Shell side products

The highly exothermic nature of the butane-to-maleic anhydride reaction and the principal by-product reactions require substantial heat removal from the reactor. Thus the reaction is carried out in what is effectively a large multitubular heat exchanger which circulates a mixture of 53% potassium nitrate [7757-79-1/, KNO 40% sodium nitrite [7632-00-0], NaN02 and 7% sodium nitrate [7631-99-4], NaNO. Reaction tube diameters are kept at a minimum 25—30 mm in outside diameter to faciUtate heat removal. Reactor tube lengths are between 3 and 6 meters. The exothermic heat of reaction is removed from the salt mixture by the production of steam in an external salt cooler. Reactor temperatures are in the range of 390 to 430°C. Despite the rapid circulation of salt on the shell side of the reactor, catalyst temperatures can be 40 to 60°C higher than the salt temperature. The butane to maleic anhydride reaction typically reaches its maximum efficiency (maximum yield) at about 85% butane conversion. Reported molar yields are typically 50 to 60%. 

Figure 10-8. Single-pass shell and tube Teflon tube heat exchanger, countercurrent flow. Tube bundles are flexible tube Teflon joined in integral honeycomb tubesheets. Shell-side baffles are provided for cross-flow. Standard shell construction is carbon steel shell plain or Teflon (LT) lined. Heads are lined with Teflon . Tube diameters range from 0.125-0.375 in. O.D. the temperature range is 80-400°F pressures range from 40-150 psig. (Used by permission AMETEK, Inc., Chemical Products Div., Product Bulletin Heat Exchangers of Teflon . )...

In this case study, an enzymatic hydrolysis reaction, the racemic ibuprofen ester, i.e. (R)-and (S)-ibuprofen esters in equimolar mixture, undergoes a kinetic resolution in a biphasic enzymatic membrane reactor (EMR). In kinetic resolution, the two enantiomers react at different rates lipase originated from Candida rugosa shows a greater stereopreference towards the (S)-enantiomer. The membrane module consisted of multiple bundles of polymeric hydrophilic hollow fibre. The membrane separated the two immiscible phases, i.e. organic in the shell side and aqueous in the lumen. Racemic substrate in the organic phase reacted with immobilised enzyme on the membrane where the hydrolysis reaction took place, and the product (S)-ibuprofen acid was extracted into the aqueous phase. 

Ionol is a commercial antioxidant, 2,6-di-/cr/-butyl- -cresol, manufactured by Shell Chemical Corp. Inhibitors appear to minimize formation of polymeric side products, although with isoprene the effect is often small. 

Porous alumina tube externally coated with a MgO/PbO dense film (in double pipe configuration), tube thickness 2.5 mm, outer diameter 4 mm, mean pore diameter 50 nm, active film-coated length 30 mm. Feed enters the reactor at shell side, oxygen at tube side. Oxidative methane coupling, PbO/MgO catalyst in thin film form (see previous column). r-750X,Pr ed 1 bar. Conversion of methane <2%. Selectivity to Cj products > 97%. Omata et al. (1989). The methane conversion is not given. Reported results are calculated from permeability data. 

Gos from the wellhead with its associated condensate is first cooled in the Production Cooler. This cooler is o shell ond tube heat exchanger with the process fluid on the tube side and cooling water on the shell side. 

The liquid system from the production separator, consisting of a condensate/ water mixture, is first coded to ensure thot no gas breakout occurs during the subsequent stages and to reduce the level of dissolved water in the condensate. The Condensate Cooler is o shell and tube heat exchanger with inhibited fresh water on the shell side ond condensote on the tube side. 

Finally, the shell-side brine and the condensate reach the lowest pressure stage. At this point, the condensate is pumped from the system as product. The brine in excess of that required for recycle is pumped from the system and discharged to the ocean as blowdown. The remainder of the brine is mixed with the make-up and recycled through the system. 

Steam Superheater This unit superheats saturated steam from 250°C (and 4000kPa) to 380°C. The product steam is of medium pressure and suitable quality for in-house application and also for export. The superheater cools the reaction gases from the reactor exit temperature of 645°C to 595°C. Design pressure on the shell side is approximately 5000 kPa. The steam superheater is constructed from mild steel. 

The types of hollow fiber membranes in production are illustrated in Figure 3.32. Fibers of 50- to 200-p.m diameter are usually called hollow fine fibers. Such fibers can withstand very high hydrostatic pressures applied from the outside, so they are used in reverse osmosis or high-pressure gas separation applications in which the applied pressure can be 1000 psig or more. The feed fluid is applied to the outside (shell side) of the fibers, and the permeate is removed down the fiber bore. When the fiber diameter is greater than 200-500 xm, the feed fluid is commonly applied to the inside bore of the fiber, and the permeate is removed from the outer shell. This technique is used for low-pressure gas separations and for applications such as hemodialysis or ultrafiltration. Fibers with a diameter greater than 500 xm are called capillary fibers. 

Figure 13.19 A hollow fiber membrane reactor. Nutrients (S) diffuse to the microbial cells on the shell side of the reactor and undergo reaction to form products (P) such as monoclonal antibodies [31]. Reprinted from J. Membr. Sci. 39, K. Schneider, W. Holz, R. Wollbeck and S. Ripperger, Membranes and Modules for Transmembrane Distillation,...

The reactor effluent is fed to the shell side of reactor REACT2 that contains 30,000 kg of catalyst. The vessel contains 10,000 tubes, 0.0184 m in diameter and 12.2 m in length. The overall heat transfer coefficient between the two process gas streams is 144 kcal h-1 m-2 °C 1. Note that this is smaller than the U used in the first reactor because of the low film coefficients in gas-gas heat transfer. The heat transfer rate is 39 x 106 kcal/h. The total production rate of methanol in the two reactors is 3250 kmol/h (2260 kmol/h in the first reactor). 

Species-concentration profiles, obtained by integrating Equation (13.20), are plotted in Figure 13.7 for the case of two reactions in series (A —> B —> C) occurring in a catalytic hollow-fiber membrane. The reactant A contained in the bulk phase on shell-side flow through the membrane where reacting produces the intermediate product B then, B is converted in the final product C. Variations on concentration profiles are present only inside the fiber, outside the fiber there is no variation due to the reaction. No diffusion limitation in the films were considered in the present model in order to focus on transformation inside the membrane. 

Another source of oil, but of very different composition than the previously described oils, is cardanol oil, the major component of cashew nut shell liquid. This is a low-value side product of the mechanical processing of the cashew nut and is therefore a widely available source of cardanol oil. Cardanol oil is a mixture of 3-pentadecylphenol with either a saturated alkyl chain or a one-, two-, or threefold unsaturated alkyl chain (Fig. 10). 

Phosgene synthesis from CO and Cl2 in a multitubular reactor (Fig. 19-225). The activated carbon catalyst is packed inside the tubes with water on the shell side. Reaction by-products include CCl4. The temperature profile in a tube (shown in the figure) is characterized by a hot spot. The position of the hot spot moves toward the exit of the reactor as the catalyst deactivates. 

Heating and cooling of reactants and products are generally carried out in tubular or coil heat exchangers. Two fluids at different temperatures flow in the tube and shell sides of the exchanger, and heat transfer takes place from the hot to the cold fluid. The rate of heat transfer (Q) is the product of the heat transfer area (A), the temperature difference between the two fluids (AT), and the overall heat transfer coefficient (U). In other words Q = UA AT. 

Mechanism of shell-side corrosion in gasoline and light products storage tanks.124... 

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