低温余热驱动的合成氨吸附分离流程的模拟及比较

提出了不同的合成氨吸附分离流程,通过计算模型分析和比较了余热温度及冷却水温度对无回热流程、一级回热流程和二级回热流程的吸附剂用量、余热用量、回热量的影响。结果表明,有回热流程的余热用量要明显低于无回热流程,二级回热流程的节能优势最为显著。在随余热温度升高过程中,吸附剂用量、余热用量、回热量存在1个突变点,余热温度选在突变点右侧附近,余热用量较低。与现行的冷凝分离法相比,吸附分离法不仅能有效地利用低温余热,而且其耗也明显低于冷凝分离法。

Simulation and comparison of separation process of ammonia adsorption driven by low-temperature waste heat

Different separative processes of ammonia adsorption are put forward,and the effects of waste heat temperature and cooling-water temperature on the mass of adsorbent,the quantities of waste heat and recovery heat are analyzed and compared through the calculative models for the processes of non-heat recovery,Ⅰ-heat recovery and Ⅱ-heat recovery.The results show that the waste heat quantity of heat recovery processes is lower than that of the non-heat recovery process,and the advantage of Ⅱ-heat recovery process is very evident.With the increase of waste heat temperature,the mass of adsorbent,the quantity of waste heat and recoveried heat increase,but there is a mutant point.When the waste heat temperature is at about the right of mutant point,the quantity of waste heat is lower.While,under the same conditions,the adsorptive separation can not only use low temperature waste heat effectively,but also the exergy consumption is lower than that of condensational separations.