Fe基和Mn基载氮体的化学链合成氨特性

基于氨能源广阔的发展前景,创新性地提出了一种高效、低耗能的化学链合成氨技术,其特点是将传统工业法合成氨技术分为氮化及氨化两步反应,通过金属氮化物在2个反应器之间循环输运氮及热量完成氨的合成。基于HSC Chemistry 6.0热力学计算及TG-MS联用技术,分析了氮化和氨化过程的化学反应机理,研究了载氮体种类及反应温度对合成氨过程的影响。结果表明：Fe基、Mn基载氮体在氮化和氨化过程中表现出了明显的差异,Fe基载氮体固氮效果较弱,但氨化过程性能良好;Mn基载氮体固氮性能突出,其氮化质量增加量可以达到同样反应条件下Fe基载氮体质量增加量的4.5~5倍,但氨化较为困难。将Fe基载氮体与Mn基载氮体按一定比例混合,2种载氮体的协同作用对化学链合成氨过程产生了重要的影响。

Fe,Mn Based Nitrogen Carrier in Chemical Looping Ammonia Synthesis Technology

Based on the broad development prospects of ammonia energy, an efficient and low energy consumption technology (chemical looping ammonia synthesis) was proposed. It divided the traditional ammonia synthesis reaction into two steps: N-sorption and N-desorption reactions. The nitrogen carrier transported the nitrogen and heat between two reactors to complete the ammonia synthesis process. Here, HSC Chemistry 6.0 and TG-MS techniques were used to study the reaction mechanism and performance of Fe, Mn based nitrogen carriers at different temperatures in the chemical looping ammonia synthesis process. The results show that Fe based nitrogen carrier show weak performance in N-sorption process, while it performs better in N-desorption process; Mn based nitrogen carrier, however, has outstanding performance in N-sorption process but is harder to react with H2 in N-desorption process. Under the same reaction conditions, the mass gain rate with Mn based nitrogen carriers in the N-sorption process could reach 4.5-5 times of that with Fe based nitrogen carriers. The synergistic effects of two nitrogen carriers may play an important role in the chemical looping ammonia synthesis process when Fe and Mn mixed in a certain proportion.