Thermodynamic Optimization of Ammonia Decomposition Solar Heat Absorption System Based on Membrane Reactor

Abstract

In this paper, an ammonia decomposition membrane reactor is applied to a solar heat absorption system, and thermodynamic optimization is carried out according to the usage scenarios. First, a model of an ammonia decomposition solar heat absorption system based on the membrane reactor is established by using finite time thermodynamics (FTT) theory. Then, the three-objective optimization with and the four-objective optimization without the constraint of the given heat absorption rate are carried out by using the NSGA-II algorithm. Finally, the optimized performance objectives and the corresponding design parameters are obtained by using the TOPSIS decision method. Compared with the reference system, the TOPSIS optimal solution for the three-objective optimization can reduce the entropy generation rate by 4.8% and increase the thermal efficiency and energy conversion rate by 1.5% and 1.4%, respectively. The optimal solution for the four-objective optimization can reduce the heat absorption rate, entropy generation rate, and energy conversion rate by 15.5%, 14%, and 8.7%, respectively, and improve the thermal efficiency by 15.7%. The results of this paper are useful for the theoretical study and engineering application of ammonia solar heat absorption systems based on membrane reactors.

Promotion effects of different methods in COx-free hydrogen production from ammonia decomposition

“…Xie et al 125 used the finite time thermodynamics (FTT) theory to establish an ammonia decomposition membrane reactor model, which was equipped with a solar heat absorption system. Finally, the thermal efficiency and energy conversion rate have different degrees of optimization.…”

Performance Analysis of a Solar Heating Ammonia Decomposition Membrane Reactor under Co-Current Sweep

“…According to the surface light intensity on the ground, the solar power density absorbed by the reactor can be converted as [ 19 , 20 ]: where P sun is the average light intensity on the ground, in W/m 2 ; P tube is the power density of absorbed solar energy, in W/m.…”

“…The energy conversion rate is defined as the ratio of incremental chemical energy to solar energy input. Xie et al [ 19 , 20 ] established the solar endothermic system model for ammonia decomposition based on membrane reactors. The effects of factors such as the reactor radius, ammonia flow rate, light intensity and permeation zone pressure on system performance were analyzed.…”

“…This is not enough to meet the boundary conditions of practical engineering. The membrane reactor model of Xie et al [ 19 , 20 ] utilizes the vacuum insulation layer outside the reactor for hydrogen permeation. This will result in a higher heat loss and thus affect system performance.…”