CO2 Compression and Dehydration for Transport and Geological Storage

This study seeks to further understand the intricacies of Carbon Dioxide Capture and Storage (CCS), a critical technique in minimizing anthropogenic carbon dioxide emissions and mitigating the greenhouse effect. It thoroughly explores the main technologies involved in CO2 capture, separation, and dehydration, alongside the methodologies used for its transportation and geological storage site selection. A design was proposed for a dehydration and compression installation for carbon dioxide captured post-combustion, operating at a temperature of 35°C, a pressure of 1.51 bar, and a mass flow rate of 2.449 million tons/year, assuming the geological storage site is 30 km from the capture location.

The study implemented a multistage compression and cooling system for the dehydration process, coupled with a triethylene glycol (TEG) dehydration unit. The selected mass flow rate for TEG was 0.5 kg/s, with an output of 26.6 ppm of H2O. To optimize the process, the energy required to compress the gas was minimized by limiting the post-compression gas temperature to 95°C per cycle, reducing operating costs. The total power demand and heat input varied depending on the plant load. The use of more compressors contributed to reducing the gas temperature and the overall energy required, and the heat that must be gathered during the cooling process. The findings indicate that integrating CO2 compression and cooling systems to recover heat and enhance the efficiency of power units is a crucial consideration in CCS operations.