Effect of Heavy Hydrocarbons on CO2 Removal from Natural Gas by Low-Temperature Distillation

Natural gas is expected to have the most important growth among fossil fuels being the cleanest-burning one and also taking into account the ever-increasing role liquefied natural gas is playing within the gas sector. To meet the increasing demand for natural gas, it will be necessary to develop both new unconventional gas fields and conventional gas fields that have not been developed yet because of the high acid gas content. The conventional acid gas removal technology (chemical absorption into aqueous alkanolamine solutions) is energy-intensive when applied to low-quality gas reserves. This is why, more recently, low-temperature processes have gained attention as an alternative to traditional CO2 removal technologies. An important advantage the use of such novel technologies poses consists in the separation of CO2 as a liquid at high pressure, which is very interesting for further applications, such as geo-sequestration or Enhanced Oil Recovery. This work investigates the use of a new low-temperature CO2 removal process that is based on dual pressure distillation. This simulation study shows how the presence of hydrocarbons heavier than methane can affect the energy requirements of the overall process, also including natural gas liquids fractionation.