Spray reactor

Other reactor types are also used for gas-liquid reactions, but they are not very common in fine chemicals manufacture. Spray towers and jet reactors are used when the liquid phase is to be dispersed. In spray towers the liquid is sprayed at the top of the reactor while the gas is flowing upward. The spray reactor is useful when a solid product, possibly suspended in the liquid, is formed, or if the gas-phase pressure drop must be minimized. In a jet reactor, the liquid is introduced to the reaction zone through a nozzle. The gas flows in, being sucked by the liquid. 

Kaufman, E. N. Harkins, J. B., and Borole, A. P., Comparison of Batch-Stirred and Electro-Spray Reactors for Biodesulfurization of Dibenzothiophene in Crude Oil and Hydrocarbon Feedstocks. Applied Biochemistry and Biotechnology, 1998. 73(2-3) pp. 127-144. 

The spray reactor with the ultrasonic nozzle provided sufficient heat and mass transfer in the laboratory tests as essentially all of the CuCl2 was converted to Cu2OCl2. The ultrasonic nozzle provided droplets with an estimated size of 25 microns. Mass and heat transfer was achieved by injecting these small droplets/dehydrated particles into an atmosphere of superheated, humidified Ar. These results provide... 

Ferrandon, M.S., et a 1. (2010), Production of Cu2OCl2 Using a Spray Reactor and Formation of HC1 and Cl2 During the Hydrolysis of CuCl2 in the Cu-CI Thermochemical Cycle , International Journal of Hydrogen Energy, 35, 992-1000. 

Figure 1.3 Multiphase reactors (a) packed-bed reactor, (b) moving-bed reactor, (c) flui-dized-bed reactor, (d) bubbling column reactor, (e) spray reactor, and (/) kiln reactor.

Others [e.g., spray reactor (Fig. 1.3e), slurry reactor, kiln reactor (Fig. 1.3/), membrane reactor, etc.]. 

Product yields were increased by removing hydrazine in a liquid absorbent film and it was considered that a more efficient absorption technique should lead to even greater yields. The role of the absorbent was viewed solely as a device for reducing the residence time of the hydrazine in the discharge zone. In order to obtain a more intimate gas-liquid dispersion a spray reactor was used of the general design shown... 

Spray (indirect convection) residence time 3 to 30 s gas velocity 0.2 m/s thermal efficiency 50% adiabatic efficiency 100% solid temperatnre = adiabatic satnration temperatnre volnmetric heat transfer coefficient 0.13 to 0.18 kW/m K 1.8 to 2.7 kg steam/kg water evaporated. Ap = 1.5 to 5 kPa. See size redaction sprays, Section 16.11.8.2 spray reactor, Section 16.11.6.12 heat exchange. Section 16.11.3.12 and size enlargement. Section 16.11.9.4. Flash/transported (indirect convection) 175 to 630°C, gas velocity 3 to 30 m/s or 2.5 to 3 times the terminal velocity of the particles gas reqnirement 1 to 5 Nm /kg solid or 1 to 10 kg air/kg solid exit air temperatnre 20°C greater than exit dry solid temperatnre 4000 to 10,000 kJ/kg water evaporated. See transported slnrry, transfer Une reactors. Section 16.11.6.9. Heat transfer coefficient for gas drying h = 0.2 kW/m -K. Flnidized bed (indirect convection) residence time 30 to 60 s for surface fluid vaporization 15 to 30 min for internal diffnsion 3500 to 4500 kJ/kg water evaporated. See fluidized bed reactors. Section 16.11.6.27 heat transfer. Sections 16.11.3.4 and 16.11.3.8 size enlargement. Section 16.11.9.5 and mixing. Section 16.11.7.1. Tray/gas flow through the bed 0.24 to 3.3 g water evaporated/s m tray area. Residence time 2 to 8.5 h superficial air velocity 0.2 to 1 m/s steam 2 to 6.8 kg steam/kg water evaporated. Fan power 1.6 to... 

Equation 13.28 shows the very important role of the interface gas-liquid surface. Generally, a very high PO consumption rate is obtained if a reaction mass with a high surface area is generated, either by spray reactor type or by ejector reactor type (described in detail in Chapter 4). 

The reaction rate can be defined in different ways using a unit volume of liquid, a unit volume of reactor, or unit interfacial area as a basis. Since mass transfer coefficients for tanks and packed columns are often based on the volume of the apparatus, the overall reaction rate will be expressed in units such as Ib-mol-A/hr, ft or kg mol A/hr, m. The volume is the active reactor volume, which is the volume of the gas liquid mixture in a stirred tank or bubble column, the packed column volume, or the chamber volume for a spray reactor. The mass transfer of A to the interface is the first step ... 

Oxidation processes that could potentially eliminate reliance on a valuable solvent have been explored by a number of researchers. In these cases, the homogeneous catalyst must be modified so that it is soluble in a hydrocarbon, which serves simultaneously as a feedstock [101]. As discussed earlier, expanded solvents such as CO2 and HOAc have also been explored with conventional MC-type catalysts [79,102,103]. Supercritical H2O as a solvent was explored for Mn-Br catalyst for pX oxidation [104-109]. Combinations of ionic liquids and HOAc were recently disclosed by UOP investigators for pX oxidation to TA [110]. Lastly, the use of HOAc in a spray reactor in combination with the MC catalyst for pX oxidation was explored by Li. etal. [111]. 

Li, M. (2013) A spray reactor concept for catalytic oxidation of />-xylene to produce high-purity terephthalic acid. PhD Thesis. University of Kansas, p. 14. 

R-7 Spray reactor SC-a Oversize screen SC-9 Product screen GR-10 Crusher... 

At this stage the reactor product contains residual salts (sodium, potassium, and calcium chlorides) from the brine that were not affected by the thermal regime of the spray reactor. The raw magnesium oxide is mixed with water in settling tanks and converted to insoluble magnesium hydroxide,... 

FIGURE 15.7 Scheme of a spray reactor with circulating line. 

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