一种具有高CO吸附容量和高CO/N_2及CO/CO_2分离选择性的CuCl@β吸附剂（英文）

研制了一种新型的CuCl@β分子筛吸附剂材料,它不仅对CO有着高吸附容量,而且对CO/N2和CO/CO2的二元混合气有着高吸附选择性。利用自发单层分散的原理制备了一系列的CuCl@β分子筛材料,分别应用氮气吸附以及XRD进行表征。CO在CuCl@β分子筛上吸附等温线和动态透过曲线分别通过静态吸附和固定床实验获得。依据IAST理论模型计算了CuCl@β分子筛对CO/N2二元混合物和CO/CO2二元混合物的吸附选择性。研究结果表明:(1)氯化亚铜的负载增强了一氧化碳在CuCl@β分子筛上的吸附容量,其最佳负载量为0.4g·g-1。(2)CuCl@β分子筛吸附剂在增强CO的吸附量的同时,还降低了对二氧化碳和氮气的吸附。由于Cu+-COπ位络合键的存在,提高了CuCl@β分子筛对二元混合物CO/N2和CO/CO2的吸附选择性。(3)在低压下(0~10kPa)下0.4CuCl@β分子筛对CO/N2和CO/CO2的吸附选择性分别高达1600~5200和120~370,远大于原始的β分子筛。CuCl@β分子筛对CO有着超高吸附容量以及吸附选择性,将会是一种很有潜力的CO分离提纯材料。     

CO2和N2吸附的研究札记

Experiments were made for the adsorption of CO2 and N2 on typical adsorbents to investigate the effects of porous structure and surface affinity of adsorbents as well as those of adsorption temperature and pressure that might cause the variation of adsorption mechanism. It is shown that polar surface tends to enlarge the adsorption difference between CO2 and N2, and the difference is more sensitive to temperature than the adsorbents with non-polar surface. The adsorbents with non-polar surface are not much sensitive to the effect of water vapor, though the water vapor interferes the separation remarkably. The separation coefficient linearly increases with the micropore volume per unit surface area of activated carbons, but no rule is shown on mesoporous silicon materials. The function of adsorption mechanism on the separation is not as much as expected.     

一种用于CO吸附的分子筛吸附剂的制备及研究

以分子筛作为载体,添加氯化亚铜作为活性组分,并采用适当的黏结剂和成型方法制备出适用于吸附混合气中CO的吸附剂。在吸附剂制备过程中,考察了黏结剂种类、还原温度、吸附压力对吸附剂强度和CO吸附量的影响。研究表明:采用树脂型有机黏合剂能够大幅度提高吸附剂的强度,同时对吸附剂的吸附容量影响较小;当还原温度180℃,吸附反应温度40℃,吸附压力0.5 MPa时,对于组分(φ)为H247.1%,CO 31.5%,N219.1%,CH42.28%的模拟气体,吸附剂性能最优,CO吸附量达到最大值50 m L/g。制备的分子筛吸附剂吸附量大、强度较好、耐磨损,能够满足工业化应用的要求。     

AC/X-G吸附剂的制备及CH4/N2吸附分离性能

采用浓度为0.2g·ml^-1的葡萄糖溶液对13X沸石/活性炭复合材料(AC/X)进行碳沉积,研究沉积次数对复合吸附剂(AC/X-G)孔结构、表面性质和CH₄/N₂吸附分离性能的影响。通过X射线衍射,77K下的N₂吸附/脱附,扫描电镜,CO₂-TPD以及红外光谱表征样品的晶型、孔结构和表面性质,在298K、100kPa下对其CH₄和N₂吸附等温线进行测定,并将吸附结果与文献中碳材料和13X沸石的吸附性能进行比较。结果表明:随着沉积次数的增加,AC/X-G吸附剂中X型沸石的相对含量降低,微孔比表面积和微孔体积减少。AC/X-G的表面被碳膜覆盖,碱量降低,但出现强碱位和含氧基团C-O键。AC/X-G的CH₄和N₂吸附量下降,但吸附分离系数提高,沉积3次的样品AC/X-G-3的CH₄/N₂吸附分离系数达到3.0,表面的含氧基团有利于提高复合材料的CH₄/N₂吸附分离性能。     

