Montagem e teste de uma unidade experimental para estudo de envelhecimento de materiais adsorventes utilizados no processo de secagem do gás natural

Abstract

Natural gas has emerged as an important global energy source due to its role in the energy transition process in several countries, as well as its lower carbon emissions when compared to other fossil fuels, contributing to mitigating the environmental impacts associated with their use. Several institutions, such as the International Energy Agency (IEA) and the European Union through the European Green Deal, aim to reduce and neutralize the effects of climate change by 2050, establishing targets to reduce greenhouse gas emissions by at least 55% by 2030. In Brazil, approximately 60% of the energy produced comes from hydroelectric generation; however, the use of natural gas has been increasing due to the expansion of national reserves. For commercialization, natural gas must undergo several purification steps, including water removal, since the presence of moisture during transportation can promote corrosive processes and the formation of hydrates, which may obstruct pipelines and compromise the integrity of the ducts. In this context, natural gas dehydration becomes a critical step to enable its transportation and commercialization. This work aims to develop and evaluate a laboratory-scale protocol for natural gas drying using Temperature Swing Adsorption (TSA), considering operational parameters such as feed flow rate, regeneration temperature, particle size of the adsorbent material, and operating time. These parameters were analyzed through breakthrough curves monitored by dew point temperature (DPT) sensors. The results demonstrated that the LTA 4A zeolite presents high affinity for water vapor, predominantly microporous structure, and adequate thermal stability for successive adsorption–regeneration cycles under the evaluated conditions. The analysis of operational variables allowed the definition of reproducible experimental conditions, highlighting a feed flow rate of 80 mL·min⁻¹ and thermal regeneration at 250 °C with a heating rate of 5 °C min⁻¹ as suitable parameters to ensure process efficiency and operational stability. The water vapor adsorption capacity obtained in dynamic tests showed good agreement with the values determined from equilibrium isotherms, and the initial aging cycles did not indicate significant loss of material performance. Therefore, the results demonstrate that the developed experimental system can be used to study the aging of adsorbent materials in fixed-bed systems.