微等离子体转化二氧化碳发射光谱诊断

火星大气层的主要成分为二氧化碳,如果能够利用低温等离子体方法高效分解二氧化碳,使其转化为氧气和一氧化碳加以利用,可以大幅降低航天员生命保障相关载荷长途运输的成本,进一步提高生命保障能力。低温等离子体放电过程中会产生大量活性组分,可以在数百度温度下实现二氧化碳的高效解离,是具有很大潜力的二氧化碳解离与转化方式。设计了一种尺度在亚毫米级、功率输入为数瓦的直流微槽等离子体反应器,可以在较低气体温度下实现二氧化碳分解。测量了反应器电流、功率等放电参数,采用发射光谱确定了体系中激发态组分,分析了激发态粒子谱线强度随输入电压、稀释气体比例等反应器工作参数变化,利用氮气分子振转谱带测量了等离子体放电区振动温度和气体温度。研究表明,添加氩、氦、氮气均可以增强二氧化碳的分解,添加氦气可以促进二氧化碳的电离过程。稀释气体激发态因具有高能量,可以通过潘宁解离通道增强二氧化碳分解。氦组分激发态的能量高于二氧化碳电离能,可以促进二氧化碳的电离反应。微等离子体内存在强烈的振动-平动非平衡现象:振动温度约为4400~4800 K,而气体温度仅为450~600 K,表明可以通过合理的放电和结构设计,定向将能量注入到振动态,从而进一步促进二氧化碳的振动解离。

铁酸镍用于热化学循环反应CO_2分解制CO的研究

采用共沉淀法制备了NiFe2O4和NiFe2O4/ZrO2催化剂,用TGA考察了其热化学法,CO2高温分解反应性能。通过对反应前后催化剂的表征发现,反应高温使两种催化剂都发生了明显的烧结,导致在热还原反应中形成的还原态氧化物不能完全被CO2氧化从而降低了催化剂的反应性能;ZrO2的加入对于提高催化剂的热稳定性以及循环反应稳定性具有重要的作用。在高温反应炉中考察了NiFe2O4/ZrO2的CO2分解实验,结果表明,提高热还原温度可以提高CO产量,然而,随着循环次数的增加CO的产量降低得更明显。

CO_(2)/Ar气液相等离子体处理盐酸四环素的研究

研究采用温室气体、氩气(CO_(2)/Ar)作为载气,产生气液相等离子体处理水中的盐酸四环素。研究了CO_(2)/Ar气液相等离子体CO_(2)分解、活性物质产生(如O、·OH、^(1)O_(2)、H_(2)O_(2)、O_(3))及不同参数条件下对盐酸四环素的降解机理。气相方面考察了CO_(2)/Ar比例、气体流量对CO_(2)转化的影响;液相方面考察了CO_(2)/Ar比例、不同初始浓度、气体流量及初始pH对盐酸四环素降解的影响。结合光谱诊断、液相活性物质表征、相关淬灭剂,分析了不同活性物质的产生规律及对盐酸四环素降解的影响。最后检测了降解过程产生的中间产物,提出了本体系盐酸四环素降解原理及可能的降解途径。为CO_(2)利用以及水污染治理提供一个新的思路。

焦油车间生产现场尾气治理

针对生产现场实际情况,分析焦油生产现场尾气来源,进行尾气治理。

Measurement and Correlation of Solubilities of C.I. Disperse Red 73,C.I. Disperse Blue 183 and Their Mixture in Supercritical Carbon Dioxide

The solubility of disperse dyes and their mixture in supercritical carbon dioxide is an important property in study and development of supercritical fluid dyeing technology.In this study,solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183 and their mixture in supercritical CO2 are measured at temperatures from 343.2 to 383.2 K and pressures from 12 to 28 MPa with a static recirculation method.Under the experimental conditions for the binary(C.I.Disperse Red 73+CO2 or C.I.Disperse Blue 183+CO2) and ternary(C.I.Disperse Red 73+C.I.Disperse Blue 183+CO2) systems,the solubilities increase with pressure.The solubility of C.I.Disperse Blue 183 decreases with the increase of temperature when the pressure is lower than 16 MPa,and the trend is opposite when the pressure is higher than 16 MPa.However,there is no crossover pressure for C.I.Disperse Red 73.The solubilities are also affected by molecular polarity of dyes.The co-solvent effect exhibited in the dissolving process of mixed dyes promotes their dissolution in supercritical CO2.The experimental data of solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183,and their mixture are correlated with the Chrastil model and Mendez-Santiago/Teja model. The former is more accurate.

