活性炭脱硫工业实验

研究了水洗涤脱附对活性炭脱硫性能的影响.工业实验表明,采用水洗涤脱附,减少了湿活性炭干燥再生过程,活性炭脱硫效率能够达到90%以上.选择适当的脱附频率,用活性炭脱硫能够使高浓度SO2烟气达标排放。     

超高比表面积活性炭结构与天然气脱附量的关系

以石油焦为原料、KOH为活化剂,在不同的活化条件下制得系列超高比表面积活性炭(SBET>2500m2.g-1)样品。将实验制得的不同比表面积和孔分布的超高比表面积活性炭作为天然气吸附剂,测定了不同孔径范围孔所占的表面积与天然气脱附量的关系,讨论了孔分布对天然气脱附量的影响;用数学方法求得了活性炭吸附剂孔表面上单位表面积天然气的脱附量,并利用线性回归求出了天然气脱附量(V)与中孔表面积的关系。经相关性分析表明,天然气的脱附量与活性炭吸附剂中孔所具有的比表面积(Smid)具有显著的相关性,说明在活性炭吸附剂上天然气脱附量主要取决于中孔表面对天然气分子的吸附;求得中孔表面上单位表面积天然气脱附量达0.350mL.m-2,是微孔单位表面积上天然气脱附量的2倍以上;在各吸附温度、吸附压力下,天然气脱附量随活性炭吸附剂中孔表面积呈线性增加,满足线性方程:V=k.Smid b。     

活性炭和活性炭纤维烟气脱硫技术

分析了活性炭烟气脱硫及再生机理,通过与颗粒活性炭为代表的传统炭材料在结构、性能方面的对比,总结出活性炭纤维优良的吸附、脱附、催化氧化等特性,提出了活性炭和活性炭纤维脱硫的主要问题和发展方向。     

煤制活性焦用于脱除烟道气中的SO2

考察了山西煤炭化学研究所研制的三种活性炭的吸附与脱附情况，对其SO2吸附能力进行了评价，并讨论了活性焦的物理性质（比表面积及孔径分布）及化学性质（每平方米比表面积的碱性位含量）对其脱硫性能（SO2吸附量及吸附速率）的影响。结果表明，活性焦的微孔是SO2吸附转化的主要场所，合适的孔结构及丰富的表面碱性位可以较大地提高活性炭的脱硫能力。在O2与H2O（g)存在下，吸附SO2的活性焦的脱附情况不仅与脱附温度有关，还受活性焦的物理、化学性质的影响。而且，活性焦的物理、化学性质不仅决定了其对SO2的吸附量，还决定了吸附在活性焦内SO2以不同形式物理吸附SO2、H2SO4存在时的量。     

NO2在活性炭上的动态吸附研究

采用固定床吸附及程序升温脱附（TPD）方法考察了NO2在活性炭上的吸附形态以及温度、O2、H2O等因素对活性炭吸附性能的影响。研究结果表明,活性炭在低温奈件下可有效吸附NO2,其饱和吸附形态主要为-C（ONO2）基团。-C（ONO2）基团受热可分解为NO与NO2,残留在发表面的舍氧官能团在高温条件下可分解脱附为CO与CO2。随着吸附温度的升高,活性炭的吸附性能逐渐丧失。在低温条件下,O2对活性炭吸附性能无明显影响,而HO2的加入能有效提高其吸附量。     

蜂窝活性炭对乙酸乙酯吸附脱附性能研究

针对市售蜂窝活性炭对乙酸乙酯的吸附脱附性能进行中试研究,旨在为实际工程选型应用提供数据支撑。通过测定蜂窝活性炭不同工况条件对乙酸乙酯污染物的动态吸附穿透曲线,利用Yoon-Nelson模型拟合和回归分析,获得不同条件对蜂窝活性炭吸附性能的影响和关系式。结果表明废气中乙酸乙酯浓度对蜂窝活性炭的饱和吸附量和无效层厚度的影响为正相关;相对湿度对蜂窝活性炭的饱和吸附量的影响为负相关,对无效层厚度的影响为正相关。在已知废气浓度和湿度的工程应用中,可采用关系式Y1=16.65+0.03X1-0.2X2和Y2=-5.00+0.0086X1+0.075X2分别对蜂窝活性炭的动态饱和吸附量和无效层厚度进行初步估算。在热空气脱附过程中,开始脱附需保证最后一层炭的入口温度达到55℃;阶梯升温可以获得稳定的脱附浓度,但其脱附浓度的高低受起始温度的影响。     

