变压吸附分离工业废气二氧化碳的研究进展

概述了未来人类对过量二氧化碳排放的处理办法,即碳的捕获和存储(CCS).简介了4种二氧化碳的分离工艺及特点和工业中二氧化碳的捕获系统.阐述了变压吸附工艺的基本原理和其在捕获工业废气中二氧化碳上的应用,以及变压吸附分离二氧化碳的工艺在循环结构设计、吸附剂材料和数值模拟等方面的研究进展和国内外的工业化应用.分析了目前该工艺仍存在的问题,指出该技术具有广阔的应用前景.     

改性活性炭脱除二氧化碳中的微量苯

将工业废气中的CO2回收利用,使之变废为宝具有重要的意义。研究了活性炭(AC)分别经湿氧化和N2还原改性后对苯吸附性能,并测定了改性活性炭的孔结构和表面官能团。结果表明,AC经N2还原改性能增大其比表面积,减少表面含氧官能团,增强其表面非极性,有利于苯的吸附。孔径分布是影响苯吸附的主要因素,吸附剂的孔径分布在0.6nm范围内时,有利于对苯的吸附。     

活性炭液相吸附脱除二甲基二硫醚

通过椰壳活性炭对模拟硫酸盐松节油进行液相吸附脱硫的研究,考察了活性炭的结构和表面化学对活性炭吸附的影响。通过Gaussian03计算模拟油中各化合物的化学硬度,根据软硬酸碱理论解释表面化学对该吸附过程的影响。同时考察了活性炭吸附过程的热力学性质。结果表明,由于吸附体系中的二甲基二硫醚和莰烯的化学硬度相接近,活性炭表面的含氧官能团的变化对吸附性能影响不大,但活性炭比表面积和孔结构的变化对吸附性能的影响较为明显;等温吸附平衡数据符合Freundlich等温吸附模型,热力学数据显示该活性炭吸附过程是一个放热、混乱度降低的自发物理吸附过程。     

改性球形活性炭对氨气吸附性能的研究

研究了不同金属盐溶液浸渍改性的球形活性炭对氨气的吸附性能以及同种浸渍剂的最佳浸渍比。采用扫描电镜、透射电镜、X射线衍射仪、康塔吸附仪探究了不同浸渍比对浸渍炭样品的表面形貌、物相结构及孔径分布的影响。通过固定床吸附装置对基炭和浸渍炭进行了氨气吸附性能的研究。结果表明：浸渍剂种类对氨气吸附效果有很大影响, 同等浸渍条件下, 氯化钴浸渍的活性炭具有最优氨气吸附效果, 氯化钴浸渍比为50%的样品对氨气的吸附量最高, 可达54.05 mg/mL, 为基炭的37倍。对吸附氨气后样品的物化性质进行分析以及程序升温脱附表征, 结果表明氯化钴与氨气反应生成了[Co（NH₃）₆]Cl₃。     

Application of high‐pressure swing adsorption process for improvement of CO2 recovery system from flue gas

Although the super cold separator applied to the system for CO₂ recovery from flue gas can produce pure CO₂ liquid, the CO₂ recovery efficiency is low. Therefore, the addition of a PSA plant was considered for the secondary CO₂ recovery from the noncon‐densing gas to improve the efficiency. The PSA plant was operated for adsorption at the same pressure as that of the super cold separator and for desorption at the atmospheric pressure. From both the simulation and the experimental data, it was confirmed that CO₂ could be concentrated from 50% in the noncondensing gas to 70% in the recovery gas by the PSA plant and the CO₂ recovery efficiency of the plant was about 90%.     

工业尾气变压吸附提纯一氧化碳中试

Using pressure swing adsorption （PSA） technology to purify carbon monoxide （CO） discharged from industrial gases is a high-efficiency and economical method. In this article, a four-bed PSA experiment for CO purification was improved and optimized, in which a set of 120 m^3·h^-1 pilot-scale PSA device was developed to purify CO from industrial tail gases, a set of control systems suitable for industry production was developed, and the influences of the operating parameters on CO purification were investigated. The experimental results indicated that the pilot-scale PSA device could produce qualified product gas and get high CO recovery ratio under optimized conditions. The research may provide reliable fundamental data, for industrial scale utilization of CO, from industrial tail gases, and have strong market competitive power and a broad promoted application prospect.     

