自养微生物反硝化法去除沼气中H2S工艺研究

通过将营口污水处理厂二沉池的泥水混合物进行静置沉淀,取上清液进行稀释筛选得到一株革兰氏阴性菌D-12.然后采用生物反应器内的营养液(NaOH+驯化液)对沼气中的H2S进行洗脱,再采用筛选菌株D-12对含有H2S的营养液进行反硝化脱硫(试验周期为38 d).以初始S2-浓度、微生物添加量和NO3-浓度为自变量,以降解试验...     

OMC法对煤气中H2S脱除效率影响的试验研究

基于煤气脱硫系统运行条件,模拟OMC法脱硫工艺过程,在小型试验台上对模拟煤气进行脱硫效率试验研究。讨论了在OMC法煤气脱硫过程中,碳酸钠溶液浓度、脱硫剂OMC浓度、入口H2S浓度等因素对煤气脱硫效率的影响,得出最优的脱硫生产条件,指出该法适用于煤气中硫化物含量波动大的脱硫方法,与传统ADA脱硫法相比更有利于脱硫效率的提高。     

生物法脱除沼气中硫化氢的研究进展

生物脱硫是一种新兴的脱硫方法,在一定条件下通过微生物的代谢作用将硫化氢转化为单质硫,既解决了传统脱硫方法的污染问题,又可以回收硫资源,实现了环保和低成本脱硫,发展前景十分广阔。文章介绍了脱硫微生物以及生物脱硫的机理,综述了近年来国内外沼气生物脱硫技术的研究进展,并对今后的研究方向做了一定的展望。     

沼气中硫化氢气体的生物处理法

沼气中硫化氢的存在限制了沼气能源的推广。文章阐述了沼气生物脱硫法的原理、方法和可行性,介绍了该方法在国内外的研究发展现状。     

英国开发出生物燃料净化技术

英国科学家最近开发出一种用植物油制成的对生物燃料进行净化的技术，可将生物燃料中主要副产品丙三醇清除。英国莱斯特大学一个化学小组利用由氯化胆碱和丙三醇混合物制成的离子液体，成功地对以植物油为基本原料制成的生物燃料进行净化，将生物燃料中的丙三醇完全清除。     

英国开发出生物燃料净化技术

英国科学家最近开发出一种用植物油制成的对生物燃料进行净化的技术，可将生物燃料中主要副产品丙三醇清除。英国莱斯特大学一个化学小组利用由氯化胆碱和丙三醇混合物制成的离子液体．成功地对以植物油为基本原料制成的生物燃料进行净化，将生物燃料中的丙三醇完全清除。这种技术使用简单，成本低，可在不产生废物的情况下持续净化生物燃料。     

生物燃料可能增加温室气体排放

一项新的研究表明，生物燃料的生产可能会增加温室气体的排放。该研究的第一作者、诺贝尔奖获得者Paul Crutzen来自欧美的同事认为，生产生物燃料作物所需的氮肥，可能导致比人们此前所认为的更大数量的一氧化二氮排放到大气中。根据这项研究，微生物把化肥中的3％到5％的氮转化成了一氧化二氮，而不是政府间气候变化委员会所估计的1%。     

生物柴油燃料特性的研究

植物油及其衍生物被用作柴油的代用燃料,其中甲酯被定义为“生物柴油“.燃用生物柴油可降低汽车尾气中有害排放物HC,CO和颗粒物PM的浓度,降低CO2的净排放量.文章着重讨论了生物柴油的热值,CN,IV和低温流动性等参数,认为不饱和双键的数目和位置对燃油品质的影响极大.     

藻类生物燃料研究开发进展

藻类生物燃料作为一种非粮生物质燃料已成为当今的研究热点,具有广阔的发展前景,有可能成为未来最重要的可再生能源之一。介绍了藻类制备生物燃料的研发概况,综述了国内外研究开发历程与最新进展,分析了目前藻类生物燃料研究开发中存在的困难和问题,指出了当前和今后的研发方向。     

生物燃料在我国公路交通中替代潜力分析

首先从我国生物燃料开发的资源保障性、生产的技术经济性以及现代汽车技术利用的可能性等方面,对生物燃料的开发利用潜力进行了分析。之后重点论述了利用IPAC模型研究我国未来公路交通能源需求以及生物燃料替代的发展情景。研究表明:未来我国公路交通倍增的油品需求对我国石油供应造成巨大压力,推广新型汽车技术和发展替代燃料是降低公路交通油品消耗的战略措施,混合动力汽车技术与生物燃料结合是我国未来公路交通最佳的技术选择,并且生物燃料在我国未来公路交通中将展现出很强的燃料替代前景。     

