The Optimization Study Of Automotive DME Reforming For Hydrogen Production Reactor Performance

Now, hydrogen is a popular renewable energy. In the automotive industry, the development of Hydrogen Electric Vehicle is very fast. However, due to technical difficulties of hydrogen transport, storage, etc., the trend of study of hydrogen is a higher ratio of hydrogen in organic compounds or other substances. In these, because the dimethyl ether(DME) has the feature of non-toxic, high hydrogen content, easy to store and transport, environment friendly etc., it is studied by many scholars. Meanwhile, the D ME steam reforming reaction can expand its role in combustion applications and environmental protection fields. Therefore, in order to study DME steam reforming reactions and conducive to promoting the development of the DME reforming technology and its academic value, it is necessary to study the high performance DME reforming reactor.Combining with the DME-related domain knowledge such as chemistry, dynamics and thermodynamics etc., this paper focuses on performance optimization of DME reforming reactor. In the process of optimization of dimethyl ether reforming reactor, the dynamics of DME reforming reactor was studied and a mathematical model was established about DME reforming reactor. The optimization method of DME reforming reactor was obtained and validated by experiments.First, based on the process of exploring dynamics of the DME reforming reactor, this paper established a two-dimensional model of dynamics about dimethyl ether reforming reactor and derived a simplified rate equation of elementary reaction of dimethyl ether steam reforming reaction by L-H mechanism and got the pre-exponential factor of the rate constants by modifying the Arrhenius equation. When the conditions of the ratio of water and DME and pressure etc. were determined, the influence law of DME steam reforming reaction was obtained.Second, based on the kinetic model, the mathematical model of dimethyl ether reforming reactor was established. This paper studied the transport equation of the reactor in detail, including the momentum equation, energy transfer equation and mass transfer equations, etc. This paper also analyzed the distribution of the reforming catalyst within the reactor, the heat transfer of the heat exchanger and the temperature without external changes of heat source and the flow rate within the chamber of the reactor. Then, a three-dimensional physical model of DME reforming reactor was established. At last, a kind of experimental verification was provided to prove that it was a reliable model.Finally, based on the mathematical model, the performance optimization of D ME reforming reactor was studied once again to determine the effects of operating parameters and structure parameters. The reaction rate of dimethyl ether reforming reaction increases with increasing temperature and varies little with the increasing pressure. The temperature drops at first and increases with length of the reactor. The temperature drops at first, because DME steam reforming reaction is endothermic reforming reaction. Then, the temperature increases, because the heat transfer efficiency increases with reaction bed length. With the increase of the reaction bed length, the volume fraction of 2 and C2 rapidly increase, while the volume fraction of dimethyl ether and water will be reduced. With increasing exhaust velocity, DME conversion and hydrogen yield will increase. At the same time, DME conversion and hydrogen yield will increase with the increasing of the ratio of water and DME. This paper can provide some theoretical support and basis for the design and research of DME reforming reactor.