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1.
铜基脱硫剂的TPS研究   总被引:1,自引:0,他引:1  
煤气化联合循环发电(IGCC)技术由于具有较高的热效率和良好的环保效果而得到迅速的发展,IGCC技术的利用成为二十一世纪的必然趋势,作为整体技术主要组成部分之一的热煤气净化技术也越来越得到重视.美国能源部为此投入了大量的资金,资助摩根城能源中心、麻省理工学院等从事  相似文献   

2.
Intermolecular potential energy curves for the hydrogen bonded systems H2O·H2S, H2O·H2Se and H2S·H2S were calculated with nonempirical pseudopotentials using optimized-in-molecules basis sets augmented by polarization functions. The H2O·H2O interaction energy curve has been also considered as a test case. The present results for H2O·H2S and H2S·H2S indicate much weaker intermolecular interactions than those found in previous ab initio calculations. The H2O·H2Se interaction was found to be quite similar to H2O·H2S.This work was partly supported by the Polish Academy of Sciences within the Project PAN-09, 7.1.1.1On leave from Quantum Chemistry Laboratory, Dept. of Chemistry, University of Warsaw, Pasteura 1, 02-093. Warsaw, Poland  相似文献   

3.
B3LYP calculations of density functional theory with the 6-311 + G(3df,2p)basis set level are used to investigate the equilibrium structures and intramolecular rearrangement reaction between the linear HSSH and branched H2SS isomers. The predicted geometrical parameters and scaled harmonic vibrational frequencies for HSSH are in good agreement with the available values experimentally. The predicted S-S and S-H bond lengths in the thiosulfoxide structure H2SS are 0.1986 and 0.1366 nm respectively and the values of 5SSH and 5HSH bond angles are 108. 3o and 89. 5o respectively. The transition-state for the unimolecular isomerization is suitably characterized by diagonalizing the matrix of energy second derivatives to determine the unique imaginary vibrational frequency and confirmed by the IRC calculation. The calculated results show that the linear structure is stable with respect to the branched form(lower 109.8 kJ/mol corrected with zero point vibrational energy)energetically. The calculated energy barrier for the direct intramolecular hydrogen atom transfer isomerization process is 190.3 kJ/mol. The kinetic results demonstrate that the isomerization is a unimolecular process,but the reaction rate is pretty slow. This agrees with the thermodynamical results. So the isomerization process should proceed via the other likely processes.  相似文献   

4.
Natural gas demand has dramatically increased due to the emerging growth of the world economy and industry. Presently, CO2 and H2S content in gas fields accounts for up to 90% and 15%, respectively. Apart from fulfilling the market demand, CO2 and H2S removal from natural gas is critical due to their corrosive natures, the low heating value of natural gas and the greenhouse gas effect. To date, several gas fields have remained unexplored due to limited technologies to monetize the highly sour natural gas. A variety of conventional technologies have been implemented to purify natural gas such as absorption, adsorption and membrane and cryogenic separation. The application of these technologies in natural gas upgrading are also presented. Among these commercial technologies, cryogenic technology has advanced rapidly in gas separation and proven ideally suitable for bulk CO2 removal due to its independence from absorbents or adsorbents, which require a larger footprint, weight and energy. Present work comprehensively reviews the mechanisms and potential of the advanced nonconventional cryogenic separation technologies for processing of natural gas streams with high CO2 and H2S content. Moreover, the prospects of emerging cryogenic technologies for future commercialization exploitation are highlighted.  相似文献   

5.
The microkinetics os H2S removeal by ZnO desulfurization in H2O-CO2-N2,H2O-CO-N2 and H2O-O2-N2 gas mixtures was studied by thermogravimetric andlysis.Experiments were carried out with 100-120 mesh ZnO powder at temperatures from 473K to 563K.The results show that the kinetic behaviors of desulfurization could all be described by an improved shrinking-core model.The activation energies of the reaction and the diffusion in different gas atmospheres were estimated.  相似文献   

