Determination of Acid Number of Biodiesel and Biodiesel Blends |
| |
Authors: | Aijaz Baig Flora T T Ng |
| |
Affiliation: | (1) Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada |
| |
Abstract: | Due to an increase in the commercial use of biodiesel and biodiesel blends, both ASTM D 6751 and EN 14214 include the acid
number (AN) as an important quality parameter. It was found that determination of AN of biodiesel and biodiesel blends using
the ASTM D 974 results in large values of repeatability (up to 73.41%) and larger percentage error (up to 42.88%). Therefore,
ASTM D 974 has been modified using a lower concentration of base (0.02 M KOH instead of 0.1 M KOH) as well as reducing the
amount of toxic titration solvent from 100 mL to only 10 mL. This makes the modified ASTM D 974 as a green analytical method
which uses a reduced amount of toxic solvent. This modified method significantly reduced the maximum percentage error from
42.88 to 5.92%. The application of this modified ASTM D 974 for the determination of AN of biodiesel and biodiesel blends
was studied. The accuracy of this modified ASTM D 974 for biodiesel (B100) was measured to be within 3.51% over the AN range
of 0.313–0.525 mg KOH/g and maximum repeatability was decreased from 8.37 to 2.75% within this AN range which is far below
the ASTM D 974 stated repeatability specifications. For B20, B10, B5, B2, and B1, the most accurate values were measured at
AN values of 0.177, 0.067, 0.072, 0.126, and 0.096 mg KOH/g, respectively. Excellent linearity values of R
2 for calculated and experimentally determined AN were obtained. The difference between the experimental and the calculated
AN for all biodiesel and biodiesel blend samples was within ± 0.018 mg KOH/g. This extensive study has demonstrated that this
modified ASTM D 974 is a reliable method for the determination of AN and could be used for establishing the specifications
of AN for biodiesel and biodiesel blends ranging from B1 to B20 in quality standards. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|