to measure tryglyceride amount using a GC to find conversion efficiency ?
Dear Suraj,
In biodiesel production industry, yield is defined as weight of biodiesel/weight of feedstock. And of course the yield can not reach to 100% because of the loss in the production process.
However, in order to assess the quality of biodiesel, the most important standard is ester content. This value shows the percentage of all of esters in biodiesel. Some studies can call this value with a different name - yield of ester. According to EN 14103 standard, it is 96.5 min. You can use GC to test ester content (or yield of ester).
About the conversion efficiency in a biodiesel production, For me, I think that you don't need use this value. Conversion should be applied for esterification process and it is used to determine the conversion of FFA content in esterification for high FFA feedstock oil.
Hope this comment will be quite useful for you
Good luck,
Dang
Dear suraj
Yield means how much vegetable oil you get from seed and conversion efficiency means that vegetable oil is converted in Biodiesel with the help of different transesterification process
Yield is mass of prime pruct referred to mass of ferdstock, conversio is the eszer content referred to ferdstock. Chevk the EN 14124 for definitions
yeas, mistyped, the standard for FAME specifications, including test methods applicable
The link can help resolve your question.
http://www.sciencedomain.org/abstract/16850
hi Suraj
you can find the yield by dividing the weight of oil after the reaction to that of the feedstock oil used for the reaction. it may be slightly more than 100 as we are adding the sodium or potassium methoxide solution to it.
Ester conversion efficiency can be found out by mixing 250 mg of BD with 5ml of stock solution( a mixture of the internal standard like C17, C19 with n-hexane) and from the peaks obtained we can find the ester conversion efficiency.
I am sorry, Checked the content of my message and have learned that the system did screw everything upside-down and back. Yield: whatever you get in reaction, conversion?: whatever did convert into the desired product. You have to specify conversion in term of FAME/feedstock, apolar phase/feedstock for yield.
Got the Answer, Thank you all,
1. Yield of biodiesel(%) =mass of biodiesel obtained / mass of oil used
Normally we get an yield of 95-100%. Mass of biodiesel ( mass of oil + mass of alcohol - mass of glycerol - mass of unreacted chemicals ) it could be greater than the mass of oil. Theoretically it possible to have an yield slightly higher than 100%.
Method : measure weight of row oil before the reaction and weigh biodiesel after reaction and post treatment.
2. Ester Content (%)= cumulative mass of methyl esters/ mass of biodiesel.
It is very important to understand that biodiesel does not means that its 100% methyl ester (or pure) it may even contain un-reacted triglyceride and partially reacted mono-glyceride and di-glycerides. Fatty acid methyl ester /ester content could calculate using EN-14103 method. According to EN-14103 minimum ester content should be 96.5%. we should use an internal standard like C17. In GC area of a peak is proportional to the concentration of that component.
method
a. take a known amount of internal standard (x gram) and mix with known amount of biodiesel (y gram).
b. perform Gc test
c. find out area corresponding to C17 ( area A)
d. find total area (Area B)
Please try to understand that y gram biodiesel does not contain y gram of methyl ester it contain 'U' gram of methyl ester and 'V' gram of contaminants ( we dont know value of U and V , test doing to find these values)
Area A proportional to x gram
total area corresponds to x+U gram not for x+y/ x+U+V
Area B proportional to x+U gram
Area (B-A) proportional to U gram
ester content = U/y
U= (B-A)*x/A
ester content = (B-A)*x/(A*y)
Ester content(%) = ((Area total/Area C17:0)-1)*(mass of C17:0/mass of biodiesel)
3. Conversion Efficiency(%).
It denotes amount of raw oil converted to methyl esters.
Conversion Efficiency(%)=Ester content(%)* Yield (%)
Note:
1. If the ester content is above the limit (96.5%) then other physical properties like density and viscosity will be within the limit.
2. if you loose biodiesel during washing or though any other way , it reduces the yield and there by conversion efficiency but not ester content value.
This would interest you all
Article Comparative effect of reaction time on biodiesel production ...
Kind regards!
Conversion is the amount of starting material that has reacted, regardless of what product it goes to.
Yield is the percentage of theoretical maximum for each product, so if you isolate 10% of your material as your desired product, it's 10% yield.
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