基于钙基的吸收增强式水气变换反应实验研究

Experimental Study of the Absorption Intensified Type Water-gas Conversion Reaction Based on a Calcium-base Absorbent

利用CaO能同时催化水气变换反应和吸收CO2的双功能特性,在流化床反应器上进行了基于钙基CO2吸收剂的吸收增强式水气变换过程的实验,研究了反应温度、H2O/CO比对水气变换反应的影响,讨论了石灰石对水气变换的催化作用,分析吸收剂循环反应活性下降特性并进行了乏吸收剂水蒸气活化改性实验。实验结果表明,在400～600oC范围内,升高温度同时提高CaO的催化和CO2实验吸收能力。增加H2O/CO比例有利于水气变换反应中CO转化率的提高,但当H2O/CO比例高于2时,水蒸气对水气变换的促进作用减弱。石灰石只有在高于700℃时才体现出一定的催化效果。钙基吸收剂催化活性和CO2吸收能力均随循环次数的增加而下降,通过水蒸气活化可以部分恢复CaO反应活性,提高钙基吸收剂在吸收增强式水气变换循环过程中的利用效果。

To use CaO can achieve dual functional characteristics,i.e.not only catalyze the water gas conversion reaction but also absorb CO2.In a fluidized bed reactor,conducted was an absorption intensified type water-gas conversion reaction based on a calcium-base CO2 absorbent and studied was the influence of the reaction temperature and H2 O/CO ratio on the water-gas conversion reaction.Furthermore,the catalytic action of the limestone on the water-gas conversion and the activity degradation characteristics of the absorbent circulation reaction were described with the exhaust absorbent being activated and denatured by steam.The test results show that in a temperature range from 400 ℃ to 600 ℃,to increase the temperature can both enhance the catalytic action of CaO and the absorption capacity to CO2.To increase the H2 O/CO ratio is contributive to the enhancement of the CO conversion rate in the water-gas conversion reaction.However,when H2 O/CO ratio is above 2,the promotion action of the steam on the water-gas conversion will be weakened.The limestone can play a certain catalytic role only when the temperature is higher than 700 ℃.The catalytic activity of the calcium-base absorbent and the absorption activity to CO2 will be degraded with an increase of the recycling frequency.To activate it by using steam can partially restore the reaction activity of CaO and enhance the utilization effectiveness of the calcium-base absorbent in the absorption intensified type watergas conversion and circulation process.