Nie Yuming, Li Ye, Wang Huanjun, Guo Dongfang, Liu Lianbo, Fu Yonghong
Xi'an University of Architecture and Technology, Xi'an 710055, China.
Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an 710055, China.
ACS Omega. 2023 Mar 21;8(13):11813-11823. doi: 10.1021/acsomega.2c06482. eCollection 2023 Apr 4.
Fly ash from coal-fired power plants can enter chemical absorbents along with flue gas. Silica and metal oxides are the main components of fly ash. To explore the effect of the metal oxides on absorbents, we analyzed the integrated CO absorption-desorption process using -methyldiethanolamine (MDEA) as the standard and an amine absorbent after adding different metal oxides. The effects of each metal oxide on CO capture by the MDEA solution, including CO reaction heat, absorption rate, cyclic loading, and carbonation rate, were assessed. It was found that supplementation with appropriate calcium oxide and magnesium oxide proportions accelerates the CO absorption rate and shortens the saturation time of the MDEA solution by 9%-17%. Magnesium oxide and calcium oxide were precipitated as carbonates during absorption. The CO reaction heat of the MDEA solution increased by 95% after adding magnesium oxide, thereby significantly increasing the energy consumption of the desorption process. On the basis of the experimental studies, the increase in CO absorption rate by MDEA after adding MgO and CaO may be mediated through two different mechanisms.
燃煤发电厂的粉煤灰可与烟气一同进入化学吸收剂中。二氧化硅和金属氧化物是粉煤灰的主要成分。为探究金属氧化物对吸收剂的影响，我们以甲基二乙醇胺（MDEA）为标准，分析了添加不同金属氧化物后的胺基吸收剂的CO整体吸收 - 解吸过程。评估了每种金属氧化物对MDEA溶液捕获CO的影响，包括CO反应热、吸收速率、循环负载量和碳酸化速率。结果发现，补充适当比例的氧化钙和氧化镁可加快CO吸收速率，并使MDEA溶液的饱和时间缩短9% - 17%。氧化镁和氧化钙在吸收过程中以碳酸盐形式沉淀。添加氧化镁后，MDEA溶液的CO反应热增加了95%，从而显著增加了解吸过程的能耗。基于实验研究，添加MgO和CaO后MDEA对CO吸收速率的提高可能通过两种不同机制介导。
