CO_2-[emim][Tf_2N]的汽液相平衡实验研究

针对氨系、水系等传统吸收式制冷工质对存在腐蚀性强、制冷量小的缺点,自行设计搭建用于测量CO_2-[emim][Tf_2N]汽液相平衡的实验台,在温度范围263. 15～358. 15 K、压力范围0. 17～2. 45 MPa条件下,测定了CO_2在离子液体[emim][Tf_2N]中的相平衡数据。结果表明,CO_2在离子液体[emim][Tf_2N]中的溶解度可达到0. 535,为CO_2-[emim][Tf_2N]在吸收式制冷系统中的应用奠定了基础数据。     

CO_2-[emim][Tf_2N]的汽液相平衡实验研究

针对氨系、水系等传统吸收式制冷工质对存在腐蚀性强、制冷量小的缺点,自行设计搭建用于测量CO_2-[emim][Tf_2N]汽液相平衡的实验台,在温度范围263. 15～358. 15 K、压力范围0. 17～2. 45 MPa条件下,测定了CO_2在离子液体[emim][Tf_2N]中的相平衡数据。结果表明,CO_2在离子液体[emim][Tf_2N]中的溶解度可达到0. 535,为CO_2-[emim][Tf_2N]在吸收式制冷系统中的应用奠定了基础数据。     

[Emim][Tf2N]离子液体支撑膜吸收CO2性能研究

为了研究离子液体支撑膜吸收CO_2的性能,针对CO_2的传统捕获方法造成环境污染、腐蚀设备等缺点,文章选用新型绿色工质离子液体[Emim][Tf_2N]作为CO_2的吸收剂,并负载于PVDF、PES 2种支撑膜上,在压力为0.2 MPa、流量为50 mL/min,温度为298—318 K范围内变化的条件下进行吸收CO_2的实验,并利用渗透系数、溶解度和扩散系数来评定支撑膜的吸收性能,其中溶解度数据采用van′t Hoff方程进行关联,扩散系数数据和渗透系数数据采用Arrhenius方程进行关联。模拟和实验结果表明:CO_2在2种离子液体支撑膜中的渗透系数和扩散系数随着温度的升高而增大,而溶解度随着温度的升高而降低,且PVDF离子液体支撑膜对CO_2的吸收性能优于PES离子液体支撑膜。因此,PVDF支撑膜较PES支撑膜更加适合用于工业应用中。     

离子液体[BMP][Tf_2N]基本物性的实验及模型关联研究

针对离子液体[BMP][Tf_2N]的物性数据缺乏的问题,在101.325 kPa下对[BMP][Tf_2N]在温度范围为278.15～338.15 K的黏度和温度范围为298.15～338.15 K的密度、电导率进行了实验测定。结果表明,黏度、密度和电导率在温度范围内的值分别是21.6～193.4 mPa·s、1 356.0～1 389.2 kg/m³和0.273～0.893 S/m,黏度、密度和电导率均受温度的影响较大,当压力一定时,[BMP][Tf_2N]的黏度、密度随温度的升高而减小;而电导率随温度的升高而增大;分别采用Arrhenius方程、自然对数方程和VFT方程关联[BMP][Tf_2N]的黏度、密度和电导率的实验数据表明,模型值与实验值的最大相对误差和平均相对误差分别是2.25%和0.94%,5.74%和5.39%,4.412%和4.245%;进一步说明关联模型与实验数据具有良好的一致性。     

功能离子液体[NH_2ebim][PF_6]的合成及其吸收CO_2的研究

采用两步法合成了离子液体1-胺乙基丁基咪唑六氟磷酸盐([NH2ebim][PF6]),进行吸收CO2的研究。结果表明,CO2与离子液体[NH2ebim][PF6]的反应摩尔比介于0.5~1.0,模拟[NH2ebim][PF6]的溶解度参数为18.09 MPa0.5,比常规离子液体的溶解度参数更接近CO2的溶解度参数,说明[NH2ebim][PF6]与CO2有更好的互溶性,利于对CO2的吸收。     

功能离子液体[NH_2ebim][PF_6]的合成及其吸收CO_2的研究

采用两步法合成了离子液体1-胺乙基丁基咪唑六氟磷酸盐([NH2ebim][PF6]),进行吸收CO2的研究。结果表明,CO2与离子液体[NH2ebim][PF6]的反应摩尔比介于0.5¹.0,模拟[NH2ebim][PF6]的溶解度参数为18.09 MPa0.5,比常规离子液体的溶解度参数更接近CO2的溶解度参数,说明[NH2ebim][PF6]与CO2有更好的互溶性,利于对CO2的吸收。     

