An evaluation of autotrophic microbes for the removal of carbon dioxide from combustion gas streams

Carbon dioxide is a greenhouse gas that is believed to be a major contributor to global warming. Studies have shown that significant amounts of CO₂ are released into the atmosphere as a result of fossil fuels combustion. Therefore, considerable interest exists in effective and economical technologies for the removal of CO₂ from fossil fuel combustion gas streams. This work evaluated the use of autotrophic microbes for the removal of CO₂ from coal fired power plant combustion gas streams. The CO₂ removal rates of the following autotrophic microbes were determined: Chlorella pyrenoidosa, Euglena gracilis, Thiobacillus ferrooxidans, Aphanocapsa delicatissima, Isochrysis galbana, Phaodactylum tricornutum, Navicula tripunctata schizonemoids, Gomphonema parvulum, Surirella ovata ovata, and four algal consortia. Of those tested, Chlorella pyrenoidosa exhibited the highest removal rate with 2.6 g CO₂ per day per g dry weight of biomass being removed under optimized conditions. Extrapolation of these data indicated that to remove CO₂ from the combustion gases of a coal fired power plant burning 2.4 × 10⁴ metric tons of coal per day would require a bioreactor 386 km² × 1 m deep and would result in the production of 2.13 × 10⁵ metric tons (wet weight) of biomass per day. Based on these calculations, it was concluded that autotrophic CO₂ removal would not be feasible at most locations, and as a result, alternate technologies for CO₂ removal should be explored.     

贵金属的结合能、体膨胀系数的研究

本文在郑伟涛等提出的贵金属位能函数理论基础上,从体系的自由能出发,并结合Midha状态方程,对贵金属Cu、Ag、Au多晶体的结合能、体膨胀系数进行了理论研究和计算,理论计算得到的结果与实验相当符合,其误差均在9％以内。     

HDO-18选择性加氢催化剂的工业应用

抚顺石油化工研究院开发的HDO-18选择性加氢催化剂是以氧化铝为载体的贵金属钯催化剂,首次在茂名炼油化工股份公司苯抽提装置进行了工业应用。结果表明,该催化剂及工艺技术可用于重整生成油苯馏分的选择性加氢脱烯烃,取代常规的后加氢和白土精制工艺,在反应温度170℃,反应压力1.8 MPa,氢油体积比220:1,体积空速3.2 h-1的条件下,产品的溴指数降低到小于50 mgBr／(100 g),芳烃损失小于0.5个百分点,满足产品指标要求。     

Economic global warming potentials

A reformulation of global warming potentials is propounded, that combines the time-horizon and discounting definitions, and covers both ordinary atmospheric forcing (via greenhouse gases) and its rate-of-change. Insofar as GWPs are used to guide investment and socioeconomic choices, there is merit in adopting cost-benefit techniques. The parametric equivalence of the two definitions applies for the ordinary atmospheric forcing; but for its rat-of-change, only the discounting definition gives realistic results, as shown in application to methane, a short-lived greenhouse gas.     

Reactive plasma spraying of wear-resistant coatings

A method for producing wear-resistant, carbide-reinforced coatings has been investigated. A conventional low-pressure plasma gun has been modified with a downstream reactor into which carbon-containing gases are mixed, heated, and disassociated. The disassociated gas ions—H* and C* —are subsequently brought into contact with heated, molten metal matrix powders. Experiments with NiCr/Ti blends and W powders have shown that uniformly dispersed carbides such as, TiC, Cr^Cy, WC, and W2C were formed in situ on the metal precursor powders during deposition. The in situ formed particles, being formed directly from the matrices, show excellent matrix cohesion and lead to high and uniform deposit microhardnesses. The process is described and several evaluations of materials, reactive gases, and spray conditions are reported. Microanalysis of the coatings are presented, microhardness values are reported, and XRD identifies the in situ formed phases.     

标准混合气配制装置的研究

本文提出了一种在阻塞流动状态下精确控制纯气体流过喷咀的时间，进行高精度配制标准混合气的方法；并研制了相应智能标准气发生装置。该装置配气精度高、轻便、可靠、操作方便，可用于现场配制各种标准混合气。     

两性水溶性卟啉的合成及其与贵金属配合反应的分光光度研究

合成了两性水溶性卟啉四(N-羧甲基-4-吡啶)卟啉[T(l-PC)P]和四(4-(N,N,N-羧甲基二甲氨基)苯)卟啉[T(4-CDMAP)P]。研究了这两种卟啉与贵金属 Ag(Ⅰ)、Pd(Ⅱ)和 Au(Ⅲ)配合的紫外-可见分光光度性质。确立了最佳配合条件、配合物的摩尔吸光系数以及配合物的组成。     

Prospects for laser wakefield accelerators and colliders using CO2 laser drivers

Energy directly acquired by an electron from the laser electromagnetic field is quadratically proportional to the laser wavelength. Exploiting this feature, the emerging terawatt picosecond (TWps) CO₂ lasers, having an order of magnitude longer wavelength than the well-known table-top terawatt (T³) picosecond solid state lasers, offer new opportunities for strong-field physics research. Laser accelerators serve as an example where application of the new class of lasers will result in enhancement in gas ionization, plasma wave excitation, and relativistic self-focusing. Ponderomotively strong CO₂ laser permits a 100 times reduction in the plasma density without impeding the acceleration. The improved performance of the low-pressure laser wakefield accelerators (LWFA) is potentially due to higher electric charge per accelerated bunch and better monochromaticity. The multi-kilowatt average power, high repetition rate capability of the TWps-CO₂ laser technology opens new opportunities in development of compact, 1 m long, GeV accelerators and < 1 km long high-luminosity multi-stage LWFA colliders of the TeV scale. The first TWps-CO₂ laser is under construction at the BNL Accelerator Test Facility (ATF).     

Kinetics of absorption of carbon dioxide into aqueous solution of 2-(1-piperazinyl)-ethylamine

The absorption of CO₂ into aqueous solution of 2-(1-piperazinyl)-ethylamine (PZEA) were studied at 303, 313, and 323 K within the amine concentration range of 0.083-1.226 kmol m⁻³ using a wetted wall column absorber. The experimental results were used to interpret the kinetics of the reaction of CO₂ with PZEA within the amine concentration range of 0.150-1.226 kmol m⁻³ for the above mentioned temperature range. Based on the pseudo-first-order condition for the CO₂ absorption, the overall second order reaction rate constants were determined from the kinetic measurements. The reaction order was found to be in between 0.99 and 1.03 with respect to amine for the later mentioned concentration range. The kinetic rate parameters were calculated and presented at each experimental condition. The second-order rate constants k₂, were obtained as 31867.6, 56354.2, and 100946 m³ kmol^-1 s^-1 at 303, 313, and 323 K, respectively, with activation energy of 47.3 kJ mol⁻¹. This new amine in the field of acid gas removal can be used as an activator by mixing with other alkanolamine solvents due to its very high rate of reaction with CO₂.     

二氧化钛光催化技术在污水处理领域中应用

分析了TiO2光催化技术研究现状,探讨了光催化反应机制,讨论了影响TiO2光催化反应活性的主要因素:(1)贵金属沉积可以提高催化剂表面光生载流子的分离效率,有利于生成更多的·OH;(2)金属离子掺入TiO2晶格中可能引起晶格位置缺陷或改变结晶度,抑制了电子与空穴的复合,延长载流子的寿命,从而使光催化的性能得以改善;(3)半导体复合可以提高系统的电荷分离效果,扩大对光谱的吸收范围.阐述了TiO2光催化技术在处理有机及无机污染物领域中的应用.