Activated carbon and carbon molecular sieves in gas separation and purification 1993 7 195-6
半导体专业名词解释
Cd cadmium
AWS advanced wet station
Manufacturing and Science
Sb antimony
===B===
B billion; boron
Ba barium
BARC bottom antireflective coating
BASE Boston Area Semiconductor Education (Council)
ACF anisotropic conductive film
ACI after-clean inspection
ACP anisotropic conductive paste
ACT alternative control techniques; actual cycle time
Al aluminum
ALD atomic layer deposition
ALE atomic layer epitaxy; application logic element
ALS advanced light source; advanced low-power Schottky
===A===
A/D analog to digital
AA atomic absorption
AAS atomic absorption spectroscopy
ABC activity-based costing
ABM activity-based management
AC alternating current; activated carbon
改性活性炭吸附脱除一氧化碳的研究
华南理工大学硕士学位论文改性活性炭吸附脱除一氧化碳的研究姓名：吕玄文申请学位级别：硕士专业：环境化工指导教师：叶菊招2000.3.1摘要ｌ＼一氧化碳是无色、无臭、毒性很大的气体，它是八大类气体污染物之一，随着国民经济的发展和人们生活水平的提高，大量生产和使用易燃产生一氧化碳和氢氰酸等有毒气体的高分子建筑材料和装饰时料，工业发达，交ｉ匝繁忙，排出大量的工业和汽车尾气等均严重污染环境，危害人类身体健康，所以，如何监测、控制和脱除高浓度的一氧化碳有害气体、显得非常迫切和重要。
活性炭是一种有发达孔隙结构的含碳物质，具有吸附和催化特性，是性能优良的万能吸附剂。
所以早用在军用防毒面具和工业用呼吸器内作防毒滤毒物质。
但对于—氧化碳气体的防御，必须使用装有干燥剂和催化剂混合物的专用滤毒器（通常用氧化铜和二氧化锰混合物一霍加拉特剂），使一氧化碳被氧化为二氧化碳。
但催化剂受潮很快失去活性，严重影响滤毒器的有效期，这是防毒面具致命的弱点。
为此，本研究提出新的设想．利用活性炭的各种优良特性，选用木质活性炭为基础吸附剂，疏水性的有机物质为改性剂，合理地偶合吸附剂和改性剂的协同吸附效应，直接从混合气体中吸附脱除一氧化碳有毒气体。
这对保护环境和研制消防逃生自救、劳动保护面具和工业通风滤毒装置的防毒滤毒吸附剂提供理论实验依据，具有重要的学术意义和应用价值矿√本论文对一氧化碳的来源和危害，活性炭的结构性能与应用、吸附分离技术的发展背景、基础理论、及本论文的选题背景和重要性等进行了综述，对一氧化碳含最的测定方法、基础吸附剂的评选、改性、和改性后的吸附剂对混合气体中一氧化碳的静态吸附和动态吸附以及解吸、再生等进行了’一系列的研究。
通过研究选定了用静态浸渍法改性吸附剂，确立了用静态吸附和动态吸附的理论方法来研究和评价改性吸附剂对一氧化碳的吸附效果，并研究探索了改性吸附剂的应用方向。
，ｆ研究结果表明：混合气体中一氧化碳含量的测定可以用简单快捷、重复性好的气固色谱法来测定，其最佳操作条件是以１３Ｘ分子筛为固体吸附剂，选用Ｈ’作载气、载气流速为１６～２０ｍｌ／ｍｉｎ、热导池作检测器，桥流１６０ｍＡ，，柱温为３０＂Ｃ，进样量为４０～５０ｕｌ，在此条件下空气和ＣＯ能彻底分离，重复性好，’既明这种方法可作为本研究中对ＣＯ含量的分析测定手段。
生物质活性炭制备及应用研究(硕士论文)
Adsorption of CO2, CH4, and N2 on Gas Diameter Grade Ion-Exchange Small Pore Zeolites
Adsorption of CO 2,CH 4,and N 2on Gas Diameter Grade Ion-Exchange Small Pore ZeolitesJiangfeng Yang,Qiang Zhao,Hong Xu,Libo Li,Jinxiang Dong,and Jinping Li *Research Institute of Special Chemicals,Taiyuan University of Technology,Taiyuan 030024,Shanxi,P.R.Chinastructure like CO 2.From the viewpoint of the equilibrium selectivity for CO 2and N 2or CO 2andof CO 2;K-zeolites with high S CO 2/N 2and S CH 4/N 2,adsorption potential order was K-zeolites >Na-zeolites >The removal of CO 2from gaseous mixtures is important for CO 2capture from flue gas,biogas,or land fill gases.These sources of natural gas mainly contain CH 4,CO 2,and N 2.Therefore,the separation of CO 2,CH 4and N 2mixtures canupgrade low quality natural energy gas and also mitigate the problem of excess CO 2emissions.1Of the available adsorption-based separation processes,energy (CH 4)and CO2capture isconsidered to be an energy-and cost-e fficient alternative.Thus,adsorption is an important solution for separation,CO 2capture,CH 4storage,and transportation.2−4This approach uses various types of sorbents or adsorption materials such as carbon materials (activated carbon and carbon molecular sieves),5,6molecular sieves (zeolites),7−10and the popular new metal −organic frameworks (MOFs).11−14Sorbents are considered to be the most important factors a ffecting adsorption techniques.A comparison of di fferent adsorption materials showed that carbon materials are di fficult to have a balance of small pores and large pores,for optimum balance between capacity and dynamics,and MOFs had lower thermal stability,but zeolites produced very homogeneous structures with high surface area and good thermal stability,and the size of the pore volume could be modulated.15,16Thus,zeolites are the most commonly used adsorbents in the field,such as LTA structures (4A,5A,and 13X).17The question is how do we choose appropriate zeolites for a speci fic application such as CO 2,CH 4,and N 2adsorption and First,an analysis of gases showed that nonpolar gases have very similar diameters and gas dynamics:CO 2=0.33nm,CH 4=0.38nm,and N 2=0.36nm,18while the adsorptionstrength of the sorbents was CO2>CH4>N2.19,20Therefore,the adsorption and separation of most gases by zeolites isreliant on their surface potential or the balance of ions in surface channels,particularly the low silicon Li-X zeolite usedfor O 2and N 2separation.21The pore diameters of zeolites areusually bigger than the gas molecules,so gases can di ffusethrough these pores.But what would happen if the pores had a similar size to or smaller than the molecular diameter of the three gases during zeolite adsorption?Titanium silicalite ETS-4had a pore size that is similar to the molecular diameter,and it can be modulated by temperature changes for the aperture separation of various gases,such as CO 2and CH 4,N 2,and CH 4,although its lower adsorptioncapacity limits theapplication of this approach.22−24The ori fice diameters of the zeolites,KFI,CHA,and LEV,are very close to the kinetic diameters of CO 2,CH 4,and N2(Figure 1).These three small-pore zeolites have cage-like structures,and the larger cavity in the hole is ideal for gas uptake.This type of small-pore size microporous zeolite is a hot research area in the field of catalysis and adsorption.25−27Received:August 28,2012Accepted:October 31,2012Published:November 7,2012Krishna and van Baten found frequent correlation e ffects with cage-type zeolites,such as LTA,CHA,and DDR,where narrow windows separated the cages.26Webley et al.studied the gas adsorption selectivity of M(Ca,K)-CHA and concluded that the high O 2/Ar selectivity was possibly due to partial pore blockage by a large K +located near the 8-member ring,producing a 20-hedron cage.28The small pore size and the metal cation balance probably plays an important role in the gas diameter grade structure of zeolites where it determines the adsorption capacity and shape-selective catalysis.It is less common to focus on these types of small pore size cage-like structures and the adsorption of gas molecules close to the aperture.In this study,we synthesized three types of zeolites,Na-LEV,K-CHA,and K-KFI,using the hydrothermal method,whereas Na-KFI,Li-KFI,Ca-KFI,Na-CHA,Li-CHA,and Ca-CHA were obtained by ion exchange.The aims of this study were to evaluate the pore size e ffect and the metal cation e ffect on the adsorption of CO 2,CH 4,and N 2.We also discuss the most suitable method for the separation of CO 2,CH 4,and N 2based on calculations of the adsorption equilibrium.