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.     

CO2/N2开关微乳液及其油污洗涤和分离性能

采用等摩尔的十二烷基苯磺酸钠与N-十二烷基-N,N-二甲基叔胺为主乳化剂,正丁醇为助乳化剂,正庚烷为油相,制得O/W型微乳液。在CO_2/N_2交替作用下,可实现微乳液-相分离-微乳液的可逆转换;原始微乳液与复原微乳液半径分别为(10.89±0.21)和(11.50±0.47)nm。该微乳液对多孔固体和织物表面烃类矿物油的洗油率分别为99.13%±0.32%和98.30%±0.28%,对油砂表面原油的洗油率为54.52%±0.25%。活性物质量分数相等时,微乳稀释液对织物表面油性记号笔渍的去污力是市售洗衣粉的1.90倍;而微乳原液的去污力是市售洗衣粉的2.02倍。洗后含油废液通入CO_2可迅速实现油水分层,分离油相后的残余水相经阴、阳离子交换树脂和活性炭常规处理,COD和TOC分别为40.62和17.51 mg/L,符合GB 18918-2002中一级水排放标准(COD≤100 mg/L,TOC≤20 mg/L)。     

基于生物质活性炭对煤层气中CH4/N2的吸附分离性能研究

为了制得性能良好的吸附剂材料,本实验以氢氧化钾为活化剂,改用山楂树枝为碳源并通过一步炭化法制备得到用于分离CH4、N2的活性炭材料,以期提高对CH4/N2吸附分离性能.实验过程中通过考察不同KOH浓度对活性炭孔结构、表面性质及CH4/N2吸附分离性能的影响,并结合一系列表征手段探究样品对CH4/N2吸附分离性能的影响因...     

CO2分离方法的研究进展

CO_2作为温室效应的主要气体,近些年来一直备受关注。综述了CO_2脱除的方法,主要有吸收法(主要包括物理吸收法、化学吸收法和混合溶剂吸收法)、膜分离法、低温蒸馏法和变压吸附分离法;详细介绍了变压吸附分离法,因其能耗低、易操作、污染小等优点,在CO_2分离过程中发挥着越来越重要的作用,并对未来CO_2的吸附分离进行了展望。     

混合胺修饰的介孔硅胶吸附CO2性能研究

以介孔硅胶为载体,采用"嫁接+浸渍"两步法制备了混合胺(APTS+TEPA)修饰的介孔硅胶吸附剂。在固定床中考察了3-氨丙基三乙氧基硅烷(APTS)和四乙烯五胺(TEPA)负载量、吸附温度、进气流量对CO2吸附性能的影响,并研究了吸附剂的循环稳定性。结果表明,当APTS负载量30%,TEPA负载量30%(TEPA30-APTS30-MSG),吸附温度为70℃,进气流量为30 m L/min时,该吸附剂表现出最好的吸附性能,饱和吸附量高达3.04 mmol/g,较纯TEPA浸渍提高了37.6%。该吸附剂经10次吸脱附循环后,饱和吸附量仅下降2.96%,具有较好的循环稳定性。     

壳聚糖的接枝改性及其CO2/N2响应乳化性能研究

通过化学反应将甲基丙烯酸二甲氨基乙酯(DMAEMA)接入壳聚糖(CTS)的分子结构中,获得改性产物CTS-gDMAEMA。使用红外光谱和核磁氢谱对其进行了结构表征。向CTS-g-DMAEMA的聚集体分散液中依次通入CO_2和N_2后,其外观形态、透光率和电导率发生了明显的循环变化,证实了CTS-g-DMAEMA的CO_2/N_2刺激响应性。水-液体石蜡的乳化实验证明,与原料CTS相比,CTS-g-DMAEMA具有更好的稳定乳液的能力;并且在CO_2/N_2作用下,由CTS-g-DMAEMA制备的乳液可以发生破乳和再乳化的循环。     

水对胺改性吸附剂吸附分离CO_2的影响

针对燃煤电厂烟道气中CO2的捕集,采用变压吸附法,从穿透时间、吸附量、分离因子、氨基利用率等方面研究了TEA(三乙醇胺)负载率对胺改性硅胶吸附分离CO2的影响,并进一步考察了胺改性吸附剂中含水量对CO2分离性能的影响。结果表明:TEA改性硅胶对CO2的选择性增强,TEA负载率越高,分离因子越大,TEA负载率为0.8时的分离因子为3.86,是无负载时1.7倍;水的存在能大幅度增强CO2的吸附,水负载率越高,分离因子越大,水负载率为0.35时的分离因子高达24.50,为无水时的7倍,且常温下吸附剂仍可完全再生并具有良好稳定性;氨基利用率随TEA负载率的增大而降低,随水负载率的增大而增大。     