载硫活性炭脱汞性能及其反应机理研究

以市售商业载硫活性炭为研究对象,在固定床实验台上进行汞吸附实验,分析吸附温度、入口汞浓度对其脱汞性能的影响,通过表征方法对失活前后吸附剂的物理化学性质进行对比,采用程序升温热脱附实验得到样品中吸附的汞形态,并探究其脱汞机理。结果表明：实验样品的适宜脱汞温度为70 ℃,脱汞效率随着汞浓度的升高而降低;活性炭样品失活后比表面积下降,表面含氧官能团减少,非氧化态硫含量降低,其汞吸附形态以HgS、HgO为主;载硫活性炭样品对汞的吸附脱除主要依靠含氧官能团和含硫官能团的化学吸附作用。     

太阳能吸附制冷用复合吸附剂制备及其吸附机理探讨

以乙醇为吸附质，选取13X分子筛、凹凸楱土和氯化锶等为主要吸附材料．通过混合法制备了一系列有着优良吸附能的复合吸附剂。测定了乙醇在主要吸附材料和自制复合吸附剂上的吸附量，用TG-DTA法对主要吸附材料的热稳定性和自制吸附剂DTA脱附乙醇峰端温度进仃了分析.对吸附剂原料复合比例和扩孔剂种类等制备条件进行了实验研究。结果表明：自制复合吸附剂比单一吸附材料对乙醇确着更大的吸附能力；DTA分析的脱乙醇峰端温度明显低于单一吸附材料；加入扩孔剂E1或E2，可增加自制复合吸附剂孔容和孔径，改善其吸附性能；自制复合吸附剂对乙醇的吸附量显著高于活性炭。其中，M4-0003和M1-0001复合吸附剂对乙醇的平衡吸附量约为活性炭的2．5～4倍；M1-0001—乙醇工质对的吸附制冷量是活性炭—乙醇的2～6倍。对吸附剂复合的机理初步探讨表明：增加复合吸附剂弱吸附中心数，可降低其脱附温度。     

垃圾填埋气中的甲苯对脱碳提纯吸附剂工作性能的影响

文章以甲苯作为垃圾填埋气中的典型挥发性有机物,选择了3种可用于吸附脱碳提纯工艺的吸附剂(13X分子筛、5A分子筛和活性炭),研究了甲苯在这3种吸附剂上的吸附-脱附特征,以及吸附剂在吸附甲苯后的CO_2吸附性能。研究结果表明:真空条件下,吸附剂的甲苯脱附量很小,在吸附-脱附循环过程中,吸附剂中的甲苯含量较高且保持稳定;当吸附剂吸附甲苯后,其对CO_2的吸附能力均有所下降,其中13X分子筛和活性炭的CO_2吸附能力显著下降,5A分子筛的CO_2吸附能力下降程度较小,吸附剂对CO_2吸附能力的下降程度,与其对甲苯的吸附量呈正相关。     

铁改性活性炭对水中镉的吸附和再生实验研究

制备了铁改性活性炭,通过快速动态小柱实验研究了活性炭改性前后对镉的吸附性能,同时考察了进水pH、进水流量和初始质量浓度等因素对吸附材料穿透特性的影响,最后对铁改性活性炭再生方法进行了研究.结果表明,铁改性活性炭对镉的吸附量是未改性活性炭的3.7倍,负载的铁氧化物大大提高了改性活性炭对镉的吸附能力,同时铁改性活性炭对镉的吸附受溶液pH、进水流量和初始质量浓度的影响.0.05 mol·L-1的EDTA-2Na溶液能有效再生吸附饱和后的改性活性炭,再生后的改性活性炭可重复使用.     

