Feed/product heat exchange

The treated crude oil leaves the 2nd stage desalter and is sent to the dry storage tank via feed product heat exchanger where it gets Coolod down. A BE A W monitor at the 2nd stage outlet automatically diverts the product to feed tank if it is out of specifications. 

Figure 17.19. Reactors for the oxidation of sulfur dioxide (a) Feed-product heat exchange, (b) External heat exchanger and internal tube and thimble, (c) Multibed reactor, cooling with charge gas in a spiral jacket, (d) Tube and thimble for feed against product and for heat transfer medium, (e) BASF-Knietsch, with autothermal packed tubes and external exchanger, (f) Sper reactor with internal heat transfer surface, (g) Zieren-Chemiebau reactor assembly and the temperature profile (Winnacker- Weingartner, Chemische Technologie, Carl Hanser Verlag, Munich, 1950-1954).

The stage for each feed, product, heat exchanger, and pumparound... 

The HPC feedstock is mixed with recycle gas containing hydrogen and is preheated to reactor temperature in a feed/product heat exchanger and a furnace. In the reactor the charge mixture is contacted with a fixed bed of hydroconversion catalyst under mild conditions. 

The feed-product heat exchanger areas decrease regularly with increased operating temperature and they may be eliminated completely for F-31. This would represent a very substantial saving in initial plant cost, since these ex-... 

Incomplete feed-product heat exchange All work input to both compressors Work input of recycle brine pumps... 

Since the main contribution to the secondary refrigeration cycle load is the incomplete heat exchange between the feed and products, the energy required for this cycle may be varied at the expense of feed-product heat exchanger area. 

The reactor effiuent passes into a feed-product heat exchanger, where it is partially condensed. After washing with dilute caustic soda to neutralize traces of phosphoric acid, it passes into a second exchanger and on to a high-pressure separator tO give a liquid and a vapor stream. The condensate goes to purification and the vapor to recycle. The vapor is cooled by the recyde-gas cooler and scrubbed with water to remove alcohol. The build-up of impurities like methane and ethane is controlled at this point by venting a small stream of the recycle gas. 

Use pre-flash, feed conditioning, feed-product heat exchange, heat pumps, dividing-wall columns (Premkumar and Rangaiah, 2009), intermediate heat exchangers, optimize pump around flows. Organic Rankine Cycle (ORC) and Kalina Cycle (KC) to recover power (Chew et al., 2014)... 

The next synthesis step involves task integration, that is, the combination of operations into process units. In one task integration, shown in Figure 4.20, reactor effluent is quenched rapidly to 1,150 F, primarily to avoid the need for a costly high-temperature heat exchanger, and is sent to a feed/product heat exchanger. There, it is cooled as it heats the mixture of feed and recycle chemicals to 1,(X)0°F. The stream is cooled further to 100°F, the temperature of the flash separator. The liquid from the quench is the product of the reactor section, yet a portion of it is... 

Figure 4.30 Reactor with feed/product heat exchanger.

Return to the design of the toluene hydrodealkylation process, as it is presented in Section 4.3. In the reactor section, after heuristics are utilized to set (1) the large excess of H2 in the hydrodealkylation reactor, (2) the temperature level of the quenched gases that enter the feed-product heat exchanger, and (3) the temperature in the flash vessel, the simulator is used to complete the material and energy balances and to examine the effects of these heuristics on the performance of the reactor section. In the distillation section, after heuristics are used to set (1) the quahty of the feed, (2) the use of partial or total condensers, (3) the use of cool-... 

Let s consider an exothermic, reversible reaction, such as sulfur dioxide oxidation or methanol synthesis, occurring in an adiabatic, ideal PFR. A feed/product heat exchanger is... 

Figure 8-13 Schematic diagram of reactor and feed/product heat exchange .

Figure 8-14 Diagram of combination of reactor and feed/product heat exchanger, showing temperature profiles in both pieces of equipment, and the profile of fractional conversion of reactant A in reactor.

Figure 8-16 Representation of the simultaneous solution of the design equation and energy balance for an adiabatic PFR, plus the energy balance for a feed/product heat exchanger.

Figure 8-18 Feed/product heat exchanger with partial bypass of the feed stream.

In this chapter, we have seen that multiple steady states can occur when an exotirermic reaction takes place in an ideal CSTR, and when a feed/product heat exchanger is used in conjunction with an adiabatic PFR. We might ask whether this multiplicity is coincidental, or whether there is a link between these two examples. 

CSTRs and combinations of an adiabatic reactor and a feed/ product heat exchanger can exhibit multiple steady states and associated phenomena, such as feed-temperature hysteresis and blowout ... 

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