Reformate yield effect

The model provides a performance reference to evaluate commercial reformer operation by taking into account the wide variation in operating conditions, feedstocks, and product octane typically experienced commercially. Such variations in reformate yield have already been discussed in Fig. 29, where the model effectively predicts the yield variations. As a monitoring tool, the model is routinely used to assess reformer yield and activity losses due to catalyst deactivation relative to fresh catalyst model estimates. When commercial yield and/or activity losses relative to the model are uneconomical, a decision to regenerate the catalyst is made. A typical monitoring trend (Fig. 36) illustrates the use of the model as a performance reference. 

By varying both initial and final boiling points of the feedstock, octane numbers, reformate yields and composition as well as gas yields were measured in a once-through, isothermal pilot reactor. The effect of the feedstock boiling point properties on catalyst deactivation was also studied. 

Work on mercury alkyls has been done by Heitz and Adloff (31-33), who studied Hg(CH3)2, Hg(C2Hj)2 and HgPh2. They found no isotope effect between " Hg, Hg, and ° Hg, and no correlation with the respective conversion coefficients. They also noted that the retentions could not be satisfactorily explained by exchange of the respective ligands, and thus concluded that the molecules are reformed by an epithermal not by a thermal process. Parent yields were typically 74, 15, and 8% for the diphenyl-, dimethyl- and diethylmercury, respectively. 

In the first part of the chapter, a state-of-the-art review and also a thermodynamic analysis of the autothermal reforming reaction are reported. The former, relevant to both chemical and engineering aspects, refers to the reaction system and the relevant catalysts investigated. The latter discusses the effect of the operating conditions on methane conversion and hydrogen yield. 

Anthracene (404) and its derivatives are reported to yield 9,10-sndoperoxides (405). No mechanistic studies were made with respect to the influence of substituents and their positions on the reactivity of the anthracenes toward oxygen, except those discussed earlier. However, substituent effects have been observed with regard to the thermal stability of the anthracene endoperoxide and its thermal transformation reactions, which either lead to quinone formation or to evolution of oxygen and reformation of the hydrocarbon (Table XIII). 

This phenomenon is not fully understood, but may be due to the effect of radiant heating and frictional heating on the redistribution and reformation of all wax into a loosely knit wax crystal lattice. The new wax lattice yields an oil with a higher pour point. 

R16H selectivity and activity kinetics were fit over a wide range of temperature and pressure. Reforming selectivity is shown in Figs. 16 and 17, where benzene and hexane are plotted against C5-, the extent of reaction parameter. The effect of pressure on reforming a 50/50 mixture of benzene and cyclohexane at 756 K is shown in Fig. 16. Selectivity to benzene improves significantly when pressure is decreased from 2620 to 1220 kPa. In fact, at 2620 kPa, hexane is favored over benzene when the C5 yield exceeds 10%. This selectivity behavior can be seen in the selectivity rate constants ... 

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