Simulations atmospheric distillation unit

In this chapter, we address several important issues relevant to the simulation of atmospheric distillation units (CDUs) ... 

The first step in the building the atmospheric distillation unit is entering the composition of the crude in order to generate the necessary hypothetical components for model. For the purposes of this simulation, we will consider the crude assays given in Table 2.5 to Table 2.8. It is important to remember that that we may have to remove extraneous details from the distillation curve to avoid unusual column behavior. We use the TB P distillation, density distribution and overall bulk density to define this system in Figure 2.14. 

The next step in building the set of hypothetical components is creating a blend. A blend represents a combination of two or more assays on a weight or volume basis. The combined blend is the input to the hypothetical component generator in Aspen HYSYS. For the purposes of this simulation, we use the data from the representative atmospheric distillation unit of Section 2.7. We can use the blend... 

Specialised units are used to simulate complex fractionation processes in petroleum refining. Typical configuration consists of a main column with pump-around and side strippers (Fig. 3.14). Among applications, we may cite pre-flash tower, crude atmospheric distillation, or Fluid Catalytic Cracking (FCC) main fractionator. 

Water used in the experiments was doubly distilled and passed through an ion exchange unit. The conductivity was approximately 1 x 10"6 S/m. Simulated HLLW consisted of 21 metal nitrates in an aqueous 1.6 M nitric acid solution as shown in Table 1 and was supplied by EBARA Co. (Tokyo, Japan). Concentrations were verified by AA for Na and Cs with 1000 1 dilution and by ICP for the other elements with 100 1 dilution. Total metal ion concentration was 98,393 ppm. The experimental apparatus consisted of nominal 9.2 cm3 batch reactors (O.D. 12.7 mm, I.D. 8.5 mm) constructed of 316 stainless steel with an internal K-type thermocouple for temperature measurement. Heating of each reactor was accomplished with a 50%NaNO2 + 50% KNO 2 salt bath that was stirred to insure uniform temperature. Temperature in the bath did not vary more than 1 K. The reactors were loaded with the simulated HLLW waste at atmospheric conditions according to an approximate calculated pressure. Each reactor was then immersed in the salt bath for 2 min -24 hours. After a predetermined time, the reactor was removed from the bath and quenched in a 293 K water bath. The reactor was opened and the contents were passed through a 0.1 pm nitro-ceflulose filter while diluting with water. Analysis of the liquid was performed with methods in Table 1. Analysis of filtered solids were carried out with X-ray diffraction with a CuK a beam and Ni filter. Reaction time was defined as the time that the sample spent at the desired temperature. Typical cumulative heat-up and cool-down time was on the order of one minute. Results of this work are reported in terms of recoveries as defined by ... 

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