Separation Of Carbon Dioxide From Methane By Membrane

In natural gas mining and the transportation process, the gas frequently has the carbon dioxide, if the carbon dioxide can not be removed from the gas, it will affect the quality of the natural gas, corrode the pipeline and calorific value of the natural gas. Membrane separation is a new method, and it is simple,effective,saving energy,separation effect well compared to the traditional method. This article uses the PDMS/PEI membrane to separate the carbon dioxide from the methane and inspect the influences under different conditions.Measure the diffusion coefficient,solubility coefficient and permeability coefficient of carbon dioxide,methane and nitrogen. Research the change rules of three coefficients under different temperature and pressure. From the result, we can see that the permeability coefficient,solubility coefficient of carbon dioxide is bigger than methane and nitrogen, but the diffusion coefficient of it is smaller than the nitrogen and methane. So it indicates that the gas separation by membrane is controlled by the dissolution step. Increase the pressure or reduce the temperature is useful for the gas separation.Separate the carbon dioxide from the methane by the PDMS/PEI membrane. Measure the permeation rate and separation factor of carbon dioxide under different experimental conditions. The result shows that increase the temperature,volume fraction of carbon dioxide,or reduce the pressure will increase the permeation rate of carbon dioxide. Reduce the pressure or increase the flow and temperature is good for the separation process.According to the known solution-diffusion model and the Florry-Huggins mathematical function, calculate the simulated values of CO2/CH4 under different conditions and compare the simulated values and the experimental results together. Use this model to calculate the permeation rate and separation factor of C3H8/CH4.