Standard Test Method for Acid Number
of Petroleum Products by Potentiometric Titration, 2006.
is defined as the number of milligrams of potassium hydroxide (KOH) necessary to neutralize one gram of biodiesel in order to provide the quantity of free fatty acids and acids originating from degradation reactions of biodiesel during the production process and its storage .
It was reported that the acid wash applied after the transesterification aiming to the removal the alkaline catalyst in order to avoid soap formation can be responsible for high acid numbers
. An increase in the AV can cause deposits in the motor and corrosion problems .
Total Acid Number
(mg KOH gm-1)###D-664###0.16###0.22###0.23###0.19###0.19###0.16###0.09###0.10###0.05 max
Total acid number
(TAN) was measured using ASTM method D664 .
Meanwhile, these compounds, stronger in polarity, contributed to the enhancement of the acid number
, increasing from 0.173 mg KOH/g in [EO.sub.180] to 10.450 mg KOH/g in [EO.sub.300].
With respect to acid number
, if this parameter is too high, excessive engine corrosion can occur.
value must be low otherwise soap may be formed in the product
The lubricant in the sealed tubes was analyzed for total acid number
(TAN) and by ion chromatography (IC) to determine refrigerant and/or lubricant decomposition.
The acid number
of MA-g-SEBS was determined by titration method , A sample of 0.1 g was placed in a volumetric flask with 10 ml acetone, 10 ml hydrochloric acid (0.1 M) and 100 ml water.
The acid number
was determined through indicator method (Paquot, 1986b).
And once the acid number
reaches 0.3-0.4, carbon starts to form.
The effects of temperatures and initial process fluid concentrations on the Total Acid Number
(TAN), Total Organic Acid (TOA) anion concentrations, metal concentrations, lubricant and/or refrigerant decomposition were determined.
ASTM D664: 11 standard test method for acid number
of petroleum products by potentiometric titration.