针对氨法脱除CO2再生能耗高问题,提出混合吸收剂氨法捕碳新工艺.新工艺以混合吸收剂强化结晶,以晶体再生代替原富液再生工艺,大大降低再生能耗.采用升温法及恒温热解法,利用热重分析仪对不同工况下晶体产物进行研究.结果表明:在40～80℃时,分解反应活化能可达48.38 kJ/mol;分析在60、80、100℃恒温条件下晶体的失重曲线表明,以80℃为恒温再生温度,即可得到较好的再生速率;晶体产物以5 K/min加热时,80℃下晶体即可完全分解,不仅能耗低而且再生速率快,效果远优于碳化液富液再生工艺;由于晶体再生的温度低,以电厂废热作为晶体再生热源,可进一步降低能耗;对于混合吸收剂,不同的溶析剂配比对再生过程影响不大,混合吸收剂组成仅由吸收速率决定;经过对16种经典模型的计算,选出了对本研究晶体产物适合的模式函数.%Using a new kind of absorbent which is the mixture of aqueous ammonia and ethanol, a process of carbon capture by ammonia of low concentration with reinforced crystallization and lower energy consumption is presented. By the application of antisolvent crystallization to reinforce crystallization process, low energy consumption of regeneration could be achieved easily due to saving the energy to heat the water of carbonized ammonia in the desorption process. TGA is adopted to study the regeneration process of crystal product, and heating method pyrolysis and constant temperature pyrolysis are used respectively. What' s more, if the waste heat from the power plant can be used as heat source of the regeneration process, the more energy can be saved for the technology. With the regeneration temperature between 40 ℃and 80 ℃, the active energy can be as low as 48.38 kJ/mol. The regeneration process is studied at the constant temperature of 60℃, 80℃ and 100℃. And if the rate of rising temperature is 5 K/min, the crystal product will be totally decomposed when the temperature reaches 80℃,not only can achieve low energy consumption but also have fast regeneration rate which have the advantage over the process of rich carbonated ammonia. For the mixed absorbent, the different proportion of the dissolved agent has little effect on the regeneration process, and the composition of the mixture is determined only by the absorption rate. The better regeneration rate can be obtained by the constant temperature of 80 ℃. After the calculation of 16 classical models, the model function was selected for the study of crystal products.
展开▼
