The role of carbon dioxide and water in the degradation of zeolite 4A, zeolite 13X and silica gels

The degradation of desiccants is important in designing natural gas conditioning processes. Previous studies have focused on the effect of changes in regeneration gas water content, regeneration temperature and number of thermal cycles. However, less is known about how other components impact the lifespan of desiccants over thousands of thermal cycles. Herein we present results on how desiccant degradation is influenced by CO2 in a process fluid. Increasing the CO2 concentration resulted in less degradation across unsupported zeolite 4A, zeolite 13X and silica gels. Additionally, higher water concentrations in the regeneration gas resulted in a decrease in the degradation at the same CO2 concentration. For zeolite 13X, the surface area and pore volumes were larger in the samples subjected to greater CO2 concentrations. For silica gels, a higher capacity for water adsorption after 5000 thermal swing adsorption cycles was observed in samples with a lower concentration of surface silanol groups.

Automated summary

The degradation of desiccants is an important factor in natural gas conditioning processes. Previous studies have mainly focused on the effects of regeneration gas water content, regeneration temperature, and number of thermal cycles. However, the impact of other components on the lifespan of desiccants over numerous thermal cycles remains less understood. This study explores the influence of CO2 in the process fluid on desiccant degradation. The findings reveal that increasing CO2 concentration leads to reduced degradation in zeolite 4A, zeolite 13X, and silica gels. Moreover, higher water concentrations in the regeneration gas contribute to decreased degradation at the same CO2 concentration.