PRODUCTION OF 40 TONS PER DAY OF PURE TEREPHTHALIC ACID (PTA) FROM CRUDE TEREPHTHALIC ACID (CTA) VIA CRYSTALLIZATION

Abstract

This thesis designs and operates a smaller purified terephthalic acid (PTA) plant in tandem with an existing facility to increase production capacity and eliminate bottlenecks. The study begins by emphasizing PTA production and the problem. A comprehensive literature review covers PTA basics, methods for converting crude terephthalic acid (CTA) to PTA, and PTA crystallization processes. This literature evaluation lays the groundwork for the planned study and future research. Thesis then presents a process flow diagram and details PTA production procedures. CTA, hydrogen, water/steam, and nitrogen are important basic ingredients for high-quality PTA. The specifications and design criteria for crystallization equipment such feed tanks, centrifugal pumps, pre-heaters, packed bed reactors, crystallizers, centrifuges, and dryers are carefully studied. Feed tanks, pumps, pre-heaters, reactors, crystallizers, centrifuges, and dryers undergo material and energy balances. Thesis also covers critical equipment component design and specifications. The design, function, and design considerations of shell-and-tube heat exchangers are examined. Discussed include packed-bed reactor design and reactions. The crystallizer's design and operation are analyzed. Aspen Hysys and Aspen Plus software simulate process dynamics and behavior, providing a complete picture. Component lists, fluid packages, parameters, and reactor and crystallizer requirements are simulated. Simulations reveal process performance and enable optimization. Operation and process monitoring require instrumentation and control. Ratio and cascade control solutions are described for process stability and production optimization. This thesis assesses primary equipment costs, total investment, direct production expenses, income generation, and payback period for any industrial operation. These financial studies reveal the parallel PTA plant's economic viability. Hazard and Operability (HAZOP) research identifies process hazards and recommends risk assessment and reduction. Explaining HAZOP and identifying process hazards ensures safety and regulatory compliance. This final-year thesis suggests designing and operating a smaller PTA factory alongside an existing facility to boost production capacity and eliminate bottlenecks. Process overview, material and energy balance calculations, equipment design, simulation, instrumentation and control strategies, cost estimation, and HAZOP studies are examined in detail to inform future research