Sulfur Surrogate

The ANL catalyst (not identified, but presumably a Pt supported on Gd-doped ceria) was also successfully used for ATR of diesel fuel. Tests of three different types of diesel fuels (n-Cie, low-sulfur diesel, and regular diesel) showed complete conversion of hydrocarbons at 800°C. The diesel surrogate n-Ci6 yielded 60% H2 on a dry, N2-free basis at 800°C, whereas the other two diesel fuels required higher temperatures (>850°C) to yield similar levels of H2 in the product gases. Similar or improved H2 yields from diesel ATR were observed with a microchannel monolith catalyst, compared with extruded pellets in a fixed-bed reactor. ... 

Due to the good nucleophilic nature of sulfur, formation of new C—S bonds is relatively easy. This property has been used for intramolecular peptide cyclization 1 and was exploited for preparation of methylenethio ether surrogates, t >[CH2—S], initially as peptide gap inhibitors for blocking collagenase action. 2 These surrogates were later converted into sulfoxide and sulfone derivatives. This expansion of amide replacements compelled a more generalized nomenclature system for pseudopeptides (amides with one or more amide bond surrogates) and led directly to the psi-bracket convention. 1 ... 

Rate of substitution by sulfur nucleophile deemed negligible (see Table VIII). gRate of dehydrohalogenation by H20 deemed negligible (78). hkH2o,SN for hydrolysis of 2-bromobutane used as a surrogate. 

In 1884, C. Paal and L. Knorr almost simultaneously reported that 1,4-diketones upon treatment with strong mineral acids underwent dehydration to form substituted furans. This transformation soon became widely used and now it is referred to as the Paal-Knorr furan synthesis. The general features of the method are 1) virtually any 1,4-dicarbonyl compound (mainly aldehydes and ketones) or their surrogates are suitable substrates 2) the dehydration is affected by strong mineral acids such as hydrochloric acid or sulfuric acid, but often Lewis acids and dehydrating agents (e.g., phosphorous pentoxide, acetic anhydride, etc.) can be used and 3) the yields are usually moderate to good. The two major drawbacks of the reaction are the relative difficulty to obtain the 1,4-dicarbonyl substrates, and the sensitivity of many functionalities to acidic conditions. 

Jet fuel (surrogate and real) 2% Rh-10% Ni/Al203-Ce02 515 3 2000-3000 Capable of reforming the real JP-8 jet fuel containing 22ppm sulfur. Ni-Rh synergism plays a role for improved catalytic activity Strohm et al.137... 

Two separate test bums were conducted in accordance with the EPP to demonstrate that project emission limits could be met. First, sulfur hexafluoride (SF ), a thermally-stable surrogate, was injected and burned to optimize operating conditions and demonstrate thermal destruction efficiency and acid gas removal capabilities. Batches of frozen mustard were then processed under the optimized conditions to establish system performance for regulatory approval. The SF6 and mustard test bum results are summarized in Table 6.3. 

Figure I. Lightoff curves for a thermally aged Pd catalyst sample using propylene as a hydrocarbon surrogate. Each curve was obtained using a different sulfur dioxide concentration in the synthetic exhaust feedstream. The dashed line was the result of a lightoff test using 30 ppm sulfur dioxide in the feedstream which was repeated using 0 ppm sulfur dioxide in the feedstream.

Figure 5. Isothermal (500 °C) activity of the thermally aged Pd catalyst using propylene as a hydrocarbon surrogate. In these experiments, the sulfur dioxide concentration is maintained at 0 ppm for 5 min, then increased to either 5, 10, 20 or 30 ppm for 15 min, then decreased to 0 ppm for an additional 45 min.

Figure 9. Effect of sulfur dioxide on the activity of thermally aged Pd in a cycled stoichiometric exhaust as a function of mean air/fuel ratio using propylene as a surrogate hydrocarbon.

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