Spouted bed reactors

The cracking of PE/LCO and PP/LCO blends over HZSM-5 zeolite catalysts in the riser simulator at 450°C led towards mainly a C5-C12 hydrocarbon fraction of aromatic nature and a low yield of C1-C2 gases and coke. 

---

FIGURE 11.10 Spouted-bed reactor with (a) normal gas outlet (b) side outlet. 

Figure 11.10(b) can be modeled as a piston flow reactor with recycle. The fluid mechanics of spouting have been examined in detail so that model variables such as pressure drop, gas recycle rate, and solids circulation rate can be estimated. Spouted-bed reactors use relatively large particles. Particles of 1 mm (1000 pm) are typical, compared with 40-100 pm for most fluidizable catalysts. 

Split-boundary problems 123, 644 Spouted bed reactor 466 Stability of chemical reactors 361 Stage... 

Thermal plasma-assisted decomposition (cracking) of heavy hydrocarbons is reported in Ref. 141. Decomposition of paraffinic hydrocarbons including C16H34 by Ar-H2 plasma was carried out by continuous injection of the hydrocarbon in the spouted-bed reactor. Controlling temperature, residence time, and H2 concentration allows reaching the... 

Voutetakis, S. et al., Catalytic partial oxidation of methane in a spouted bed reactor, in Natural Gas Conversion V, Studies in Surface Science and Catalysis, vol. 119, Parmaliana, A. et al., Eds., Elsevier, Amsterdam, 807 1998. 

SPBEDRTD - Spouted Bed Reactor Mixing Model System... 

Bioremediation of Soil Particles 591 Spouted Bed Reactor Mixing Model 390 Steady-State, Two-Pass Heat Exchanger 515 Multicomponent, Semi-Batch Steam Distillation 508 Space-Time-Yield and Safety in a Semi-Continuous Reactor 365... 

Deoxygenation reactions are catalyzed by acids and the most studied are solid acids such as zeolites and days. Atutxa et al. [61] used a conical spouted bed reactor containing HZSM-5 and Lapas et al. [62] used ZSM-5 and USY zeolites in a circulating fluid bed to study catalytic pyrolysis (400-500 °C). They both observed excessive coke formation on the catalyst, and, compared with non-catalytic pyrolysis, a substantial increase in gaseous products (mainly C02 and CO) and water and a corresponding decrease in the organic liquid and char yield. The obtained liquid product was less corrosive and more stable than pyrolysis oil. 

Defluidization modelling of pyrolysis of plastics in a conical spouted bed reactor... 

J. Bilbao, M. Olazar, A. Romero, J.M. Arandes, Design and operation of a jet spouted bed reactor with continuous catalyst feed in the benzil alcohol polymerization, Ind. Eng. Chem. Res. 26 (1987) 1297-1304. 

Thermal pyrolysis for upgrading plastic wastes is one of the better methods for recycling plastics in terms of its perspectives for industrial implementation. The conical spouted bed reactor proposed in this paper may be a solution to the problems arising in fluidized beds handling sticky solids, as particle agglomeration phenomena, which can cause defluidization. In order to avoid defluidization, experiments have been carried out in batch mode in the temperature range of 450-600 °C. A good performance of the reactor is proven under the conditions of maximum particle stickiness. 

The good behaviour of the conical spouted bed reactor is quantified on the basis of the critical thickness of the fused plastic that may be handled. The critical thickness is the value above which the particles fuse when they collide and is a function of the thickness (viscosity) and of the momentum of the colliding particles. From the hypothesis of the critical thickness model of Arena and Mastellone [12], the following expression has been deduced for the critical thickness for... 

Atutxa A, Aguado R, Gayubo AG, Olazar M, Bilbao J. Kinetic description of the catalytic pyrolysis of biomass in a conical spouted bed reactor. Energy Fuels. 2005 19 765-74. 

Nonagitated three-phase countercurrent-flow reactors (spouted-bed reactors)... 

The three-phase continuous countercurrent fluidized-bed reactor and the spouted-bed reactor have been used on the laboratory scale. Pruden and Weber88 have shown that the countercurrent mode of operation for hydrogenation of a-methyl styrene performs better than the cocurrent fixed-bed operation under similar reaction conditions. 

R. Aguado, M. Olazar, B. Gaisan, R. Prieto and J. Bilbao, Kinetics of polystyrene pyrolysis in a conical spouted bed reactor. Chemical Engineering Journal, 92, 91-99 (2003). 

---