Autoclave test

Agitator autoclave tests can be used as screening tests despite the more intensive localized corrosion attack and the generally greater erosion rates. This test method elucidates the influences of certain test parameters including temperature, H2S/CO2 ratio, and flow [564]. 

Other types of equipment available to investigate the gas evolution are various autoclave tests (Section 2.3.3.2), isoperibolic autoclave tests (Section 2.3.1.2), and closed Dewar tests (Section 2.3.2.2). Mass flux data are also required in designing any vent facilities (Chapter 3). 

From the autoclave testing, it is concluded that in case of a runaway, the substance produces a significant quantity of gases. The end stage of the runaway will certainly result in a thermal explosion. The venting evaluation should be conducted by the test methods and calculation procedures described in Chapter 3. 

The equipment is quite adequate for screening purposes. In its simplest form (i.e., a glass tube in an oven), it is a relatively low cost technique that can be assembled with standard laboratory equipment. However, the simple test set-up provides no quantitative thermal data for scale-up purposes, but only T0 values. The more advanced instruments like the SEDEX and SIKAREX, which are also isoperibolic calorimetry equipment, acquire specific thermal stability data that can be used for scale-up. Furthermore, the small autoclave tests provide gas evolution data. 

When large quantities of a substance are handled, sensitivity of the material to heating under confinement may need to be considered to demonstrate the effect on the stored/handled, and probably confined, substance in the event of an external heat load. Tests such as the steel sleeve test or Koenen test [24, 137], the Dutch pressure vessel test (DPVT) [143], and the United States pressure vessel test (US-PVT) [143] may be applicable. These tests are used mostly for transportation considerations. The tests generally subject the sample substances to very high energy inputs under confined conditions, and thus are more severe than the deflagration and autoclave tests previously discussed in Section 2.3.3.2. As an example, the Koenen test, used mainly in Europe, is illustrated in Figure 2.32. 

A feature of corrosion studies which has been stressed recently (2) is the complete failure of laboratory tests on their own to predict how reliable operation of some nuclear steam generators can be maintained. At least a part of this problem is likely to arise from different redox and/or pH conditions imposed by the solution in autoclave tests and in plant conditions and many low level contaminants could be involved. In view of what has been said earlier concerning the role of Mo(VI) in stagnant water it is clear that some data, at least on the thermodynamics of aqueous Mo species, should be sought at high temperatures. 

Bench unit and autoclave testing of the electron withdrawing substituted chlorophosphite ligands demonstrated that these intermediate compounds can serve as viable hydroformylation ligands (11). Compounds 6- representative of... 

ASTM D 3574 - Test K covers dry-heat aging of flexible cellular materials. This test consists in exposing foam samples in an air-circulating oven at 140°C for 22 hours. The specimens are then removed and conditioned for not less than 12 hours at 23°C and 50 percent RH. As with the Steam Autoclave Tests (Jj and J2) physical tests are carried out before and after agiqg. According to Shah (1) tensile properties are usually studied after dry-heat aging. 

Note Use of borosilicate glass as a storage-disposal medium for high-level radioactive wastes has been under research for some time. Tentative conclusions based on high-temperature and high-pressure autoclave tests indicate that this method would be suitable for geologic storage of such wastes. 

Table 1 Autoclave Test Results (120°C Over Water)...

Autoclaving with steam involves time/temperature relationships, i.e. 134°C for 3 min or 121°C for 15 min or 115°C for 30 min or such combinations of temperature and time which ensure sterilisation. It is advisable to carry out autoclave tests on any plastic as part of the development programme. Now that autoclaves have balanced or overpressure facilities, experiments have to be carried out in order that the correct conditions can be selected. It should be noted that distortion or extension (initially due to internal pressure in the pack) is likely to occur during the cooling cycle and it is during this period that additional pressure is required to overcome the internal pressure. 

These catalysts were screened with a range of aliphatic and aromatic alcohols, namely 1, 2 3-pentanol, geraniol, benzyl alcohol, 2 4-hydroxybenyl alcohol, 2-thiophene methanol and sec-phenethyl alcohol. Selected catalysts from the range were also used in the larger scale autoclave test programme. 

