Product yields with temperature products

C. Bouster, P. Vermande, and J. Vernon, Evolution of the Product Yield with Temperature and Molecular Weight in the Pyrolysis of Polystyrene, J. Anal. Appl. Pyrolysis. 15, 249 (1989). 

Pesson DeAmorim, S., Bouster, C., Vermande, P, and Veron, J, Evolution of the product yield with temperature and molecular weight in the p5nol5 is of polystyrene. J. Anal. Appl. Pyrol, 3,19, 1981. 

Similar compositional changes of the two feedstocks cracked on GX-30 are reported by Kraemer (1991) plotting each oil lump versus reaction time for the three temperatures. The same general trends for product yields with temperature and reaction time as discussed for Octacat catalyst were also observed with GX-30. 

The dependence of the volatile product yield with structure can be a very sensitive probe of radiation resistance and the protective effect of aromatic rings. G(H ) was observed to decrease from 5.6 to 0.038 for cyclohexane (3) and benzene (A) after gamma irradiation at ambient temperature. Since all polymers under investigation contained the sulfone moiety, G(SO ) (Table III) is an ideal probe for radiation resistance for this series. 

For the temperature dependence of the maximum yield in kinetically controlled processes, detailed data are generally not available. In all cases, where this has been studied experimentally, a decrease in the maximum product yield with increasing temperature is observed (Kasche, 1986). 

A synthesis of quinolines from reaction of 2-isopropenylaniline hydrochloride with cyclic ketones was described. The method employs a hydrothermal process with no organic solvents involved <030L1605>. The authors suggest this as an environment-friendly process. The product yields and side product formations are heavily dependent upon reaction temperature. 

Table 11.3 shows that, in most cases, the three polyalkene plastics prodnced very similar product yields, with high yields of wax, and hydrocarbon gas and negligible char yields. Higher temperatnres of pyrolysis result in thermal cracking of the oil/wax to prodnce increased concentrations of gas. For example, Kaminsky et al. [9] reported an oil/wax yield of 92.3 wt% and 7.6 wt% gas, at a pyrolysis temperature of 530°C in a flnidized bed. However at the higher temperature of 760°C, the oil/wax was thermally degraded to produce 42.4 wt% oil/wax and 55.8 wt% gas. 

On the other hand, the spent AITPApva-peg catalyst was washed with dichloromethane at 20 °C, dried at room temperature and then reused. The evolution of the product yield with time for the fresh and the washed AITPApva-peg is compared in Fig. 4. 

Analysis of thermal regime under fast polymerization reactions in turbulence regime showed that it is necessary to use internal heat removal (boiling of reaction mass) or its combination with preliminary cooldown of initial crude (autothermal regime) [60, 61]. In dependence on heat efficiency of process q and reaction product yield AP temperature rise ATad in apparatus may come to hundreds of degrees, and all heat evolves quickly (for seconds or their parts) and at a very small distance along the reactor length Lch V-Tcn = V/k[C]" (under polymerization Lch = V/ka) [40,41]. 

In dependence on numerical values of heat effect q of process and reaction product yield All temperature rise ATad in reaction zone according with (1.4) may be equal to tens and even hundreds of degrees. By this all heat is evaluated very quickly (for seconds or parts of seconds) and for a very little distance along reactor length (Table 4.1). As a consequence effective heat removal directly in reaction zone at the expense of external cooling is practically impossible, and one should always take this fact into account. 

Schwarz et al. [85] studied the efficiency of different microstructured mixers followed by microchannels and their influence on the space time for obtaining high product yields. With increasing mass transfer performance of the micromixer and decreasing channel diameter of the microchannel reactors, shorter reaction times of several minutes at lower reaction temperatures compared to conventional batch reactor were obtained. Similar observations are reported for the synthesis of biodiesel in capillary microreactors [86] and in zigzag microchannels [87]. 

Among metal-BINOL complex catalysts developed by Shibasaki et al., (I )-ALB is found to be the most effective catalyst for the asymmetric Michael addition of malonate to 2-cyclohexen-l-one. In 1998, Shibasaki et al. further fine-tuned the reaction 9onditions by adding the base (e.g., KO-r-Bu) and MS (4 A) to the system. These optimizations accelerate the catalytic asymmetric Michael addition without lowering the enantioselectivity. They suggested that the base was used to activate the Aluminum-Lithium-BINOL (ALB) complex. The 4-A molecular sieve (MS) was used to remove the trace amount of H2O that could otherwise gradually lead to ALB-KO-f-Bu catalyst decomposition. In the presence of ALB (0.3 mol%), KO-f-Bu (0.27 mol%), and 4-A MS, the Michael addition of dimethyl malonate to cyclohex-2-enone proceeded smoothly to give 94% product yield with 99% ee even at room temperature. Particularly noteworthy was that this reaction could be carried out on a 100-g scale without deleterious effect. Later, Xu and co-workers modified and streamlined the work-up procedures... 

The previous correlations, except those proposed by Schabron and Speight (1997), which require properties of asphaltenes, were used to predict the product yields with different vacuum residua. The predicted values were compared with real information recovered from commercial cokers. The comparisons were done to examine the effect of feed properties, the effect of pressure, and the effect of temperature. 

The effect of feed was examined with only three points. Moreover, all the feeds come from similar crude oils (blends of Maya and Isthmus oils). For these reasons, it is anticipated that more information is needed for a better ranking of correlations. In spite of this, it can be established that those approaches that include pressure and temperature effects tend to reproduce coking product yields with lower error. 

A mixture of 0.10 mol of the acetylenic alcohol, 0.12 mol of triethylamine and 200 ml of dichloromethane (note 1) was cooled to -50°C. Methanesulfinyl chloride (0.12 mol) (for its preparation from CH3SSCH3, (08300)30 and chlorine, see Ref. 73) was added in 10 min at -40 to -50°0. A white precipitate was formed immediately. After the addition the cooling bath was removed and the temperature was allowed to rise to -20°0, then the mixture was vigorously shaken or stirred with 100 ml of water. The lower layer was separated off and the aqueous layer was extracted twice with 10-ml portions of CH2CI2. The combined solutions were dried over magnesium sulfate and concentrated in a water-pump vacuum (note 2). The yields of the products, which are pure enough (usually 96%) for further conversions, are normally almost quantitative. 

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