Water reaction testing

Free water in jet fuels can be detected by the use of the Karl Fischer titration method (ASTM D-1744) or by observing color changes when chemicals go into aqueous solution (ASTM D-3240). The standard water reaction test for jet fuel (ASTM D-1094, IP 289) is the same as for aviation gasoline, but the interface and separation ratings are more critically defined. Test assessment is by subjective visual observation and, although quite precise when made by an experienced operator, the test can cause rating difficulties under borderline conditions. As a consequence, a more objective test, known as the water separometer test, is now included in many specifications (ASTM D-2550). 

There is also a water reaction test that is used to estimate, and prevent, the addition of high-octane, water-soluble components such as ethyl alcohol to aviation gasoline. The test method involves shaking 80 ml of fuel with 20 ml of water under standard conditions and observing phase volume changes and interface condition. 

Kerosene, because of its higher density and viscosity, tends to retain fine particulate matter and water droplets in suspension for a much longer time than gasoline. Free water in kerosene can be detected by the use of a Dean and Stark adaptor (ASTM D-4006, IP 358) (Fig. 7.3), by the Karl Fischer titration method (ASTM D-1744, ASTM D-6304), by the distillation method (ASTM D-95, IP 74), or by a series of alternate tests (ASTM D-4176, ASTM D-4860). The standard water reaction test method (ASTM D-1094, IP 289) can also be used. 

Sodium-Water Reaction Tests in the Super Noah Rig... 

BOARDMAN, C.E., HUI, M., NEELY, H.H., Test results of sodium-water reaction testing in near prototypical LMR steam generator, paper presented in the Specialists Meeting on Steam generator failure and failure propagation e q)erience, 26-28 September 1990, Aix-en-Provence, France. 

Specifications for gas turbine fuels prescribe test limits that must be met by the refiner who manufactures fuel however, it is customary for fuel users to define quality control limits for fuel at the point of delivery or of custody transfer. These limits must be met by third parties who distribute and handle fuels on or near the airport. Tests on receipt at airport depots include appearance, distfllation, flash point (or vapor pressure), density, freezing point, smoke point, corrosion, existing gum, water reaction, and water separation. Tests on delivery to the aircraft include appearance, particulates, membrane color, free water, and electrical conductivity. 

Alcohol can be detected h,v dislilJicig a few c.c. of Ihc sample with water, aud testing the distillate by the usual iodoform reaction. It the sample bo wHshed with warm waler in a separator, and the retractivu index of the washed otto l>c examined, it will be found to he higher than that ol the original otto. II this exoes.s be more (ban fl-Ofll i is almost certainly due to alcohol. 

As an example of the problem of species in solution, consider the case of a solution made by dissolving some potassium chrome alum, KCrfSO s-12H20, in water. On testing, the solution is distinctly acidic. A currently accepted explanation of the observed acidity is based upon the assumption that, in water solution, chromic ion is associated with six H20 molecules in the complex ion, Cr(H20) a. This complex ion can act as a weak acid, dissociating to give a proton (or hydronium ion). Schematically, the dissociation can be represented as the transfer of a proton from one water molecule in the Cr(H20) 3 complex to a neighboring H20 to form a hydronium ion, H30+. Note that removal of a proton from an H20 bound to a Cr+3 leaves an OH- group at that position. The reaction is reversible and comes to equilibrium ... 

Catalytic activity for the selective oxidation of H2S was tested by a continuous flow reaction in a fixed-bed quartz tube reactor with 0.5 inch inside diameter. Gaseous H2S, O2, H2, CO, CO2 and N2 were used without further purification. Water vapor (H2O) was introduced by passing N2 through a saturator. Reaction test was conducted at a pressure of 101 kPa and in the temperature range of 150 to 300 °C on a 0.6 gram catalyst sample. Gas flow rates were controlled by a mass flow controller (Brooks, 5850 TR) and the gas compositions were analyzed by an on-line gas chromotograph equipped with a chromosil 310 coliunn and a thermal conductivity detector. 

The compositions of reactant flow are Usted in Table 1. The composition A is for the basic reaction test under water-free reaction condition, the composition B is for the reaction test under the influence of water, and the composition C is for the reaction test with the coal-derived synthesis gas. 

In the laboratory the chemical was put into water at the ordinary spray dilution of 1 to 800 and after 24 hours standing the treated water was used as drinking water for test animals. There were no reactions, evidence of poison, or undesirable effects on any animals as a result of these tests, even with long feeding periods. It was not possible to differentiate between test animals and check animals by any of the customary tests. 