■MATERIALS AND METHODSThe chemicals used in this study are described in more detail in Table 1.Partial Aluminum Potassium.[50.00g of water +29.76g of potassium hydroxide +15.80g of alumina]were heated to boiling until clear,cooled to room temperature,and corrected for any weight loss due to boiling.30,31K-KFI.The synthesis following the procedure reported by Johannes et al.30−32The batch composition was:7.2partial aluminum potassium/0.1strontium nitrate/7.5silicon dioxide/130water,and the typical procedure involved mixing the required amounts of partial aluminum potassium and water,followed by the addition of silica sol,and mixing until smooth (approximately 10min),before strontium nitrate was added to the mixture and stirred for 10min.The resulting mixture was transferred into a 23mL Te flon-lined autoclave and heated in an oven for 5days at 423K.After cooling to ambient temperature,the product was filtered,washed with water,and dried at 373K.The crystal structure of KFI and the degree of crystallinity were con firmed by powder X-ray di ffraction(XRD).Figure 1.Structures of zeolites KFI (a),CHA (b),and LEV (c).29Table 1.Purity of Chemicals Used in This Study and Their Detailschemical name source initial mass fraction purityalumina Aladdin,China >0.99silica sol QingdaoHaiyang Chemical Co.,Ltd.0.401,1-dimethylpiperidinium chloride Shanghai Bangcheng Chemical Co.,Ltd.0.98strontium nitrate Aladdin,China >0.99potassium hydroxide TianjinKemiou Chemical Reagent Co.,Ltd.0.82sodium hydroxide TianjinKemiou Chemical Reagent Co.,Ltd.0.96sodium chloride TianjinKemiou Chemical Reagent Co.,Ltd.0.99lithium hydroxide Tianjin Kemiou Chemical Reagent Co.,Ltd.0.98lithium chloride TianjinKemiou Chemical Reagent Co.,Ltd.0.97calcium hydroxide TianjinKemiou Chemical Reagent Co.,Ltd.0.95calcium chloride Tianjin Kemiou Chemical Reagent Co.,Ltd.0.96K-CHA.The synthesis method was similar to that for K-KFI,but the batch composition was:7.2partial aluminum potassium:0.1strontium nitrate:6silicon dioxide/130water,so there were lower levels of Si/Al.The crystal structure of CHA and the degree of crystallinity were con firmed by powder XRD.Na-LEV.This was prepared from:6partial aluminum sodium/10silicon dioxide/31,1-dimethylpiperidinium chlor-ide/200H 2O,which was made according to our previously reported method.33Ion Exchange.The Na-KFI described above was converted from its potassium form (K-KFI)via three consecutive ion exchanges.In general,300mL of 1M sodium chloride at pH =9(adjusted with 0.01M sodium hydroxide)was added to 5g of zeolite,and the solution was heated to 363K and stirred for 12h.The solution was decanted,and fresh solution was added.After successive washes with the requisite solution,the resulting zeolite was vacuum-filtered and washed with 500mL of deionized water.The zeolite was dried at 373K for 24h.Li-KFI was prepared from Na-KFI by five consecutive ion exchanges of Na-KFI with 2M lithium chloride (5g of zeolite:300mL of lithium chloride)at pH =9(adjusted with 0.01M lithium hydroxide).Ca-KFI was prepared from Na-KFI by five consecutive ion exchanges of Na-KFI with 1M calcium chloride (1g of zeolite:300mL of calcium chloride).The solution was heated at 353K for 12h and decanted,and fresh solution was added.This procedure was repeated five times.Finally,the Ca-KFI was filtered and washed with copious amounts of deionized water and dried at 373K overnight.Na-CHA,Li-CHA,and Ca-CHA,were prepared using the same procedure.34Characterization.The crystallinity and phase purity of the molecular sieves were measured by powder XRD using a Rigaku Mini Flex II X-ray di ffractometer with Cu K αradiation operated at 30kV and 15mA.The scanning range was from 5to 40°(2theta)at 1°/min.Morphological data were acquired by scanning electron microscopy (SEM)using a JEOL JSM-6700F scanning electron microscope operated at 15.0kV.The samples were coated with gold to increase their conductivity before scanning.The Si/Al ratio and the metal ion content of the zeolites were determined by elemental analysis using a spectrophotometer-723P.High-Pressure Gas Adsorption Measurements.The purity of the carbon dioxide was 99.999%,methane was 99.95%,and nitrogen was 99.99%.The adsorption isotherms were measured under high pressure using an Intelligent Gravimetric Analyzer (IGA 001,Hiden,UK).Before measuring the isotherm,a 50mg sample was predried under reduced pressure and then outgassed overnight at 673K under a high vacuum until no further weight loss was observed.Each adsorption/desorption step was allowed to approach equilibrium over a period of 20−30min,and all of the isotherms for each gas were measuredusing a single sample.