Abstract:
The objective of this work was to study CO2 absorption in the membrane contacting process by
using 2 hollow fiber membranes, Polyvinylidenefluoride (PVDF) and Polytetrafluoroethylene
(PTFE). The aqueous monoethanomine(MEA) and water solutions were used as the absorbents.
There were 3 parts of experiments. In the first part,the main mass transfer resistance in absorption
process was analyzed for various liquid velocities (0.14-0.77 m/s) and gas flow rates (100-300
ml/min). It was found that the main mass transfer resistance of the physical absorption (using water
as absorbent) and chemical absorption (using 0.5 M MEA as absorbent) for PVDF and PTFE
membranes were in the liquid phase. The second part studied the long term performance to observe
the membrane wetting .It was found that the PTFE membrane maintained the constant absorption
flux for 3 days, while for PVDF membrane the absorption flux dropped after 2 days. Moreover, this
part compared the CO2 flux at various liquid velocities. It was found that the PTFE membrane had a
higher CO2 flux than PVDF membrane. The last part studied mathematical modeling to compare
with experimental results. It was revealed that the results of simulation by the dynamic stagedprocess
model agreed well with the experimental results.