A sample of hops which had been treated with tetraethyl pyrophosphate showed a negative chemical analysis. The plant material was also extracted and the extract added to the drinking water of test animals and sensitive insects. The animals and insects that drank this treated water for several days showed no reaction. With the sensitive insects it would have been possible to detect even a few parts per million. In addition, there have been extensive commercial field applications of the chemical in dust and spray form to crops such as apples, pears, grapes, celery, broccoli, Brussels sprouts, and others up to within a few days of harvest there has been no detectable poison residue on any of the crops. The lack of poison residue with use of tetraethyl pyrophosphate is due to the fact that it hydrolyzes within a few hours of application, breaking down into transient nonresidual and nonpoisonous chemicals. Thus it is possible to use tetraethyl pyrophosphate well up to harvest time of food products without danger of residual poison on crops. The fact that the chemical is used in extremely small amounts is a definite advantage in respect to freedom from poison residue. 

Since mild activation conditions appear to be important, a number of solution activation conditions were tested. PAMAM dendrimers are comprised of amide bonds, so the favorable conditions for refro-Michael addition reactions, (low pH, high temperature and the presence of water) may be able to cleave these bonds. Table 1 shows a series of reaction tests using various acid/solvent combinations to activate the dendrimer amide bonds. Characterization of the solution-activated catalysts with Atomic Absorption spectroscopy, FTIR spectroscopy and FTIR spectroscopy of adsorbed CO indicated that the solution activation generally resulted in Pt loss. Appropriate choice of solvent and acid, particularly EtOH/HOAc, minimized the leaching. FTIR spectra of these samples indicate that a substantial portion of the dendrimer amide bonds was removed by solution activation (note the small y-axis value in Figure 4 relative... 

This is more than enough time to allow for the complete irreversible isomerization. The extent of isomerization is checked by removing a small quantity of the reaction mixture, isolating the product by dilution with water, and testing its solubility in dilute potassium hydroxide solution. It should be completely soluble. 

Compatibility Reaction with common contaminants (e.g., water) Specialized tests... 

RhHL3 was found to be an even more efficient catalyst than its Pt counterpart. However, pyridine tended to stabilize the hydrido-hydroxo-metal species relative to acetone, such that pyridine promoted the water-gas shift rate. Otsuka and coworkers28,40 tested a wide range of Rh complexes. Results of reaction testing for both Pt[P(iPr)3]3 and the Rh complexes are provided in Table 13. The conditions were 0.1 mmol catalyst, 2.0 ml H20, 20 kg/cm2 CO, and 5 ml solvent at 100 °C for 18 hours. 

A mechanism similar to Scheme 10 was proposed, involving CO addition, followed by H20 addition (in lieu of hydroxide anion) to form a metallocarboxylic acid complex. Then, decomposition to C02 and a metal hydride was proposed, followed by hydride elimination. Table 15 provides data from reaction testing in the temperature range 140 to 180 °C. In later testing, they compared Rh and Ir complexes for the reduction of benzalacetone under water-gas shift conditions. 

Figure 11. The influence of residual H2O2 on the reaction testing of phenol hydroxylation to catechol (CAT), hydroquinone (HQ), and para-benzoquinone (BQ) [61], Reaction conditions 4 g phenol 50 mL water solvent 0.2 g a-Fe203 catalyst inner standard ethanol reaction temperature 70°C. Aliquots were sampled at different times and analyzed by (a) HPLC and (b) GC to determine the conversions of PHE (A) and yields of CAT + HQ + BQ ( ), CAT ( ), and BQ (T). Aliquots were also analyzed by (c) iodometric titration to determine the conversion of H2O2 (o). [Reproduced by permission of Elsevier from Ma, N. Ma, Z. Yue, Y. H. Gao, Z. J. Mol. Catal. A 2002, 184, 361-370.]...

Elemental composition Ca 71.47%, O 28.53%. Acidified CaO solution may be analyzed for Ca by flame AA or ICP spectrometry (see Calcium). The oxide may be determined by x-ray techniques. The compound may be identified by adding a small quantity slowly and carefully to water (reaction may be violent) and testing the pH (pH should be alkaline). Passage of CO2 into its clear solution should turn the solution milky due to formation of CaCOs. 

A sample of the fuel is shaken, using a standardized technique, at room temperature with a phosphate buffer solution in very clean glassware. The cleanliness of the glass cylinder is tested. The change in volume of the aqueous layer and the appearance of the interface define the water reaction of the fuel. 

Richards, H. G., Savage, D. Andrews, J. N. 1992. Granite-water reactions in an experimental Hot Dry Rock geothermal reservoir Rosemanowes test site, CORNWALL, U. K. Applied Geochemistry, 7, 193-222. 

---