Methane stability

Chemical Reactivity - Reactivity with Water Reacts vigorously, generating flammable methane gas Reactivity with Common Materials Will react with surface moisture to generate flammable methane Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

However, this particular product was a solvent treated with about 2 percent of nitro-methane stabilizer and not like the other intermediates or products. If any chemist from the control lab had been contacted, he would have opposed this neutralization scheme. 

As shown in Fig. 7 we compared the frequency of the cesium Di line at 895 nm with the 4th harmonic of the methane stabilized He-Ne laser operating at 3.4 pm (/ = 88 THz). The laser that creates the frequency comb, the fourth harmonic generation and the HeNe laser are identical with the systems shown in Fig. 4. However, the HeNe laser was stabilized to a methane transition in this experiment and was used as a frequency reference instead of the Cs fountain clock. The frequency of this laser has been calibrated at the Physikalisch Technische Bundesanstalt Braunschweig/Germany (PTB) and in our own laboratory [51] to within a few parts in 1013. 

Fig. 3. Set-up of the frequency chain used to measure the absolute frequency of the two iodine spectrometers. The chain links the 532 nm radiation of the frequency doubled Nd YAG lasers (563 THz) to a methane-stabilized He-Ne laser at 3.39 /rm (88 THz). The two input frequencies of the frequency interval divider stage at 852 nm and 946 nm determine the frequency of the NdtYAG lasers at 1064 nm. The input frequencies are phase-coherently linked to the methane-stabilized He-Ne laser at 3.39 /xm by use of a frequency comb generated with a Kerr-lens mode-locked femtosecond laser...

One interesting reference standard may be the methane stabilized helium neon laser at 3.39 pm. Its infrared frequency can be compared directly with the microwave cesium frequency standard with the help of a relatively short frequency chain [32], An accuracy of 1 part in 1012 or better appears feasible for a transportable secondary standard. 

One way an optical standard could be provided is by harmonic multiplication of a microwave frequency standard in a synthesis chain. By use of this technique, a laser at 88 THz (3.39 pm) has been made phase coherent with a microwave oscillator. - The best optical frequency standards may be made by locking a local oscillator (laser) to an atomic or molecular resonance line. State-of-the-art accuracies are characterized by measurements on methane stabilized He-Ne lasers in which reproducibilities in the 10— -- range have... 

Here, the unknown laser frequency is compared (via heterodyne methods) to a harmonic of some well known reference line such as the methane stabilized He-Ne laser at 3.39 pm.- -... 

Hannum (Ref 12) patented mixts of fuels, consisting of NMe (Nitromethane), NEt (Nitro-ethane), and mono-, di-, or trinitropropane, with oxidants HNEt or TeNMe (Tetranitro-methane), stabilized by the addn of substituted ammonias in amts of 1 to 10% by wt. 

K.M. Evenson, J.S. Wells, F.R. Petersen, B.L. Danielson, G.W. Day, R.L. Barger, J.L. Hall Speed of light from direct frequency and wavelength measurements of the methane-stabilized laser. Phys. Rev. Lett. 29, 1346 (1972)... 

H. Hellwig, H.E. Bell, P. Kartaschoff, J.C. Bergquist Frequency stability of methane-stabilized He-Ne-lasers. J. Appl. Phys. 43, 450... 

The most profound observation in Fig. 7.4 is the significant difference between propane and methane stability limits. At the extinction branch of the stability limits (f/jN < 0.2 m/s at 5 bar), the propane-fueled catalytic reactor is substantially more robust against external heat losses. Despite the higher catalytic [22] and gas-phase reactivity of propane when compared to methane, at the blowout branch this trend is reversed. Methane has much broader limits, in terms of maximum allowable critical heat transfer coefficient h and of inlet velocity Um- This behavior of catalytic microreactors comes in stark contrast to pure gas-phase microreactors [23], whereby the stability diagrams of methane are substantially narrower than those of propane. 

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