Combined feed

I. Catalytic reformer, combined feed/effluent exchanger shell plate postweld heat treated at 1250°F. 

K. Catalytic reformer combined feed piping welds and base metal postweld heat treatment. 

In the reverse flow type, the hydrotreater reactor is fed with fresh and recycled feeds, and is operated to accomplish partial conversion of that combined feed in the first stage. A graded HDT-HCK bed or a multi-functional catalyst can be used in the first stage. A very effective H2 separation is used for the first-stage effluent gas. A bottoms fractionator or an adsorption unit is used for removal of heavy PAHs. Carbon adsorption extends the catalyst life. The liquid product of the first reactor is mixed with a mixture of fresh and recycled H2. The whole second stage effluent is hydrotreated in the first stage. 

Referring to Fig. E72a, noting that the starting concentration of each reactant in the combined feed is C o = Cbo = 10 mol/liter and that = Cg everywhere, we find from Eq. 9 that... 

Interpolated Yields of Base and Combined Feeds at 70% and 55% Conversion... 

Figure 1.10 shows the yields of gasoline, LCO, bottoms, and coke as a function of conversion for cracking of the base feed (the first-pass cracking). The same figure also shows the corresponding yields, normalized to the fresh feed basis, for cracking of the combined feed (base feed -t- maximum recycle of the 650°F-750°F stream at... 

Fig. 7.70. Combined feed-forward/feedback control of the overhead product stream of a distillation column. Feed composition is the only significant load variable...

The essential equipment requirements for a tetramer unit are a combined feed-charge drum, charge pump, catalyst chamber, depropanizer, recycle column, rerun column, and attendant pumps and exchangers. Figure 1 shows such a unit as designed to produce tetramer and cumene alternatively. Table VII shows yields from the tetramer operation when a 350°-485°F. boiling-range tetramer is produced. 

The program numerically integrates the differential component and heat balances for the combined feed and recycle gas through the individual beds of both reactors accounting for the addition of cold quench gas between reactor beds and the recycling of fractionator bottoms to the second reactor inlet. 

In order to process SRC in the pilot plant equipment without using an extraneous solvent, a portion of the hydrotreated product was recycled to the feed reservoir as diluent. Recycle was essentially internal, and SRC and hydrogen were the only net feeds to the system. Pulverized SRC was added to the hot reservoir at a ratio of two parts SRC to three parts recycled product (combined feed ratio = 2.5). Vigorous stirring ensured that no undissolved solids were taken into the feed pump system. 

The program calculates total dissolved solids (TDS), conductivity, and the Langelier and Stiff-Davis Saturation Indexes (see Chapter 3.9). The screen allows the designer to use sodium, calcium, magnesium, chloride, sulfate, or bicarbonate to balance the water analysis. Water quality for up to five feed streams can be entered and blended together to make the total, combined feed water to the system. 

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). 

A condensed version of the ERDL alkylation pilot plant flow plan is shown in Figure 4. Olefin and isobutane feed streams are separately pumped to the unit from large feed storage vessels with Lapp Pulsafeeder diaphragm pumps and metered with turbine flow meters. The streams are then combined, caustic scrubbed, water washed and dried with molecular sieves before being sent to the reactor. The combined feed stream is then injected into the acid-hydrocarbon emulsion in the stirred reactor vessel. In order to maintain a constant temperature environment both reactor and settler are coolant jacketed. 

As a general rule, the combined feed to the reactor is a convenient stream to use as a basis of calculation for recycle problems when the stream composition is known. We will therefore temporarily ignore the specified methanol production rate, balance the flowchart for the assumed basis, and then scale the process to the required extent. In terms of the labeled variables, the problem statement will be solved by determining no, - oc, - sc, -Tsh. ip, and for the assumed basis, then scaling up no,... 

The combined feed to the reactor contains 53.7 moIe% C2H4, 36.7% H2O and the balance nitrogen which enters the reactor at SIO C. The reactor operates isothermally at 310°C An ethylene conversion of 5% is achieved, and the yield of ethanol (moles ethanol produced/mole ethylene consumed)... 

---