Reactor multi-zone

Figure 5.1-8. Multi-zone autoclave reactor. E, Ethylene I, initiator P, product a, reactor b, motor c, stirrer d, connecting cable e, bearing.

High conversion, similar to that in a tubular reactor with multiple feed, is obtained in a multi-chamber or multi-zone autoclave reactor. This is an elongated cylindrical vessel with a ratio of length to inner diameter of 10 - 12. It is subdivided by baffles and the stirrer into two to five chambers (Fig. 5.1-8, left). 

Description The Spherizone process is Basell s new proprietary gas-loop reactor technology based on a Multi-Zone Circulating Reactor (MZCR) concept. Inside the reactor (1) the growing polymeric granule is continuously recirculating between two interrelated zones, where two distinct and different fluodynamic regimes are realized. 

The development of the Spherizone technology started in 1995 and was subsequently scaled up from pilot plant to commercial size in 2002, when the new multi-zone circulating reactor (MZCR) was installed at Basell s plant in Brindisi, Italy. 

The catalyst is fed continuously to the multi-zone circulating reactor, which is the core of this new technology. This loop reactor consists of two distinct reaction zones, each operating under its own peculiar fluid-dynamic regime. 

Figure 8.18. Three-zone TAP reactor (D. Constales, G. S. Yablonsky, G. B. Marin and J. T. Gleaves, Multi-zone TAP-reactors theory and application. Ill Multi-response theory and criteria of instantaneousness, Chemical Engineering Science, 59 (2004) 3725).

LyondellBasell Polypropylene Propylene Gas-loop reactor technology, Sperizone process, based on Multi-Zone Circulating Reactor (MZCR) concept, produces polypropylene-based polymers, including homopolymer polypropylene (PP), random, heterophasic impact and specialty dual-composition copolymers 13 2010... 

Clarke,B.L., 1974. Stability analysis of a model reaction network using graph theory. J.Chem.Phys. 60,1493-1501. Constales, D., Yablonsky, G.S., Marin, G.B., Gleaves, J.T., 2001. Multi-zone TAP-reactors theory and application I. 

Multi-zone, Tanks-in-Series, and Axial dispersion models (Fig. 12.3-1 F) Other, less fundamental approaches accounting for mixing limitations in reactors are described in Section 12.7. They are based on simplified descriptions of the mixing pattern, e.g., a ID axial dispersion approach, or on the decomposition of the complex flow reactor into multiple interconnected regions or zones, each of these being described by a different idealized mixing pattern. Such semi-empirical models contain model parameters which have to be determined, experimentally or a posteriori from PDF, CFD, or RTD data. 

To account to a certain extent for the effects of macro-mixing in the species balance equations, so-called multi-zone models have been developed. The reactor is divided in multiple, not necessarily geometrical, zones and, within each zone, an idealized mixing or flow pattern is assumed in the derivation of the species... 

Reactor type Multi-plate-stack with mixer-reactor sections Diffusion zone length 1 mm... 

This system is a chip version of three dimensional micro mixer-tube reactor setups [21]. It comprises a triangular interdigital micro mixer with a focusing zone that thins the multi-lamellae and a subsequent reaction channel that is surrounded... 

Similar to chemical vapor deposition, reactants or precursors for chemical vapor synthesis are volatile metal-organics, carbonyls, hydrides, chlorides, etc. delivered to the hot-wall reactor as a vapor. A typical laboratory reactor consists of a precursor delivery system, a reaction zone, a particle collector, and a pumping system. Modification of the precursor delivery system and the reaction zone allows synthesis of pure oxide, doped oxide, or multi-component nanoparticles. For example, copper nanoparticles can be prepared from copper acetylacetone complexes [70], while europium doped yttiria can be obtained from their organometallic precursors [71]. 

A packed bed membrane reactor is an assembly of usually uniformly sized catalytic particles, which are randomly arranged and firmly held in position within a vessel or tube. A permeable membrane (generally tubular) is immersed within the particles or represents the tube wall of the fixed bed. The PBMR could look, for example, like a tube-in-shell or a multi-tubular reactor. Zooming in on the reaction zone the different phenomena occurring in the reactor can be described as follows ... 

Reactor power is chosen in the range of 1500-2KX) MW (thermal). Sodium void reactivity effect is (0 to -0.1) x l0 The number of the zones with different enrichment is 2 or 3. A multi-batch loading scheme is assumed. The following reactivity effects are taken into account sodium thermal expansion and void reactivity Doppler effect axial core expansion radial core expansion control rod drive expansion. IPPE provides reactivity worth tables and specifies correlations for calculations of structural feedback effects of reactivity (with reference data). The duration of the LOF scenario to be computed is taken as about KXX) s. 

ICl patented polymerization or copolymerizati(Hi of ethylene using transition metal complex (preferably Z-N catalyst on support) at P = 30-100 MPa and T = 100 °C in pentane. Multi-reactor with different feeds and/or conditions or a tubular reactor with different reaction zones may be used. Several other LDPE manufacturers (e.g., DuPont, Mitsui)... 

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