The adsorption dynamics of zeolite 13X, 10X and 5A beds was investigated for recovering ethylene (C2H4) from fluidized catalytic cracking fuel-gas. As a feed gas, a ternary mixture (CH4 : C2H4 : C2H6) and a model FCC fuel-gas (CH4 : C2H4 : C2H6 : C3H6 : N2 : H2) were used for breakthrough experiments. In the ternary mixture, the concentration profiles showed similar patterns in all zeolite beds. C2H4 showed higher adsorption affinity than the others in all zeolites and zeolite 5A had the highest adsorption capacity of C2H4. In the six-component mixture, the breakthrough curves in the zeolite 5A bed showed similar patterns to the results of the ternary mixture. Although weak adsorbates could be removed during the adsorption step, CH4 and N2 imparted a steric hindrance to the initial stage of C2H4 adsorption in the zeolite 5A bed. Since vacuum desorption contributed to producing a high purity of C2H4, a pressure vacuum swing adsorption process was recommended to recover C2H4.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)