In this work, the potential of a new low-temperature distillation process for natural-gas sweetening has been investigated. The proposed technology consists of a dual pressure-distillation scheme designed to avoid the formation of a solid phase in all parts of the process while remaining able to fulfill the required natural-gas-purity specifications. The new process offers the competitive advantages of low-temperature technologies while avoiding carbon dioxide (CO2) solidification and solvent addition.
The industry must find technologies that allow the profitable exploitation of low-quality and high-CO2-content gas reserves in order to meet increasing demand while still decreasing production costs. Low-temperature processes are preferred to traditional chemical or physical absorption for gas purification when the CO2 concentration in natural-gas streams is high. For this reason, attention on low-temperature processes for CO2 removal has increased in recent years.
In this work, an analysis has been carried out to determine the trade-off between classical methyldiethanolamine (MDEA) gas-sweetening units, still representing the industry benchmark for acid- and sour-gas purification, and a low-temperature distillation process. The MDEA unit typically requires steam at the reboiler of the regeneration column, while the low-temperature distillation processes consume electric energy to drive the refrigeration cycle. In amine regeneration units, the steam consumption is a significant part of the total energy demand of the process and thus of the total operating costs. The complete paper defines a merit-index function to determine the trade-off between the two considered technologies....
A New Distillation Process for the Upgrading of Acid Gas
01 April 2017