ROTATING CONE REACTOR

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 Biomass Technology Group (BTG, Enschede, The Netherlands) process is based on a rotating cone reactor that serves mechanical fluidization of hot sand, which is recirculated in the reactor system. Since 2005, there is a plant in Malaysia with a throughput capacity of 50 t/day of palmoil residues. 

The majority of the scientific literatnre devoted to pyrolysis of plastics is focused on the development of equipment or processes having recycling as their ultimate goal. Many of these have been introdnced in previous chapters and include studies using fluidized beds [61-77], cycled-sphere reactors [78, 79], fixed-bed reactors [80, 81], rotary kilns [82], screw reactors [83] and rotating cone reactors [84]. In all these studies the chemical analysis of the pyrolysis prodncts has been an important goal in order to asses the behavionr of the pyrolysis of plastics. 

R. W. J. Westerhout et al. Recycling of polyethene and polypropene in a novel bench-scale rotating cone reactor by high-temperature pyrolysis. Industrial and Engineering Chemistry Research, 37, 2293-2300 (1998). 

Wagenaar B, The rotating cone-reactor (1994), Ph.D. thesis University of Twenie... 

The rotating cone reactor, invented at the University of Twente (27) and being developed by BTG, is a recent development and effectively operates as a transported... 

Venderbosh R.H., Janse A.M.C., Radovanic M., Prins W., Van Swaaij W.P.M, (1997) Pyrolysis of Pine Wood in a Small Integrated Pilot Plant Rotating Cone Reactor, In Biomass Gasification and Pyrolysis, (Ed, by M, Kaltschmitt A.V. Bridgwater), pp. 345-353, CPL Press, Newbury. 

Which pre-treatment steps are required to produce a suitable feedstock for the rotating cone reactor. 

The development of the rotating cone reactor started a decade ago at the University of Twente. Since then the technology has evolved from laboratory scale to a pilot scale unit which is characterized by a biomass throughput of 200 kg per hour. In this section first the pyrolysis reactor is described as the core of the teclmology. Then the entire pilot plant is described and finally, characterization results of the plant are presented. 

The Aston and IWC liquids were produced in a fluid bed and the BTG liquid was produced in the rotating cone reactor, all using wood feedstocks. 

The pyrolyser is a patented rotating cone reactor. Biomass particles ( 1) are fed near the bottom of the pyrolysis reactor (Rl) together with an excess flow of hot heat carrier material such as sand, where it is being pyrolysed at 500 to 600°C. The... 

Figure 4.28 Schematic diagrams of a pilot plant for the thermal conversion of plastic wastes with a continuous rotating cone reactor (a) pilot plant, (b) cone reactor, (c) cone dimensions.l9...

Recent work at the University of Twente, Netherlands [5] focused on the design of a Rotating Cone Reactor to meet BTM process requirements such as short solid and gas phase residence time, high heat transfer, no carrier gas, economic scale-up, uniform reactor temperature. Problems still not solved include removal of HCl, requirements for very small particle size of feedstock, removal of heavy metals and additives. 

A wide range of reactors such as bubbling and circulating fluidized beds, ablative, entrainment, rotating cone, auger, and vacuum have been operated. Fluidized beds were the most often used because of their ease of... 

Figure 8. Principle of rotating cone pyrolysis reactor Vacuum pyrolysis...

Wagenaar BM, Vcndeibosch RH, Carrasco J, Strenziok R, van der Aa BJ, Rotating cone bio-oil production and applications , these proceedings Yang J, Blanchette D, de Caumia B, Roy C Modelling, scale-up and demonstration of a vacuum pyrolysis reactor , These proceedings. 

The rotating cone was developed at the University of Twente in the Netherlands. It is also based on the solid biomass being heated up by contact with a hot surface. The reactor is essentially a cone upside down with its base open. The cmie is heated on the outside surface, and it rotates continually. Biomass is fed along with sand, and it is driven centrifugaUy, rotating in a spiral trajectory until it leaves the reactor at the top (base). It has been proposed that the biomass and sand recovered at the top should go to a burner so that the char can be burned and the sand returned to the reactor. Figure 9 shows a rotating cone. 

Of course, the operation of this system is very complex, and it requires the smooth integration of three units the rotating cone pyrolyzer, a riser for the sand being recycled, and a bubbling bed char combustor. The system requires gas for the sand transport and char bum-off. Similarly to the vortex reactor, the scale-up of the cone reactor is considered extremely difficult. 

Alternatively, flash pyrolysis processes were developed for biomass liquefaction as well [5]. On a water- and ash-free basis, from wood typically 75% liquids (including 25% of water), 10% of solid char, and 15% of gases, mainly CO2 and CO, are formed at 5 00 ° C with gas retention times of only a few seconds. Several reactor concepts such as stationary and fluidized fluidized beds, the mechanically agitated rotating cone and Auger reactors, a well as ablative and vacuum pyrolysis have been carried out and operated on a semi-technical and pilot scale. For fast pyrolytic treatment of... 

Geocomet reactor Geoma AG Rotating tubular bed or impact rod Continuous as settled powder via a sludge cone No ... 

Cell Line Product Reactor Volmne (L) Max. Perfusion Rate (d ) Cultivation Filter Material/ Time Pore Size (d) Rotation Speed (rpm) Did fouling occur Max. Viable Cell Cone. (10 mL ) Separation Efficiency (%) Ref... 

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