Reactors rotary kilns

Liquid Fuel from Plastic Wastes Using Extrusion-Rotary Kiln Reactors... 

Rotary kiln processes are continuous processes that use a rotary kiln reactor to depoly-merize plastic [4, 5]. They have a lower capital cost compared with fluidized-bed processes and their liquid product resembles crude oil. The following are some general characteristics of kiln processes ... 

The Veba Oel pyrolysis processes was originally designed for the upgrading of heavy oil hydrogenation residues (such as coal and petroleum residues). The pyrolysis process uses a rotary kiln reactor with spheres and crossform bodies to prevent coke deposition. The kilns used in this process were operational until 1964. However, it was found that these kilns had three disadvantages [8] ... 

Li et al. [16] also stndied the influence of pyrolysis temperature on the pyrolysis products derived from solid waste in a rotary kiln reactor. They used an externally heated laboratory-scale rotary kiln pyrolyser (Figure 19.8). The length of the rotary kiln was 0.45 m with an internal diameter of 0.205 m. Kiln rotation speed can be adjusted from 0.5 to 10 rpm. The raw materials used in this study were polyethylene (PE), wood and waste tyres. The results obtained by Li et al. [16] reiterated that as the reaction temperature profile changes so does the product yield (Figure 19.9). 

Figure 19.8 Rotary kiln reactor. 1 thermometer 2 bearing 3geartransmission 4electric furnace 5 rotary kiln 6 temperature controller 7 seal 8 tube condenser 9 filter 10 total flow meter 11 computer 12 gas sampling device 13 tar reservoir 14feed and discharge opening 15 electric motor [16]. (Reproduced with permission from Elsevier)...

As described previously pyrolysis is a process that thermally degrades organic waste at high temperatures in absence of air and oxygen. This process can be carried out in a rotary kiln reactor or in a fluidized bed. In a rotary kiln process the feed material is conveyed through a rotating drum (i.e. reactor) and is then pyrolysed in the hot atmosphere into gas and solid residues. The residence time of the reaction is dependent on the rotating... 

The most popular type of gasification furnace in Europe is the vertical shaft gasifier, used in the Andco-Torrax, Saarberg Fernvarme and Pyrogas process. Pyrolysis processes are often conducted in an indirectly heated rotary kiln reactor, e.g. in the Kiener, GMU or Krauss-Maffei process. Fluidized bed reactors are used at the universities of Hamburg, Eindhoven and Brussels and thus seem more popular in academic than in industrial spheres. 

A schematic of the Gravimelt Process is shown in Fig. 26. Feed coal is premixed with anhydrous sodimn hydroxide or mixed sodium and potassium hydroxides, and then fed to a rotary kiln reactor where the mixture is heated to reaction temperatures of 325 15°C, causing the caustic to (1) melt and become sorbed in the coal matrix, (2) react with the coal sulfur and mineral matter, and (3) dissolve the reaction products containing sulfur and inorganic components. The kiln reactor can be seen in operation in Figiue 27. 

Conrad process—American Plastics Council Variable residence time and pyrolysis temperatures, rotary kiln reactor, CaO for HCl capture Feedstock for steam crackers giving higher amount of monomers, 86% naphta grade products 381a... 

Besides solvolysis, processes are employed working at high temperatures and using steam as water source in order to reduce the pressure necessary for the reaction. Such processes are performed in fluidized beds, rotary kiln reactors or by reactive extrusion. 

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