Research On Integrated Hydrogen Production Based On Reforming Combined With Membrane Separation Reactor

In the future energy development,hydrogen energy is considered to be the most promising clean energy,with the highest calorific value per unit mass,the product of combustion is water,and it is environmentally friendly.The fuel used as a proton exchange membrane fuel cell is the main application field of hydrogen energy.The unique hydrogen permeation characteristics of the membrane reactor can be applied to the integration of natural gas reforming reaction and separation to produce high-purity hydrogen,which is one of the hot spots of hydrogen energy research.Appropriate process conditions can allow hydrogen gas to permeate from the high-pressure side to the low-pressure side of the palladium membrane,thereby achieving pure hydrogen production by membrane separation.Combining the palladium membrane with the natural gas reforming hydrogen production reaction,the palladium membrane can continuously move the hydrogen source out of the feed side,thereby breaking the thermodynamic equilibrium of reforming reaction and obtaining higher CH₄ conversion and H₂yield at lower temperatures.Before experimental investigations,Aspen Hysys has been used for a simulation of the reaction and separation integrated hydrogen production process,and obtained the regularity of CH₄ conversion and H₂ content under different conditions of temperature,pressure,water to methane molar ratio and membrane separation efficiency.The methane steam reforming reaction integrated with palladium membrane separation has been carried out the reaction and separation integrated hydrogen production studies.The results show that temperature and pressure have a significant effect on the reaction-separation integrated hydrogen production.The temperature needs to exceed 500℃to separate more H₂ through the palladium membrane,while improving the conversion of CH₄.Increasing the pressure is beneficial to the separation of H₂ and can significantly increase the conversion of CH₄,which is completely opposite to the thermodynamic equilibrium.Increasing the water to methane molar ratio can also significantly increase the CH₄ conversion,but it can inhibit the hydrogen separation of the palladium membrane.Under the optimized temperature of 560℃,pressure of 0.9 MPa,water to methane molar ratio of 3.0,the methane conversion of 87.80%has been achieved,which is correspdoned to 810℃of thermochemical reaction of steam reforming.Meanwhile,the produced hydrogen purity is more than 99.80%.The results demonstrate that the reaction and separation integrated hydrogen production used for methane steam reforming is workable and the temperature is dramatically decreased.The high methane conversion and high purity hydrogen can be obtained by this way.