6.
Removal of H2S from Exhaust Gas by Use of Alkaline Activated Carbon   总被引:2,自引:0,他引:2  
The purpose of this research was to select an activated carbon and alkaline solution blend that generated the best H2S adsorption on alkaline-activated carbon. RB2 (activated carbon) impregnated with NaOH solution was shown to have the optimum H2S removal efficiency. The optimum NaOH concentration was 50 mg per gram of carbon. H2S adsorption via RB2-NaOH50 was five times that of a corresponding fresh-activated carbon. The adsorption equivalent of H2S is nearly 1 (mol-H2S/mol-AOH), therefore, H2S + AOH AHS + H2O was the major reaction. The H2S adsorption isotherm corresponded to the Freundlich isotherm.  相似文献   

7.
南玉明  徐吉庆 《分子催化》1996,10(6):461-464
钼铁钴硫簇合物催化乙炔还原性质的研究①南玉明②(大庆石油学院石化系,安达151400)徐吉庆蔡辉(吉林大学化学系,长春130023)关键词簇合物类立方烷结构催化电化学性质在化学模拟生物固氮研究的推动下,人们已合成了上百种Mo-Fe-S簇合物,并研究了...  相似文献   

8.
Treatment of H2S and NH3 using the non-thermal plasma (NTP) methods was investigated. Two NTP systems were used in this study, one consisting of a multi-cell plate-to-wire reactor (PTW), and the other consisting of an ozonization chamber and the multi-cell PTW reactor. Each cell of the PTW reactor had a sheet of copper foil embedded in dielectric layers as its high voltage electrode and a wired rack as its gounded electrode. Use of the wired rack type electrode allowed large flow throughput, and promoted intense local electric fields. The experiments showed that under constant energy input, the decomposition efficiency of H2S or NH3 decreased with increasing initial concentration of the gas, and increased with increasing injected ozone and relative humidity. Injection of NH3 into H2S stream did not improve the H2S decomposition efficiency but was necessary for removal of sulfite-containing compounds in the discharge air.  相似文献   

9.
Swamps and tidal flats are believed to he important natural sources of atmospheric H2S, though it is very difficult to detect the low concentrations of this trace gas above the surface of these regions. In view of this problem an air sampling device has been developed for the sampling of atmospheric H2S with chemically impregnated filters. The sulfide generated on the filter is analyzed in a washing solution employing a very sensitive fluorescence method. The quality of the method is demonstrated by comparative calibrations. The fluorescence method is calibrated in the liquid phase with standard solutions of sulfide. Furthermore the sampling and analyzing method is calibrated together by using H2S calibration gases. The detection limit of the method is shown to he 10ng/m3 STP. Data of test-measurements in ambient air and some results of field-measurements in the lower troposphere are presented.  相似文献   

10.
用沉积沉淀法制备了Au-CuO/TiO2催化剂和Au/TiO2催化剂,考察了沉淀温度、沉淀pH、焙烧温度和Cu/Au摩尔比等制备工艺条件对Au-CuO/TiO2催化剂性能的影响,确定了适宜的催化剂制备工艺条件.结果表明,Au-CuO/TiO2催化剂对CO2中微量H2的脱除具有较好的活性和稳定性.还考察了还原和H2S中毒处理先后的顺序对催化剂H2脱除活性的影响.结果表明,Au/TiO2催化剂基本上不受处理顺序的影响,而H2S处理顺序对Au-CuO/TiO2催化剂的性能有较为明显的影响,这说明还原后的Au-CuO/TiO2催化剂形成了Au-Cu合金。  相似文献   

11.
范方禄  靖金球  陈雪梅 《有机化学》2014,(10):2178-2183
以叠氮基为识别基团,合成和表征了一种苯并噻唑类荧光增强型硫化氢探针(FL),并研究了它的光谱性质.实验结果表明,FL对硫化氢有较高的选择性和灵敏度,且响应快速,抗干扰能力强,细胞毒性低,它的检出限度为8.78×10-7 mol·L-1,在He La活细胞和各种水体样品中对硫化氢的检测表明FL具有潜在的应用价值.  相似文献   