Numerical model of internal heat source capacity in desorption step of ETSA process

A new electrothermal desorption process in which the heat for desorption is generated inside adsorbent bed by passing an electric current through them (Joule's heat) is considered. The novel numerical model of volumetric internal heat source capacity in Sorbonorit 4 activated carbon bed, loaded with carbon tetrachloride or 2-propanol is developed on experimental basis. The quantitative relationships between a specific electric resistance ρ(a,T) of the Sorbonorit 4 activated carbon bed and average VOC concentration in solid phase a, and average temperature of the bed T is determined. The capacity of the volumetric internal heat source in Sorbonorit 4 activated carbon bed depends on: electrodes supply voltage, concentration of adsorbate in the solid phase and temperature.     

Simulation studies of a vacuum and temperature swing adsorption process for the removal of VOC from waste air streams

A theoretical study of the cyclic combined vacuum and temperature swing adsorption (VTSA) process for removing of volatile organic compounds (VOC) from waste air streams is done on the basis of computer simulation. The VTSA system consists of two adsorption columns with a fixed bed of activated carbon. The adsorption cycle for each column is operated in four steps: adsorption, indirect adsorbent bed heating, vacuum desorption and cooling. A nonequilibrium, nonisothermal mathematical model of the VTSA process is developed and solved using the numerical method of lines. Exemplary simulation results are presented for the system: 2-propanol–activated carbon Sorbonorit 4. The effect of desorption temperature, pressure and purge gas use on 2-propanol desorption efficiency is investigated.     

Surface functionalization-enhanced spillover effect on hydrogen storage of Ni–B nanoalloy-doped activated carbon

Surface functionalization-enhanced spillover effect on hydrogen storage behaviors of Ni–B nanoalloy-doped activated carbon is investigated in comparison to the 3D graphene-based material. It is discovered that the hydrogen storage capacity of the activated carbon increases from Ni–B nanoalloy-doping but much less than that of graphene. After surface functionalization, although the specific surface area and micropore volume of the doped activated carbon decrease significantly, a hydrogen storage capacity is still almost as same as that of the unfunctionalized larger surface one, while showing a large desorption hysteresis. We argue that the surface functionalization greatly enhances the spillover process on carbon based adsorbents, thus playing an essential role in hydrogen storage capacity improvement.     

Internal heat source capacity at inductive heating in desorption step of ETSA process

A new electrothermal desorption process in which the heat for desorption is generated inside modified adsorbent bed by electromagnetic induction is considered. The novel numerical model of volumetric internal heat source capacity in bed composed of Sorbonorit 3 activated carbon and granular iron mixture, loaded with butan-1-ol is developed on experimental basis. The quantitative relationship between an electrical conductivity γ_AC(q,T) of the Sorbonorit 3 activated carbon and average butan-1-ol concentration in solid phase q, and average bed temperature T is determined. The relationship between an electrical conductivity γ_Fe(T) of the granular iron and temperature T is also derived. The capacity of the volumetric internal heat source in bed of Sorbonorit 3 activated carbon and iron granular mixture bed depends primarily on: volume fraction of granular iron, current intensity of the inductor coil and temperature.     

潜艇燃料电池AIP氢燃料活性炭低温吸附储存

设计利用潜艇液氧冷量的燃料电池(FC)-AIP活性炭低温吸附储氢系统,在模拟潜艇航行中晃动和振动的平台上,测试氢在活性炭上的吸附等温线和储氢系统在为质子交换膜燃料电池(PEMFC)供气时的特性。结果表明,吸附等温线受平台晃振的影响小;温度为113K、压力为6MPa时,比表面积为1450m2.g-1的SAC-02活性炭储氢系统的质量储氢密度可超过当前艇用储氢合金的质量储氢密度;在2kW PEMFC电堆典型工况所需的氢气量(质量流率21.44L.min-1)下,通过充气过程的液氧预冷和放气过程的循环介质加热,可使储罐中心和壁面在整个过程中的最大温差小于5℃。活性炭低温吸附储氢系统的质量密度和储放氢特性能满足艇用FC-AIP系统的要求。     

Modelling of a hydrogen thermally driven compressor based on cyclic adsorption-desorption on activated carbon

