关键词: 沸石咪唑骨架-8, 吸收, 二氧化碳捕集, 分离, 鼓泡塔

Abstract:

Effective CO₂ capture is of great significance for reducing greenhouse gas emissions and controlling global warming. Zeolitic imidazolate framework-8 (ZIF-8) and ethylene glycol are mixed to form a flowable slurry via the combination of absorption and adsorption. A series of separation experiments were carried out in an atmospheric pressure transparent PMMA column (height 3.7m, inner diameter 50mm) and a high pressure stainless steel bubble column (height 3m, inner diameter 40mm) respectively. The rich slurry is desorpted in the desorption tank and then returned to the absorption tower to capture carbon dioxide. The whole separation process can be carried out continuously. The results show that the lower the absorption temperature and the mixed air flow rate, the higher the slurry regeneration temperature and the tower pressure, the greater the amount of carbon dioxide absorbed by the slurry. The optimum operating conditions were determined as follows: absorption temperature 0.5℃, gas flow rate 47mL/min, slurry regeneration temperature 333.13K, and operation under normal pressure. Under the optimum operating conditions, the separation factor was 395. After more than 100hours of operation, the structure of ZIF-8 did not change and the ZIF-8/glycol slurry could be reused, which demonstrated the potential industrial application value of ZIF-8/glycol slurry.

Key words: ZIF-8, absorption, CO₂ capture, separation, bubble column