■RESULTS AND DISCUSSION Synthesis,Ion Exchange,and Characterization.The zeolite K-KFI was synthesized according to a published method.32Figure 2a shows the XRD pattern of the synthesized molecular sieve K-KFI compared with the standard XRD data for the molecular sieve KFI.The peak positions and relative di ffraction intensity were similar to the reported values,which demonstrated that the molecular sieve K-KFI had been synthesized.Figure 2a also shows the XRD pattern of the molecular sieve K-KFI,which was calcined from (573to 1073)K.Its peak positions and relative di ffraction intensity were the same as a sample synthesized below 973K,while the skeleton collapse temperature was 1073K.The method used for the synthesis of K-CHA was similar to that used for K-KFI.Figure 2b shows the XRD pattern of the synthesized molecular sieve K-CHA compared with the standard XRD data for the molecular sieve CHA.The peak positions and relative di ffraction intensity were similar to the reported values,which demonstrated that the molecular sieve K-CHA had been synthesized.The samples had similar behavior at below 973K,while the skeleton collapse temperature was 1073K.The data showed that the structures of KFI and CHA had good thermal stability.The Si/Al values in K-KFI and K-CHA were 4.59and 2.63,respectively.The low Si/Al value indicated that K +occupied more channels in the zeolites,where the large space allowed access to small metal ions or divalent ion exchange.In addition,K-CHA with a lower Si/Al value indicated that more ions could be exchanged,while the size of the pore space could change greatly.However,the higher Si/Al value of K-KFI indicated lower ion exchange,so the size of the pore space could be regulated at a finer level.Table 2shows the experimental K-zeolites,which were changed to Na-zeolites via ion exchange,and the uncertainty is within ±0.005.This shows that the ion exchange degree was increased with temperature and frequency.K-CHA with a lower Si/Al value was produced more completely and easier than K-KFI with a higher Si/Al value from Na +exchanged with K +.The ion exchange degree of Na-CHA from K-CHA wasveryFigure 2.XRD patterns of KFI (a)and CHA (b).high in the first cycle,because the higher temperature is helpful to ion exchange in low Si/Al zeolites.35We selected the highest exchange degree for K +(Na-KFI with 0.91and Na-CHA with 0.99)and the Na-zeolites were used to obtain Li-zeolites and Ca-zeolites.Table 3shows that Li-KFI and Ca-KFI were 0.96and 0.83,respectively,based on Li +and Ca 2+exchange for Na +,while Li-CHA and Ca-CHA were 0.92and 0.96,respectively.The XRD patterns of the Na-,Li-,and Ca-zeolites showed that the zeolite structures were highly stable throughout ion exchange (Figure 3).The samples that changed in appearance are shown in Figure 4.The morphologies of the zeolites with KFI and CHA structures were observed by SEM.For K-KFI to Na-KFI,Li-KFI,and Ca-KFI,the morphologies of the crystals changed from regular cubic accumulations until they completely lost their regular structures.We also showed that there was a slight change in their appearance after a single exchange of materials,followed by a more obvious change after the secondary exchange of materials,particularly M 2+exchange with M +based on the morphologies of M-CHA (M-metal).The pore diameter of some of the samples was too small to be measured or analyzed using a liquid nitrogen adsorption isotherm,for LEV with the ori fice very close to the nitrogen-diameter,so the surfaces of all samples were measured andanalyzed using a CO 2adsorption isotherm at 273K (Figure 5).The microporous surface area and microporous volumes werecalculated using the Dubinin −Radushkevitch (D-R)equation(Table 4):β=−··⎡⎣⎢⎤⎦⎥V V B T PP log()log()log0202(1)where V was volume adsorbed at equilibrium pressure;V 0was the micropore capacity;P 0was saturation vapor pressure of gas attemperature T ;P was equilibrium pressure;B was a constant,βwasthe a ffinity coe fficient of analysis gas relative to P 0gas (for this application βis taken to be 1);T was the analysis bath temperature.36−38All of the samples with a high surface area could be used foradsorption;the surfaces and the pore volumes of the zeoliteswere changed very obvious by ion exchange.Table 4shows thesurface of the samples where the greatest changes were in theappearance of the M-CHAs with the lowest surface areas (K-CHA with 278.5m 2·g −1)and the highest (Li-CHA with 638m 2·g −1,the same situation also appear in the pore volumechange (K-CHA with 0.07cm 3·g −1and Li-KFI with 0.17cm 3·g −1).because they had lower Si/Al values and morebalanced metal ions could be exchanged,so with the smallersize of Li +instead of K +(Table 3),more space can be obtained.However,M-KFI had a higher Si/Al value than M-CHA,so the area of its surface and microporous volume that could be regulated by ion exchange was smaller;that is,the surface area ranges from 333.5m 2·g −1(Ca-KFI)to 566.2m 2·g −1(Na-KFI),and the pore volume ranges from 0.07cm 3·g −1(Ca-KFI)to 0.15cm 3·g −1(Na-KFI).We also found that the surfaces and pore volumes of Ca-zeolites were smaller than Li-or Na-zeolites,which showed that the introduction of Ca 2+reduced the number of balanced ions,while the plug was very strong because the size of Ca 2+larger than Li +and Na +.Li-KFI and Na-KFI had similar surfaces,so it was inferred from Li +that there was no hole in Na-KFI to produce major changes.The systematic errors of surface areas and pore volume have been estimated to be less than 5m 2·g −1and 0.01cm 3·g −1.Table 2.Ion Exchange Degree from K-Zeolite to Na-Zeolite at Di fferent Exchange Times