Case Scenario

Recycling is one of the most effective approaches to reduce the impacts of plastic wastes on the environment. Generally, there are two common methods of recycling plastic waste, i.e. physical recycling and chemical recycling. The core principle of physical recycling of plastic wastes is a thermal process to heat and melt the thermoplastics into recycled resins which are low priced and quality. Nonetheless, physical recycling remains dominant in the industry due to low CAPEX while requiring simple technical skills to operate compared to chemical recycling. Chemical recycling is a process to break down the macromolecule chains of polymers into a spectrum of chemical molecules under high temperature and inert conditions. The products of chemical recycling include pyro-gas, pyro-oil, and pyro-char. Thanks to the advanced separation technology, high purity output compounds can be obtained and further supplied to the relevant industries as virgin compounds for production. On the other hand, residues such as oil and char can be used as fuel for heaters and building materials.

CETD Corporation is seeking recommendations from your company for the potential valorization of plastic wastes using chemical recycling technology. The recommendation should include an analysis of the technical, economic, health and safety aspects of the project. The plant should be able to process 10 to 100 metric tonnes per day of plastic waste. The design should attempt to employ new modular manufacturing methods which are becoming more common in the chemical process industry. Modular manufacturing is the concept that complete chemical processes or sub-sections of chemical processes can be prefabricated in a factory setting. By comparison, many existing chemical plants are “stick-built”, meaning they were constructed outdoors at the plant site. Modular manufacturing can offer several advantages such as quality control, increased worker safety and labor efficiency, cost savings, faster time-to-market, and scalable capacity.

Special issues to be addressed:

• The types of plastic wastes should be limited from 1 to 6 according to the international resin code. The process of cleaning and preparation of plastic waste needs to be covered. The handling of wastewater during the cleaning process needs to be considered as well.
• Since plastic additives are commonly used in plastic products. The robustness of the chemical recycling process to tackle such additives needs to be considered with design solutions.
• Take into consideration the implementation of unitary modular manufacturing or parallel modular manufacturing. The assumptions made during the estimation of plant capital costs using correlations/correction factors for conventional, large process equipment should be noted and addressed in your report.

The design submitted shall be original and have not been previously submitted or published elsewhere. The proposed plant should have at least one reactor and at least one separation unit operation.