Studying the effect of sorbent sintering in the thermodynamic simulations of sorption enhanced chemical looping steam methane reforming

This study examines the influence of sorbent sintering on the thermodynamic performance of the Sorption Enhanced Chemical Looping Steam Methane Reforming (SE-CL-SMR) process, employing natural limestone as the sorbent. In contrast to prior research, this analysis incorporates the effects of sorbent deactivation resulting from sintering, which is essential for comprehending the long-term viability of the process. Utilizing thermodynamic simulations conducted with Aspen Plus, the optimal operating parameters of the process were evaluated both in the presence and absence of sorbent sintering. Additionally, the external energy consumption of the SE-CL-SMR process was minimized through comprehensive sensitivity analyses and the application of pinch technology. The results of this combined process optimization and heat integration indicate that the natural limestone-based process can achieve a methane conversion of 95.91 %, a CO₂ capture efficiency of 93.15 %, and a hydrogen yield of 89.31 % with a purity of 98.12 %. These outcomes were achieved under conditions of a reformer temperature of 600°C and atmospheric pressure, with molar ratios of Steam/CH₄ = 3, NiO/CH₄ = 0.25, CaO/CH₄ = 2.5, and CaCO_{3, make-up}/CH₄ = 0.3123. Similar results were obtained without sorbent sintering under the same operating conditions, with the exception of zero sorbent make-up and a CaO/CH₄ ratio of 0.9315. These findings highlight the significance of considering sorbent sintering in the design and optimization of SE-CL-SMR systems, ultimately contributing to advancements in sustainable hydrogen production and carbon capture technologies.