and Temperatures of (323and 363)K a 0.5870.7570.8800.910363Na-CHA 0.7500.7640.9240.9343230.9240.9710.9740.991363a Uncertainties are:U (exchange degree)=0.005;U (T )=0.1K.Table 3.Ion Exchange Degree of Li and Ca-Zeolite from Na-Zeolite a zeolites cation ionic radius (nm)Na +per unit cell (wt %)exchange degree for Na +K-KFI 0.133Na-KFI 0.095 5.29Li-KFI 0.0680.200.96Ca-KFI 0.0990.900.83K-CHA 0.133Na-CHA 0.0957.94Li-CHA 0.0680.640.92Ca-CHA 0.0990.290.96a Uncertainties are:U (Na +contents)=0.02wt %;U (exchange degree)=0.005.Figure 3.XRD patterns of Na,Li,and Ca-KFI (a)and Na,Li,and Ca-CHA (b).Gas Sorption Isotherm Measurements.The CO 2,CH 4,and N 2adsorption and desorption isotherms of the samples are shown in Figure 6,where all of the isotherms have a Langmuir I form and the relative uncertainties of adsorption volumes are estimated to be 0.05V .Most of the samples exhibited rapid desorption,and this correlated with their adsorption curve.Only sample K-CHA exhibited desorption hysteresis during CH 4adsorption.We inferred that the pore size of K-CHA was too close to the kinetics of the di ffusion diameter of CH 4,so it had a very strong CH 4adsorption potential,whereas desorption was hindered by the steric e ffect of the micropores.Table 5also shows the orders of the volumes for CO 2,CH 4,and N 2adsorption of the samples at 0.1MPa.The order of CO 2adsorption at 298K corresponded to the surfaces of the samples.Based on the CO2adsorption,we can also determine the zeolites with Li +and Na +exchange with bigger surfaces and greater adsorption volumes.Based on the high levels (>100cm 3·g −1)of CO 2adsorption with Li,Na-KFI,and Li,Na-CHA at high pressurea,we conclude that micropore Li-zeolites and Na-zeolites could be used for CO 2capture and storage (CCS).The smallest CH 4adsorption volume was found with Na-LEV,so we inferred that CH4adsorption would not occur in itsmicropores because the levels were far less than with othersamples.We conclude that CH4could not di ffuse through theholes in Na-LEV because the ori fice diameter (0.36×0.48nm)was too small.The CH 4adsorption results showed thatM-Figure 4.SEM of the samples:(a)K-KFI,(b)Na-KFI,(c)Li-KFI,(d)Ca-KFI,(e)K-CHA,(f)Na-CHA,(g)Li-CHA,(h)Ca-CHA.CHA was better than M-KFI,so CH 4adsorption or storage was based on the surface features and the ori fice diameter (CHA with 0.38×0.38nm,KFI with 0.39×0.39nm),which indicated a higher adsorption potential.39The low N 2adsorption with Na-LEV shows that molecules could not di ffuse through its pores.N 2adsorption was not a ffected by the metal ion or the structure,so the pore size or surfaces of porous materials were always su fficient for liquid nitrogen adsorption.In the other samples,the N 2adsorption results showed that the pores were expanded by small metal ions or divalent ion exchange,that is,twice then once,because the order was Li,Ca-zeolite >Na-zeolite >K-zeolite (Table 5).Adsorption Equilibrium Selectivity.To evaluate the adsorption equilibrium selectivity and predict the adsorption of the gas mixture from the pure component isotherms,the adsorbent selection parameter S i /j is de fined in the following equation:=ΔΔS qq a i j i j /12/(2)where Δq 1and Δq 2are the adsorption equilibrium capacity di fferences at the adsorption pressure and desorption pressure for components 1and 2.The adsorption equilibrium selectivity a i /j between components i and j is de fined as follows:==a K K q b q b i j i j mi imj j /(3)Henry ’s law:=q Kp (4)Langmuir isotherm model:=+q q bpbp 1m (5)where q m and b are Langmuir isotherm equation parameters,which can be determined from the slope and intercept of a linear Langmuir plot of (1/q )versus (1/p )where q m i and q m jand b i and b j are the Langmuir equation constants for components i and j ,respectively.The equilibrium selectivity de fined in the above equation is basically the ratio of Henry ’s constants for the two components.40Based on the results for S CO 2/CH 4and S CO 2/N 2(in Table 6andthe relative uncertainties of S i /j are estimated to be 0.05S ),all ofthe micropore zeolites produced excellent results in the evaluations,because of the high adsorption of CO 2in the gas diameter grade micropore structures.Na-LEV was the bestmicroporous sieve for gas materials with the highest S CO 2/CH 4=137and S CO 2/N 2=934due to the almost total nonadsorption ofCH 4and N 2but high adsorption of CO 2,which is rare among sorbents.41The second best was Na-KFI (S CO 2/CH 4=92andS CO 2/N 2=374),which had produced better results than otherM-KFIs.In addition,Na-CHA had a higher SCO 2/CH 4than K andLi-CHA,and at the same time Na-CHA also had a higher S CO 2/N 2than Li,Ca-CHA,so we can conclude that Na-zeoliteshad higher CO 2adsorption.A reanalysis of the data showed that Li-zeolites were followed by Na-zeolite,so the e ffects of the smaller Li +were lower than the e ffects of the bigger Na +,and we inferred that the size of the metal ions was an important impact in zeolites.The aerodynamic diameter and physicochemical propertiesof CH 4and N 2were very similar,so separating CH4and N 2wasmuch more di fficult than CO 2and CH4or CO 2and N 2separation which used an adsorption technique.The exper-imental data for S CH 4/N 2in Table 6also con firmed this point.K-CHA had the highest S CH 4/N 2=14.5,while the second was K-KFI (S CH 4/N 2=8.5),which indicated that the introduction of alarge K +increased the potential adsorption of CH4.The Na-zeolites and Li-zeolites have very low data for S CH 4/N 2.Based on the relatively good K-zeolite data for S CO 2/N 2and the smallersurface pores,we can conclude that K +had a signi ficant role in the adsorption of CH4and CO 2,although a smaller hole did not allow greater nitrogen di ffusion.From the perspective of the adsorption potential,we conclude that the large K +was better than Na +and the small Li +;the order was K-zeolites >Na-zeolites >Li-zeolites,indicating that bigger ions had a stronger a ffinity.While the introduction of divalent ions could halve the total number of ions,thus,Ca 2+formed fewer of these small pore type zeolites,and it did not produce very good resultsfor adsorption separation.