变压吸附法净化含N2气体中微量CO的脱附过程

对N2/CO混合气中的CO在NA型吸附剂上的动态吸附和脱附行为进行研究.使用单塔吸附装置测定CO在不同分压和停留时间条件下的动态吸附量,考察降压过程中CO浓度随床层压力的变化特征,确定合适的脱附方法和条件.结果表明：0.9min是比较合适的停留时间;在床层利用率为80%条件下,顺放的气体可以达到产品气体积分数不超过5mL/m^3的要求;抽真空并使用200mL/minN2吹扫是合适的脱附再生方式.三塔的变压吸附结果表明,在常温下,反复吸附与脱附再生,可以达到吸附净化含N2气体中微量CO的效果.     

煤基含硫活性炭的制备及其CO2吸附性能

将无烟煤与褐煤的混合物掺杂KOH一步法共热解,再将产物酸洗制得含硫活性炭。通过分析不同碱炭质量比对活性炭比表面积和微孔孔体积的作用,探究硫含量对活性炭CO_2吸附性能的影响。当混煤掺杂KOH在碱炭质量比为2∶1、活化温度为800℃、活化时间为2 h时,氮气气氛条件下制备煤基活性炭(AC-S1),并对其进行表征和CO_2吸附性能测试。结果表明:AC-S1的BET比表面积达到682.9 m~2/g,以微孔结构为主,孔径主要分布在0.4 nm～1.2 nm,微孔体积为0.24 cm~3/g,硫含量为0.89%(质量分数);红外光谱分析结果表明,煤基活性炭表面存在含硫官能团;扫描电镜结果表明,含硫煤基活性炭表面结构粗糙,存在一定的孔结构;X射线衍射结果表明,煤基活性炭为无定型非晶材料;X射线光电子能谱分析数据得出,煤基活性炭存在碳硫键和噻吩硫;在常压、298 K条件下,AC-S1的CO_2吸附量为3.16 mmol/g,对CO_2/CH_4体系的分离因子达到8.10。     

CO2,H2,N2在MDEA水溶液中的溶解 度

ＣＯ２、Ｈ２、Ｎ２在ＭＤＥＡ水溶液中的溶解度徐国文张成芳钦淑均（华东理工大学无机化工研究所，上海２００２３７）关键词：ＣＯ２Ｈ２Ｎ２溶解度ＭＤＥＡ１前言国外报道的ＣＯ２溶解度数据［１～９］，布点稀疏，无法满足工程计算及动力学研究之需。王挹薇等采...     

PVAm–PIP/PS Composite Membrane with High Performance for CO2/N2 Separation

Polyvinylamine (PVAm) was modified using a cross‐linking agent containing carriers piperazine (PIP). Attenuated total reflectance fourier transform infrared, elemental analyzer, and X‐ray diffraction were used to characterize the PIP‐modified PVAm. The PVAm–PIP/polysulfone (PS) composite membrane was developed by coating PVAm–PIP mixed solutions with different mass ratios of PIP/PVAm (m_PIP/m_PVAm) on the PS ultrafiltration membrane. The effects of m_PIP/m_PVAm (from 0.715 to 2.860) in the coating solutions and wet coating thickness on the gas performance of the PVAm–PIP/PS composite membrane were investigated. The PVAm–PIP/PS composite membrane prepared showed higher performance than other membranes reported in the literature due to the large increase of the introducing carrier concentration and low crystallinity. Moreover, the separation performance stability of the PVAm–PIP/PS composite membrane was investigated and no deterioration in the membrane permselectivity was observed. Finally, the economic evaluation of the membrane with the highest performance prepared was carried out. © 2012 American Institute of Chemical Engineers AIChE J, 59: 215–228, 2013     

Shell气化炉以CO_2代替N_2作为粉煤输送气的研究

介绍了Shell粉煤加压气化工艺中CO_2替代N_2作为煤粉输送气的工艺流程及项目实施情况,并对掺入CO_2后的合成气组成及尾气排放量,粗甲醇产量等指标进行了对比。掺入CO_2后,减少了甲醇生产装置中N_2含量,提高了甲醇产量,开辟了副产CO_2应用的新途径。     

