Removal of 𝐶𝑂2 from Polymer Grade Propylene

Abstract

It is required to create an efficient and feasible solution for the purification of propylene before initiating the polymerization process while maintaining the characteristics of the final products (polymers) intact. The main objective of this project was to design and simulate an adsorption process, as part of the pretreatment chain, achieving a purity greater than 99.5% in the propylene stream by reducing CO and CO2 concentrations to levels below 0.4 ppm and 1 ppm, respectively. This in order to maintain the quality of the produced polypropylene, ensuring it meets purity standards and specified characteristics, reduce the amount of catalyst needed to maintain process efficiency, which could translate into an increase in propylene conversion and minimize the occurrence of unwanted secondary reactions during polypropylene production. This project features an adsorption process in a packed bed with zeolite 13X and an Aspen Adsorption simulation as well as an economic evaluation, utilizing two dynamic indicators—net present value and cost-benefit index— that clearly demonstrate the project's viability. It not only ensures the avoidance of economic losses but also promises substantial gains. Engineering standards such as API 610, API 617, TEMA and ASME were considered in the design of the equipments: centrifugal pump, centrifugal compressor, shell and tube heat exchanger and adsorber. Some of the courses whose contents were applicable in the project were separation processes, process engineering, unit operations, economic engineering, fluid mechanics, thermodynamics, material and energy balance, solid handling, transport phenomena, statistics and plant design. Learning challenges were indeed encountered, yet mastery was achieved in handling Aspen Adsorption software, equipment design, and the corresponding regulatory standards. Furthermore, knowledge was expanded in the realm of adsorption processes, encompassing their diverse configurations, critical variables, and the mathematical models delineating adsorbate-adsorbent interactions.