12.
The urgency to address global climate change induced by greenhouse gas emissions is increasing. In particular, the rise in atmospheric CO2 levels is generating alarm. Technologies to remove CO2 from ambient air, or “direct air capture” (DAC), have recently demonstrated that they can contribute to “negative carbon emission.” Recent advances in surface chemistry and material synthesis have resulted in new generations of CO2 sorbents, which may drive the future of DAC and its large‐scale deployment. This Review describes major types of sorbents designed to capture CO2 from ambient air and they are categorized by the sorption mechanism: physisorption, chemisorption, and moisture‐swing sorption.  相似文献   

13.
The study of the reactions of water and hydrogen sulfide with palladium and platinum cations has been completed in this work, in both low‐ and high‐spin states. Our calculations predict that only the formation of platinum sulfide is exothermic (in both spin states), whereas for the remaining species the oxides and sulfides are found to be more reactive than their corresponding bare metal cations. An in‐depth analysis of the reaction paths leading to metal oxide and sulfide species is given, including various minima, and several important transition states. All results have been compared with existing experimental and theoretical data, and earlier works covering the reaction of nickel cation with water and hydrogen sulfide to observe the trends for the group 10 transition metals.  相似文献   

14.
就工业气休中有害物质H2S的综合利用开发进行了有益的探索,采用MTsPc(M=Fe,Co,Ni,Cu)做催化剂,水做溶剂,研究了催化剂物种及浓度、碱浓度反应温度对H2S还原硝基苯制备苯胺反应性能的影响。结果表明,在诸多催化剂中双核磺化酞菁钴(CoPc-PcCo)催化活性最高,且得到最佳反应条件为:氨水浓度0.6mol/L,反应温度40℃,催化剂质量浓度1g/L,在此条件下苯胺的产率达35.9%,表明在传统的脱硫工艺上加以技术改造不仅是可行的,而且是有效的。  相似文献   

15.
Catalysts using α-FeOOH nanoparticles as the active ingredient were tested by a microreactorchromatography assessing apparatus at atmospheric pressure between 25 and 60℃ with a gas hourly space velocity of 10,000h^-1,while the removal performance of H2S with catalysts was investigated using the thermal gravimetric method.The results show that the catalysts are highly active for COS hydrolysis at low temperatures(≤℃)and high gas hourly space velocity,and the highest activity can reach 100%.The catalyst is particularly stable for 12h,and no deactivation is observed.Nanoparticle α-FeOOH prepared using hydrated iron sulfate shows higher COS hydrolysis activity,and the optimum calcination temperature for the catalyst is 260℃.In addition,the catalysts can remove COS and H2S simultaneously,and 60℃ is favorable for the removal of H2S.The compensation effect exists in nanoparticle-based catalysts.  相似文献   

16.
In this study, straetlingite-based sorbents were used for NH4+ ion removal from a synthetic aqueous solution and from the wastewater of an open recirculation African catfish farming system. This study was performed using column experiments with four different filtration rates (2, 5, 10, and 15 mL/min). It was determined that breakthrough points and sorption capacity could be affected by several parameters such as flow rate and mineral composition of sorption materials. In the synthetic aqueous solution, NH4+ removal reached the highest sorption capacity, i.e., 0.341 mg/g with the S30 sorbent at a filtration rate of 10 mL/min and an initial concentration of 10 mg/L of NH4+ ions. It is important to emphasize that, in this case, the Ce/C0 ratio of 0.9 was not reached after 420 min of sorption. It was also determined that the NH4+ sorption capacity was influenced by phosphorus. In the wastewater, the NH4+ sorption capacity was almost seven times lower than that in the synthetic aqueous solution. However, it should be highlighted that the P sorption capacity reached 0.512 mg/g. According to these results, it can be concluded that straetlingite-based sorbents can be used for NH4+ ion removal from a synthetic aqueous solution, as well as for both NH4+ and P removal from industrial wastewater. In the wastewater, a significantly higher sorption capacity of the investigated sorbents was detected for P than for NH4+.  相似文献   

17.
The fragmentation dynamics of core-excited H(2)S has been studied by means of partial anion and cation yield measurements around the S L(2,3)-subshell ionization thresholds. All detectable ionic fragments are reported, and significant differences between partial ion yields are observed. Possible dissociation pathways are discussed by comparison to previous studies of electron spectra.  相似文献   

