Browse Prior Art Database

Automated FTIR Method for the Determination of the Base Number of Lubricants as an Alternative to ASTM D2896 (Base Number of Petroleum Products by Potentiometric Perchloric Acid Titration)

IP.com Disclosure Number: IPCOM000126654D
Publication Date: 2005-Jul-26

Publishing Venue

The IP.com Prior Art Database

Abstract

This paper describes a FTIR, Fourier transform infrared, method as an alternative to ASTM D2896 method for the determination of the Base Number (BN) of lubricants. ASTM D2896, currently the standard reference method for BN, has great disadvantages e.g. it is labour-intensive as it can be only partly automated; it uses substantial amounts of organic solvents and corrosive reagents; and interferences are taking place when testing sooty lubricants. The purpose of the method described herein is to overcome these shortcomings by having a method that is precise, that can be fully automated and is environmentally friendly. Similar as with the reference method, the FTIR method described herein is applicable to fresh and used lubricants and it covers a range of BN values up to 65 mg KOH/g.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 14% of the total text.

Automated FTIR Method for the Determination of the Base Number of Lubricants as an Alternative to ASTM D2896 (Base Number of Petroleum Products by Potentiometric Perchloric Acid Titration)

This paper describes a FTIR, Fourier transform infrared, method as an alternative to ASTM D2896 method for the determination of the Base Number (BN) of lubricants. ASTM D2896, currently the standard reference method for BN, has great disadvantages e.g. it is labour-intensive as it can be only partly automated; it uses substantial amounts of organic solvents and corrosive reagents; and interferences are taking place when testing sooty lubricants. The purpose of the method described herein is to overcome these shortcomings by having a method that is precise, that can be fully automated and is environmentally friendly.

Similar as with the reference method, the FTIR method described herein is applicable to fresh and used lubricants and it covers a range of BN values up to 65 mg KOH/g.

Background

Current ASTM D2896

ASTM D2896 is the common reference method for the determination of the Base Number of Petroleum Products by potentiometric perchloric acid titration.

Base Number (BN) is equal to the quantity of perchloric acid expressed in terms of the equivalent number of milligrams of potassium hydroxide that are required to titrate 1 g of the sample dissolved in the specified solvent to a well-defined inflection point as specified in the ASTM D2896 test method. To solve the sample a mixture of chlorobenzene and glacial acetic acid is used. Chlorobenzene can be replaced by a mixture of xylenes as an alternative less harmful solvent, but then the test precision decreases to 6% of the mean for repeatability and 16.2 % of the mean for reproducibility. Because the sample treatment is dependent on the estimated BN value of the lubricant the method cannot be fully automated. Also the preparation and the maintenance of the electrode system require manpower and time.

Published FTIR method

In cooperation between McGill IR Group, McGill University Ste. Anne de Bellevue,

Quebec

and Thermal-Lube Inc,

Montreal

,

Quebec

, a FTIR method was developed for Acid Number and Base Number analyses of lubricants with the potential to replace ASTM methods. The final method that also includes the water content determination of lubricants is patented and commercialized by Thermal-Lube Inc. They state that their COAT analyzer is designed to rapidly and accurately determine e.g. the Base Number of lubricants up to 20 mg KOH/g. Lubricants having BN values greater than 20 and less than 40 can be analysed by pre-diluting the sample 1:1 with polyalphaolefin.

The FTIR BN method uses an IR responsive acid to quantify the amount of base present in the lubricant. The sample is diluted with kerosene and split into two parts: to one half is added a defined amount of IR active acid dissolved in 1-propanol, while only 1-propanol is added to the other half. The two test solutions are scanned and through the...