CO/N2/CO2在MOF-74(Ni)上吸附相平衡和选择性

主要研究了MOF-74(Ni)材料对CO/N₂/CO₂的吸附分离性能。应用水热法合成制备MOF-74(Ni),分别采用全自动表面积吸附仪、P-XRD、扫描电子显微镜对材料的孔隙结构和晶体形貌进行了表征,应用静态吸附法测定了CO、N₂和CO₂在MOF-74(Ni)上的吸附等温线,应用DSLF方程模拟了3种气体MOF-74(Ni)上的吸附等温线,依据IAST理论模型计算了MOF-74(Ni)对CO/N₂二元混合物和CO/CO₂二元混合物的吸附选择性。研究结果表明:在0.1 MPa和常温条件下,MOF-74(Ni)材料对CO吸附容量高达6.15 mmol·g^-1,而相同条件下N₂的吸附量只有0.86 mmol·g^-1。MOF-74(Ni)在低压下(0～40 kPa)对CO的吸附量明显高于其对CO₂的吸附量。应用IAST模型估算MOF-74(Ni)对二元混合物吸附选择性的结果表明:MOF-74(Ni)对CO/N₂混合物的吸附选择性在1000以上;MOF-74(Ni)对CO/CO₂的吸附选择性在4～9范围,在所研究的二元气体混合物吸附体系中,MOF-74(Ni)都能优先吸附CO。     

CO吸附剂制备及其吸附脱除微量CO的性能

介绍了CO吸附剂的制备方法,研究了该吸附剂在固定床温度30 ℃、CO分压为6 kPa(a)下吸附一氧化碳的动态吸附性能,测定了穿透曲线,动态吸附容量为2.138 5 mmol/g,并用BET吸附仪测定了制备的CO吸附剂比表面积,用电感耦合等离子体原子发射光谱(ICP)测定其离子交换度为52%,含铜量为9.52%(质量分数)。通过粉末X射线衍射仪(XRD)和场发射扫描电子显微镜(SEM)表征发现,水热交换法制备CO吸附剂,Cu²⁺有效地取代了NaY原粉中Na⁺,经过焙烧还原后仍然能够维持原骨架结构的完整。用NH₃-TPD考察了改性前后吸附剂酸度的变化以及用H₂-TPR考察了吸附剂合适的还原温度。采用130 ℃氮气吹扫的方法再生,再生彻底并且吸附效果稳定。     

改性硅胶吸附分离N2/CO2的研究

目前,人类在能源系统中产生大量CO2并直接排放,导致了大气温室效应和地球变暖。因此从环境保护和节约能源角度考虑,对排放的N2/CO2混合气进行回收和利用是非常必要的。选择高沸点的N-甲基二乙醇胺（MDEA）作为涂渍液,用不同浓度的涂渍液对粗孔微球硅胶进行预处理,并分别进行了N2/CO2混合气的穿透实验研究,实验结果表明：以粗孔微球硅胶为担体涂渍35%MDEA的吸附剂,在操作压力为0.4MPa时,对N2/CO2混合气分离效果最好。     

菌丝体表面分子印迹吸附剂的选择性吸附

采用制备得到的菌丝体表面分子印迹吸附剂;系统研究了菌丝体表面分子印迹吸附剂对模板金属离子的吸附选择性。结果表明：与非印迹吸附剂相比;以Ni+为模板制备的菌丝体表面分子印迹吸附剂;对Ni+、Cu+与Cr3+的吸附速率和吸附容量都有较大幅度的提高。对于含有Ni+的金属离子混合溶液;菌丝体表面分子印迹吸附剂对Ni+的吸附容量和选择性都比另一种金属离子（如Cr3+和Cu+）明显提高;与非印迹吸附剂相比;印迹吸附剂对非模板金属离子Cr3+和Cu+的选择性明显降低。     

固体吸附剂吸附二氧化碳的研究进展

综述了近年来介孔硅分子筛负载型吸附剂、聚合物负载型吸附剂、沸石负载型吸附剂、活性炭等不同载体CO2固体吸附剂的制备及其对CO2的吸附性能研究情况,同时指出了该研究领域中仍存在的一些问题。     

分子筛负载CuCl制备CO吸附剂的研究

利用机械混合法将CuCl直接负载于分子筛13X、NaY和NH4X表面上制备高效CO吸附剂.实验结果表明,样品在320℃真空活化后,13X和NaY载体制备的吸附剂表现出较好的CO吸附性,CuCl的最佳分散质量分数分别为0.40 g CuCl/g 13X及0.45 g CuCl/g NaY,CO吸附量分别高达76 mL/g及84 mL/g,脱附质量分数分别为40％和60％,且CO/CO2分离比分别可达1.4和1.9.XRD表明,吸附剂经真空活化后CuCl晶相消失,表明CuCl在载体表面均匀分散,并且可能部分阳离子发生交换,进而提高了CO的吸附量.     

