化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2015年
8期
2953-2961
,共9页
离子液体%传质%二氧化碳%吸收%规整填料%压降%计算流体力学
離子液體%傳質%二氧化碳%吸收%規整填料%壓降%計算流體力學
리자액체%전질%이양화탄%흡수%규정전료%압강%계산류체역학
ionic liquid%mass transfer%carbon dioxide%absorption%structured packing%pressure drop%computational fluid dynamics (CFD)
在规整填料塔中采用离子液体吸收二氧化碳气体，利用计算流体力学（CFD）软件建立可靠的数学模型，系统考察了离子液体结构及规整填料几何参数对吸收过程的传质特性和流体力学性能的影响规律。结果表明，床层压降随气体流速增大而增大，液相传质系数随液体流速的增大而增大。相同阴离子时，随着阳离子碳链长度的增长，吸收过程压降增大，同时液相传质系数减小。相同阳离子时，不同阴离子的离子液体压降大的同时传质系数也大。但离子液体的结构对压降影响不明显。离子液体筛选主要考虑传质系数和溶解度因素，但二者与离子液体结构表现出相反的规律。两种折线结构的规整填料传质性能优于传统的X型和Y型结构。
在規整填料塔中採用離子液體吸收二氧化碳氣體，利用計算流體力學（CFD）軟件建立可靠的數學模型，繫統攷察瞭離子液體結構及規整填料幾何參數對吸收過程的傳質特性和流體力學性能的影響規律。結果錶明，床層壓降隨氣體流速增大而增大，液相傳質繫數隨液體流速的增大而增大。相同陰離子時，隨著暘離子碳鏈長度的增長，吸收過程壓降增大，同時液相傳質繫數減小。相同暘離子時，不同陰離子的離子液體壓降大的同時傳質繫數也大。但離子液體的結構對壓降影響不明顯。離子液體篩選主要攷慮傳質繫數和溶解度因素，但二者與離子液體結構錶現齣相反的規律。兩種摺線結構的規整填料傳質性能優于傳統的X型和Y型結構。
재규정전료탑중채용리자액체흡수이양화탄기체，이용계산류체역학（CFD）연건건립가고적수학모형，계통고찰료리자액체결구급규정전료궤하삼수대흡수과정적전질특성화류체역학성능적영향규률。결과표명，상층압강수기체류속증대이증대，액상전질계수수액체류속적증대이증대。상동음리자시，수착양리자탄련장도적증장，흡수과정압강증대，동시액상전질계수감소。상동양리자시，불동음리자적리자액체압강대적동시전질계수야대。단리자액체적결구대압강영향불명현。리자액체사선주요고필전질계수화용해도인소，단이자여리자액체결구표현출상반적규률。량충절선결구적규정전료전질성능우우전통적X형화Y형결구。
In this work, ionic liquids (ILs) were proposed for the capture of CO2 over the structured packings. The pressure drop and mass transfer coefficient were investigated using computational fluid dynamics (CFD). The relationship among the structure of ILs, performance of pressure drop and mass transfer coefficient, as well as the relationship among the corrugation angles of structured packings, performance of pressure drop and mass transfer coefficient were identified. The results showed that under the same operating conditions with same anion, the increase of carbon number in the alkyl chain on the cation of ILs leads to the increase of the pressure drop (i.e., [HMIM][Tf2N] > [BMIM][Tf2N] > [EMIM][Tf2N]), and decrease of the mass transfer coefficient (i.e., [EMIM][Tf2N] > [BMIM][Tf2N] > [HMIM][Tf2N]). Thus, the cation [EMIM] is the optimum choice with regard to the pressure drop and mass transfer performance. Moreover, for ILs with different anions the pressure drop and mass transfer coefficient show the same trend,i.e., [EMIM][BF4] > [EMIM][TFA]≈ [EMIM][TfO] > [EMIM][Tf2N]. There is an inverse relationship between the mass transfer coefficient and solubility of CO2 for different ILs. Thus, there is a tradeoff when choosing IL for the capture of CO2. In addition, four types of structured packings with different corrugation angles (X type, Y type, and two transition types) were compared. From the viewpoint of mass transfer performance the two transition types structured packings are superior to thetraditional X or Y types.
