Ebullating

In a 2-1. two-necked round-bottomed flask having a capillary ebullator tube in one neck (Note 1) arc placed 371 g. (5 moles)... 

Column reactors for gas-liquid-solid reactions are essentially the same as those for gas-liquid reactions. The solid catalyst can be fixed or moving within the reaction zone. A reactor with both the gas and the liquid flowing upward and the solid circulating inside the reaction zone is called a slurry column reactor (Fig. 5.4-10). The catalyst is suspended by the momentum of the flowing gas. If the motion of the liquid is the driving force for solid movement, the reactor is called an ebullated- or fluidized-bed column reactor (Fig. 5.4-10). When a catalyst is deactivating relatively fast, part of it can be periodically withdrawn and a fresh portion introduced. 

Laboratory reactor for studying three-phase processes can be divided in reactors with mobile and immobile catalyst particles. Bubble (suspension) column reactors, mechanically stirred tank reactors, ebullated-bed reactors and gas-lift reactors belong the class of reactors with mobile catalyst particles. Fixed-bed reactors with cocurrent (trickle-bed reactor and bubble columns, see Figs. 5.4-7 and 5.4-8 in Section 5.4.1) or countercurrent (packed column, see Fig. 5.4-8) flow of phases are reactors with immobile catalyst particles. A mobile catalyst is usually of the form of finely powdered particles, while coarser catalysts are studied when placing them in a fixed place (possibly moving as in mechanically agitated basket-type reactors). 

Products Company and Davison (W.R. Grace) Catalysts) and Hydrocarbon Technologies, Inc. ART provides non-zeolitic catalysts for ebullating residue hydrocracking and fixed bed pretreating HDT [140], A nanoscale iron based, slurry catalyst is recommended for coal liquefaction, while a molecule-sized and chemically in situ generated catalyst is employed for the high conversion of asphaltenic fractions or heavy oils [141],... 

Reported residue conversion is significantly high for the five types of included reactors and largest for the slurry type of reactor. Besides, the slurry reactor together with the ebullated bed reactor can handle heaviest feedstocks and highest metal contents. Resid conversion requires higher temperatures, and pressure drop is essentially zero in these two reactors. However, product quality is better for the fixed and moving bed processes. 

Product yields and qualities obtained from HCK of heavy Safaniya VR are compared in Table 12 [142], As can be seen, higher yields on slurry and ebullated beds are associated with poorer product quality, besides the asphaltene concentration in the hydrocracked VR makes almost impossible any further improvement by further processing. 

Reactor Type Moving Ebullated Slurry Fixed Swing Fixed... 

The T-STAR ebullated bed is shown schematically in Fig. 6. The figure demonstrates that a uniform catalyst distribution is maintained throughout the reaction chamber via the upward flow of the hydrogen, feed oil, and recycle oil. The internal recycle allows for increased conversion and assists in maintaining a uniform temperature throughout the reactor. Careful monitoring of the temperature in an ebullated bed... 

Figure 6. T-STAR three-phase ebullated bed for hydrotreating petroleum intermediates. (From Clausen et al, 1992.)...

In normal operation of ebullated bed reactors, the reactor feed temperature is the control variable. The desired reactor feed temperature depends on both the feed rate and feed composition. The feed temperature is chosen such that the overall heat generation in the reactor is used to elevate the low temperature feed material to the bed temperature during... 

Johns, W. F., Clausen, G., Nongbri, G., and Kaufman, H., Texaco T-STAR Process for Ebullated Bed Hydrotreating/Hydrocracking, paper presented at the 1993 National Petroleum Refiners Association Annual Meeting, San Antonio, TX (1993)... 

An ebullator tube through which dry nitrogen was drawn has been used for the subsequent distillation under reduced pressure, but it is far more advantageous to use about six boiling-chips. Because of its rapid reaction with water, ketene acetal must be protected from moisture of the air. 

H-Coal A coal gasification process. Crushed coal is mixed with process-derived oil and catalytically hydrogenated in an ebullated bed under pressure at 455°C. The catalyst is a mixture of cobalt and molybdenum oxides on alumina. Developed by Hydrocarbon Research from the 1960s and piloted in Catlettsburg, KY, from 1980 to 1982. See also CSF, H-Oil, CSF, Synthoil. 

LC-Fining [Lummus Cities refining] A hydrocracking process using an ebullated catalyst bed. Developed by Lummus Crest and Cities Service Research and Development Company since the 1960s, initially for upgrading bitumen from tar sands. Three units were operating in 1996. 

In the reactor of Figure 8.3, a stable fluidized bed is maintained by recirculation of the mixed fluid through the bed and a draft tube. An external pump sometimes is used instead of the built-in impeller shown. Such units were developed for the liquefaction of coal and are called ebullating beds.. 

Figure 8.3. Gas-Liquid Fluidized Bed C"Ebullating" Reactor for Hydroliquefaction of Coal CKampiner, in Winnacker-Kuehler, Chemische Technolagie 52, 19723. ...

The H-Cocd Process, based on H-Oil technology, was developed by Hydrocarbon Research, Inc. (HRI). The heart of the process was a three-phase, ebullated-bed reactor in which catalyst pellets were fluidized by the upward flow of slurry and gas through the reactor. The reactor contained an internal tube for recirculating the reaction mixture to the bottom of the catalyst bed. Catalyst activity in the reactor was maintained by the withdrawal of small quantities of spent catalyst and the addition of fresh catalyst. The addition of a catalyst to the reactor is the main feature which distinguishes the H-Coal Process from the typical process. 

The H-Coal and CFFC Processes are unique In the sense that first-stage liquefaction is achieved by circulating the coal-donor slurry through an "ebullated" (i.e., partly fluidized) bed of uniformly sized catalyst pellets. 

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