Determination of organically and inorganically bound chlorine in ethanol according to ASTM D4929 method B

The ASTM D4929 standard describes three possible methods for determining the content of organically bound chlorine in the naphtha fraction of crude oil, which is the fossil component used in the production of a high quality gasoline blend. In all three methods described, the naphtha is first washed several times with water to remove inorganically bound chlorine; after which the remaining content of organically bound chlorine (OCl) in the naphtha is determined. If one wishes to directly determine the content of organically bound chlorine in the pure fuel additive ethanol, the washing procedure described above cannot be used, since ethanol and water are highly miscible. However, an indirect method allows for a very simple and rapid determination of OCl even in this case. By measuring the total chlorine content (TCl) and the proportion of inorganically bound chlorine (ICl) the OCl can be calculated. The proportion of organically bound chlorine is the difference: OCl = TCl – ICl. In practice, the expectedconcentrations of OCl are often very low, and the primary focus is on the proportion of inorganically bound chlorine (ICl). The multi EA 5100 offers a solution for the direct measurement of inorganic chloride. The results obtained are comparable to those of an ion chromatography system.