■CONCLUSION We prepared nine di fferent surfaces of gas diameter grade small pore zeolites,which were characterized by XRD,SEM,and elemental analysis.We synthesized K-CHA with a lower Si/Al value,and more balanced metal ions could be exchanged,so the surfaces and microporous volumes were changedgreatly.Figure 5.CO 2adsorption of the samples on 273K.Table 4.Microporous Surface (MS)and Microporous Volume (MV)of the Samples Obtained from CO 2Adsorption Isotherms at 273K a K-KFI 430.40.10Na-KFI 566.20.15Li-KFI 550.60.14Ca-KFI 333.50.07K-CHA 278.50.07Na-CHA 594.80.16Li-CHA 638.00.17Ca-CHA 487.20.12a Uncertainties are:U (MS)=5m 2·g −1;U (MV)=0.01cm 3·g −1.However,K-KFI had a higher Si/Al value,and the area of its surface and microporous volumes could be modulated to make it smaller.We focused on the CO 2,CH 4,and N 2adsorption isotherms of the samples under high pressure (1MPa)at room temperature (298K),and we found that the smaller Li +and Na +exchanged more with the surface and they had higher adsorption volumes,whereas the larger K +led to severe channel congestion.We calculated and evaluated the adsorption equilibrium selectivity of CO 2/CH 4/N 2,which showed that the ori fice diameter had a very important role in the sieving of CO 2and N 2or CO 2and CH 4,where Na-LEV produced the best sieving e ffect.From the viewpoint of the adsorption equilibria,the Na-zeolites produced the best results for adsorption equilibrium selectivity with CO 2and N 2or CO 2and CH 4,followed by Li-zeolites,whereasK-zeolites withhigh Figure 6.CO 2(▲),CH 4(■),and N 2(●)adsorption (solid)and desorption (hollow)isotherm of the samples at 298K and 1MPa:(a)K-KFI,(b)K-CHA,(C)Na-LEV,(d)Na-KFI,(e)Li-KFI,(f)Ca-KFI,(g)Na-CHA,(h)Li-CHA,(i)Ca-CHA.Table 5.Volumes of CO 2,CH 4,and N 2Adsorption on the Samples at 0.1MPa a K-KFI 67.317.57.1Na-KFI 93.617.79.5Li-KFI 88.315.99.3Ca-KFI 54.816.29.5K-CHA 47.119.1 5.5Na-CHA 104.330.316.7Li-CHA 106.633.016.9Ca-CHA 83.221.418.7a The relative uncertainties of adsorption volumes are estimated to be 0.05V .Table 6.Separation Factor of CH 4/N 2,CO 2/CH 4,and CO 2/N 2Calculated from Pure Component Adsorption Isothermsof the Samplesa zeolite S CO 2/CH 4S CO 2/N 2S CH 4/N 2Na-LEV 137934 6.8K-KFI 353038.5Na-KFI 92374 4.1Li-KFI 80237 3.0Ca-KFI 1959 3.0K-CHA 2435214.5Na-CHA 42187 4.3Li-CHA 32154 4.7Ca-CHA 51127 1.6a The relative uncertainties of Si /j are estimated to be 0.05S .S CH 4/N 2and S CO 2/N 2.Based on the adsorption equilibrium selectivity results,we can conclude that the adsorption potential order was K-zeolites >Na-zeolites >Li-zeolites,so the bigger ions had a stronger a ffinity.Divalent ions were less likely to be captured in the structures than univalent ions,so their separation was somewhat poorer.■AUTHOR INFORMATION Corresponding Author *E-mail:Jpli211@.Tel.:86-3516010908.Fax:86-3516010908.Funding We gratefully acknowledge financial support from the National Natural Science Foundation of China (Nos.21136007,51002103)and Research Fund for the Doctoral Program of Higher Education of China (No.20091402110006).This work was financially supported by the program for the Top Science and Technology Innovation Teams of Higher Learning Institutions of Shanxi.Notes The authors declare no competing financial interest.■REFERENCES (1)Kikkinides,E.S.;Yang,R.T.;Cho,S.H.Concentration and recovery of CO 2from flue gas by pressure swing adsorption.Ind.Eng.Chem.Res.1993,32,2714−2720.(2)Hao,G.P.;Li,W.C.;Qian,D.;Wang,G.H.;Zhang,W.P.;Zhang,T.;Wang,A.Q.;Schu t h,F.;Bongard,H.J.;Lu,A.H.Structurally Designed Synthesis of Mechanically Stable Poly-(benzoxazine-co-resol)-Based Porous Carbon Monoliths and TheirApplication as High-Performance CO 2Capture Sorbents.J.Am.Chem.Soc.2011,133,11378−11388.(3)Matranga,K.R.;Myers,A.I.;Glandt,E.D.Storage of natural gas by adsorption on activated carbon.Chem.Eng.Sci.1992,47,1569−1579.(4)Matranga,K.R.;Stella,A.;Myers,A.L.;Glandt,E.D.Molecular simulation of adsorbed natural gas.Sep.Sci.Technol.1992,27,1825−1836.(5)Liu,Y.;Wilcox,J.Effects of Surface Heterogeneity on the Adsorption ofCO 2in Microporous Carbons.Environ.Sci.Technol.2012,46,1940−1947.(6)Chen,J.;Loo,L.S.;Wang,K.An Ideal Absorbed Solution Theory (IAST)Study of Adsorption Equilibria of Binary Mixtures ofMethane and Ethane on a Templated Carbon.J.Chem.Eng.Data 2011,56,1209−1212.(7)Ducrot-Boisgontier,C.;Parmentier,J.;Faour,A.;Patarin,J.;Pirngruber,G.D.FAU-Type Zeolite Nanocasted Carbon Replicas for CO 2Adsorption and Hydrogen Purification.Energy Fuels 2010,24,3595−3602.(8)Jayaraman,A.;Hernandez-Maldonado,A.J.;Yang,R.T.;Chinn,D.;Munson,C.L.;Mohr,D.H.;Donald,H.Clinoptilolites for nitrogen/methane separation.Chem.Eng.Sci.2004,59,2407−2417.(9)Wang,Y.;LeVan,M.D.Adsorption Equilibrium of BinaryMixtures of Carbon Dioxide and Water Vapor on Zeolites 5A and 13X.J.Chem.Eng.Data 2010,55,3189−3195.(10)Bao,Z.;Yu,L.;Dou,T.;Gong,Y.;Zhang,Q.;Ren,Q.;Lu,X.;Deng,S.Adsorption Equilibria of CO 2,CH 4,N 2,O 2,and Ar on High Silica Zeolites.J.Chem.Eng.Data 2011,56,4017−4023.