Plasticizers continuous flow reactors

Plastic microcapillary flow disk (MFD) reactors have been constructed from a flexible, plastic microcapillary film (MCF), comprising parallel capillary channels with diameters in the range of 80-250 jxm. MCFs are wound into spirals and heat treated to form solid disks. These reactors are capable of carrying out continuous flow reactions at elevated temperatures and pressures with a controlled residence time. ... 

M. C. Gosnell, R. E. Snelling, and H. A. Mottola, Construction and Performance of Plastic-Embedded Controlled-Pore Glass Open Tubular Reactors for Use in Continuous-Flow Systems. Anal. Chem., 58 (1986) 1585. 

Copolymers are typically manufactured using weU-mixed continuous-stirred tank reactor (cstr) processes, where the lack of composition drift does not cause loss of transparency. SAN copolymers prepared in batch or continuous plug-flow processes, on the other hand, are typically hazy on account of composition drift. SAN copolymers with as Httle as 4% by wt difference in acrylonitrile composition are immiscible (44). SAN is extremely incompatible with PS as Httle as 50 ppm of PS contamination in SAN causes haze. Copolymers with over 30 wt % acrylonitrile are available and have good barrier properties. If the acrylonitrile content of the copolymer is increased to >40 wt %, the copolymer becomes ductile. These copolymers also constitute the rigid matrix phase of the ABS engineering plastics. 

The catalytic degradation of PS was carried out in a semi-batch reactor where nitrogen is continuously passed with a flow rate of 30 mL/min. A mixture of 3.0 g of PS and 0.3 g of the catalyst was loaded inside a Pyrex vessel of 30 mL and heated at a rate of 30 C/min up to the desired temperature. The distillate from the reactor was collected in a cold trap(-10 °C) over a period of 2 h. The degradation of the plastic gave off gases, liquids and residues. The residue means the carbonaceous compounds remaining in the reactor and deposited on the wall of the reactor. The condensed liquid samples were analyzed by a GC (HP6890) with a capillary column (HP-IMS). 

Figure 6.25 (a) Flow scheme of the continuous production of fuels from waste plastics (b) schematic diagram of the pyrolytic reactor used in the pilot plant. (Reproduced with permission from Elsevier)... 

The reactor section of the plant consists of the reactor, which together with other equipment carries out a continuous conversion of waste plastic to fuels. The molten waste plastic, free of chlorine, nitrogen and other organic impurities, is fed in to the reactor at the top end and allowed to flow over a heated surface at 350°C in the presence of the coal and patented additives. Upon contact with the hot surface and the mixture of coal and additives, the viscous waste plastic converts to gaseous form. 

The biggest difference between this process and the others lies in the reactor, which was originally a fixed-bed reactor. A sand fluidized-bed reactor has been adopted for the BP process, which can guarantee a uniform temperature in the reactor due to the uniform particle size and fluidized nature of sand. In traditional processes, because of the poor heat transfer properties of plastics, a uniform temperature is difficult to achieve in the plastics feedstocks so a long reaction time was always required. On the other hand, after waste plastics are heated and melted, they usually adhere to the surface of reactors owing to their poor flow characteristics. The BP process has successfully solved all these problems, and a continuous production of liquid oil is achieved. 

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