基于熵产分析的氨分解制氢反应条件优化

Ammonia decompose to hydrogen requires a significant amount of energy input. Previously, ammonia decomposition reactors were optimized primarily based on the first law of thermodynamics. It is limited by the complex influencing factors of the reactor. Hence, we presented a one-dimensional optimization of hydrogen production via ammonia cracker using entropy analysis, which determined the optimal heat source temperature distribution configuration for the reactor. The optimization results improved the reaction uniformity in the reactor. The optimal heat source temperature configuration has been demonstrated to reduce the specific entropy production by 1.00% to 27.48%. In light of the limited validation of the one-dimensional optimization results, a three-dimensional CFD simulation was established. It was found that temperature gradient is the key factor affecting the simulation results. The dimensional reduce deviation of the one-dimensional model also mainly caused by the temperature field differences. The results of entropy production optimization provide thermodynamic theoretical guidance for the design of ammonia hydrogen production reactors, decreasing exergy loss due to the irreversibility of reaction, flow, heat and mass transfer in the reactor.