(11)Coudert,F.O.-X.;Mellot-Draznieks,C.;Fuchs,A.H.;Boutin,A.Prediction of Breathing and Gate Opening Transitions Upon Binary Mixture Adsorptionin Metal −Organic Frameworks.J.Am.Chem.Soc.2009,131,11329−11331.(12)Zheng,S.T.;Bu,J.T.;Li,Y.;Wu,T.;Zuo,F.;Feng,P.;Bu,X.Pore Space Partition and Charge Separation in Cage-within-Cage Indium −Organic Frameworks with High CO 2Uptake.J.Am.Chem.Soc.2010,132,17062−17064.(13)He,Y.;Xiang,S.;Chen,B.A Microporous Hydrogen-BondedOrganic Framework for Highly Selective C 2H 2/C 2H 4Separation at Ambient Temperature.J.Am.Chem.Soc.2011,133,14570−14573.(14)Sumida,K.;Rogow,D.L.;Mason,J.A.;McDonald,T.M.;Bloch,E.D.;Herm,Z.R.;Bae,T.H.;Long,J.R.Carbon Dioxide Capture in Metal −Organic Frameworks.Chem.Rev.2012,112,724−781.(15)Gemma,L.H.;Edward,B.;Martin,C.S.;Neil,C.H.;Ewan,M.M.;Paul,F.M.;Joseph,A.H.High-Pressure and Temperature IonExchange of Aluminosilicate and Gallosilicate Natrolite.J.Am.Chem.Soc.2011,133,13883−13885.(16)Aguilar-Armenta,G.;Hernandez-Ramirez,G.;Flores-Loyola,E.;Ugarte-Castaneda, A.;Silva-Gonzalez,R.;Tabares-Munoz, C.;Jimenez-Lopez,A.;Rodriguez-Castellon,E.Adsorption Kinetics of CO 2,O 2,N 2,and CH 4in Cation-Exchanged Clinoptilolite.J.Phys.Chem.B 2001,105,1313−1319.(17)Walton,K.S.;Abney,M.B.;LeVan,D.M.CO 2adsorption in Yand X zeolites modified by alkali metal cation exchange.Microporous Mesoporous Mater.2006,91,78−84.(18)Yang,R.T.Adsorbents:Fundamentals and Applications ;Wiley-Interscience:New York,2003.(19)Van den Bergh,J.;Mittelmeijer-Hazeleger,M.;Kapteijn,F.Modeling Permeation of CO 2/CH 4,N 2/CH 4,and CO 2/Air Mixturesacross a DD3R Zeolite Membrane.J.Phys.Chem.C 2010,114,9379−9389.(20)Dunne,J.A.;Mariwala,R.;Rao,M.;Sircar,S.;Gorte,R.J.;Myers, A.L.Calorimetric Heats of Adsorption and Adsorption Isotherms.1.O 2,N 2,Ar,CO 2,CH 4,C 2H 6,and SF6on Silicalite.Langmuir 1996,12,5888−5895.(21)Baksh,M.S.A.;Kikkinde,E.S.;Yang,R.T.Lithium Type XZeolite as a Superior for Air Separation.Sep.Sci.Technol.1992,27,277−294.(22)Kuznicki,S.M.;Bell,V.A.;Nair,S.;Hillhouse,H.W.;Jacubinas,R.M.;Braunbarth,C.M.;Toby,B.H.;Tsapatsis,M.A titanosilicatemolecular sieve with adjustable pores for size-selective adsorption ofmolecules.Nature 2001,412,720−724.(23)Marathe,R.P.;Farooq,S.;Srinivasan,M.P.Modeling GasAdsorption and Transport in Small-Pore Titanium ngmuir2005,21,4532−4546.(24)Pillai,R.S.;Peter,S.A.;Jasra,R.V.Adsorption of carbondioxide,methane,nitrogen,oxygen and argon in NaETS-4.Micro-porous Mesoporous Mater.2008,113,268−276.(25)Altwasser,S.;Welker,C.;Traa,Y.;Weitkamp,J.Catalyticcracking of n-octane on small-pore zeolites.Microporous MesoporousMater.2005,83,345−356.(26)Krishna,R.;van Baten,J.M.Onsager coefficients for binary mixture diffusion in nanopores.Chem.Eng.Sci.2008,63,3120−3140.(27)Saxton,C.G.;Kruth,A.;Castro,M.;Wright,P.A.;Howe,R.F.Xenon adsorption in synthetic chabazite zeolites.Microporous Mesoporous Mater.2010,129,68−73.(28)Singh,R.K.Adsorption of N 2,O 2,and Ar in PotassiumChabazite.Adsorption 2005,11,173−177.(29)Baerlocher,Ch.;McCusker,L.B.;Olson,D.H.Atlas of Zeolite Framework Types ,6th revised ed.;Elsevier:New York,2007.(30)Johannes,V.Zeolite ZK-5.U.S.Patent US4994249,1991(31)Robson,H.How to read a patent.Microporous Mesoporous Mater.1998,22,551−662.(32)Schwarz,S.;Corbin,D.R.;Sonnichsen,G.C.The effect ofcrystal size on the methylamines synthesis performance of ZK-5zeolites.Microporous Mesoporous Mater.1998,22,409−418.(33)Dong,J.;Wang,X.;Xu,H.;Zhao,Q.;Li,J.Hydrogen storage inseveral microporous zeolites.Int.J.Hydrogen Energy 2007,32,4998−5004.(34)Zhang,J.;Singh,R.;Webley,P.A.Alkali and alkaline-earthcation exchanged chabazite zeolites for adsorption based CO2capture.Microporous Mesoporous Mater.2008,111,478−487.(35)Xu,R.;Pang,W.Chemistry-Zeolites and Porous Materials(Chinese);Science Press:Beijing,2004.。
三羟甲基丙烷油酸酯的合成及其性能研究
摘要传统矿物润滑油的原料来源于不可再生的石油资源，其生物降解性差、易积聚等缺点给环境带来了巨大挑战，开发可生物降解的润滑油迫在眉睫。
因此，以植物油为原料合成绿色润滑油代替传统的矿物油受到人们的重视。
酯类合成润滑油具有优异的润滑性能、良好的热稳定性、可生物降解性以及较高的粘度指数，能够满足更加苛刻的工况需求。
因此，以油酸和三羟甲基丙烷为原料通过酯化反应合成的绿色酯类润滑油三羟甲基丙烷油酸酯（TMPTO）具有广阔的应用前景。
工业生产的油酸纯度不高，通常含有亚油酸、亚麻酸等多不饱和脂肪酸，对后期合成的TMPTO性能产生不利影响。
本文采用等体积浸渍法合成贵金属Pd-Pb/SiO2选择性加氢催化剂，通过固定床反应装置对催化剂进行评价，考察了活性组分Pd负载量、第二金属Pb添加量对催化活性的影响，同时对工艺条件进行优化。
结合活性评价数据和双键键长计算，多不饱和脂肪酸在选择性加氢过程中，首先发生双键位置异构生成更高加氢能力的共轭脂肪酸，进而加氢生成目标产物油酸。
工业生产中酯类润滑油的催化合成过程繁琐、分离困难，影响产品质量，因此本文采用自催化酯化法合成TMPTO，设计实验装置并对合成工艺条件进行优化，反应温度230 o C，酸醇摩尔比3.3:1，反应时间6 h，体系压力0.09 MPa，酯化率高于96%。
采用活性炭吸附、分子蒸馏以及氧化镁吸附法对产物进行脱酸脱色处理，结果表明：加入活性炭后脱色效果明显；采用分子蒸馏和氧化镁吸附脱酸，最终产物酸值从20.63 mgKOH/g降至0.27 mgKOH/g。
经FT-IR分析结果显示，产物经后处理精制后，结构并未发生变化，此处理方法可行。
对采用不同油酸组成的粗油酸为原料合成的TMPTO进行性能测试，实验结果表明，油酸纯度对TMPTO的理化性质影响较小，但当饱和脂肪酸含量增加时，导致合成酯的倾点有所升高。
采用恒温箱氧化法并结合产物酸值和粘度测试，对两种油酸酯进行了氧化稳定性测试，结果表明，多不饱和脂肪酸中双键极易被氧化，导致TMPTO的氧化稳定性下降。
干燥剂加工制作流程
干燥剂加工制作流程英文回答：The manufacturing process of desiccants involves several steps to ensure the production of high-quality and effective moisture-absorbing products. These steps include material selection, mixing and blending, shaping, drying, packaging, and quality control.Firstly, material selection is a crucial step in the desiccant manufacturing process. Various materials can be used as desiccants, such as silica gel, activated carbon, clay, and molecular sieves. The choice of material depends on the specific application and desired moisture-absorbing properties.Once the materials are selected, they are mixed and blended together in the appropriate proportions. This ensures a homogeneous mixture and enhances the moisture-absorbing capabilities of the desiccant. The mixing processmay involve the use of specialized equipment such as mixers or blenders.After