Ammonia Synthesis at Reduced Pressure via Reactive Separation
Ammonia Synthesis at Reduced Pressure via Reactive Separation
复制标题
通过反应分离在减压下合成氨
DOI：
10.1021/acs.iecr.6b01880
复制
发表时间：
2016
影响因子：
4.2
通讯作者：
E. Cussler
中科院分区：
文献类型：
--
作者：
M. Malmali;Yong;A. Mccormick;E. Cussler
氨通常在高温高压下使用促进的铁催化剂制备。需要高温以获得快速动力学;高压用于确保高转化率。或者，如果产物氨被快速分离，氨可以在高温但较低压力下制备。本文系统地研究了温度和压力对反应速率的影响。然后，我们定性地研究了在反应分离过程中使用氯化钙的氨的吸收分离。快速分离减少了可逆反应的限制，使我们能够在相对较低的压力下获得合适的反应速率。仔细测量了不同操作条件-反应温度、压力、吸收温度和气体输送-对生产率的影响，这阐明了这种类型的低压氨合成的潜力和限制。
Ammonia is normally made at high temperature and pressure using a promoted iron catalyst. High temperatures are needed to get fast kinetics; the high pressure is used to ensure high conversion. Alternatively, ammonia can be made at high temperature but lower pressure if the product ammonia is rapidly separated. Here, we have systematically studied the effect of temperature and pressure on the rates of reaction. We then have qualitatively investigated the absorptive separation of ammonia using calcium chloride in a reaction–separation process. Rapid separation reduces the constraint of reversible reaction and enables us to obtain appropriate reaction rates at relatively lower pressure. The effect of different operating conditions—reaction temperature, pressure, absorption temperature, and gas transport—on production rates is carefully measured, and this elucidates the potential and the limits of this type of low-pressure ammonia synthesis.