18.
Based on 4-bromo-1,8-naphthalic anhydride, one novel ratiometric fluorescence H2S-probe (IDNA) was designed and synthesized. Further studies indicate that IDNA can sensitively recognize H2S (detection limit of 7 μmol/L) with good selectivity and anti-interference ability. In addition, IDNA has satisfactory photostability in HeLa cells, ability of mitochondrial co-localization, and can be utilized in fluorescence imaging of H2S.  相似文献   

19.
Sulfide species may be present in groundwater due to natural processes or due to anthropogenic activity. H2S contamination poses odor nuisance and may also lead to adverse health effects. Advanced oxidation processes (AOPs) are considered promising treatments for hydrogen-sulfide removal from water, but conventional AOPs usually require continuous chemical dosing, as well as post-treatment, when solid catalysts are applied. Vacuum-UV (VUV) radiation can generate ·OH in situ via water photolysis, initiating chemical-free AOP. The present study investigated the applicability of VUV-based AOP for removal of H2S both in synthetic solutions and in real groundwater, comparing combined UV-C/VUV and UV-C only radiation in a continuous-flow reactor. In deionized water, H2S degradation was much faster under the combined radiation, dominated by indirect photolysis, and indicated the formation of sulfite intermediates that convert to sulfate at high radiation doses. Sulfide was efficiently removed from natural groundwater by the two examined lamps, with no clear preference between them. However, in anoxic conditions, common in sulfide-containing groundwater, a small advantage for the combined lamp was observed. These results demonstrate the potential of utilizing VUV-based AOP for treating H2S contamination in groundwater as a chemical-free treatment, which can be especially attractive to remote small treatment facilities.  相似文献   

20.
In-depth understanding of the mechanisms of hydrogen sulfide (H2S) adsorption on catalysts during desulfurization from industrial waste gas streams is important for developing effective catalysts to be used in the decomposition of H2S. In this work, the dissociation behavior of H2S adsorbed on a single-atom catalyst (Ti or V-decorated Ti2CO2 surface) was investigated by performing density functional theory (DFT) calculations. The corresponding diffusion behavior revealed that Ti or V atoms could be dispersed on the Ti2CO2 monolayer, without aggregation in the form of single atoms. In addition, analyses of the partial density of states (PDOS), Hirshfeld charges, and electron density difference indicated that the decorated Ti or V atoms led to charge redistribution on the Ti2CO2 surface and significantly improved the interaction between the H2S gas molecules and Ti2CO2, thereby enhancing the catalytic activity of V/Ti2CO2. In order to gain a deeper understanding of the mechanism of H2S decomposition (H2S → HS* + H* → H2 + S*), a comparative analysis of the results for the decomposition of H2S on the Ti/Ti2CO2 and V/Ti2CO2 surfaces was carried out. The catalytic dissociation behavior of H2S is explained as follows: once H2S is adsorbed on the V/Ti2CO2 or Ti/Ti2CO2 surface, it spontaneously dissociates into HS*/H* without any energy barrier on the catalyst surface. Subsequently, the V atoms would not only promote the cleavage of the H-S bond, but also play a major role in the formation of S atoms. Moreover, the rate-limiting step for the entire process proceeded on the Ti/Ti2CO2 surface with an energy barrier of 0.86 eV, while that for V/Ti2CO2 was 0.28 eV, indicating that the H2S molecules easily dissociated into S and H2 on the V/Ti2CO2 surface at room temperature. The reaction time for H2S decomposition on the V/Ti2CO2 surface at 500 K was 65.79 ns, which was almost two orders of magnitude higher than that at room temperature. Thus, the decomposition of H2S on the V-doped Ti2CO2 surface is associated very fast kinetics. Furthermore, the S atoms can form elemental sulfur with aggregation on the V/Ti2CO2 surface to promote recycling reactions. Compared with previously reported catalytic systems, the single-atom catalyst (SAC) V/Ti2CO2 catalyst has greater application prospects in terms of sustainable economy or removal efficiency for H2S treatment. Our results suggest that V-doped Ti2CO2 is an excellent candidate for a highly effective non-noble metal catalyst applicable to H2S decomposition.   相似文献   

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