微波等离子体方法分解H2S制氢

报道一种新的Ｈ２Ｓ气体处理方法。当Ｈ２Ｓ气体通过矩形共振腔反应器时，在微波的作用下产生等离子体进而分解成氢气和单体硫。国外报道的类似方法需在很低的负压下实现Ｈ２Ｓ的分解，而常压微波等离子体分解Ｈ２Ｓ未见详细报道。本工作中Ｈ２Ｓ在微波作用下于常压生成等离子体并分解为氢气和硫，Ｈ２Ｓ的转化率与已见报道数据持平，而能耗则明显降低，所需设备大大简化。     

紫外光液相光化学法分解硫化氢制氢

采用波长为253.7 nm的紫外光为光源,以Na2S溶液为反应液,进行了紫外光液相光化学法分解硫化氢(H2S)制氢反应。考察了S的存在形式、Na2S溶液的浓度、Na2SO3溶液浓度及H2S通入流量对制氢的影响。研究结果表明,溶液中S以HS-的形式存在有利于紫外光的分解;加入Na2SO3可以提高体系的产氢量;在体系中通入H2S可以使产氢速率保持稳定。     

氩气、氢气和空气中球磨改性的多壁碳纳米管的吸氢性能

研究了氩气、氢气和空气不同气氛下球磨改性对多壁碳纳米管储氢性能的影响。发现球磨促使碳管变短和开口，从而更有利于储氢。空气中球磨24h的碳管吸氢量从未球磨时的0．29wt％提高到1.81Wt％。空气中氧化球磨融合了机械力与高温氧化的双重作用，处理后碳管石墨化程度降低、管端开口增加，处理效果最好。     

一种低电耗制氢的新工艺研究(Ⅰ)

该文提出了电化学溶解一沉淀法这一全新的工艺，可实现超低电耗(1．7kWh／Nm^3H2以下)制氢并同时联产环保型颜料磷酸锌。该工艺的制氢电耗比目前工业电解水法低50％以上，且工艺简单清洁，设备投资少，经济效益高。在前期静态研究的基础上，笔者对连续运转条件下影响电解产氢的重要因素(电解液碱度，进料流量及温度)进行了单因素研究，初步确定了系统优化工艺条件。     

一种低电耗制氢的新工艺研究(Ⅱ)

提出了一种全新的工艺:电化学溶解-沉淀法,可实现超低电耗(低于1．5kWh/Nm3H2)制氢并同时联产 性能优良的磷酸锌产品。在前期研究的基础上,补充考察了电压、锌配离子浓度及阳极自发产氢等因素对电解 过程的影响,并通过对几个关键因素的正交实验研究进一步确定了该工艺的优化操作条件,取得了较好的实验 结果。     

Electrocatalytic hydrogen evolution properties of anionic NiS2-Ni(OH)2 nanosheets produced on the surface of nickel foam

To circumvent the expensive cost of precious metal electrocatalysts, a hydrothermal method and a plasma-enhanced chemical vapor deposition (PECVD) method have been used to prepareNiS₂-Ni(OH)₂/NF-PECVD (N-PECVD) with excellent properties. After XRD, SEM, XPS, and other characterization methods, it can be seen that after the hydrothermal reaction of Ni foam (NF), 50-60 nm Ni(OH)₂ nanosheets have grown on the NF frame. The subsequent PECVD reaction produces 90 nm NiS₂-Ni(OH)₂ nanosheets on the NF frame. The hydrogen release overpotentials in the acidic solution and alkaline solution are 90 and 95 mV (j = 10 mA/cm²), respectively. And the Tafel slopes reach 80 and 83.6 mV/dec, respectively. The chronopotential (CP) test shows that the material has good HER stability over 12 h. The results from the subsequent electric double layer capacitance and alternating current impedance (EIS) tests show that N-PECVD synthesized by PECVD has a relatively large active electrochemical surface area (ECSA) and a low electrochemical impedance. This study not only finds good inspiration for the synthesis of cheap HER catalysts but also provides a valuable reference for the synthesis of materials in other fields.     

