传统合成氨装置主要采用冷凝分离氨,通常无法深度分离,限制了合成效率的提高。燃料电池等应用对供氢纯度有不同要求。理论上具有路易斯酸性的物质可对氨进行深度吸附,为此选取典型碱土金属氯化物作为氨的酸性吸附剂,研究了颗粒状和片状MgCl₂以及刺球状CaCl₂的吸附性能。结果表明,2种氯化物可以实现氨的深度分离,均能将气相中的氨含量降至接近热力学平衡值;3种吸附剂吸附过程压降为进口压力的0.95%~3.5%;另外,对吸附剂进行热重脱附研究发现,MgCl₂和CaCl₂可分别在420℃和230℃下实现基本脱附,具有再生性。

Conventional ammonia synthesis plant mainly utilizes condensation to separate ammonia,which hardly separates ammonia in-depth,limiting the improvement of synthesis efficiency.Fuel cells have high requirements on the purity of hydrogen feedstock.Typical alkaline earth metal chlorides are selected as adsorbents to separate ammonia,and the adsorption properties of granular and flake MgCl₂ and spheroidal CaCl₂ are studied experimentally.Experimental results show that both alkaline earth metal chlorides achieve deep separation of ammonia and the content of ammonia in gas phase is close to thermodynamic equilibrium values.The pressure drop of ammonia in the adsorption process is 0.95%-3.5% of the inlet pressure.It is indicated through thermogravimetric desorption tests on adsorbents that ammonia can be desorbed from MgCl₂ at 420℃ and from CaCl₂ at 230℃,indicating both adsorbents can be regenerated.

吴崇君(1994-),女,硕士研究生,研究方向为合成氨与氨供氢,32420181153448@stu.xmu.edu.cn