Generic Reactor Description

In the reactor, the chips are heated to pyrolysis temperature, and the tire chips begin to break down. 

Reactors are operated from 237 to 1000 C (460 to 1830 F), with the maximum oil yield occurring at 450 C (840 F).1 Conrad s reactor, which is a cylindrical-shaped furnace chamber with two reaction tubes or retorts, is operated between 900 and 1,000 F.1 

Because of high reactor temperatures, the hydrocarbon volatiles vaporize immediately, and are vented from the reactor to a quench tower (Item 3), where they are sprayed with cooled, recycled, heavy oil, and the larger molecules (molecules containing eight carbon atoms (C8) or more) are condensed. The condensate leaves from the bottom of the quench tower and is collected in the heavy oil receiver (Item 4). Compounds that are not condensed (i.e., light oil, C3-C7) in the quench tower enter a non-contact condenser that uses cold water The light oils, C3 to C7, are condensed and collected in the light oil receiver (Item 6). 

Although pyrolytic oil contains significant quantities of benzene and toluene that have high value in the pure form, removal of these compounds from the pyrolytic oil requires expensive fractional distillation equipment. Pyrolysis operators have been reluctant to make the capital investment in distillation equipment because the risk is too high and the return on investment is too low. As a result, the pyrolytic oil must be sold as a replacement for Number Six (low priced grade) fuel oil. The oils generated at Conrad s Centralia facility contain a maximum of 1.5 percent sulfur, and have a potential market as blender oils for commercial fuel.1 

The gas remaining after oil recovery, called pyrolytic gas, or pyro-gas, is typically composed of paraffins and olefins with carbon numbers from one to five. Depending on the process, the heat value of the gas can range from 170 to 2,375 Btu per cubic foot, and averages 835 Btu per cubic foot.4 (Natural gas averages around 1000 Btu per cubic foot.) Most processes use the pyrolytic gas as fuel to heat the reactor. Any surplus gas can be flared or used to replace natural gas as boiler fuel. Emissions from burning 

---

Many other, less obvious physical consequences of miniaturization are a result of the scaling behavior of the governing physical laws, which are usually assumed to be the common macroscopic descriptions of flow, heat and mass transfer [3,107]. There are, however, a few cases where the usual continuum descriptions cease to be valid, which are discussed in Chapter 2. When the size of reaction channels or other generic micro-reactor components decreases, the surface-to-volume ratio increases and the mean distance of the specific fluid volume to the reactor walls or to the domain of a second fluid is reduced. As a consequence, the exchange of heat and matter either with the channel walls or with a second fluid is enhanced. 

These data clearly show that the size of reactor is an important factor to be considered in dealing with data obtained by a reactor. The change of reactor size influences the overall performance of LCVD of a monomer, and consequently the description of operating conditions such as flow rate, system pressure, and discharge wattage cannot be used in a generic sense, unless the size factor of reactor, domain of plasma polymerization, and the relative position of the substrate with respect to the core of luminous gas phase and/or to the tip of glow could be identified. These data show the complicated system-dependent nature of LCVD, particularly that a monomer does not produce a polymer and that the externally operative parameters, such as W, p, and F, are not the actual parameters that control LCVD. 

The reaction (9.3) represents a generic description of the galvanic displacement deposition. This relatively simple process does not require any complicated equipment. Practically speaking, only a beaker (or a reactor) for a solution containing ions of the more noble metal and a less noble metallic substrate immersed into the solution is needed for this process to proceed. Although not very descriptive, other names for the galvanic displacement reaction used in practice include cementation or immersion plating. 

A detailed description of typical sulfonation systems - is omitted from the production descriptions contained in this chapter. However, all MES processes share the common use of a falling-film sulfonation system for the initial reaction of ME with air/SOj. The processes differ in the treatment of MESA after the sulfonation reactor. The sulfonation systems shown in Figure 11.1 are generic for... 

The IVMS is a monitoring system which generates data allowing detection of the motion of reactor internals. It uses linear summed detector signals from each of the ex-core neutron flux channels. The IVMS also has the capability to perform the analyses recommended by ANSI/ASME OM-5-1981. The system function, theory of operation and description are provided in CESSAR-DC, Section 7.7.1.6.1. [A related generic safety issue (GSI C-12) also addresses the IVMS.]... 

For particular cases, it maybe required to add more complex phenomena with additional effects or more evolved descriptions of the same mechanisms. In general, however, reduced models are appropriate and desirable. Historically, this stemmed from the shorter computational effort and time required for the numerical solution of such models. Today this is also an advantage for optimization, control, and real-time simulation applications, and reliable simplified models are still used for almost all purposes due to the lower number of dimensionless parameters requiring estimation and to the success found in the description of experimental results. On the other hand, complex detailed models fulfill the most generic purpose of reactor simulation, which is related to the prediction of the actual behavior from fundamental, independently measured parameters. Therefore, it is important to understand the equivalence and agreement between both detailed and reduced models, so as to take advantage of their predictive power without unnecessary effort. 

---