This paper firstly conducted the experiments for N2/CH4 separation using the vacuum pressure swing adsorption (VPSA) process based on the two-bed experimental set-up and the laboratory-made coconut shell-based activated carbon as adsorbent. The PSA mathematical models were verified by comparing the separation results of experiments and simulations employing gPROMS dynamic simulation software. On this basis

sensitivity analyses were made on the key decision variables affecting product CH4 purity and recovery. Sensitivity analysis indicated that the product purity mainly depended on the raw gas flow and displacement gas flow

while product gas recovery required a good combination of the three key variables. The results showed that the purity of the product gas was mainly regulated by the raw gas flow and displacement gas flow

while a common action of the key variables was required in order to maximize the product gas recovery. Based on the results of the sensitivity analysis

the dynamic optimization was studied for PSA process under consideration. Under optimal conditions

the molar concentration of CH4 may be enriched to 75% and product recovery can be enhanced to 97.08% with feed concentration of 35%. This optimal VPSA process has proved its practicality for the effective recycling of waste gas mixture.