复合床层变压吸附法脱除合成气中微量CO和CO_2

采用分别装载活性炭和NA型吸附剂的复合床层的变压吸附工艺来脱除合成气中微量的CO和CO2,并利用Aspen-Adsim软件对其进行模拟和优化。模拟结果表明,吹扫气量对工艺性能有较大的影响,吹扫气由处在顺放步骤的吸附塔提供,因此在顺放步骤将床层压力降至较低压力,可获得较大的吹扫气量,此时的工艺性能也较优。模拟结果还表明,均压次数对工艺性能也有影响。在相同的顺放压降下,将变压吸附过程中的3次均压变为2次均压,可减少吸附剂用量,吸附剂产率更高,但塔底尾气量要相应增加。     

TEPA负载复合氧化活性炭吸附烟气中的CO2性能

以商业煤基活性炭为原料,经低浓度氧气焙烧、H₂O₂氧化改性,并以四乙烯五胺（TEPA）浸渍,得到胺负载复合氧化活性炭,用于模拟烟道气[(15%(体积)CO₂+85%(体积)N₂）+10%(体积)H₂O]中CO₂吸附。低浓度氧气焙烧后,活性炭的最大比表面积和孔体积分别为1421.82 m²/g、0.83 cm³/g。经复合氧化改性后,活性炭的介孔体积增大,表面含氧官能团增加,使得TEPA负载复合氧化活性炭的CO₂吸附性能提高。焙烧时间为4 h,H₂O₂氧化、负载40%TEPA的样品COAC-4-40TEPA,在60℃时CO₂饱和吸附量最高为2.45 mmol/g,是TEPA负载未改性活性炭AC-40TEPA的2.02倍。经过十次吸附循环后,COAC-4-40TEPA的 CO₂饱和吸附量可维持在92.24%,而TEPA的浸出量仅有0.67%。失活模型研究表明,COAC-4-40TEPA的初始吸附速率常数是AC-40TEPA的1.64倍,且失活速率常数低于AC-40TEPA。     

活性炭吸附法在挥发性有机物治理中的应用研究进展

挥发性有机化合物(VOCs)是一类重要的大气污染物,其所带来的环境污染问题已经引起全世界的关注.活性炭吸附法是治理VOCs污染的有效手段.本文从介绍VOCs治理技术出发,简述了活性炭吸附法在VOCs治理中的使用现状,概括了活性炭吸附法治理VOCs的工艺技术和存在问题,指出变温-变压吸附、变电吸附以其高效节能环保的优点,在VOCs治理中具有较好的发展前景.分析了活性炭表面化学性质、吸附质的物性、操作条件对活性炭吸附法治理VOCs的影响,为VOCs治理专用活性炭的改进和新产品的开发,提供了理论依据.在总结现有研究进展的基础上,预测了活性炭吸附法治理VOCs技术的发展趋势,提出对工艺的改进以及与其他VOCs废气处理技术的耦合使用,针对不同VOCs排放场所开发不同活性炭品种和VOCs回收装置将是以后研究的重要方向.     

Langmuir and Dubinin–Radushkevich analyses on equilibrium adsorption of activated carbon fabrics in aqueous solutions

The present study investigated the adsorption of phenol, iodine and tannic acid onto activated carbon fabrics in aqueous solutions. The carbon fabrics were made of polyacrylonitrile with different extents of activation in steam. The increasing extent of activation is accompanied by increasing carbon porosity as well as liquid‐phase adsorption capacity. Langmuir and Dubinin–Radushkevich (D–R) models were employed to analyze the equilibrium adsorption data. The fractional filling of carbon micropores and the mean free energy for adsorption were estimated according to these models. It is suggested on the basis of the present work that the mesopore fraction of the fabrics, the extent of carbon activation, and the adsorbate size are important as well as competitive factors determining the adsorption capacity. Both the equilibrium constant and free energy for adsorption increase with the mesopore fraction, indicating that the mesopores promote the adsorption onto high energy sites, whereas the fraction filling micropores decreases with the extent of carbon activation and the size of the adsorbates. © 2000 Society of Chemical Industry     

Granular activated carbon adsorption process for removing trichloroethylene from groundwater