Thermally driven hydrogen compression by cyclic hydrogen adsorption-desorption on activated carbon is presented therein. Hydrogen compression occurs through heat exchange, which allows physisorbed hydrogen to desorb at higher temperature in a given volume. The physical nature of hydrogen adsorption on porous carbon allows reversible desorption, and a flow of compressed hydrogen is then obtained by running adsorption/desorption cycles repeatedly. We investigated the feasibility of such a system through numerical simulations by taking into account both mass and energy balances, and adsorption thermodynamics. We showed that high-pressure hydrogen, up to 70 MPa, can be obtained by simply lowering and/or increasing the system temperature. Such a system opens new perspectives in the frame of the Hydrogen Supply Chain.     

Influence of torrefaction on properties of activated carbon obtained from physical activation of pyrolysis char

In this paper, the method of ‘torrefaction–fast pyrolysis–physical activation’ was conducted to investigate the impact of torrefaction on the properties of activated carbon through CO₂ activation. It was found that torrefaction had a significantly positive influence on the quality of activated carbon and 280°C was the optimal torrefaction temperature. The activated carbon obtained under the recommended condition had a higher yield (13.0 ± 0.3% based on dried rice husk) and most developed pore structure (specific surface area of 1090.7 m²/g). The results may be helpful for the potential utilization of high ash content biomass like rice husk.     

Cryosorption storage of gaseous hydrogen for vehicular application – a conceptual design

A conceptual design for the cryosorption storage of gaseous hydrogen in activated carbon for vehicular application has been presented. In this work, a novel concept for the storage/discharge of hydrogen has been proposed. This system ensures faster filling and gradual release of hydrogen on demand. These two features are important for making onboard hydrogen storage effective for small cars. Numerical models for adsorption and desorption half cycles are presented. Assuming that the pressurisation and depressurisation are occurring adiabatically, transient analysis has been done to critically study the effective hydrogen storage capacity of activated carbon. The amount of activated carbon required to store hydrogen for travelling a specific distance has been computed.     

Enhancement on hydrogen production performance of Rhodobacter sphaeroides HY01 by overexpressing fdxN

Ferredoxin I (FdI), encoded by fdxN gene, is proved to be the main electron donor of nitrogenase for hydrogen production. In this work, fdxN gene overexpression was implemented in a mutant MHY01, which was constructed by inserting fdxN gene into the hupSL region in Rhodobacter sphaeroides HY01 genome. Its photo-fermentative H₂ production performance was studied. The results showed that the expression level of fdxN and nitrogenase activity in MHY01 (hupSL::fdxN) were enhanced by 177% and 61.7% respectively compared with that of wild type HY01. Using 25 mM acetate and 34 mM butyrate as carbon source and 6 mM l-glutamate as nitrogen source, the maximum H₂ production rate was 156.1 mL/(L·h), which was increased by 50.7% compared with that of HY01. The maximum H₂ production rates of MHY01 were enhanced by 30.0%, 52.5% and 50.7% compared with those obtained from HY01 at the inoculation size of 5%, 10% and 15% respectively. The results suggested that overexpressing fdxN could enhance the nitrogenase activity and H₂ production performance of purple non-sulfur bacteria. The abundancy of ferredoxin I might limit the efficiency of electron transfer flux associated with the biohydrogen production process.     

Conceptual design analysis of a compressor‐driven sorption cooling system

The feasibility of using activated carbon/nitrogen pair as an alternative to metal hydride–hydrogen combination in a compressor‐driven sorption refrigerator (CDSR) has been studied in the present article. The motivation behind the selection of this particular adsorbent/adsorbate pair is due to its high heat of adsorption/desorption, in addition to the fact that nitrogen is absolutely eco‐friendly and a nonhazardous gas to handle with. A conceptual design of the cooling system has been envisaged for near room temperature applications with this activated carbon/nitrogen pair. In order to evaluate the performance of the CDSR system, mathematical models have been developed separately for the adsorption and desorption processes involving transient heat and mass transfer analysis. The present analysis also helped to conduct a parametric evaluation of the cooling system. Copyright © 2009 John Wiley & Sons, Ltd.