双温低品位热驱动跨临界CO_2-[emim][Tf_2N]吸收制冷系统的性能

在能量梯级利用的基础上,建立了双温热驱动跨临界CO_2-[emim][Tf_2N]吸收制冷系统,针对该系统的特点构建了相应数学模型,分析了各关键参数对系统性能的影响.结果表明,在一定条件下,与使用相同工质对的传统吸收制冷循环相比,本工作提出的系统性能系数(COP)最高增加50%.     

用于CO_2分离的[bmim][Tf_2N]-PAN共混膜制备及性能

咪唑类离子液体对CO2有良好的溶解性,利用其进行气体分离可以同时提高膜对CO2的选择性和渗透性。利用1-丁基-3-甲基咪唑双三氟甲磺酰亚胺([bmim][Tf2N])离子液体对CO2具有较高的溶解选择性,将[bmim][Tf2N]和聚丙烯腈(PAN)共混制备膜液,涂覆在聚丙烯(PP)支撑层上,利用溶剂蒸发法制备共混复合膜。结果表明,[bmim][Tf2N]的添加对复合膜气体分离性能有明显提高,在离子液体质量分数达到50%后,离子液体逐渐变为连续相,增加了CO2气体的传递通道;气体渗透性能显示其CO2渗透速率可达34.76 GPU,CO2/N2和CO2/CH4理想选择性分别可达49.51和25.14;在随后改变操作压力和测试温度的实验中发现,增大跨膜压差和测试温度均有利于复合膜渗透速率的提升。     

[emim]Ac-CO_2二元体系相平衡实验研究

通过实验测定[emim]Ac-CO_2二元体系的相平衡数据,研究[emim]Ac吸收CO_2的性能。结果表明,当压力一定时,CO_2在[emim]Ac中的溶解度随着温度的升高而减小;当温度一定时,CO_2在[emim]Ac中的溶解度随着压力的升高而增大;在温度和压力的耦合作用下,CO_2在[emim]Ac中的溶解度,在温度263.15K、压力1.37 MPa时高达0.391 6,由此可知[emim]Ac是一种良好的CO_2吸收剂。     

负载[APMIm][Br]离子液体吸收CO_2的性能

1-氨丙基-3-甲基咪唑溴盐([APMIm][Br])离子液体通过化学反应捕集CO2。采用浸渍-蒸发将[APMIm][Br]离子液体负载在硅胶表面,通过比表面孔隙吸附测定仪、热重分析仪(TGA)对吸收剂的结构与性能进行研究,负载量为10%~50%,温度为303.15~323.15 K,CO2浓度分别为10%、30%、50%。结果表明:硅胶表面的离子液体薄膜厚度达到86 nm(负载40%)时,具有最快的吸收速率,且受CO2浓度和温度变化的影响较小,平衡吸收量在50%CO2体系中达到理论吸收量的80%,随着温度的升高而降低,当负载量为50%时,膜厚增加到230 nm,导致吸收速率和平衡吸收量大幅度下降。值得注意的是:负载离子液体吸收剂在循环使用3次之后,结构与性能均保持不变,表现出一定的工业运用前景。     

A new approach for correlating of H2S solubility in [emim][Lac], [bmim][ac] and [emim][pro] ionic liquids using two-parts combined models

Two bi-part combined models containing reaction equilibrium thermodynamic model and an equation of state (EoS) including cubic plus association (CPA) or modified Soave-Redlich-Kwong (SRK), were employed to correlate H₂S solubility in ionic liquids [emim][Lac], [bmim][Ac] and [emim][Pro]. RETM and CPA/mSRK are responsible for chemical and phase equilibria calculations, respectively. The RETM defines a complex formation reaction between an H₂S and two IL molecules into the liquid phase so that a complex in the form of H₂S(IL)₂ is probable to produce. On the other side, CPA/mSRK EoSs perform phase equilibria computations to find pressure and vapor phase concentrations. In the case of CPA, both of H₂S and the ionic liquids were considered as self-associating components which pursue 4C and 2B schemes, respectively. This model computes the pure IL parameters using experimental density data. In this work, critical properties were estimated through the modified Lydersen-Joback-Reid method, Eotvos and Guggenheim relations. Afterward, the binary systems were investigated by applying RETM. CPA presents average absolute deviations (AADs) equal to 2.41%, 13.42% and 3.52% for [emim][Lac], [bmim][Ac], and [emim][Pro], respectively. Moreover, the AADs obtained by mSRK are 3.75%, 5.07%, and 6.06%, respectively. As it is evident from the results, the combination of RETM with both CPA and mSRK EoSs will result in good correlation accuracy.     

