Effect of Feed Properties

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. 

Properties of the Feeds and Product Yields from Delayed Coking at 30psia, and 900 F 

FIGURE 5.5 Effect of type of feed on coking product yields and comparison with prediction with correlations. ( ) Gary and Handwerk (2001), ( ) Volk et al. (2002), (A) Maples (1993), (x) Smith et al. (2006), ( ) Castiglioni (1983). 

Surprisingly, the most-used and well-known correlations (Gary and Handwerk, 2001 Maples, 1993) as well as and Smith et al. (2006) correlation presented errors of 21%-32% for gas yield, 31%-62% for naphtha yield, 35%-46% for gasoil yield, and 17%-21% for coke yield. It should be remembered that Gary and Handwerk (2001) and Maples (1993) approaches only use CCR content, while Smith et al. (2006) method incorporates the effect of pressure, which slightly improves its accuracy, but not too much. 

On the other hand, Volk et al. (2002) and Castiglioni (1983), in addition to CCR content and effect of pressure, include the effects of temperature and feed flow rate. These two additional effects improve the accuracy of these two approaches to a 

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At this point, the yield model can be used to represent the pyrolysis behavior of specific feedstocks. To generalize the model, the effect of feed properties must be incorporated. Naphthas are complex mixtures of hydrocarbons. Feed characterization is needed to condense a detailed naphtha description into a manageable set of parameters, which uniquely defines feed-dependent conversion and yield effects. 

In Section IV, the kinetics and mechanisms of catalytic HDM reactions are presented. Reaction pathways and the interplay of kinetic rate processes and molecular diffusion processes are discussed and compared for demetallation of nickel and vanadium species. Model compound HDM studies are reviewed first to provide fundamental insight into the complex processes occurring with petroleum residua. The effects of feed composition, competitive reactions, and reaction conditions are discussed. Since development of an understanding of the kinetics of metal removal is important from the standpoint of catalyst lifetime, the effect of catalyst properties on reaction kinetics and on the resulting metal deposition profiles in hydroprocessing catalysts are discussed. 

German, J.B., Simoneau, C., DePeters, E., Tong, P.S., Mattas, J. and Sullivan, J. (1995) Effects of feeding supplemental fat to dairy cattle on milk fat composition and properties. 2. Triglyceride distribution and milk fat functionality. J. Dairy Set, 78, (Suppl. 1), 134. 

Polymeric C02-selective membranes consisting of both mobile and fixed carriers in cross-linked PVA were synthesized. The membranes showed good C02/H2 and CO2/ CO selectivities, and high C02 permeability up to 170 °C. The effects of feed pressure, water content, and temperature on transport properties were investigated. The C02 permeability and C02/H2 selectivity decreased with increasing feed pressure,... 

In summary of foam-spray drying, all available literature results confirm a strong effect of feed foaming on final product properties of porous and skin-forming materials, for example, an increase of Sauter mean diameter and porosity of the products decrease of bulk, tap density, and apparent density and effect on particle morphology. Foam-spray drying enhances retention of highly volatile substances and... 

Figure 7.7. Effects of feed condition on feasibility boundaries. Systems features Da=0.10 z=l p=l physical properties are listed in table 7.3 governing expressions are given in table 7.2.

Effect of Feed Rate Initially 10,(XX) spherical, inelastic, frictional particles with material properties described in Table 14.3 were deposited in the hopper with a closed outlet. After deposition, particles were discharged from the hopper into the mill. The blades/impellers were then set into motion at prescribed rotational velocity of 600 or IMOrpm. 

A comparative study of the energy requirements and control properties of three thermally coupled distillation schemes and two conventional distillation sequences for the separation of ternary mixtures is presented. The responses to set point changes under closed loop operation with proportional-integral (PI) controllers were obtained. Three composition control loops were used, and for each separation scheme, the parameters of the PI controllers were optimized using the integral of the absolute error criterion. The effects of feed composition and of the ease of separability index were considered. The results indicate that there exist cases in which integrated systems may exhibit better control properties than sequences based on conventional distillation columns. 

A systematic analysis of the foam spray drying process, including investigations of spray hydrodynamics (particle size distribution, particle velocity, centricity), heat and mass transfer between the phases, drying kinetics and the effects of feed foaming on final product properties, was carried out by Zbicinski and Rabaeva (2010) and Rabaeva (2012). 

AD available studies revealed a strong effect of feed foaming on the final product properties. 

Extensive experiments on the effects of feed rate and admixed gas flow rate on the final product properties for skin-forming materials (maltodextrin) and porous... 

A review of our recent work on the synthesis and transport properties of new C02-selective membranes follows. Transport properties of the membranes synthesized, including CO2 permeability and flux, H2 flux, CO2/H2, CO2/N2, and CO2/CO selectivities, were studied. The effects of feed pressure, water concentration, and temperature on transport properties were investigated. 

Apart from these rules of thumb, various correlations have been reported in the literature to calculate the yields, API gravity, and snlfur content of the products of delayed coking. Most of them only use the CCR content of the feed, while only a few incorporate the effect of pressure and temperature. The correlations have been developed using a wide range of type of feeds, whose properties can be found in the respective literature. Due to the empirical nature of correlafions, applying them beyond the range of feed properties, operating conditions, and product yields from which they were derived is risky, and the calculated values should be taken only as approximate estimates. 

The use of vitamins in humans consumes ca 40% of vitamins made worldwide. The majority of the vitamins, particularly in countries outside the United States, are used in animal husbandry. It is well estabUshed (21) that vitamins are critical to animal productivity, especially under confined, rapid growth conditions. Newer information (22) has shown that vitamin E added to catde feed has the additional effect of significantly prolonging beef shelf life in stores. Additional appHcations of vitamins exist. A small but growing market segment involves cosmetics (qv) (23). The use of the chemical properties of the vitamins, particularly as antioxidants (qv) in foods and, more recently, in plastics (vitamin E (24)), has emerged as a growing trend. 

The type of evaporator to be used and the materials of construc tion are generally selected on the basis of past experience with the material to be concentrated. The method of feeding can usually be decided on the basis of known feed temperature and the properties of feed and produc t. However, few of the listed variables are completely independent. For instance, if a large number of effects is to be used, with a consequent low temperature drop per effect, it is impractical to use a natural-circiilation evaporator. It expensive materials of construction are desirable, it may be found that the forced-circulation evaporator is the cheapest and that only a few effec ts are justifiable. 

Small variations in feed properties can have a pronounced effect on maximum pressure P, and press performance. RoU presses are scaled on the basis of constant maximum pressure. The required roll loading increases approximately with the square root of increasing roll diameter or gap width. 

Studies of the incineration of liquid and solid wastes must determine the rates at which hazardous compounds are released into the vapor phase or are transformed in the condensed phase, particularly when the hazardous materials make up a small fraction of the liquid burned. We must be particularly concerned with understanding the effects of the major composition and property variations that might be encountered in waste incinerator operations—for example, fluctuations in heating value and water content, as well as phase separations. Evidence of the importance of variations in waste properties on incinerator performance has been demonstrated by the observation of major smges in emissions from rotary-kiln incinerators as a consequence of the rapid release of volatiles during the feeding of unstable materials into the incinerator. 

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