the mixing process, the desiccant mixture is shaped into the desired form. This can be in the form of packets, sachets, or canisters. The shaping process may involve the use of molding machines or other shaping techniques. The size and shape of the desiccant can vary depending on the application and packaging requirements.Next, the shaped desiccants are dried to remove any moisture present in the mixture. This is a critical step as it ensures that the desiccants are ready for use and can effectively absorb moisture. The drying process may involve the use of ovens, dryers, or other drying equipment. The desiccants are typically dried at specific temperatures and for a specified duration to achieve optimal moisture-absorbing properties.Once the desiccants are dried, they are packaged in suitable containers or packaging materials. This ensures that the desiccants remain dry and protected until they areready for use. Packaging can vary depending on the specific application and market requirements. For example, desiccants used in pharmaceutical packaging may be individually packaged in sealed foil pouches, while those used in industrial applications may be packaged in bulk containers.Finally, quality control is an essential part of the desiccant manufacturing process. This involves testing the desiccants for their moisture-absorbing capabilities, durability, and overall quality. Various quality control tests may be conducted, such as moisture absorption tests, strength tests, and visual inspections. Any desiccants that do not meet the specified quality standards are rejected and not released for sale.In conclusion, the manufacturing process of desiccants involves material selection, mixing and blending, shaping, drying, packaging, and quality control. Each step plays a crucial role in producing high-quality and effective moisture-absorbing products. By following these steps, manufacturers can ensure that their desiccants meet thedesired specifications and provide optimal moisture control in various applications.中文回答：干燥剂的加工制作流程包括几个步骤，以确保生产出高质量和有效的吸湿产品。
氯乙烯合成用无汞触媒的研究与应用
Vol. 49 , No. 2Feb. , 2021第49卷第2期2021年2月聚氯乙烯Polyvinyl Chloride【助剂】氯乙烯合成用无汞触媒的研究与应用苗乃芬*，赵曰剑，付炳伟，王坤，王谡，张继梁 (山东新龙科技股份有限公司，山东寿光262700)* ［收稿日期］2020 -01 -13［作者简介］苗乃芬(1981-),男，工程师,2013年毕业于北京化工大学化学工程与技术专业，现任山东新龙集团有限公司副总经理、研发中心主任，主要从事PVC 生产管理、氯碱化工、氯碱下游产品研发等工作。
［关键词］氯乙烯；无汞触媒；氯化亚锡；活性炭；离子液体［摘要］利用活性炭的强吸附能力和锡的催化性能，在活性炭上负载氯化亚锡，制备了负载型氯乙烯合成触 媒。
研究了不同温度、反应时间和乙烘流量下，触媒的使用寿命和乙块的转化率。
分析了氯化亚锡作为活性组分的优缺点。
［中图分类号］TQ325.3 ［文献标志码］B ［文章编号］1009 -7937(2021 )02 -0010 -05Research and application of mercury ・free catalysts for vinyl chloride synthesisMIAO Naifen , ZHAO Yuejian , FU Bingwei , WANG Kun , WANG Su , ZHANG Jiliang(Shandong Xinlong Technology Co. , Ltd. , Shouguang 262700 , China)Key words : vinyl chloride ; mercury-free catalyst ； stannous chloride ； activated carbon ； ionic liquid Abstract : Based on the strong adsorption capacity of activated carbon and the catalytic performance of tin , the supported catalyst for vinyl chloride synthesis was prepared by loading stannous chloride on activated carbon. The service life of the catalyst and the acetylene conversion under different temperature , reaction time and acetylene flux were studied. The advantages and disadvantages of stannous chloride as the active component were analyzed.聚氯乙烯是一种性能优越、用途广泛的合成树 脂之一，而乙烘氢氯化法制备氯乙烯必须使用汞触媒F 。
臭氧-生物活性炭-砂滤组合工艺运行效果分析
臭氧-生物活性炭-砂滤组合工艺运行效果分析刘建广;李芳;李世俊;王逸群;刘海勇【摘要】介绍某水厂采用“臭氧-生物活性炭-砂滤”深度处理组合工艺处理引黄水库水,考察了不同进水浑浊度对组合工艺长期运行效果的影响,同时对组合工艺各单元的有机物种类及分子量分布的变化进行了分析.长期运行结果表明:(1)组合工艺对不同水质条件下的有机物指标有较高的去除效果,较高的温度有利于水中有机污染物的去除.(2)臭氧的主要作用在于将大分子量的有机物氧化为小分子量有机物,故臭氧—生物活性炭工艺对CODMn、UV254和DOC有良好的去除作用.整个工艺对氨氮的去除率在40％～50％,对亚硝酸盐氮的去除率在80％～ 90％.(3)臭氧—活性炭工艺对可生物降解有机物有较好的去除效果,砂滤工艺主要去除DOCD&A.(4)上向流BAC柱活性炭颗粒间空隙率较大,降低了对浊度的机械截留,其后置的砂滤池可起到稳定出水浊度,保证出水微生物安全性的作用.%Combined processes of "ozone-biological activated carbon-sand filtration" applied in a WTP with reservoir raw water of Yellow River is introduced.And the effect of different influent turbidity on the long term operation of the combined process are investigated.At the same time,changes of organic species and molecular weight distribution of each unit of the combined process are analyzed.Long term operation results show as follows:(1) Combination process has high removal efficiency of organic matter indexes under different water quality conditions.Higher temperature is conducive to the removal of organic pollutants in water.(2) The main effect of ozone is the oxidation of organic compounds with large molecular weight to small molecular weight organic compounds.The removal rate of ammonianitrogen in the whole process is between 40％～ 50％,the removal rate of nitritenitrogen is between 80％～ 90％.(3) Ozone activated carbon process has a good effect on the removal of biodegradable organic compounds.Sand filtration process removes DOCD & A mainly.(4) The upper flow BAC activated carbon particles column with a larger porosity gives low removal efficiency of turbidity,the rear sand filter can play a stable effluent turbidity to ensure the safety of the role of water effluent.【期刊名称】《净水技术》【年(卷),期】2017(000)008【总页数】8页(P72-79)【关键词】饮用水;臭氧;生物活性炭;砂滤;组合工艺;深度处理【作者】刘建广;李芳;李世俊;王逸群;刘海勇【作者单位】山东建筑大学市政与环境工程学院,山东济南250101;山东建筑大学市政与环境工程学院,山东济南250101;济南水务集团有限公司,山东济南250012;山东建筑大学市政与环境工程学院,山东济南250101;山东建筑大学市政与环境工程学院,山东济南250101【正文语种】中文【中图分类】TU991.2Keywordsdrinking water ozone biological activated carbon（BAC） sand filtration combined processes advanced treatment虽然活性炭具有很强的吸附性能，但是由于活性炭的再生成本高、技术要求高［1］，使得活性炭吸附使用周期较短，通常将臭氧氧化法与活性炭吸附联用［2］，称作臭氧-生物活性炭法。
