关键词:

氨法脱碳, 二氧化碳, 再生能耗, 吸收热

Abstract:

Aqua ammonia is thought to be a feasible new absorbent for CO₂ capture in recent years because of its high CO₂ removal efficiency, high loading capacity and the possibility of removing NO_x and SO_x simultaneously.The heat of reaction for aqua ammonia regeneration was considered as low as 26.88 kJ·（mol CO₂）^-1 before, which was much lower than 85 kJ·（mol CO₂）^-1 for MEA regeneration.Data from literature were collected and compared, and their reliability was analyzed in this work.It was found that both our theoretical estimation and experimental data disagreed with those from earlier economic analyses for aqua ammonia capture system.The experimental data in this paper also confirmed that the heat of absorption was about 60—70 kJ·（mol CO₂）^-1 and was seemingly independent of CO₂ loading at a low temperature (35℃).The heat of absorption at a high temperature (80℃) was about 60 kJ·（mol CO₂）^-1 at the beginning, rose to a maximum of around 120 kJ·（mol CO₂）^-1 with increasing loading, and then decreased to 80 kJ·（mol CO₂）^-1 after a certain high loading value was reached.It was impossible to get heat of absorption as low as 26.88 kJ·（mol CO₂）^-1 according to the experimental data of CO₂ in ammonium carbonate solutions.Therefore，aqua ammonia had advantage in energy saving, however the advantage of aqua ammonia over other amine solutions was not as obvious as expected.

Key words:

氨法脱碳, 二氧化碳, 再生能耗, 吸收热