离子液体[emim]Ac密度和电导率的实验与理论研究

对离子液体[emim]Ac的密度和电导率进行了实验测定与理论模型关联。结果表明,离子液体[emim]Ac的密度随温度的升高逐渐减小,当温度范围为298.15～338.15 K时,[emim]Ac的密度值变化范围为1 072～1 024 kg/m~3;离子液体[emim]Ac的电导率随温度的升高逐渐增大,当温度范围为298.15～338.15 K时,[emim]Ac的电导率值变化范围为0.369～0.983 S/m;通过比较离子液体[emim]Ac密度及电导率的理论模型关联数据与实验测定数据,得出[emim]Ac密度及电导率的理论模型关联平均相对偏差和最大相对偏差分别为:0.82%,2.65%和1.43%,2.91%,关联结果与实验测定结果一致,故认为所选模型可用于实验数据关联。     

New process development and process evaluation for capturing CO2 in flue gas from power plants using ionic liquid [emim][Tf2N]

Using the ionic liquid [emim][Tf_2N] as a physical solvent, it was found by Aspen Plus simulation that it was possible to attempt to capture CO_2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination, the density, isostatic heat capacity,viscosity, vapor pressure, thermal conductivity, surface tension and solubility of [emim][Tf_2N] were obtained.Based on the NRTL model, the Henry coefficient and NRTL binary interaction parameters of CO_2 dissolved in[emim][Tf_2N] were obtained by correlating [emim][Tf_2N] with the gas–liquid equilibrium data of CO_2. Firstly,the calculated relevant data is imported into Aspen Plus, and the whole process model of the ionic liquid absorption process is established. Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process. Finally, the density, constant pressure heat capacity,surface tension, thermal conductivity, and viscosity of [emim][Tf_2N] were changed to investigate the effect of ionic liquid properties on process energy consumption, solvent circulation and heat exchanger design. The results showed that based on the composition of the inlet gas stream to the absorbers, CO_2 with a capture rate of 90% and a mass purity higher than 99.5% was captured. These results indicate that the [emim][Tf_2N] could be used as a physical solvent for CO_2 capture from coal-fired units. In addition, the results will provide a theoretical basis for the design of new ionic liquids for CO_2 capture.     

离子液体[emim]Ac密度和电导率的实验与理论研究

对离子液体[emim]Ac的密度和电导率进行了实验测定与理论模型关联。结果表明,离子液体[emim]Ac的密度随温度的升高逐渐减小,当温度范围为298.15～338.15 K时,[emim]Ac的密度值变化范围为1 072～1 024 kg/m³;离子液体[emim]Ac的电导率随温度的升高逐渐增大,当温度范围为298.15～338.15 K时,[emim]Ac的电导率值变化范围为0.369～0.983 S/m;通过比较离子液体[emim]Ac密度及电导率的理论模型关联数据与实验测定数据,得出[emim]Ac密度及电导率的理论模型关联平均相对偏差和最大相对偏差分别为:0.82%,2.65%和1.43%,2.91%,关联结果与实验测定结果一致,故认为所选模型可用于实验数据关联。     

离子液体[bmim][Tf2N]的分子动力学模拟

建立了离子液体1-正丁基3-甲基咪唑双（三氟甲基磺酰基）酰亚胺（[bmim][Tf₂N]）的全原子模型,并分别在五种不同的温度和五种不同的压力下对其进行了分子动力学模拟。将[bmim][Tf₂N]密度的模拟结果与实验结果进行了比较,两者吻合良好,验证了模型准确性。此外,还对[bmim][Tf₂N]内部的相互作用能随温度和压力的变化规律进行了分析,结果表明：离子液体内部的库仑能、范德华能、长程作用能均随温度的升高而增加,系统达到平衡所需时间随之变短;相对温度而言,压力对离子液体内部相互作用能的影响较小;在各种相互作用能中,范德华能随温度和压力的变化最大;温度和压力对离子液体的构型不会产生影响。