Noack volatility

Vise, at 100°C, mm2/s Viscosity index (V.l.) Pour point, °C Noack volatility, %... 

Noack volatility (lubricants) T 60-161 Weight of a crucible before and after evaporation... 

As illustrated in Fig. 8.4, RHC significantly increases the VI, particularly for ports 7 to 10. This is characteristic of a lower concentration of multi-ring aromatic components, at least a portion of which have been converted by hydrogenation to naphthenes. Furthermore, in addition to the increase in VI, the RHC treated oil has a lower Noack volatility and a similar pour point. 

Another advantage of RHC, is that it provides the flexibility to tailor the product by adjusting the severity of the processing. Fig. 8.5 illustrates the ability of RHC to decrease both Noack volatility and viscosity for a given feedstock. 

Noack volatility, where the sample is heated for 1 hour at 250 C and the weight loss is measured, DIN 51581. 

Traditionally, synthetic PAOs have had significant performance advantages over equiviscous mineral base oils by their higher viscosity index, lower pour point, reduced volatility and improved oxidation stability in the presence of antioxidants. GTL base oils now challenge PAOs in performance and can be very cost competitive with the relatively expensive synthetics. A review in 2006 described performance comparisons of base oils with a viscosity of 4 cSt at 100°C [37]. It is suggested that the GTL fluids can match the PAOs in Noack volatility, oxidation resistance and thermal stability, whereas the PAOs retain some superiority in their extreme low-temperature fluidity. 

Fuel and Solvent Residues. These contaminants can be present in varying amounts depending upon the efficiency of the re-refining processes used. Flash point and Noack volatility values in excess of those in Table 15.2 indicate unacceptable contamination from these sources. 

In a pair of papers, Selby et al. (Savant, Inc. and Astaris LLC) describe using phosphorus as an indicator of volatility of engine oils. Phosphorus is volatilized during Noack volatility test (ASTM D 5800). The volatile material is trapped and analyzed for total phosphorus using ICP-AES, and for phosphorus species using P NMR spectroscopy. 

Association of Phosphorus Emission with Oil Consumption and Volatility—Oil consumption caused by oil volatility has always been a concern for automotive engineers because of the associated deposits often formed on piston rings, combustion chambers, and valves. Concern that oil volatility could cause phosphorus in the exhaust stream adds to the desire to reduce oil volatility. Consequently, progressively lower formulated engine oil volatility (as measured by the classic Noack volatility test [9-12]) was required for oils meeting API and ILSAC GF-2 (22 % loss) and GF-3 (15 % loss) specifications. 

Selby-Noack Volatility Test—The toxic nature of the Woods Metal used for heat transfer in the classic Noack volatility test [9-12] led to the development of a new approach [13-17]. This approach, while retaining all Noack test conditions, was designed to heat the test oil safely using noble metal resistive heating and to collect 99-i- % of all the material volatilized. Figures la and b show a picture of the special Noack instrument and a sketch of the arrangement of the essential components, respectively. 

The Noack volatility test determines percent loss of volatile material from 65 grams of the test oil when exposed to a small vacuum of 20 mm water at 250°C for one hour. 

Identity Condittons of Test 9eiby Noack Volatility pnosphorus Fresh Volatiles PEI mg/L... 

Foims of ZDDP and Alcohol NOACK Noack Volatility Phosphorus by AS1 BBm 1HD4951 mg PEI... 

Reichenbach, E., et al., A New Approach to the Noack Volatility Test, Proceedings of Ninth International Colloquium, Esslingen, Germany, 1994 Tribotest Journal, Vol. 1, No. 1, Leaf Coppin Publishing, September 1994, pp. 3-29. 

Selby, T. W., et al., Base Oil Characterization Techniques Using a New Approach to the Noack Volatility Test, ACS Symposium on "The Processing, Characterization, and Application of Lubricant Base Oils Part II, San Diego, CA, March 1994. 

Sample EO-7450 Selby - Noack Volatility PEI, mg/L Chemical shifts (ppm)... 

Sample preparation, 33 Selby-Noack volatility test, 255 Selenate, 42 Selenite, 42 Selenium, 42 Selenocyanate, 42 Speciation, 181 Spray chamber, 17, 51 Sulfur, 108, 116, 128, 164, 221 analysis, 85 ultralow, in diesels, 85 Sulfur chemiluminescence detection, 164 Sulfur/nitrogen chemiluminescence, 232... 

Lube oil volatility is a measure of oil loss due to evaporation. Noack volatility measures the actual evaporative loss which is grade dependent, and a function of molecular composition and the efficiency of the distillation step. The volatility is generally lower for higher viscosity and higher VI base stocks. The gas chromatographic distillation (GCD) can be used to measure the front end of the boiling point curve and may be used as an indication of volatility, e.g. 10% off at 375°C. 

This is evident in Figure 2, which shows the relationship between boiling point (and the associated Noack volatility) for a basestock with a typical boiling range distribution versus kinematic viscosity. Each curve represents a class of lube hydrocarbons that have been assayed into fractions with viscosities spanning the typical lube range of 10 to 1000 cSt at 40°C... 

The percentage mass of condensed water and fuel in the samples was measured using a ThermoGravimetric Analyser (TGA) though the TGA version of the NOACK volatility method", a typical TGA analysis for a cold start lubricant sample is given in Fig 1 showing the considerable mass of water and petrol fuel residue lost at relatively low temperatures. 

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