Pyrolysis continued pilot plant

Industrial Engineering Chemistry Research 37, No.6, June 1998, p.2316-22 DEVELOPMENT OF A CONTINUOUS ROTATING CONE REACTOR PILOT PLANT FOR THE PYROLYSIS OF POLYETHENE AND POLYPROPENE... 

A pilot plant for the high temperature pyrolysis of polymers to recycle plastic waste to valuable products based on rotating cone reactor (RCR) technology. The RCR used in this pilot plant, the continuous RCR was an improved version of the bench-scale RCR previously used for the pyrolysis of biomass, PE and PP. 9 refs. 

The pyrolysis of mixed waste thermoplastics in a pilot plant of 360 ton/year at the Korea Institute of Energy Research (KIER), as shown in Figure 5.6, has an oil yield of about 82% for continuous process control over two days. The distribution of oil product is 27% gasoline product and 73% heavy oil product. Also the yield, of gas product is 10-15% and consists of about 18.1% Ci, 15.2% C2, 30.3% C3, 21.9% C4 and 14.3% C5 components. Similar results were obtained by other researchers, as shown in Table 5.1. 

An oil of low flash point in the range 14-18°C, and of 41-43 MJ Kg gross calorific value has been obtained in batch pyrolysis [36] of automobile tyre waste. In a pilot plant with semi-continuous feeding [37] the liquid yield of tyre waste decreased seriously with increasing temperature, and it was always lower in an atmosphere containing oxygen that in nitrogen. 

Laboratory experiments were first conducted using a continuous pyrolysis reactor to establish optimal conditions for lube base oil production from polyethylene (PE). A pilot plant study was then carried out in a 1-gallon-per-day unit. The main findings included ... 

The PDU vacuum pyrolysis reactor is a semi-continuous horizontal pilot plant reactor 3 m long with a diameter of 0.6 m and a throughput capacity of about 50 - 200 kg/h, depending on the feedstock treated. The configuration of the PDU reactor is almost the same as that of the industrial reactor, except t t the PDU has smaller agitation blades. Two types of tests have been conducted with this reactor, the cold and the hot runs. In the cold tests, the particle flow behaviour is studied by a stimulus-response technique, under different agitation speeds and feed rates. The hot tests enable the conversion to be determined as a function of the feed rate and the agitation speed. 

The authors had already conducted the laboratory scale study and the preliminary pilot plant study, and proposed that "drying-pyrolysis process" (pyrolysis followed by indirect steam drying of dewatered sludge cake) (Fig,-i) could be one of the most economical and feasible alternatives for conventional incineration process. The authors have further conducted the feasibility study on a continuous system of "drying-pyrolysis process to evaluate the performance of the process in pilot scale, and to demonstrate its effectiveness as a thermal processing of sewage sludge. This paper presents the results of this pilot plant study. 

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