Tubular reactors in series

Tubular reactors in series in heating box with external isolation valves... 

There is also a wider variety of reactor and system types for tubular reactors. Many operate adiabatically, while others are heated or cooled. Multiple tubular reactors in series with intermediate heating or cooling are quite common. The most common industrial use of tubular reactors is in systems where a solid catalyst is required. The catalyst is installed in beds or inside tubes in the shell of the reactor vessel, and the process reacting fluid (gas or liquid) flows through the fixed catalyst. 

Figure 2-7 Dinwraot G (an organometaHic catalyst) unit (two CSTRs and one tubular reactor in series) to dimeiise propylene into isohexanes. Instisit Fran ais du Ptetrdle process. [Ptioto courtesy of Editions Technip Institut Franjais du PetnSie).]...

Consider first the case of two tubular reactors in series, making high-impact polypropylene. Reactor 1 produces isotactic polypropylene, while random ethylene-propylene copolymer is made in Reactor 2. Assuming that both reactors are ideal plug-flow reactors, the residence time of all the polymer particles in each reactor is exactly the same. Consequently, if the distribution of active sites in the... 

Reactor design 2x2 m tubular reactors in series Adiabatic beds for < 30% C3H6 Tubular reactors for 50-60% olefins... 

Tanks-in-series reactor configurations provide a means of approaching the conversion of a tubular reactor. In modelling, they are employed for describing axial mixing in non-ideal tubular reactors. Residence time distributions, as measured by tracers, can be used to characterise reactors, to establish models and to calculate conversions for first-order reactions. 

Alternatively a series of several continuous stirred tanks could be used in place of the tubular reactors in (a) and (d)... 

An industrial system consists of a nonisothermal CSTR (with a cooling jacket) and a tubular adiabatic reactor in series. The reaction is a first-order irreversible reaction ... 

A tubular prereactor, in series with CSTR system, can offer stability advantages, which will he discussed later. A number of other flow alternatives are also possible with a CSTR-series system but these alternates are not widely utilized. An obvious flow alternative for a reactor system consisting of a series of CSTRs would he to introduce some portion of the total recipe at places other than the front end of the reactor train. These intermediate feeds would, in many respects, be analogous to semicootinuous operation of batch reactors. 

Heavy Oil Preparation and Separation. Hydrogenation of Hiawatha, Utah, coal [C 72.0 H 5.6 N 1.7 S 0.90 O 19.8 dry, ash-free (DAF) %] was performed at a reaction temperature of 510°C and 12.4-MPa hydrogen pressure with ZnCl2 impregnated on the coal as catalyst in an entrained-flow, tubular coil reactor (10). The reaction products were trapped in three reservoirs connected to the reactor in series and were separated according to their condensability. Heavy-oil products collected in the first reservoir, nearest to the reactor, were used in this study. 

In the case of refinery cuts from FCC units, having a relatively low isobutene concentration (Table 11.2), the plant layout is less sophisticated because it is sufficient to achieve 90-95% of isobutene conversion in this case the plant configuration is based on a single reaction stage with tubular and adiabatic reactors in series with intermediate cooling. 

In the previous example increasing the number of stirred-tank reactors from one to two (with the same total residence time) caused an increase in conversion from 61.2% to 68.8%. Further increase in number of tank reactors in series would lead to a maximum conversion of 79.4%, the value for a tubular-flow reactor with the same residence time. Thus an infinite number of stirred-tank reactors in series is equivalent to a tubular-flow reactor, provided the total residence time is the same. This may be... 

The experimental rig consisted of a stainless tubular preheater and reactor in series, 17 mm ID and 250 mm long with 5.5 mm axial thermowell. Electric tapes controlled by Eurotherm heated the reactor and preheater. 1-4 g of catalyst (extrudates 1.5 mm in diameter and 2-3 mm length) diluted with 4-8 g of inert SiC pellets to keep the reactor isothermal, was located between two layers of SiC particles of 3-4 mm in diameter. The preheater, operated at 300°C was filled with SiC. 

The reactors with recycle are continuous and may be tanks or tubes. Their main feature is increasing productivity by returning part of unconverted reactants to the entrance of the reactor. For this reason, the reactant conversion increases successively and also the productivity with respect to the desired products. The recycle may also be applied in reactors in series or representing models of nonideal reactors, in which the recycle parameter indicates the deviation from ideal behavior. As limiting cases, we have ideal tank and tubular reactors representing perfect mixture when the recycle is too large, or plug flow reactor(PFR) when there is no recycle. 

LLDPEs from tubular or cascade loop reactor have fewer LCB and broader MWD than autoclave products. Modeling of an industrial slurry-phase olefin catalytic polymerization of two loop reactors in series was carried out by U. Thessaloniki and Total Petrochemicals... 

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