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Activated carbon and carbon molecular sieves in gas separation and purification
It was not until the beginning of this century that the fundamentals of commercial production of carbonaceous adsorbents, in accordance with present-day definitions, were established by the work of Ostrejko. The principles of chemical activation and gas activation he discovered have remained, to this day, the basis of commercial production. Powdered activated carbon is obtained predominantly by chemical activation, whereas granulates and pellets of activated carbon are mostly obtained by steam activation. The technical implementation of Ostrejko’s patents took place rapidly. As early as 1909 the first powdered activated carbon was produced by chemical activation, followed two years later by gas activation to give activated carbon granulates. The production of pelletized activated carbon, which excelled in hardness, abrasion resistance and low pressure losses in gas separation processes, became successful during the thirties. Nowadays we distinguish carbonaceous adsorbents by their disparate pore structures and the resulting specific application fields so that we have the three variants; activated coke, activated carbon and carbon molecular sieves (Table I ). The economic relevance for industry and environmental protection becomes clear from the fact that at present more than 100 manufacturers worldwide produce roughly 350000 tons of carbonaceous adsorbents per
Bulk density (g 1-l) BET-surface (m* g-r) Pore volume (cm3 g-r) for radii < 10 nm for radii > 10 nm Appficetions in gas separation and purification
co.10
> 0.4 Purifi~tion of flue and waste gases Desulfurization NO,-removal Hg-removal Simultaneous SO,/NO,-removal Separation of dioxins214/93/040195-02 @ 1993 Butterworth-Heinemann
Table 1 Properties and application of carbonaceous adsorbents Carbon molecular sieves Activated coke From hardcoal Powder Granulates Pellets of 1-9 mm 600 100 From lignite Powder Granulates 450550 300 <0.15 >0.3 Purification of flue and waste gases SO,-separation D~ulfuri~tion Hg-removal Separation of dioxins and furans Activated carbon Powder Granulates Pellets of l-5 mm 300-550 400-l 500 >0.2 > 0.4 Solvent recovery Waste gas purification Air conditioning Deodorization Separation of radioactive gases Decoffeinetion Catalysis Type I Kinetic separation Granulates Pellets of 2 mm 620680 cl00 <O.l >0.3 N,-recovery from air CH,-recovery from Tvpe ff Adsorptive separation Granulates Pellets of 2 mm 550 600800 co.25 > 0.3 H,-recovery CH,-enrichment in subquality natural gases He-enrichment CO,-enrichment
Ltd
Gas Separation
& Purification 1993 Vol 7 No 4 195
molecular
sieves in gas separation:
K. Knoblaucb
separation of hydrocarbons, for methane/carbon dioxide separation, and for the enrichment of nitrogen from ambient air. Closely linked with product development was the invention of the so-called pressure swing adsorption (PSA) technology in which alternately applied high-adsorption pressure and low-desorption pressure are used as a method of adsorptive gas separation. This special issue provides an overview on the state-ofthe-art in gas separation and purification processes based on activated carbon and carbon molecular sieves. The following contributions describe both basic investigations into carbonaceous adsorbents as well as mathematical approaches to the modelling of adsorption mechanisms. Practical work on the layout of adsorption processes is also reported. Further progress in adsorption technology is expected by the use of improved adsorbents, by the development
of new products, such as activated carbon fibres and carbonaceous membranes, and by the development of new separation processes. These approaches are dealt with in the different contributions of the present issue. As guest editor I would like to thank all of the authors for their readiness to cont~bute to the success of this special issue. At the same time I would like to ask for your understanding in that, owing to the limited scope of the special issue, some of the contributions presented to us had to be postponed but will appear in subsequent issues of ‘Gas Separation and Purification’.
year. Depending on the manufacturing method and the field of application for the products, either hardcoal, lignite, timber, peat, petrol coke or coconut shells are fed to the process. This successful market penetration became possible by the fact that, concurrent with the development and improvement of adsorbents, new separation and purification techniques were found to optimize the adsorption processes. Only by maximizing the ha~onization between adsorbent and process technologies can one achieve a really excellent performing and economic adsorption method. In this context let me quote the devising of a continuous method of simultaneous desulfurization and denitrification of flue gases from power stations, where the breakthrough was attained only after the development of a horizontally moving bed adsorber plus a tube-type desorber for the regeneration of the activated coke as an integral part of the process. The separation effect of carbon molecular sieves may be attributed either to different adsorption capacities (e.g. in the process of hydrogen recovery) or to different diffusion velocities (e.g. in the process of nitrogen recovery from air). Gas separation processes based on carbon molecular sieves proved their usefulness in many cases from the mid-fifties onwards; for the recovery of hydrogen from reforming and coke oven gases, for the