Decomposition of Cellulose to Produce 5-Hydroxymethyl-Furaldehyde in Subcritical Water

A method for decomposition of cellulose to produce 5-hydroxymethyl-furaldehyde （5- HMF） in subcritical water-carbon dioxide binary system was proposed. A series of experiments were performed in a batch reaction vessel. Main products of the decomposition of cellulose are 5-HMF, furfural, levulinic acid and 1, 2, 4-benzenetrioI.The optimum condition for the preparation of 5-HMF was found as 523.15 K, 5.0% carbon dioxide mole fraction, and 30 min reaction time. The addition of carbon dioxide to water conduced to the decomposition of cellulose to 5-HMF. As can be seen from the distribution of the prod-ucts, the decomposition mechanism of cellulose is similar to the hydrothermal reaction of D-glucose and D-fructose.

Recent advances and perspectives in cobalt‐based heterogeneous catalysts for photocatalytic water splitting,CO_(2) reduction,and N_(2) fixation

Solar‐driven conversion of carbon dioxide,water and nitrogen into high value‐added fuels(e.g.H_(2),CO,CH_(4),CH_(3)OH,NH_(3) and so on)is regarded as an environmental‐friendly and ideal route for relieving the greenhouse gas effect and countering energy crisis,which is an attractive and challenging topic.Hence,various types of photocatalysts have been developed successively to meet the requirements of these photocatalysis.Among them,cobalt‐based heterogeneous catalysts emerge as one of the most promising photocatalysts that open up alluring vistas in the field of solar‐to‐fuels conversion,which can effectively enhance photocatalytic efficiency by extending light absorption range,promoting charge separation,providing active sites,and lowering reaction barrier.In this review,we first present the working principles of cobalt‐based heterogeneous catalysts for photocatalytic water splitting,CO_(2) reduction,and N_(2) fixation.Second,five efficient strategies including surface modification,morphology modulation,crystallinity controlling,crystal engineering and doping,are discussed for improving the photocatalytic performance with different types cobalt‐based catalysts(cobalt nanoparticles and single atom,oxides,sulfides,phosphides,MOFs,COFs,LDHs,carbide,and nitrides).Third,we outline the applications for the state‐of‐the‐art photocatalytic CO_(2) reduction and water splitting,and nitrogen fixation over cobalt‐based heterogeneous catalysts.Finally,the central challenges and possible improvements of cobalt‐based photocatalysis in the future are presented.The purpose of this review is to summarize the past experience and lessons,and provide reference for the further development of cobalt‐based photocatalysis technology.

Solubility prediction of disperse dyes in supercritical carbon dioxide and ethanol as co-solvent using neural network

Nowadays artificial neural networkS （ANNs） with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility predic- tion of three disperse dyes in supercritical carbon dioxide （SC-C02） and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-C02. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash-Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.

Decomposition of Energy-related CO_2 Emissions from Shanghai's Industries and Policy Implications

This paper quantifies a decomposition analysis of energy-related CO2 emissions in the industrial sectors of Shanghai over the period 1994-2007.The Log-Mean Divisia Index(LMDI) method is applied to this study in terms of six factors:labor force,labor mobility,gross labor productivity,energy intensity,fuel mix,and emission coefficient.In addition,the decoupling effect between industrial economic growth and CO2 emissions is analyzed to evaluate CO2 mitigation strategies for Shanghai.The results show that all labor productivity has the largest positive effect on CO2 emission changes in the industrial sectors,whereas labor mobility and energy intensity are the main components for decreasing CO2 emissions.Other factors have different effects on CO2 mitigation in different sub-periods.Although a relative decoupling of industrial CO2 emissions from the economic growth in Shanghai has been found,Shanghai should keep pace with the industrial CO2 emissions reduction by implementing low-carbon technology.These results have important policy implications:Plan C is the reasonable choice for Shanghai.

In-situ observation for formation and dissociation of carbon dioxide hydrate in porous media by magnetic resonance imaging

The study of formation and dissociation of CO 2 hydrate in porous media was characterized by magnetic resonance imaging (MRI) system in in situ conditions. This work simulated porous media by using glass beads of uniform size. The growth and dissociation habit of CO2 hydrate was observed under different temperature and pressure conditions. The induction time and the hydrate saturation during the growth and dissociation process in different sizes of porous media were obtained by using the MRI signal intensity. The results indicate that hydrate growth rate and the induction time are affected by the size of porous media, pressure, and degree of supercooling. There are three hydrate growth stages, i.e., initial growth stage, rapid growth stage and steady stage. In this study,the CO2 hydrate forms preferentially at the surface of vessel and then gradually grows inward. The hydrate tends to cement the glass beads together and occupies the pore gradually. As the hydrate decomposes gradually, the dissociation rate increases to the maximum and then decreases to zero.