Cracking parameters

Table 1. Computed results from the algorithm for sizing of the cracks from Fig.4a, Fig.4b, and Fig.4c and orientation angles d)=0°, 0=30° and 0=45°, and true values of the eorresponding crack parameters.

Fig. 6.2.8. Median crack parameters under sharp indenters, general model. (After Lawn et al., 1976)...

Cracking yields are highly influenced by cracking parameters thus, better yields require better cracking conditions. Main cracking parameters are hydrocarbon partial pressure, residence time, and temperature. 

Since investment costs had to be kept low, the convection section, the fire box, and the burners were left unchanged. To fulfill these requirements, the new LSCC design was calculated for the same naphtha, P/E, hc-throughput, steam dilution, and crossover temperature. The following improvements in cracking parameters were calculated for the LSCC design pressure drop = 31% less, residence time = 28% less, and MCP = 43% less. 

The aforementioned example showed that good yield improvements can be obtained by an LSCC design because of better cracking parameters which means lower MCP. This example also shows that utility costs can be decreased considerably with LSCC revamping. 

Figure 7 shows a crossplot of an aromatic sterane cracking parameter (A3) and a hopane biomarker maturity parameter (H14). The A3... 

Table 5. Cracking parameters by temperature and stress test machine.

The TAP reactor is particularly suited to study monomolecular reactions because of the very low pressures that are applied and the high ratio of active sites to reactant concentration. For the catalytic cracking of methylcyclohexane, these conditions lead to negligible coke deposits. Moreover, it has been already been demonstrated that the TAP reactor allows the determination of sorption, diffusion and cracking parameters in for reactions over zeolite materials. ... 

The kinetic-mathematical model presented here can well be applied to determine cracking parameters, to obtain the required product yields of a given naphtha feedstock, or to calculate the product yields from the given cracking parameters. The model was completed by adding the hydrodynamic and heat transfer equations used to calculate the pressure drop and the amount of heat transferred in the reactor. 

Figure 5.7. Median crack parameter as a function of indenter half angle, equation (5.18) using V = 0.2. Glass indented with WC produces points shown as .

Consider the state J]o the system "cracked body - loading". Assume that under fixed crack sizes this state is a stable equilibrium. Together with the undisturbed state Xo consider a set of close neighboring, disturbed states X The neighboring states satisfy the following conditions time, the given surface and body forces, and given displacements are not subjected to variation in the whole body, except perhaps in the vicinities of crack-tips, all equations of equilibrium and compatibility are satisfied, as well as all constitutive equations the only mechanical parameters subjected to variation are the crack parameters. 

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