CuCI负载型吸附剂吸附CO的研究

利用Cu＋能与C0结合形成羰基络合物,将Cu＋盐负载到分子筛表面,经过热处理能达到自发单层分散状态,有效提高了C0的吸附量。利用直接混合法将CuCl负载于13X分子筛表面上制备高效的CO专用吸附剂。实验结果表明,将样品置于管式炉内,流动N2氛围保护下,在350℃焙烧4h后,CuCl／13X质量比0．4：1．0吸附剂表现出较好的吸附性能,C0吸附量可迭45mL／g,对工业分离混合气体有重要的意义。XRD也显示,不同质量比的CuCl／13X样品,在N2氛围中350℃焙烧4h后,CuCl晶相峰从有变无,说明CuCl均匀分散于栽体表面,提供了更多的与C0络合的铜离子活性中心,进而提高了吸附剂对C0的吸附量。     

A novel carbonized polydopamine (C‐PDA) adsorbent with high CO2 adsorption capacity and water vapor resistance

Novel carbonized polydopamine adsorbents (C‐PDAs) with high surface area, high CO₂ adsorption capacity and superior moisture resistance performance were prepared by one‐step synthesis method using polydopamine as carbon precursor at different KOH/C ratios, and then characterized. CO₂ and water vapor adsorption performances of C‐PDAs were examined separately by static adsorption and fixed‐bed experiments. Results showed that BET area and pore volume of C‐PDA‐4 were up to 3342 m²/g and 2.01 cm³/g, respectively. Its CO₂ adsorption capacity reached up to 30.5 mmol/g at 25 bar, much higher than many other adsorbents including metal‐organic frameworks (MOFs). C‐PDAs prepared with high KOH/C ratios had low surface element concentrations of O and N resulting in low surface hydrophilic property. H₂O(g) isotherm of C‐PDA was much lower than those on Mg‐MOF‐74, Cu‐BTC, and MIL‐101(Cr). Fixed‐bed experiments showed that co‐presence of water vapor in feed stream with 30% RH had negligible impact on CO₂ working capacity of C‐PDA. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3730–3738, 2016     

氯化钙/大球硅胶复合吸附剂的氨吸附研究

以单层分散理论为指导,研究了氯化钙在大球硅胶上的单层分散、氨吸附及吸附稳定性。结果表明,对于焙烧分散法,氯化钙/大球硅胶的适宜焙烧温度为500℃;对于微波分散法,适宜的微波辐射时间是20 min。焙烧样品的单层分散阈值为0.2~0.3 g/g,微波样品的单层分散阈值为0.3~0.4 g/g。将吸附量较大的样品进行比较,在35℃下,担载量为0.4 g/g的焙烧样品氨吸附量为0.35 g/g;担载量0.5 g/g的微波样品氨吸附量为0.41 g/g。微波样品的氨吸附量大于焙烧样品。吸附-脱附循环实验表明,2种分散法所得复合吸附剂同样具有较好的吸附稳定性。     

铝基锂吸附剂制备及其吸附性能研究

以氯化锂、无水氯化铝为原料,通过正交实验优化反应合成条件,采用“一步法”制备LiCl·2Al（OH）₃·nH₂O型铝基锂吸附剂。分别探究了吸附时间、吸附温度、溶液初始pH、溶液初始Li⁺浓度对吸附性能的影响,对吸附前后的无机铝吸附材料做了表征,并考察了吸附剂的离子选择吸附性及稳定性能。结果表明：最佳吸附条件为在45 ℃下pH=7的锂溶液中吸附2 h,吸附容量高达到8.66 mg/g。XRD、FT-IR表征结果表明：所制吸附材料有良好的稳定性。且该吸附剂对Li⁺分配系数（K=10.06）远高于其他金属阳离子,吸附材料经5次循环使用后,吸附容量仍能保持原来的91.5%。在西藏龙木错盐湖卤水中,对锂的吸附量达到5.24 mg/g。吸附平衡数据拟合结果表明：铝基锂吸附剂符合Langmuir等温吸附模型,吸附是发生在吸附剂表面的单层吸附;吸附过程符合伪二级动力学,是典型的化学吸附过程。     

Enhancement of CO2 Adsorption and CO2/N2 Selectivity on ZIF‐8 via Postsynthetic Modification