Batch adsorption capacity experiments and continuous flow breakthrough experiments were conducted to compare the effectiveness of seven granular activated carbons (GACs) in removing trichloroethylene (TCE) from groundwater. The order of GACs' adsorptive capacities for TCE was the same as their phenol numbers (indicator for <1 nm micropores). A small amount of methanol (0.05% v/v) did not affect the pure water TCE capacities, which were notably reduced by the small organic constituents of tap water. The breakthrough results show low utilization of the available adsorptive capacity due to both slow mass transport and the need to achieve a high degree of TCE removal, and that the serial bed mode of treatment is cost effective because a very high capacity utilization can be attained. The low‐cost, environmental friendly bamboo GAC is attractive as its competitive TCE capacity was readily used in actual treatment because of its favorable pore structure. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

A simple calorimeter to measure specific heat of activated carbon prepared for pressure swing adsorption refrigeration system

A new calorimeter to measure specific heat of indigenously prepared granular activated carbon (AC) for application in a refrigeration system based on gas adsorption–desorption mechanism is presented. This calorimeter allows specific heat measurements in high (305.5–317.8 K) as well as low (254.6–264 K) temperature ranges. The specific heat of prepared AC on measurement using developed calorimeter has been found to be 1.062 J g^?1 K^?1. Preparation, instrumental analyses and influence of various physical properties of AC on its specific heat have also been discussed. Characterisation results of AC demonstrate that it can be efficiently used in such cold producing system down to refrigeration and cryogenic temperature. © 2012 Canadian Society for Chemical Engineering     

改性活性炭吸附脱除二氧化碳中微量乙烷

我国对食品级二氧化碳要求较高,在其生产过程中乙烷的脱除是难点。文章首先考察了市售的不同吸附剂,包括Y型、X型、A型等分子筛类,椰壳和煤基活性炭以及吸附树脂等吸附剂对CO2中微量C2H6的吸附效果,之后考察了不同浓度盐酸酸改性与氢氧化钠碱改性、双氧水氧化改性、氨水还原改性等改性条件对吸附剂吸附性能的影响。研究表明,具有高比表面积、丰富微孔和适量中孔结构的活性炭更有益于二氧化碳中微量乙烷的吸附;浓度为1%的盐酸溶液浸渍活性炭3 h后,能增强其对CO2中微量C2H6的吸附能力;浓度3%、浸渍时间6 h为氢氧化钠碱溶液改性活性炭的最佳条件;弱氧化剂双氧水改性能略微提高活性炭对二氧化碳中乙烷的吸附能力,弱还原剂氨水改性对吸附效果无明显影响。     

Microwave treated activated carbon from industrial waste lignin for endosulfan adsorption

BACKGROUND: Disposal of large amounts of recurring industrial waste lignin is a big problem for the paper industries and there is need for a rational alternative to utilize this waste lignin. Thus highly porous activated carbons (ACs) were prepared from lignin using H₃PO₄ as an activating chemical with and without microwave treatment in a self‐generated environment at 600 °C and the influence of different types of impregnation on the adsorption–desorption capacities of endosulfan from a liquid phase was studied. RESULT: The maximum adsorption capacities (X_m) for ACs prepared by a microwave treatment and using a simple impregnation method were 6.2422 mg g^?1 and 3.9557 mg g^?1, respectively. Equilibrium adsorption time determined from kinetic experiments was 5 h and the experimental kinetic data were described by a pseudo‐second‐order rate model. Surface characteristics and desorption patterns showed considerable difference between the two ACs with the microwave treated AC showing less hysteresis, greater X_m and established overall superiority over the other. CONCLUSION: Use of microwave treatment produced more oxygen surface functional groups. Results indicate that surface chemistry of the microwave treated sample is more important than the textural properties for the higher adsorption of endosulfan. The microwave treated sample also resulted in less hysteresis and fewer carbonyl surface groups. Desorption patterns cannot be predicted from adsorption alone. Copyright © 2011 Society of Chemical Industry     

催化裂化干气分离丙烯用活性炭吸附剂的特性研究

为了获得可用于催化裂化干气中吸附分离丙烯用的活性炭,选择国内有代表性的不同材质和产地的活性炭,测定了比表面积、孔容、平均孔径和微孔体积等物性参数.在自制的吸附实验装置上,测定了101.3 kPa、40℃下丙烯和乙烯在不同活性炭上的吸附量,比较对丙烯的选择性.结果表明在上述吸附条件下,活性炭AC-1对丙烯的吸附量最大,达3.552 mmol/g,对丙烯的选掸性为1.37.测定了乙烯丙烯二元混合气中,不同丙烯分压下,活性炭AC-1对丙烯和乙烯的吸附量.活性炭AC-1适用于干气吸附分离丙烯过程.     

