A novel design for humidifying an open-cathode proton exchange membrane fuel cell using anode purge

The low performance of open-cathode proton-exchange-membrane fuel cells (OCPEMFCs) is attributed to the low-humidity ambient air supplied to the cathode using electric fans. To improve the OCPEMFC performance, this paper proposes a novel humidification method by collecting water purged from the anode and supplying it to the open cathode. The OCPEMFC performance is evaluated at various humidifier distances from the cathode inlet, and it is compared with that where no humidifier is used when the OCPEMFC operates under three different current levels of 1, 5, and 8 A. The results show that the novel design improves the stack power, and optimal performance is achieved at a humidifier distance of 2 cm. The energy efficiency achieves an improvement between 1.4% and 1.8% when a humidifier is used.     

Volatile organo-halogen trace analysis in beverages by thin-layer headspace enrichment and electron-capture gas-chromatography

Applicability of thin-layer headspace (TLHS) procedure giving an aqueous concentrate and also classical purge and trap (PT) in off-line mode to isolate and enrich volatile organohalogen compounds in common beverages was tested. Both enrichment tech-niques were used in combination with gas chromatography – electron capture detection (GC-ECD). TLHS, combined with direct aqueous injection (DAI)-GC-ECD, proved applicable in the determination of volatile organohalogen compounds in all studied beverages, while the PT in a version with no preliminary sample pre-treatment was of limited applicability. Detection limits of the TLHS-based procedure were in the order of 1 ppt. Content of volatile organohalogen compounds in a number of beverages available on the Polish market including mineral waters, beers, juices, carbonated and non-carbonated soft drinks, etc. was determined by means of TLHS-DAI-GC-ECD.     

ALPUR除气装置在25 t熔铸生产线中的应用

25 t燃油熔铝炉熔炼的铝合金熔体中氢含量较高,配备ALPUR除气净化装置,通过合理使用,达到了满意的除氢效果,保证了铸锭的内部质量。     

Textural, Water Holding, and Sensory Properties of Low-fat Pork Bologna with Normal or Waxy Starch Hull-less Barley

All ultra-low-fat (< 1%) pork bolognas had similar cook yield and composition. Addition of 4% hull-less waxy barley flour or meal to formulations provided the greatest purge control; 4% normal starch barley, wheat flour and potato starch were intermediate; 0.25% kappa-carrageenan or 1% soy protein concentrate had little effect on water holding and texture. Expressible moisture and purge were significantly correlated to moisture content and batter viscosity. Formulations with wheat flour and waxy barley meal were scored the firmest, while bologna with potato starch required the most force to compress. For most sensory properties, barley fractions performed similarly to wheat flour; however, waxy barley provided superior water holding during storage.     

回收弛放气中丙烯丙烷的技术及应用

在弛放气回收中试的基础上,进行了弛放气回收装置的工业化设计,装置弛放气设计处理能力为6.8kt/a,回收丙烯和丙烷5.5kt/a,年操作时数为8000h。该技术采用"吸收—精馏—再精馏"工艺路线,即吸收剂吸收弛放气中的丙烯、丙烷和丁醛,含丙烯、丙烷的吸收液经过精馏分离得到丙烯、丙烷的混合组分,再经过常规精馏分离得到丙烯和丙烷产品。吸收剂经提纯后可循环使用。在吸收丙烯、丙烷的同时,混合丁醛也被吸收,与丁醇分离后可作为产品抽出。应用该技术,丙烯、丙烷收率大于90%,产品丙烯纯度大于96%,丙烷纯度大于99%。该工艺技术为自有技术,其设备全部国产化。吸收塔、精馏塔和脱重塔采用天津大学开发的高效填料,精馏塔采用格里奇公司的高效塔盘,有效保证分离效果。全部设备和材料均可在国内生产制造,工程费用比较低。     

吹扫捕集气质联用法测定水中吡啶

建立了吹扫捕集气质联用法测定水中吡啶的方法,优化了吹扫条件,用自动进标样的方法绘制工作曲线,方法的检出限为0.08μg/L,相对标准偏差在1.5%～5.1%之间,方法用于地表水、生活污水和化工废水中吡啶的测定,进行了加标回收实验,回收率在82.5%～102.5%之间。     

氧气管道施工及吹扫与除锈注意事项

依据现有规范标准,结合施工实践经验,对氧气管道施工中的管道材质、阀门、垫片的选型和试压吹扫与除锈等工序进行了探讨,提出了改进性措施,以保证氧气管道安全可靠运行。     

无动力氨回收装置的运行总结

无动力氨回收装置是回收合成氨弛放气中气态氨的一项节能环保新技术装置。介绍了河北金源化工股份有限公司无动力氨回收技术的原理、工艺流程、主要设备特点、工艺指标及运行情况。该厂无动力氨回收装置各项温度压力指标均在设计范围内,氨回收率达到98%,尾气氨含量〈1.1%,年回收氨约为3 500 t,年增效益350万元。     

无动力氨回收装置运行总结

介绍新建合成氨采用无动力回收装置回收氨罐弛放气的工艺流程、设备配置,还介绍了无动力回收装置的特点。