Investigation of premature aging of zeolites used in the drying of gas streams

摘要

The presence of humidity in gas streams is usually associated to several problems in the performance of industrial unit operations. Therefore, gas drying is one of the most important primary stages in the process that is commonly carried out by adsorption, using hydrophilic porous materials. These materials are typically regenerated by temperature swings (TSA), which in the presence of contaminants in the gas stream, may lead to adsorbent degradation and reduced lifespan of the drying process. The objective of this study is to investigate the hydrothermal stability of a zeolitic material used in the process of natural gas drying, by means of an aging test developed to simulate the operating conditions of a typical TSA. The textural characteristics, elemental analysis, and H2O/CO2 adsorption capacity are determined along the heating/cooling cycles. The presence of hydrocarbons, represented by n-heptane, is the most significant factor that contributed to the aging of the adsorbent within the temperature and pressure ranges under study.