Sulfur ratios

The color obtained is a function of both the composition and the particle size of the precipitated crystals. A redder color results from both increased selenium to sulfur ratio and from larger crystals, caused by a more severe heat treatment. Hence, it is possible to make, from the same glass, a series of color filter types, by controlled reheating. 

Figure 13. Impact energy at 100% ductile fracture temperature, which is shelf energy, as a function of REM-to-sulfur ratio retained in the 80,000 psi steel. Note the progressive effect of increasing REM additions on the transverse impacts while the longitudinal values remain virtually unchanged. The X points represent untreated steel.

The sulfur ratio, defined as the ratio of weight percent sulfur in the char to the weight percent sulfur in the dye, provides an interesting parameter regarding sulfur volatilization. The three compounds with sulfur ratios between... 

Volatile Mattery tut % Sulfur Ratio Sulfur Retainedy tut % Ph s (IV) Pt (IV)... 

Figure S. Carbon sulfur ratios (wt/wt) in three cores from the north basin of Little Rock Lake. Carbon and sulfur concentrations were determined by LECCO analyzers. Cores were collected at 5 m (NB-5), 7 m (NB-7), and 9 m (NB-9). The two shallow cores are from epilimnetic sites at which the overlying water remains oxic throughout the year. The bottom water at NB-9 is anoxic in late summer.

Lime was added to the bed to reduce sulfur emissions.16 Calcium to sulfur ratio was about 1.7 to 2.0, and resulted in 90 percent sulfur capture.5 Emissions of the pilot test are summarized in Table 2-1.5... 

Figure 2. Comparison of ethyl and methyl alcohols as supercritical desulfurization fluids, for coals of varied organic sulfur/ pyritic sulfur ratio, (ethanol -------, methanol — —)...

The chemical microstructures of cis-polyisoprene (HR) vulcanised with sulfur and N-t-butyl-2-benzothiazole sulfenamide (TBBS) accelerator were studied as a function of extent of cure and accelerator to sulfur ratio in the formulations by solid-state 13C NMR spectroscopy at 75.5 MHz [29]. Conventional (TBBS/Sulfur=0.75/2.38), semi-efficient (SEV=1.50/1.50) and efficient (EV=3.00/1.08) vulcanisation formulations were prepared, which were cured to different cure states according to the magnitude of increase in rheometer torque. The order and types of the sulfurisation products formed are constant in all the formulation systems with different accelerator to sulfur ratios. However, the amount of sulfurisation has been found to vary directly with the concentration of elemental sulfur. 

The effect of the accelerator to sulfur ratio on the vulcanisation chemistry was also investigated by comparing the vulcanisation products from conventional, SEV and EV formulation systems. With increase in accelerator to sulfur ratio (from conventional to EV) there is a lowering in the sulfur rank. Also, the cis-to-trans isomerisation increases with the amount of accelerator. 

For 1,3-butadiene hydrogenation, the toxicity of sulfur is 3 (Fig. 13). which is lower than the toxicity for olefin hydrogenation. The hydrogenation of 1-butyne has also been studied for various ratios of sulfur over palladium. As was already published (86), the 1-butyne hydrogenation rate increases with time. The same effect has been observed on sulfided palladium. The turnover number is consequently presented for 1-butyne hydrogenation versus the sulfur content for various 1-butyne conversions (see Fig. 14). During the first minutes of reaction (0-25% conversion), the toxicity of sulfur appears close to 1 the rates are proportional to the free surface. However, at higher conversion, the rate becomes independent from the sulfur ratio. The toxicity is zero. 

Investigations into the calcium/sulfur ratio represent an important aspect of the evaluation of the economy of this procedure. The influence of the stoichiometric relationship for different spraying mass fluxes has been investigated, and the adjusted experimental conditions are listed in Tabs. 16.3 and 16.4. 

The amount of calcium hydroxide required can be calculated at a given gas mass flow, sulfur dioxide concentration and calcium/sulfur ratio ... 

In recent years there has been a tendency to increase volume% S02 in sulfur burning gas by lowering the input air/sulfur ratio, Fig. 3.5. An increase in S02 concentration lowers the volume of gas that must be blown through the acid plant per tonne of product H2S04. It thereby lowers ... 

Sulfur burning furnace input mass air/input mass sulfur ratio... 

