CRYOGENIC SEPARATION OF C02 FROM METHANE USING DYNAMIC PACKED BED

The high content of carbon dioxide in the natural gas is a major concern in harnessing
the natural gas. This is due to the acidity of the carbon dioxide which will impose
problem to the extraction, production and transportation of the natural gas. Cryogenic
separation of carbon dioxide from natural gas is proposed to separate carbon dioxide
from the high carbon dioxide content natural gas using the dynamic packed bed. An
effective separation between the carbon dioxide and methane can be obtained using the
cryogenic packed bed. This separation is possible due to the difference in dew and
sublimation points of carbon dioxide and methane. This is because, due to the
sublimation point of carbon dioxide which is -78.5°C which is at higher temperature
than methane, which is -182°C, the carbon dioxide will deposit on the packing material
at temperature below its sublimation point. Carbon dioxide is depositing on the packing
material by the transfer of the cold energy which is stored in the packing material. The
carbon dioxide molecule is cooled form the transfer of energy from the cold material
(packing material) to the hot material (carbon dioxide) and deposited onto the packing
material. Methane will not be deposited and will flow freely out of the bed as there are
empty spaces inside the packed bed. Mathematical analysis was performed to better
understand the separation characteristic of carbon dioxide from methane and
experiments are to be carried out for cryogenic C02 capture. From the mathematical
analysis, the mass deposition rate of the carbon dioxide is found out to be increasing
sharply as the concentration of carbon dioxide increases. The dynamic behavior of the
packed bed is described using the one dimensional plug flow model.