Control of electrothermal heating during regeneration of activated carbon fiber cloth

Electrothermal swing adsorption (ESA) of organic gases generated by industrial processes can reduce atmospheric emissions and allow for reuse of recovered product. Desorption energy efficiency can be improved through control of adsorbent heating, allowing for cost-effective separation and concentration of these gases for reuse. ESA experiments with an air stream containing 2000 ppm(v) isobutane and activated carbon fiber cloth (ACFC) were performed to evaluate regeneration energy consumption. Control logic based on temperature feedback achieved select temperature and power profiles during regeneration cycles while maintaining the ACFC's mean regeneration temperature (200 °C). Energy requirements for regeneration were independent of differences in temperature/power oscillations (1186-1237 kJ/mol of isobutane). ACFC was also heated to a ramped set-point, and the average absolute error between the actual and set-point temperatures was small (0.73%), demonstrating stable control as set-point temperatures vary, which is necessary for practical applications (e.g., higher temperatures for higher boiling point gases). Additional logic that increased the maximum power application at lower ACFC temperatures resulted in a 36% decrease in energy consumption. Implementing such control logic improves energy efficiency for separating and concentrating organic gases for post-desorption liquefaction of the organic gas for reuse.     

Steady-state and dynamic desorption of organic vapor from activated carbon with electrothermal swing adsorption

A new method to achieve steady-state and dynamic-tracking desorption of organic compounds from activated carbon was developed and tested with a bench-scale system. Activated carbon fiber cloth (ACFC) was used to adsorb methyl ethyl ketone (MEK) from air streams. Direct electrothermal heating was then used to desorb the vapor to generate select vapor concentrations at 500 ppmv and 5000 ppmv in air. Dynamic-tracking desorption was also achieved with carefully controlled yet variable vapor concentrations between 250 ppmv and 5000 ppmv, while also allowing the flow rate of the carrier gas to change by 100%. These results were also compared to conditions when recovering MEK as a liquid, and using microwaves as the source of energy to regenerate the adsorbent to provide MEK as a vapor or a liquid.     

活性碳纤维电热再生研究

用自制电热再生装置对吸附甲苯的活性碳纤维进行电热再生试验,通过二次通用旋转组合设计试验方案,以甲苯脱附率和脱附质量两个指标考察了脱附温度、载气流量和碳纤维层厚度对活性碳纤维电热再生效果的影响,得出了局部最佳组合方案:当脱附温度为170℃、载气流量为1 2∞mⅣmin、碳纤维层厚度为16 mm时,甲苯脱附率平均值为92....     

Microwave-swing adsorption to capture and recover vapors from air streams with activated carbon fiber cloth

Adsorption with regeneration is a desirable means to control the emissions of organic vapors such as hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) from air streams as it allows for capture, recovery, and reuse of those VOCs/HAPS. Integration of activated-carbon fiber-cloth (ACFC) adsorbent with microwave regeneration provides promise as a new adsorption/ regeneration technology. This research investigates the feasibility of using microwaves to regenerate ACFC as part of a process for capture and recovery of organic vapors from gas streams. A bench-scale fixed-bed microwave-swing adsorption (MSA) system was built and tested for adsorption of water vapor, methyl ethyl ketone (MEK), and tetrachloroethylene (PERC) from an airstream and then recovery of those vapors with microwave regeneration. The electromagnetic heating behavior of dry and vapor-saturated ACFC was also characterized. The MSA system successfully adsorbed organic vapors from the airstreams, allowed for rapid regeneration of the ACFC cartridge, and recovered the water and organic vapors as liquids.     

碳纤织物的设计及织造实践

根据碳纤维的特点设计了碳纤起绒织物并成功试织出小样,对碳纤织物织造工艺进行分析研究,提出了织造中应注意的问题及应采取的措施,以保证织造顺利进行.     

聚丙烯腈基活性碳纤维及其应用

活性碳纤维(ACF)是一种多孔材料,它可以通过物理或化学的方式从液体或气体中吸附多种成分,因此被用于许多应用中,特别是污染气体的净化、有毒气体的吸收、气体的分离、空调的除臭和水的净化等,ACF还可应用于医药领域。活性碳的另一种类粒状活性碳(GAC)同样可应用于以上各领域。尽管ACF的价格很高,但ACF的使用却更为广泛,这主要是因为其蓬松度大、孔径均匀,使它的吸收量和传质系数比粒状活性碳高12～15倍。原材料性能及碳化与活化工艺影响最终ACF的微孔数量和总表面积。由聚丙烯腈(PAN)原丝制得的ACF有着独特的吸收性能和相当高的强度。     

活性炭纤维形态对吸附性能的影响

比表面积和孔结构是影响活性炭纤维吸附性能的重要因素。选用相同的活化工艺,制备相似孔结构和比表面积的活性炭毡和活性炭布,讨论在比表面积相近的情况下,活性炭纤维的形态和厚度对吸附性能的影响。结果表明:在一定条件下,活性炭毡的吸附性能略优于活性炭布,活性炭纤维的吸附能力并不随着活性炭织物厚度的增加而线性增强。     

Activated carbon cloth as anode for sulfate removal in a microbial fuel cell

By employing the sulfate-reducing bacterium Desulfovibrio desulfuricans we demonstrate the possibility of electricity generation in a microbialfuel cell (MFC) with concomitant sulfate removal. This approach is based on an in situ anodic oxidative depletion of sulfide produced by D. desulfuricans. Three different electrode materials, graphite foil (GF), carbon fiber veil (CFV), and high surface area activated carbon cloth (ACC), were evaluated for sulfide electrochemical oxidation. In comparison to CFV and GF electrodes, ACC was a superior materialfor sulfide adsorption and oxidation and showed significant potential for harvesting energy from sulfate-rich solutions in the form of electricity. Sulfate (3.03 g dm(-3)) was removed from a bacterial suspension, which represented 99% removal. A maximum power density of 0.51 mW cm(-2) (normalized to geometric electrode area) was obtained with a one-chamber, air-breathing cathode and continuous flow MFC operated in batch mode at 22 degrees C.     