Table 6 shows results obtained when using the 5% Pt/C (catalyst 13) catalyst in the oxidation of geraniol to citral at various scales from the initial HTS studies employing O.lg of geraniol to autoclave tests employing 5g of geraniol (using toluene or no solvent). 

Figure 8. Effect of time at temperature on gas composition in batch autoclave test at 770°C.

Figure 9. Effect of temperature on gas yield without catalyst in batch autoclave test...

On a volume basis, hydrogen is the main component of the product gas from the direct reaction of steam with coal in the autoclave tests. This is illustrated in Figure 8 which presents data from an experiment at 770°C. with a total reaction time of 2 hrs. 

Over the entire range of experimental conditions covered by these experiments—i.e., pressure, 60-350 atm. temperature, 730-770°C.( reaction time, 2-120 min.—methane is the main product on a heating value basis. It constitutes more than 90% of the total B.t.u. in the gas at the 10% conversion level, and it still is more than 70% of the total B.t.u. in the gas formed even at 60% conversion level. All the data from batch autoclave tests are compared in Figure 10 on the basis of conversion of coal to gas and formation of preformed methane. 

Methane concentrations are especially low in those tests in which the preheating of the coal slurry did not lead to complete vaporization of the water. In tests with thermocouples inside the reactor, the temperature inside the reactor drops considerably below that of the reactor walls under such conditions and thus could easily cause these low conversions. In later tests with lignite, methane concentrations and conversions were obtained equivalent to those observed in the autoclave tests with bituminous coal. 

Experimental results on only the yield of methane in tests in the continuous flow unit are shown in Figure 12, a plot of the methane yield, expressed as percent of the calorific value of the coal converted into methane, vs. the precent of B.t.u. in coal converted to gas. The methane concentrations obtained in the flow unit are, as stated above, lower than those in the autoclave tests consequently, the points for the continuous flow experiments also lie below the autoclave correlation curve at all... 

A. Chakma and A. Meisen [Can. J. Chem. Eng.. 75, 861-871 (1997)] studied the kinetics of the hquid phase degradation of methyl diethanolamine (A) at 18°C at elevated pressures in an autoclave. Test the following data to ascertain whether they are consistent with zero-, first-, or second-order kinetics. Prepare plots of the data using coordinates that should yield straight lines if the presumed rate expression is correct Report the value of the rate constant corresponding to the proper value of the order of the reaction. Comment on the shapes of the plots. 

Total MgO content in clinker is normally maintained at less than 2.0% to avoid expansion in the autoclave test. Belite containing periclase (at an early stage of crystallization) indicates coarse grains of MgO-bearing silicates, such as diopside, pyroxene, and hornblende in the raw feed. Dendritic periclase occurs in slowly cooled clinkers from large kilns (200 t/hr) and is hardly observed in clinkers from small kilns (20 t/ hr), according to Ono (1995). 

Brown, L.S., and Swayze, M.A., "Autoclave Tests and the Microscope (Detecting Free Lime and Magnesia in Portland Cement)," Rock Products, Vol. 41, No. 6, 1938, pp. 65-70. 

Many testing methods are available to evaluate the reliability of an IC/MEMS package. For example, if the dominant failure mode of a MEMS device is water condensation in the package, autoclave tests are available to test the... 

The volume of diluent into which the sample is added is referred to as a dilution blank or, more simply, a blank. Dilutions are usually made into either sterile peptone (1% w/v) or isotonic saline (0.7% w/v). Use of sterile distilled water for purposes of dilution should be avoided due to the potential for osmotic stress which potentially compromises viability. Dilution blanks are prepared using appropriately sized autoclavable test tubes... 

A first series of 1 month autoclave tests in deaerated liquids consisting of HE + 5% or 10% of water heated to 70 °C at 6 bars yielded the results summarised below ... 

Laboratory Corrosion Testing of Metals at Atmospheric Pressure Autoclave Testing of Metals in High Temperature Water... 

---