Imidazolate framework ZIF‐8 is modified via postsynthetic method using etheylenediamine to improve its adsorption performance toward CO₂. Results show that the BET surface area of the modified ZIF‐8 (ED‐ZIF‐8) increases by 39%, and its adsorption capacity of CO₂ per surface area is almost two times of that on ZIF‐8 at 298 K and 25 bar. H₂O uptake on the ED‐ZIF‐8 become obviously lower compared to the ZIF‐8. The ED‐ZIF‐8 selectivity for CO₂/N₂ adsorption gets significantly improved, and is up to 23 and 13.9 separately at 0.1 and 0.5 bar, being almost twice of those of the ZIF‐8. The isosteric heat of CO₂ adsorption (Q_st) on the ED‐ZIF‐8 becomes higher, while Q_st of N₂ gets slightly lower compared to those on the ZIF‐8 Furthermore, it suggests that the postsynthetic modification of the ZIF‐8 not only improves its adsorption capacity of CO₂ greatly, but also enhances its adsorption selectivity for CO₂/N₂/H₂O significantly. ©2013 American Institute of Chemical Engineers AIChE J, 59: 2195–2206, 2013     

复合吸附剂MWCNT/MgCl2的水蒸气吸附性能

通过研磨将多壁碳纳米管分别与质量分数为30%、40%和50%的无水氯化镁复合,制备了3种不同配比的复合吸附剂MWCNT/MgCl₂。采用数字化扫描电子显微镜（SEM）观察复合吸附剂表面材质的结构样貌,通过Hot Disk热常数分析仪测得复合吸附剂的热导率,使用恒温恒湿箱选取具有代表性的温湿度,测试复合吸附剂在不同工况下的水蒸气吸附性能,并采用准二级动力学模型对25℃、50% RH工况下的实验数据进行拟合,应用Autosorb-IQ全自动气体分析仪测试了三种样品在25℃下的等温吸湿曲线。实验结果表明,相同温湿度工况下,随着氯化镁含量增加,复合吸附剂的吸附量提高,25℃、50% RH下氯化镁含量为30%、40%和50%的复合吸附剂M1、M2和M3的吸附量分别为0.62、0.79和0.94 g/g;恒定湿度为50% RH,温度变化为15~35℃时,复合吸附剂吸附量受温度和饱和水蒸气分压力的双重影响,表现为先增加后减小;温度固定为25℃,相对湿度从50% RH增加到80% RH时,复合吸附剂吸附量均大大提升;复合吸附剂在35℃、25% RH中高温、低湿条件下仍表现出较好的吸附能力;在相对压力P/P₀为0.3时,M1、M2和M3的吸附量分别为0.24、0.25和0.30 g/g,随着吸附压力的增加,复合吸附剂的吸附量也不断提升,最大吸附量分别达到3.54、3.75和4.42 g/g。复合吸附剂MWCNT/MgCl₂的制备研究,为吸附剂的性能研究提供了基础,对太阳能吸附式空气取水的研究具有潜在意义。     

Characteristics of as-prepared biochar derived from catalytic pyrolysis within moderate-temperature ionic liquid for CO2 uptake

A promising biochar as solid adsorbent for CO₂ uptake was prepared by the catalytic pyrolysis of coconut shell in moderate-temperature ionic liquid (IL). Then, it was characterized by means of SEM, EDS, BPEA, BET, NLDFT, FTIR, and TG-DSC, and a mechanism interpretation of the porous biochar formation was conducted. In addition, the adsorption characteristics of CO₂ on the as-prepared biochar, such as adsorption capacity, adsorption potential, isosteric heat, and static selectivity at different adsorption temperatures and pressures, were systematically evaluated. The results indicated that the as-prepared biochar exhibited an adequate CO₂ adsorption with a capacity of 4.5 mmol/g at 273 K and 100 kPa. Then, a significant number of slit-like pores were revealed to exist on the as-prepared biochar with a peak pore size between a range of 0.6 nm-2 nm. The porous structure formation was ascribed to the release of carbon-, hydrogen-, oxygen-, sulphur-, and nitrogen-containing compounds during biochar preparation. Meanwhile, both the adsorption potential and isosteric heat of the CO₂ uptake under the tested conditions decreased with an increase in the adsorption capacity, which ranged from 33 kJ/mol-21 kJ/mol and 23 kJ/mol-7 kJ/mol, respectively. Therefore, the isosteric heat could be considered as a piecewise function of adsorption capacity. In addition, the molar ratios of CO₂ over N₂ adsorbed under the tested conditions were above 11 and were accompanied by molar ratio peaks of 26 at 273 K and 19 at 298 K, respectively. Moreover, an interesting phenomenon occurred: the static adsorptive selectivity of CO₂ over N₂ first increased and then decreased and there was an increase in the adsorption pressure at the tested adsorption temperatures.