氢能发电技术的研究（Ⅳ）——电极扩散层对离子膜燃料电池放电性能的影响

研究了电极扩散层对离子膜燃料电池放电性能的影响。结果表明：制备扩散层的基体材料对燃料电池放电性能有较大的影响。本实验所采用的碳纸、碳膜和碳纤维布3种基体材料中,碳纤维布是一种较为理想的基体材料,不同扩散层所组装的燃料电池最大放电功率密度有较大的差别,碳纤维布扩散层所组装的燃料电池最大放电能量分别是碳纸和碳膜扩散层所组装的燃料电池最大放电能量的2.16倍和6.94倍。不同扩散层对燃料电池最佳放电运行时的放电电压和放电电流密度也都有一定的影响,特别是对放电电流密度影响更为强烈,电极扩散层的疏水性是影响燃料电池稳定放电寿命的一个重要因素,因此在电极扩散层的制备和基材选择过程中,必须充分考虑这一因素的影响。     

H2S effect on dry reforming of biogas for syngas production

The effect of hydrogen sulfide (H₂S) on dry reforming of biogas for syngas production was studied both experimentally and theoretically. In the experimental work, the H₂S effect on Ni‐based catalyst activity was examined for reaction temperatures ranging from 600°C to 800°C. It was found that the presence of H₂S deactivated the Ni‐based catalysts significantly because of sulfur poisoning. Although bimetallic Pt‐Ni catalyst has better performance compared with monometallic Ni catalyst, deactivation was still found. The time‐on‐stream measured data also indicated that sulfur‐poisoned catalyst can be regenerated at high reaction temperatures. In the theoretical work, a thermodynamic equilibrium model was used to analyze the H₂S removal effect in dry reforming of H₂S‐contained biogas. Calcium oxide (CaO) and calcium carbonate (CaCO₃) were used as the H₂S sorbent. The results indicated that H₂S removal depends on the initial H₂S concentration and reaction temperature for both sorbents. Although CO₂ was also removed by CaO, the results from equilibrium analysis indicated that the dry reforming reaction in the presence of CaO was feasible similar to the sorption enhanced water‐gas shift and steam‐methane reforming reactions. The simulation results also indicated that CaO was a more preferable H₂S sorbent than CaCO₃ because syngas with an H₂/CO ratio closer to 2 can be produced and requires lower heat duty.     

Ni(OH)2-CuxO-TiO2 nanocomposite for the enhanced H2 production under solar light: The mechanistic pathway

The synergistic effect of Ni(OH)₂ and Cu_xO on TiO₂ enhanced the H₂ production 4 times higher than bare TiO₂ at the optimum loading of 1.0 wt% Ni(OH)₂ and 0.5 wt% Cu_xO (1.0 wt% Ni(OH)₂-CT) under natural sunlight. Cu_xO-TiO₂ heterojunctions improved the visible activity and charge transfer efficiency of TiO₂. The layered morphology of non-precious Ni(OH)₂ cocatalyst with intercalated H₂O molecules enhanced H₂ production by improving the surface charge transfer reaction with additional formation of H⁺ ions through the redox reactions. Based on the characterization and experimental results, the double charge transfer and direct Z-scheme mechanisms were proposed for the charge carrier pathway in Cu_xO-TiO₂ heterojunction. On the whole, the improved visible light response, efficient interfacial charge transfer and production of additional excited free electrons/H⁺ ions enhanced the overall H₂ production on Ni(OH)₂-CT, which was also confirmed with various experimental and characterization results.     

In-situ synthesis of novel plate-like Co(OH)2 co-catalyst decorated TiO2 nanosheets with efficient photocatalytic H2 evolution activity

Efficient separation of photo-generated electrons and holes is a crucial aspect for photocatalytic hydrogen evolution. Herein, novel plate-like Co(OH)₂ decorated TiO₂ nanosheets for photocatalytic water splitting were synthesized by a facile in-situ synthetic method. The results of X-ray diffractometry (XRD), transmission electron microscope (TEM), UV–Vis diffusion reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS) indicate the successfully incorporation of Co(OH)₂ co-catalysts onto the surface of TiO₂ nanosheet photocatalysts. Further photocatalytic hydrogen evolution experiments illustrate that all Co(OH)₂ decorated TiO₂ samples show higher rate of hydrogen production performance than pure TiO₂ sample and the composite sample with Co(OH)₂ loading amount of 0.5mol% presents the highest photocatalytic hydrogen production activity of 746.93 μmol g^?1·h^?1. It is indicated that plate-like Co(OH)₂ particle act as an electron collector, which leads to photo-generated electrons transfer from TiO₂ to Co(OH)₂, and therefore enhance the photocatalytic activity. Based on above results, a possible mechanism is proposed and further verified by surface photovoltage spectra (SPV).