Unfortunately, decreasing the input air/input sulfur ratio also decreases the 02/S02 ratio of the gas (Fig. 3.5), potentially lowering catalytic oxidation efficiency. 

Decreasing sulfur burning s air/sulfur ratio raises product gas temperature, Fig. 3.6. If carried too far (i.e. to raise % S02-in-gas), this may damage the sulfur burning furnace or boiler. 

Fig. 3.6. Temperature of offgas from burning sulfur with excess air (calculated by means of S, O, N and enthalpy balances). Offgas temperature is decreased by raising input air/input sulfur ratio. This is because (i) excess air in offgas increases with an increasing input air/input sulfur ratio and because (ii) this excess air absorbs sulfur oxidation heat. ( For example, 7 kg of input air for every 1 kg of input sulfur.)...

Sulfur burning s product gas composition and temperature are readily controlled by adjusting the sulfur furnace s input air/input sulfur ratio. Replacement of some of the input air with oxygen gives the process independent 02/S02, temperature and volume control. 

Wolfrom and coworkers have summated their analytical data on the barium acid salt of heparin, and have expressed the data in terms of a tetrasaccharide unit which comprises two molecular proportions each of 2-amino-2-deoxy-D-glucose residue and D-glucuronic acid residue, and 5 (rather than 6) ester sulfate groups, in an N S ratio of 2 5. The barium sulfur ratio was 1 2, which indicated that the sulfur is essentially present as ester sulfate, and hence the acidity must be due to the carboxyl group, in accordance with the shape of the titration curve. " ... 

The extent of the reactions indicated by Equations 1 and 2 or the molar sulfate-to-sulfur ratio is 2.4 zb 0.2 when rock pyrite is used and 1.4 zb 0.4 for sedimentary pyrite found in the coals used in this work. Although both materials are FeS2 of the same crystal structure, differences in reacivity have been documented which are attributed to impurities and crystal defects peculiar to the various possible modes of formation (7). For coal, no significant variation in this ratio was found with ferric ion concentration, acid concentration, coal, or reaction time. The results for each coal are found in Table II. 

Table II. ulfate-to-Sulfur Ratio for Extraction of Coal and Mineral Pyrite with Ferric Chloride Solution...

The effect of added hydrochloric acid concentration was studied in order to determine whether or not the acid had any effect on pyrite and ash removal, sulfate-to-sulfur ratio, final heat content, and possible chlorination of the coal. Coal has many basic ash constituents, so increased ash removal was expected, as well as some suppression of the sulfate-to-sulfur ratio because the reaction that results in sulfate formation also yields eight moles of hydrogen ion per mole of sulfate (common ion effect). Added acid was studied in the range of 0.0 to 1.2M (0.0, 0.1, 0.3, and 1.2M) hydrochloric acid in 0.9M ferric chloride. Duplicate runs were made at each concentration with all four coals for a total of 32 runs. The results showed no definite trends (except one-uide infra) even when the data were smoothed via computer regression analysis. Apparently the concentration range was not broad enough to have any substantial effect on the production of sulfate or to cause the removal of additional ash over that which is removed at the pH of IM ferric chloride ( pH 2). 

Radiotracer analysis is particularly effective for tracking the fate of additives, because molecular fragmentation can typically be expected to result in an impurity element distribution different from that of the original molecules. For example, in nickel plating in the presence of thiourea, complete incorporation of the molecule should give a carbon/sulfur ratio of 1.0, while experiments indicate a ratio ranging from 0.01 to 0.7 depending on the deposition conditions [130,131,141,142], As with additive incorporation, the decomposition process can be a sensitive function of the co-adsorbates [145, 149, 150]. 

The tests were carried out in an experimental furnace designed to burn 500 lb/hr of pulverized coal. The sorbents were injected into the furnace flue gas as a dry powder, upstream of a baghouse filter. Operating variables considered included baghouse temperature and cleaning cycle time, sorbent particle size, sorbent/sulfur ratio, location of sorbent injection point, and sorbent injection schedule (continuous or intermittent). 

ESCA results on particles from the top and bottom of the bed substantiate the lower meuls/sulfur ratio at the bottom of the bed compared to the top. Also, some molybdenum was detected on the surface of ALL of these particles. This indicates that some molybdenum is always accessible tn the reactants, even when high levels of deposited metals arc on the calaJysL... 

Figure 7. Dehydrogenation of propane in the presence of sulfur. Ratios of helium, propane, and sulfur are approximate.

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