Method for measuring acid values of oil and products by using greening solvent based on potential jump

Abstract

The invention provides a method for measuring the acid values of oil by using a greening solvent based on potential jump, comprising the following steps of: adding an oil product with the mass of M to a clean beaker of 150mL, and dissolving the oil product in an non-toxic organic solvent, wherein the flowing oil product does not need to be dissolved; then adding an alcohol or isopropanol and alkane mixed solvent containing 0.05mol / L-0.2mol / L of alkaline reagents, placing on a titration platform of a potential titrator or an automatic sample rack, and titrating by using 0.02-0.1mol / L of organic-alkali alcohol standard solution when stirring to ensure that the titration end point is distinguished completely on the basis of potential jump; and calculating the total acid value of the oil product by consuming the volume and the concentration of the corresponding organic-alkali alcohol standard solution according to the standard method of GB / T 7304. In the method, the potential titration end point is distinguished completely on the basis of potential jump, and simultaneously the reagent is greened, therefore, the method has the advantages of automation of a measuring process, better result repeatability and higher accuracy.

Description

【Technical field】 [0001] The invention relates to a method for measuring petroleum acid value with a green solvent based on a potential jump, and belongs to the category of electrochemical analysis. 【Background technique】 [0002] Acid value is a necessary indicator of petroleum and petroleum products. Countries around the world, especially some developed countries and the International Organization for Standardization (ISO) have proposed a series of standard test methods for the acid value of petroleum and petroleum products. These methods are based on non- The principle of water acid-base titration is used to analyze the acid value of oil products. A large amount of toluene is used. The reagent is highly toxic and flammable. At the same time, the non-aqueous strong base titrant is more sensitive to carbon dioxide in the air, which is less than 0.1mg(KOH).g- 1 The acid value needs to be under the protection of nitrogen to have a more accurate result. According to the metho...

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Problems solved by technology

[0056] To sum up, there are many standard methods for measuring the acid value of petroleum and petroleum products at home and abroad, so there are many problems caused by improper method selection, (1) the data of different methods are not comparable; (2) the standard methods indicate The manual judgment of the end point by the reagent method often has a large error in the result of oil products with a darker color or additives, and it is not easy to parallel; and the potentiometric titration method in the standard method uses highly toxic chemical reagents such as toluene and m-nitrophenol; (3) Some oil products have no sudden end phenomenon; (4) especially the current standard methods are incompletely dissolved for viscous oil products, which affects the repeatability and accuracy of the measurement results

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