变压吸附制氮机的应用

介绍变压吸附的原理、工艺流程、在啤酒企业中的应用效果以及使用过程中的应注意事项。     

增大曲柄摇杆式摆布机构摆幅的设计

主要介绍了增大曲柄摇杆式摆布机构摆幅的设计方法，对比了新老式摆布机构。     

碳纤维材料与碳纤维纸

介绍了碳纤维材料的性能、制造方法，对碳纤维纸的干法、湿法抄造工艺及设备进行了介绍。碳纤维纸可用于新型抗静电材料、空气净化、水净化及高屏蔽壁纸等领域。     

Moisture swing sorbent for carbon dioxide capture from ambient air

An amine-based anion exchange resin dispersed in a flat sheet of polypropylene was prepared in alkaline forms so that it would capture carbon dioxide from air. The resin, with quaternary ammonium cations attached to the polymer structure and hydroxide or carbonate groups as mobile counterions, absorbs carbon dioxide when dry and releases it when wet. In ambient air, the moist resin dries spontaneously and subsequently absorbs carbon dioxide. This constitutes a moisture induced cycle, which stands in contrast to thermal pressure swing based cycles. This paper aims to determine the isothermal performance of the sorbent during such a moisture swing. Equilibrium experiments show that the absorption and desorption process can be described well by a Langmuir isothermal model. The equilibrium partial pressure of carbon dioxide over the resin at a given loading state can be increased by 2 orders of magnitude by wetting the resin.     

涤纶橡胶骨架布的设计与生产

介绍了涤纶橡胶骨架布的设计、生产和质量管理。对关键的后处理生产工艺作了详细说明。该类橡胶骨架布在橡胶行业得到了广泛的应用。     

碳纤维原丝材料——PBO纤维

预计2010年碳纤维的市场约为20亿美元,产量约为3.63万t。碳纤维制造工业的主要挑战是成本效率生产。随着成本的降低,其用途将急剧增加。能够直接从PBO纤维制备碳纤维,无需非常费钱耗时的纤维稳定步骤,意味着能够降低成本。PBO纤维的炭化和石墨化产生优质碳纤维,兼有非常好的热和力学性能。与其他原丝生产碳纤维相比,有非常令人感兴趣的远程有序形成。这导致极好的晶格基性能和较低的电阻率。     

改善电子玻璃纤维布电绝缘性能的途径

具有良好电绝缘性能的电子玻璃纤维布在电子工业有广阔的应用前景,如何提高电子玻璃纤维布的电绝缘性能是国内电子玻璃纤维布研发的热点课题。综合评述了从电子玻璃纤维的化学组分、纱线的物理加工、织物结构及表面处理技术的优化四个方面提高电子玻璃纤维布的电绝缘性能的研究进展,为国内电子玻璃纤维布的研发提供参考。     

碳纤维市场——日新月异

对碳纤维产业进行了综述,介绍了新老生产商和研究机构的动向。在《碳纤维市场：对现状的综述》一文的基础上,介绍了该市场的最新发展。聚丙烯腈（PAN）、沥青和纤维素是生产碳纤维的原料,着重介绍了聚丙烯腈基碳纤维。市场上出售的碳纤维中,近100%为聚丙烯腈基碳纤维。     

碳纤维市场发展趋势

<正>金融危机后,碳纤维市场又将好转。很多行业,特别是工业市场,都需要碳纤维,且碳纤维的需求在地理位置分布上正发生变化(表1、表2)。到2015年,工业市场将占碳纤维需求的大多数——65%以上。     

Electrochemical regeneration of activated carbon cloth exhausted with bentazone

The electrochemical regeneration of an activated carbon cloth exhausted with a common herbicide (bentazone) was investigated under different operating conditions. The reversibility of the desorption process was confirmed by monitoring the UV spectra of the solution while cathodic polarization is being applied. Neither nanotextural nor chemical changes are produced in the carbon cloth upon polarization in the absence of the adsorbate. Upon cathodic polarization of a carbon cloth working electrode preloaded with bentazone, negative charges appear on the surface. A partial bentazone desorption results from repulsive electrostatic interactions between the negative charges on the carbon cloth and bentazone. When the electrode potential is below the thermodynamic value for cathodic decomposition of water, hydroxyl ions are liberated. Such ions provoke local pH changes that are responsible of the dissociation of bentazone and carbon surface groups to their anionic form. As a consequence of the pH increase, an almost reversible desorption of bentazone is observed. The effects of several operating parameters on the regeneration efficiency were evaluated. Higher regeneration efficiencies were attained under potentiostatic as compared to galvanostatic conditions, as OH- production strongly depends on the applied potential.