Membranes for CO2 /CH4 and CO2/N2 Gas Separation

Membrane technology has emerged as a leading tool worldwide for effective CO₂ separation because of its well-known advantages, including high surface area, compact design, ease of maintenance, environmentally friendly nature, and cost-effectiveness. Polymeric and inorganic membranes are generally utilized for the separation of gas mixtures. The mixed-matrix membrane (MMM) utilizes the advantages of both polymeric and inorganic membranes to surpass the trade-off limits. The high permeability and selectivity of MMMs by incorporating different types of fillers exhibit the best performance for CO₂ separation from natural gas and other flue gases. The recent progress made in the field of MMMs having different types of fillers is emphasized. Specifically, CO₂/CH₄ and CO₂/N₂ separation from various types of MMMs are comprehensively reviewed that are closely relevant to natural gas purification and compositional flue gas treatment     

Synthesis and Performance Evaluation of CO2/N2 Switchable Tertiary Amine Gemini Surfactant

A type of switchable tertiary amine Gemini surfactant, N,N′‐di(N,N‐dimethyl propylamine)‐N,N′‐didodecyl ethylenediamine, was synthesized by two substitution reactions with 3‐chloro‐1‐(N,N‐dimethyl) propylamine, bromododecane and ethylene diamine as main raw materials. The structure of the product was characterized by FTIR and ¹H‐NMR. We also investigated the surface tension when CO₂ was bubbled in different concentrations of surfactant solution and the influence of different CO₂ volumes on surface tension under a constant surfactant concentration. Finally the surface tension curve and the related parameters were acquired by surface tension measurements. The experimental results showed that the structure of the synthesized compounds were in conformity with the expected structure of the surfactant, and displayed a better surface activity after bubbling CO₂. The critical micelle concentration (CMC) surface tension at CMC (γ_cmc) pC₂₀ (negative logarithm of the surfactant's molar concentration C₂₀, required to reduce the surface tension by 20 mN/m) surface excess (Γ_max) at air/solution interface and the minimum area per surfactant molecule at the air/solution interface (A_min) were determined. Results indicate that the target product had good surface activity after bubbling CO₂.     

实验室模拟脱碳装置及其脱碳溶液的综合评价

建立了实验室工业模拟脱碳装置,用于接近工业条件下对脱碳溶液进行综合评价。通过对不同浓度MDEA水溶液研究比较,获得MDEA水溶液的最佳脱碳浓度为3.0 kmol·m-3;在相同实验条件下,保持溶液总胺浓度为3.0 kmol·m-3, 对分别添加质量百分比为3%不同活化剂的MDEA溶液进行综合比较,获得了各种活化剂在MDEA溶液中的相对活性次序为哌嗪>二乙醇胺>哌啶。     

MDEA脱碳系统的模拟

应用PRO（Ⅱ）软件对MDEA脱碳系统进行了模拟计算。并提供了在年产10万t合成氨装置中的MDEA系统模拟数据。计算结果比较忠实地反映了MDEA脱碳系统过程中的设计要求。     

CO2/N2 Triggered Switchable Surfactants with Imidazole Group

In order to overcome the hydrolysis of 2-alkyl-1-hydroxyethyl imidazoline and its unsatisfactory emulsification–demulsification switchability to water-alkane, the long-chain N-alkylimidazole compounds were synthesized by n-octyl bromide, n-decyl bromide, n-dodecyl bromide, n-tetradecyl bromide and n-hexadecyl bromide with imidazole, respectively and characterized by MS, ¹H NMR and FTIR. The long-chain N-alkylimidazole compounds can be reversibly transformed into charged surfactants by exposure to CO₂. Surface tension values indicated that N-alkylimidazolium bicarbonates had excellent surface activity compared with corresponding conventional surfactants with a lower γ _CMC. The surface behaviors of the five surfactants can be illustrated by A _min. Five conductivity cycles by bubbling CO₂ and N₂ alternately indicated that these surfactants could be switched by CO₂ reversibly and repeatedly. Emulsions were repeatedly stabilized for five cycles by N-alkylimidazolium bicarbonate and broken by bubbling N₂ through the solutions to reverses the reaction, releasing CO₂.