气体中醋酸甲酯在活性炭上的动态吸附

研究了Calgon活性炭对醋酸甲酯的动态吸附行为,从穿透时间、穿透吸附量以及穿透曲线的形状等方面,考察了初始浓度、气速和温度等因素对活性炭吸附性能的影响。另外选择3种不同产地的国产活性炭在相接近的吸附条件下与Calgon活性炭进行对比,结果显示活性炭的微孔分布是与其吸附性能相关性较大的因素。     

变压吸附氢气纯化过程瞬态分析

变压吸附技术是工业上生产高纯氢气最常用的方法之一。然而,在实际生产过程中无法观察到塔内各组分在不同时刻的分布状态,因此借助模拟的手段来研究从投料至系统达到循环稳态期间各组分在塔内的动态变化规律,进而指导工艺改进是很有必要的。采用活性炭和5A分子筛为吸附剂,设计了八塔变压吸附工艺从蒸汽甲烷重整气中纯化氢气,模拟了变压吸附制氢开车过程,分析了开车过程中塔内各组分在吸附、顺放以及冲洗三个阶段以及循环稳态后吸附阶段瞬态吸附行为和塔内温度变化。结果表明,在吸附以及顺放等过程中重组分会随着循环周期向塔顶移动。这一现象是组分间竞争吸附和冲洗再生方式下重组分在床层底部累积两个作用因素共同导致的。这些因素在一定程度上也会造成CO的吸附前沿在吸附阶段就过多进入5A分子筛上,使得CO含量成为限制工艺性能的主要因素。     

中高温环境下VOCs在活性炭上的吸附性能研究

选用3种商用活性炭及其分别经HCl溶液和KOH溶液浸渍改性的商用活性炭,研究中高温烟气环境下,反应空速、吸附温度对挥发性有机物（VOCs）吸附性能的影响,以及VOCs种类、吸附剂特性等与VOCs吸脱附效果的关系。研究发现：空速对吸附穿透时间影响较大,但对饱和吸附量影响不显著。吸附温度与VOCs浓度对饱和吸附量存在较大影响,150℃时甲苯的饱和吸附量仅能达到90℃时的40％。高沸点吸附质更易被吸附,更难被脱附。     

改性蜂窝状活性炭吸附二氧化碳和氮气的热力学

蜂窝状活性炭具有较高的比表面积、多孔道、压降低、吸脱附速率快、不易堵塞等优点,因此被认为是捕集烟道气中CO₂重要吸附材料。选用蜂窝状煤基和椰壳两种活性炭吸附剂,采用磁悬浮热天平分别测定了CO₂和N₂的吸附等温线。采用1 mol·L^-1 K₂CO₃对蜂窝状活性炭材料进行浸渍改性,提高在低二氧化碳分压下的CO₂吸附性能。采用Langmuir、multi-site Langmuir和Virial 3种模型对吸附平衡数据进行拟合,得出热力学参数,为后续吸附工艺优化设计提供基础数据。结果表明在实验范围内3种模型均能对实验测量的等温线进行较好的拟合,Langmuir模型总体拟合效果最好。     

Regeneration of phenol‐saturated activated carbon in an electrochemical reactor

The regeneration of phenol‐saturated activated carbon in an electrochemical reactor was investigated in order to develop a novel regeneration method of activated carbon. The regeneration of spent activated carbon saturated with phenol was conducted in a stirred electrochemical reactor under different operating conditions. The influences of operating parameters, such as regeneration current intensity and time, on regeneration efficiency were systematically investigated. The regeneration efficiency can reach over 80% under continuous stirring in the reactor, and it only decreases by less than 5% after four regeneration cycles. Electrochemical regeneration in the stirred electrochemical reactor is shown to be an effective method for the regeneration of phenol‐saturated activated carbon with a much higher regeneration efficiency compared with a process using NaOH solution. © 2002 Society of Chemical Industry