Feed vaporization

In an equilibrium separation, a feed stream containing m components at given composition, pressure, and enthalpy (or temperature if in a single phase) is split into two streams in equilibrium, here taken to be a vapor and a liquid. The flow rates of the feed, vapor, and liquid streams are, respectively,... 

The composite curves for this flowsheet are shown in Fig. 14.86. The composite curves are dominated by the reboilers and condensers of the two distillation columns and the feed vaporizer for the acetone feed. It is immediately apparent that the two distillation columns are both inappropriately placed across the pinch. Linnhoflf and Parker ... 

The pressure in distillation column 1 has been increased to allow feed vaporization by heat recovery (from the distillation column condenser). Inspection of the new curves in Fig. 14.9a raises further possibilities. With the proposed modification, the overheads from the... 

The second step, permeation of components / andy through the membrane, is related directiy to conventional gas permeation. The separation achieved in this step, can be defined as the ratio of components in the permeate vapor to the ratio of components in the feed vapor (eq. 14). 

Fixed-Bed Vapor-Phase Oxidation of Naphthalene. A sihca gel or sihcon carbide support is used for catalyst involved in the oxidation of naphthalene. The typical naphthalene oxidation catalyst is a mixture of vanadium oxide and alkali metal sulfate on the siUca support. Some changes, such as the introduction of feed vaporizers, are needed to handle a naphthalene feed (14), but otherwise the equipment is the same. 

When feed contacts the regenerated catalyst, the feed vaporizes. Then positive-charged atoms called carbocations are formed. Carbo-cation is a generic term for a positive-charged carbon ion. Carbocations can be either carbonium or carbenium ions. 

Methanol feed/concentra-tion Liquid feed/O.SM Liquid feed/1 M Vapor feed Vapor feed Liquid feed/1 M Liquid feed/1 M Liquid feed/1 M... 

Fj, Vj, Lj = feed, vapor and liquid molar flowrates for Stage j... 

Quench pool/catch tank This type of system, as shown in Fig. 23-55, is used to condense, cool, react with, and/or collect a mixture of liquid and vapors discharging from a relief device by passing them through a pool of liquid in a vessel. Feed vapor and liquid (if present) are sparged into the pool of cool liquid, where the vapors are condensed and the liquid is cooled. If the feed materials are miscible with the pool liquid, they mix with and are diluted by the pool liquid if not, the condensate, feed liquid, and pool liquid separate into layers after the emergency relief event is over. The condensed vapors, feed liquid, and quench liquid are contained in the vessel until they are sent to final disposal. 

Operators shonld adjnst the bed level in the regenerator and observe its effect on catalyst losses, slide valve differentials, afterbnrn, and regenerator emissions. NO may be particnlarly sensitive to bed level. Recycle shonld be considered when trying to maximize diesel. It shonld always be added downstream of the feed nozzles to prevent erosion of the feed injector tips. Mix temperatnre control can be nsed when resid is processed to ensnre maximnm feed vaporization at the lower reactor temperatnres nsed in diesel operations. 

As indicated above, the heat prodnced in the FCC regenerator is ultimately balanced against the reqnirements of the reaction side. In addition to providing catalytic reaction sites, FCC catalyst also absorbs the heat of combustion and carries it to the riser to provide the heat required to vaporize and crack the feed. As catalyst circulation increases, the amonnt of heat transfer snrface available in the feed vaporization zone increases proportionately. 

Figure 9.11. Drum dryers for solutions and thin slurries (Buflovak Equip. Div., Blow Knox Co.), (a) Single drum dryer with dip feed and spreader, (b) Double drum dryer with splash feed, (c) Double drum dryer with top feed, vapor hood, knives and conveyor, (d) Double drum dryer with pendulum feed, enclosed for vacuum operation.

In the combustor, coke is burned from the spent solid that is then separated from combustion gas in the surge vessel. The surge vessel circulates regenerated catalyst streams to the contractor inlet for feed vaporization, and to the combustor bottom for premixing. 

Figure 8.13 Calculated permeate vapor concentration for a vapor-permeable membrane with a vapor/nitrogen selectivity of 30 as a function of pressure ratio. The feed vapor concentration is 1 %. Below pressure ratios of about 10, separation is limited by the pressure ratio across the membrane. At pressure ratios above about 100, separation is limited by the membrane selectivity [36]...

In the process illustrated in Figure 9.3, the first step is evaporation from the feed liquid to form a saturated vapor phase in equilibrium with the liquid. This evaporation step produces a separation because of the different volatilities of the components of the feed liquid. The separation can be defined as /3CTap, the ratio of the component concentrations in the feed vapor to their concentrations in the... 

During the period of observation, six separate incidents occurred in which hot spots started to develop. The conditions that led to these incidents are summarized in Table II. The outlet vapors include components originally in the liquid feed, vaporized during passage through the bed. The amounts of these components were estimated using correlated equilibrium ratios. 

Description The TAC9 process consists of a fixed-bed reactor and product separation section. The feed is combined with hydrogen-rich recycle gas, preheated in a combined feed exchanger (1) and heated in a fired heater (2). The hot feed vapor goes to a reactor (3). The reactor effluent is cooled in a combined feed exchanger and sent to a product separator (4). Hydrogen-rich gas is taken off the top of the separator, mixed with makeup hydrogen gas, and recycled back to the reactor. Liquid from the bottom of the separator is sent to a stripper column (5). The stripper overhead gas is exported to the fuel gas system. The overhead liquid may be sent to a debutanizer column or a stabilizer. The stabilized product is sent to the product fractionation section of the UOP aromatics complex. 

Description The Tatoray process consists of a fixed-bed reactor and product separation section. The fresh feed is combined with hydrogen-rich recycle gas, preheated in a combined feed exchanger (1) and heated in a fired heater (2). The hot feed vapor goes to the reactor (3). The reactor effluent is cooled in a combined feed exchanger and sent to a product separator (4). 

Component Fractions Components Feed Vapor Aqueous K-factor 1... 

Number of stages Feed stage location Component flows in feed Feed pressure Feed vapor fraction Pressure at the top of the column Pressure drop per stage Heat duty on each stage except reboilers and condensers Reflux ratio (replaces heat duty of condenser)... 

An energy balance on the reactor operating under adiabatic conditions and assuming negligible feed vaporization is... 

Fraction of a component in feed vapor that is not absorbed Fraction of a component in entering liquid that is not stripped Factor in Gilliland correlation... 

After completing the calculations in the second column, copy the formulas into the third and fourth columns and perform the calculations for these two sets of input parameter values. State how increasing the system pressure and feed temperature affect the fraction of the feed vaporized (nV) and the final system temperature (T), and briefly explain why your results make sense. 

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