Residuum atmospheric

Cracking imposes an additional penalty in a vacuum unit in that it forms gas which cannot be condensed at the low pressures employed. This gas must be vented by compressing it to atmospheric pressure. This is accomplished by means of steam jet ejectors. Ideally, it would be possible to operate a vacuum pipe still without ejectors, with the overhead vapors composed only of steam. In practice, however, leakage of air into the system and the minor cracking which occurs make it necessary to provide a means of removing non-condensibles from the system. In addition to the distillation of atmospheric residuum, the lube vacuum pipe still is also used for rerunning of off specification lube distillates. 

Vacuum gas oil hydrotreater Vacuum residuum hydrotreater Atmospheric residuum desulfurization hydrotreating... 

Residua are black, viscous materials obtained by distillation of a crude oil under atmospheric pressure (atmospheric residuum) or under reduced pressure (vacuum residuum). They may be liquid at room temperature (generally, atmospheric residua) or almost solid (generally, vacuum residua) depending on the cut point of the distillation or depending on the nature of the crude oil (Speight, 1999 Speight and Ozum, 2002). 

Atmospheric residuum a residuum (q.v.), obtained by distillation of a crude oil under atmospheric pressure, which boils above 350°C (660°F). 

Figure 5. Hydrodesulfurization kinetics for an Arabian light atmospheric residuum...

The distributions of Ni, V, N, and S in several atmospheric residuum fractions (Reynolds, 1985) are shown in Table VII. As is evident from the table, the distributions of heteroatoms and metals in the fractions vary greatly with the petroleum source. The Kern River resid is considerably different than that from the other petroleums in having a low asphaltene... 

Yields and Properties for High-Severity RDS of Kuwait 345°C+ Atmospheric Residuum"... 

A summary of hydrodemetallation kinetic studies is presented in Table XXVI. The list is not exhaustive but does include a diversity of feedstocks and catalysts. It is apparent that a discrepancy in reaction order rt with respect to total metal (Ni or V) concentration has been observed. Riley (1978) reported first-order kinetics for both nickel and vanadium removal when hydrotreating a Safaniya atmospheric residuum. Demetallation kinetic order of 1.0 to 1.5 depending on reactor configuration has been reported by van Dongen et al. (1980) for vanadium removal. Oleck and Sherry (1977) report a better description of the reaction system is obtained with second-order kinetics for nickel and vanadium removal from Lago-medio (Venezuelan) atmospheric residuum. All studies were conducted on CoMo/A1203 catalysts. 

Tia Juana Pesado residuum Safaniya atmospheric residuum Kuwait crude... 

Agha Jari topped crude Gach Saran atmospheric residuum Kuwait and Lagomedio atmospheric residual 3 Jobo crude resin fraction asphaltene fraction Adriatic Sea atmospheric resid Gach Saran vacuum residuum... 

Riley (1978) reported that catalyst activity for vanadium removal from Safaniya atmospheric residuum is independent of the Co and Mo loading. 

Riley reported that pore structure controlled Ni and V removal in treating a Safaniya atmospheric residuum. Metals removal activity increased with increasing pore size from 100 to 150 A in narrow-pore-size-distribution CoMo/A1203 catalysts. Larger-pore-size catalysts, typical of many of the newer HDM catalysts, were not examined. 

Narrow cuts of asphaltenes from Kuwait atmospheric residuum with molecular radius ranging from 26 to 153 A (based on size exclusion chromatography) were examined by Baltus and Anderson (1983) in pores... 

Fig. 38. Nickel, vanadium, and iron deposition profiles in aged i -in. catalyst after processing Arabian Heavy atmospheric residuum at 370 C (700°F) and 12.59 MPa H2 (1810 psig) (Tamm et al., 1981).

Fig. 40. Typical deactivation curve for residuum hydroprocessing catalyst. Arabian Heavy atmospheric residuum desulfurized to 1.10 wt. % product sulfur with a iV-in. extrudate catalyst (Tamm ei al., 1981).

Fig. 45. Effect of hydrogen partial pressure on vanadium deposition for an Arabian Heavy atmospheric residuum at a reaction temperature of 371°C (700°F) using a -in. extrudate catalyst (Tamm et at., 1981).

Fig. 49. Effect of catalyst particle size on vanadium deposition for an Arabian Heavy atmospheric residuum processed at 370° (700°F) under 12.59 MPa (1825 psia) of hydrogen (Tamm et al., 1981).

Fig. 51. Effect of catalyst pellet size on deactivation behavior for an Iranian Heavy atmospheric residuum desulfurized to 0.5 wt. % product sulfur (Tamm el at., 1981). 

Thus, in the distillation of crude petroleum, light naphtha and gases are removed as vapor from the top of the tower, heavy naphtha, kerosene, and gas oil are removed as sidestream products, and reduced crude (atmospheric residuum) is taken from the bottom of the tower. 

Figure 6-19 Effect of hydrogen partial pressure on conversion (Arabian heavy crude oil atmospheric residuum).

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