Study On Regeneraion Process Of CO₂ Capture By Ammonia Method

Carbon emission reduction has been highly focused by international society.carbon capture,Utilization and storage?CCUS?have been accepted to be one of the key technology of controlling CO₂ emission which was put forward to fight global climate change.Because of its higher carbon absorptive capacity and economy advantage,ammonia-based carbon capture technology has been studied wildly,but how to solve ammonia escape in this process is still the main issue which restricts the study and industrial application of this technology.In this study,the static experimental system and high gravity experimental system was set up,NH₄HCO₃ solution was used as rich solution of carbon capture.Influencing factors and control methods of CO₂ desorption and ammonia escape were investigated in regeneration process of carbon capture by ammonia method.Firstly,the effects of reaction temperature,NH₄HCO₃ concentration and C/N ratio on CO₂desorption and ammonia escape were investigated at first.Secondly,the effects of addition of Co?II?and Fe?III?on CO₂ desorption and ammonia escape were investigated in NH₄HCO₃ decomposition process.Thirdly,the effects of addition Fe?III?L on CO₂ desorption and ammonia escape in NH₄HCO₃ decomposition process and the effects of addition Fe?III?L on CO₂ removal efficiency and ammonia escape in CO₂ absorption process,were investigated.Finally,the effects of packing bed rotating speed,feed flow rate and temperature on CO₂ decomposition and ammonia escape in NH₄HCO₃ decomposition process were investigated under high gravity.The research results show that,in NH₄HCO₃ solution decomposition process,CO₂ desorption ratio and ammonia escape was increased with the increasing of the reaction temperature and NH₄HCO₃ concentration,and the increasing of C/N ratio of the solution leaded to the increased of CO₂ desorption ratio increase but the decrease of ammonia escape.Transition metal ion Co?II?and Fe?III?was verified to be able to complex free ammonia to reduce ammonia escape in NH₄HCO₃ solution decomposition process,CO₂ desorption ratio was increased by 2-3%and ammonia escape reduction was up to 16.46%with Co?II?,and CO₂ desorption ratio was increased by 3-4%and ammonia escape reduction was up to 19.52%with Fe?III?.Also,organic metal complex Fe?III?L has the ability to complex ammonia,and comparing with metal ions it has a better pH buffering ability,and CO₂ desorption ratio was increased by 2-6%and ammonia escape reduction was up to 31.13%with Fe?III?L in the decomposition process,and ammonia escape reduction was up to 13.23%and CO₂ removal efficiency was slightly influenced with Fe?III?L in CO₂ absorption process.High gravity has positive effect on CO₂ desorption and ammonia escape control,and ammonia escape reduction was up to 50.97%in this process.