U.S. Department of Energy, Pittsburgh, PA 15236, USA.
ChemSusChem. 2010 Aug 23;3(8):948-56. doi: 10.1002/cssc.201000056.
The CO(2) capture capacities for typical flue gas capture and regeneration conditions of two tertiary amidine N-methyltetrahydropyrimidine (MTHP) derivatives supported on activated carbon were determined through temperature-controlled packed-bed reactor experiments. Adsorption-desorption experiments were conducted at initial adsorption temperatures ranging from 29 degrees C to 50 degrees C with temperature-programmed regeneration under an inert purge stream. In addition to the capture capacity of each amine, the efficiencies at which the amidines interact with CO(2) were determined. Capture capacities were obtained for 1,5-diazo-bicyclo[4.3.0]non-5-ene (DBN) and 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU) supported on activated carbon at a loading of approximately 2.7 mol amidine per kg of sorbent. Moisture was found to be essential for CO(2) capture on the amidines, but parasitic moisture sorption on the activated carbon ultimately limited the capture capacities. DBN was shown to have a higher capture capacity of 0.8 mol CO(2) per kg of sorbent and an efficiency of 0.30 mol CO(2) per mol of amidine at an adsorption temperature of 29 degrees C compared to DBU. The results of these experiments were then used in conjunction with a single-site adsorption model to derive the Gibbs free energy for the capture reaction, which can provide information about the suitability of the sorbent under different operating conditions.
通过控温填充床反应器实验，测定了在典型烟道气捕集和再生条件下，两种负载在活性炭上的叔脒 N-甲基四氢嘧啶（MTHP）衍生物的 CO2 捕集容量。在惰性吹扫气流下进行程序升温再生的条件下，在 29°C 至 50°C 的初始吸附温度范围内进行吸附-解吸实验。除了每种胺的捕集容量外，还测定了脒与 CO2 相互作用的效率。在负载量约为 2.7 mol 脒/kg 吸附剂的情况下，测定了 1,5-二氮杂双环[4.3.0]壬-5-烯（DBN）和 1,8-二氮杂双环[5.4.0]-十一-7-烯（DBU）负载在活性炭上的捕集容量。结果表明，水分对于脒的 CO2 捕集是必不可少的，但活性炭上的寄生水分吸附最终限制了捕集容量。与 DBU 相比，DBN 在 29°C 的吸附温度下，具有更高的 0.8 mol CO2/kg 吸附剂的捕集容量和 0.30 mol CO2/摩尔脒的效率。然后，将这些实验的结果与单一位点吸附模型结合使用，得出捕集反应的吉布斯自由能，这可以为不同操作条件下吸附剂的适用性提供信息。
