Blending of streams

The heavy vacuum bottoms stream is fed to a Flexicoking unit. This is a commercial (125,126) petroleum process that employs circulating fluidized beds at low (0.3 MPa (50 psi)) pressures and intermediate temperatures, ie, 480—650°C in the coker and 815—980°C in the gasifier, to produce high yields of hquids or gases from organic material present in the feed. Residual carbon is rejected with the ash from the gasifier fluidized bed. The total Hquid product is a blend of streams from Hquefaction and the Flexicoker. 

The total liquid product is a blend of streams from liquefaction and FLEXICOKING. Product utilization studies indicate that the 350 F-fraction should be used in gasoline/petrochemical manufacture and the 350°F+ fraction in fuel oil applications. 

Consider mixing/blending of streams before considering separation. 

The heavy bottoms from vacuum distillation may be sent to a FLEXICOKING unit along with air and steam to produce additional distilled liquid products and a low quality fuel gas for process furnaces. Light hydrocarbon gases coming from the distillation unit are steam reformed to produce hydrogen. The total liquid yield is thus a blend of streams from liquefaction and flexi-coking. 

Example 5. Blending of streams with different temperatures... 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

Copper Oxides. Coppet(I) oxide [1317-39-17 is a cubic or octahedral naturally occurring mineral known as cuprite [1308-76-5]. It is ted or reddish brown in color. Commercially prepared coppet(I) oxides vary in color from yellow to orange to ted to purple as particle size increases. Usually coppet(I) oxide is prepared by pytometaHutgical methods. It is prepared by heating copper powder in air above 1030°C or by blending coppet(II) oxide with carbon and heating to 750°C in an inert atmosphere. A particularly air-stable coppet(I) oxide is produced when a stoichiometric blend of coppet(II) oxide and copper powder ate heated to 800—900°C in the absence of oxygen. Lower temperatures can be used if ammonia is added to the gas stream (27-29). 

Another entire column with a partially vaporized feed, a hqnid-sidestream rate equal to D and withdrawn from the second stage from the top, and a total condenser is shown in Fig. 13-36. The specified concentrations are Xp = 0.40, Xb = 0.05, and Xo = 0.95. The specified L/V ratio in the top sec tion is 0.818. These specifications permit the top operating hne to be located and the two top stages stepped off to determine the liqnid-sidestream composition Xs = 0.746. The operating line below the sidestream must intersect the diagonal at the blend of the sidestream and the overhead stream. Since S was specified to be equal to D in rate, the intersection point is... 

Interstage Mixing Efficiencies Mixing or stage efficiencies rarely achieve the ideal 100 percent, in which solute concentrations in overflow and underflow hquor from each thickener are identical. Part of the deficiency is due to insufficient blending of the two streams, and attaining equilibrium will be hampered further bv heavily flocculated sohds. In systems in which flocculants are used, interstage effi-... 

Blending of ehemieal reaetants is a eommon operation in tlie ehemieal proeess industries. Blend time predietions are usually based on empuieal eorrelations. When a eompetitive side reaetion is present, the final produet distribution is often unknown until the reaetor is built. The effeets of the position of the feed stream on the reaetion byproduets are usually unknown. Also, the seale-up of ehemieal reaetors is not straightforward. Thus, there is a need for eomprehensive, physieal models that ean be used to prediet important information like blend time and reaetion produet distribution, espeeially as they relate to seale and feed position. 

The teed to the cat cracker in a typical refinery is a blend of gas oils from such operating units as the crude, vacuum, solvent deasphalting, and coker. Some refiners purchase outside FCC feedstocks to keep the FCC feed rate maximized. Other refiners process atmospheric or vacuum residue in their cat crackers. In recent years, the trend has been toward heavier gas oils and residue. Residue is most commonly defined as the fraction of feed that boils above 1,050°F (565 C). Each FCC feed stream has different distillation characteristics. 

Since feed streams are not added after the start of a batch reaction one need only be concerned with proper initial addition and blending procedures. Streams flowing into a CSTR, however, are being introduced into a polymer latex. If added improperly, these streams can fail to be mixed completely and they can cause flocculation. Streams should be introduced where they are mixed rapidly and the ionic concentration should be as low as possible. Introduction of such streams as initiator solutions at high concentrations or in the wrong location can cause local flocculation and/or non-uniform reaction. 

Assuming that the properties of the mixture blend are in proportion to the volume of stream used, how much reformate and alkylate should be blended to minimize cost ... 

A process for the hydrogenation of adiponitrile and 6-aminocapronitrile to hexamethylenediamine in streams of depolymerized Nylon-6,6 or a blend of Nylon-6 and Nylon-6,6 has been described. Semi-batch and continuous hydrogenation reactions of depolymerized (ammonolysis) products were performed to study the efficacy of Raney Ni 2400 and Raney Co 2724 catalysts. The study showed signs of deactivation of Raney Ni 2400 even in the presence of caustic, whereas little or no deactivation of Raney Co 2724 was observed for the hydrogenation of the ammonolysis product. The hydrogenation products from the continuous run using Raney Co 2724 were subsequently distilled and the recycled hexamethylenediamine (HMD) monomer was polymerized with adipic acid. The properties of the polymer prepared from recycled HMD were found to be identical to that obtained from virgin HMD. 

Step functions, pulses, and square waves can be generated with a low volume, chromatographic-type 4-way valve. We have found that the desired two gas mixtures are best made up and stored in cylinders rather than made continuously by blending two streams. At the time of the switch, there is a momentary stopping of the flow, and this usually results in a change in composition if the mixture is made by the continuous blending of two streams. By this method one or more spurious peaks are added to the desired step function. Naturally these are trivial for slow responses, but important for fast ones. 

The term white distillate is applied to all the refinery streams with a distillation range between approximately 80 and 360°C (175 to 680°F) at atmospheric pressure and with properties similar to the corresponding straight-run distillate from atmospheric crude distillation. Light distillate products (i.e., naphtha, kerosene, jet fuel, diesel fuel, and heating oil) are all manufactured by appropriate blending of white distillate streams. 

Example g.l. Consider the two blending systems shown in Fig. 8.8. The flow rate or composition of stream 1 is the disturbance. The flow rate of stream 2 is the manipulated variable. In scheme A the sensor is located after the tank and therefore the... 

Detergent bars are either 100% synthetic detergent or a blend of detergent and soap. They are blended in essentially the same manner as conventional soap. Fairly frequent cleanups generate a wastewater stream. A process flow diagram is shown in Figure 19. 

Physical Form. Liquids, yellow to light brown in color. All fuel oils consist of complex mixmres of aliphatic (80-90%) and aromatic (10-20%) hydrocarbons. They may be classified as either a distillate fuel or a residual fuel, depending on the method of production. Fuel oils no. 1 and 2 are distillate fuels that consist of distilled process streams. Residual fuels such as fuel oil no. 4 are residues remaining after distillation or cracking or blends of such residuals with distillates. ... 

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