Plastics Process Analysis, Instrumentation, and Control. Группа авторов

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Plastics Process Analysis, Instrumentation, and Control - Группа авторов


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for the use of plastics.

      The scientific literature about the remediation of plastics using various methods has been discussed, which can help to promote further improvement of the existing system by competent authorities and researchers (87).

       1.15.3.2 Bioplastics

      Growing environmental concerns associated with the accumulation of plastic waste in the natural environment have incentivized considerable research into renewable alternatives, and more recently, alternative waste management strategies (88).

      To mitigate growing environmental concerns, while simultaneously facilitating an increase in plastic demand, it is imperative that the polymer industry evolves, shifting its focus from single-use and disposable plastics to a model focused on recapturing product value and reducing waste, namely the circular economy (89–91).

       1.15.3.3 Steam Cracker

      A number of processes have been described for converting plastic waste into products for further processing such as catalytic or thermal processes, hydrocracking processes, extrusion processes, etc. For example, a process has been described where plastic waste is converted into lower hydrocarbons (92). This entails the plastic waste being reacted in a fluidized bed apparatus at about 300°C to 630°C. The resulting lower hydrocarbons, such as paraffins or waxes, can be converted by means of steam cracking into olefins. Plastic waste can be converted by the combination of fluidized bed apparatus and a known steam cracking process into these olefins.

      An evident disadvantage of this process is that for the steam cracking process it is necessary to add naphtha to the feed materials obtained, i.e., it is not possible to convert the plastic waste into cracked products such as ethylene, propylene, etc., without adding traditional feed materials. Furthermore, the handling of the solids in the fluidized bed always proves to be a disadvantage. It is also problematic to scale up a process of this type to a large-scale industrial operation.

Schematic illustration of Steam cracking process.

      A comparison of Tables 1.7 and 1.8 shows that the yield of ethylene and propylene is higher if the steam cracker is operated with the feed materials obtained from the blow molded fraction than if the steam cracker is operated with naphtha.

       1.15.3.4 Decomposition into Liquid Hydrocarbon Fuels

      Methods of producing high-quality liquid fuels from solid plastic waste or high-quality liquid fuels have been developed (94).

Compound Amount/[%] Compound Amount/[%]
C3 HC 0.01 1-Butene 0.05

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