A high-density ammonia storage/delivery system based on Mg(NH3)6Cl2 for SCR-DeNOx in vehicles
A high-density ammonia storage/delivery system based on Mg(NH3)6Cl2 for SCR-DeNOx in vehicles
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DOI：
10.1016/j.ces.2005.11.038
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发表时间：
2006-04-01
影响因子：
4.7
通讯作者：
Johannessen, T
中科院分区：
文献类型：
--
作者：
Elmoe, TD;Sorensen, RZ;Johannessen, T
在本文中，我们提出了一个新的基准汽车选择性催化还原NOx：Mg（NH3）（6）Cl-2。这种固体复合物在加热时释放氨，并且可以被压缩成致密的形状，这既容易处理又安全。此外，该材料具有高达液氨体积密度的93%的高体积氨密度。这提供了持久的氨存储（对于平均中型车辆，每6.2 L Mg（NH3）（6）Cl-2大约行驶20000 km）。研究了Mg（NH_3）（6）Cl-_2的受控热分解。在体积为785 mL的小反应器中填充约260 g Mg（NH3）（6）Cl-2，得到331 kg/m3（3）的床密度。将反应器与自由体积约为200 mL的缓冲液偶联。一根缠绕在反应器外部的加热丝提供热能。使用质量流量控制器来模拟变化的NO信号。结果表明，它是可以控制的解吸使用一个简单的开-关控制器的缓冲压力作为控制变量。盐中所含的约99%的氨可被解吸并定量给料，同时保持用作设定点压力的5巴。通过将Mg（NH3）（6）Cl-2粉末压缩至1219 kg/m3（3）的密度来改善低密度，该密度非常接近1252 kg/m3（3）的理论晶体密度。程序升温脱附实验表明，对致密化材料进行加热，可以很容易地将氨脱附出来。化学计量计算已经表明，与当前选择的用于移动的DeNO（x）（32.5%wt/wt尿素水溶液的热分解）的氨输送相比，高密度Mg（NH3）（6）Cl-2化合物的重量小2.8倍，并且占用的空间小3.1倍。这使得Mg（NE 3）（6）Cl-2非常适合用作柴油和稀燃汽油驱动的汽车中的氨储存化合物。(c)2005爱思唯尔有限公司保留所有权利。
In this paper, we present a new benchmark for the automobile selective catalytic reduction of NOx: Mg(NH3)(6)Cl-2. This solid complex releases ammonia upon heating and can be compacted into a dense shape which is both easy to handle and safe. Furthermore, the material has a high volumetric ammonia density of up to 93% of that of liquid ammonia. This provides a long lasting ammonia storage (approximate to 20000 km of driving per 6.2 L Mg(NH3)(6)Cl-2 for an average medium-sized vehicle). The controlled thermal decomposition of Mg(NH3)(6)Cl-2 was demonstrated. A small reactor with a volume of 785 mL was filled with approximate to 260 g of Mg(NH3)(6)Cl-2 yielding a bed density of 331 kg/m(3). The reactor was coupled to a buffer with a free volume of roughly 200 mL. A heating wire wrapped around the outside of the reactor supplied the heat-energy. A mass-flow controller was used to simulate a varying NO, signal. It was demonstrated that it was possible to control the desorption using a simple ON-OFF controller with the buffer pressure as the control variable. Approximately 99% of the ammonia contained in the salt could be desorped and dosed, while maintaining the 5 bars used as the set-point pressure. The low density was improved by compressing the Mg(NH3)(6)Cl-2 powder to a density of 1219 kg/m(3), which is very close to the theoretical crystal density of 1252 kg/m(3). Temperature programmed desorption showed that the ammonia could easily be desorped by heating the densified material. Stoichiometric calculations have shown, that compared to the current choice of ammonia delivery for mobile DeNO(x) (thermal decomposition of a 32.5% wt/wt aqueous urea solution), the high-density Mg(NH3)(6)Cl-2 compound weighs 2.8 times less and takes up 3.1 times less space. This makes Mg(NE3)(6)Cl-2 ideal for use as an ammonia storage compound in both diesel and lean-burn gasoline-driven automobiles. (c) 2005 Elsevier Ltd. All rights reserved.