PYROLYSIS OF WASTE POLYETHYLENE TEREPHTHALATE (PET) INTO PETROLEUM PRODUCTS

Abstract

SolvoPro Engineering Sdn. Bhd.'s stakeholders intend to construct a new facility using cutting-edge recycling technologies to turn industrial waste into goods with added value, aligning with the rising demand for zero waste practices. As engineers at the company, our team is tasked with designing a recycling plant that converts waste into valuable products, with PET plastic waste selected due to its significant contribution to the global plastic waste problem, which accounts for 400 million tonnes per year. In this report, several methods for converting plastic waste into valuable fuels are identified, but pyrolysis was chosen for its relatively low temperature requirement, high product revenue potential, and moderate capital cost. Potential plant locations such as Negeri Sembilan, Johor, and Perak were selected based on criteria including waste pricing, production volume, market access, power and water supply, labor availability, proximity to waste disposal facilities, and capital costs. Supporting data and parameters were sourced from research articles to justify these decisions. A continuous yield reactor was chosen for its suitability to the pyrolysis process, offering large- capacity continuous flow, adaptability to varying stoichiometry, and operation without kinetic data. A complete Process Flow Diagram (PFD) was designed according to Petronas standards, and energy and mass balances were manually calculated to validate simulation results conducted in ASPEN PLUS, with heat integration incorporated to optimize cost and energy efficiency. From the economic evaluation, the cost of raw materials for PET feedstock at peak production was approximately RM 2,061,104.28, with projected revenue from commercialized pyrolysis products estimated at RM 1,167,769,293.67. The total annual electricity cost amounted to RM 1,269,864.44, and based on the economic potential analysis, EP 1 was calculated at RM 1,165,708,189.39 and EP 2 at RM 567,149,206.47, demonstrating that the plant design is financially viable. A hazard analysis was conducted to assess risks including hazardous material handling, operating conditions, safety protocols, and equipment management. Pollution minimization strategies were also proposed to align with climate change mitigation goals and regulatory requirements, including reducing CO₂ emissions through improved energy efficiency and optimized reactor performance.