BUBBLE TEMPERATURE MEASUREMENTS ON THE BINARY MIXTURES OF 1,4-DIMETHYLBENZENE WITH ISO-, SEC-, AND TERT- BUTANOLS AT 95 kPa

Bubble temperatures at 95 kPa over the entire composition range were measured for the three binary systems formed by 1,4-dimethylbenzene with iso-, sec-, and tert- butanols. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

BUBBLE TEMPERATURES OF THE BINARY MIXTURES OF 1,2-DIMETHYLBENZENE WITH 2-PROPANOL, 1-BUTANOL, 2-BUTANOL, 2-METHYLPROPAN-1-OL AND 2-METHYLPROPAN-2-OL AT 95 kPa

Bubble temperatures at 95?kPa over the entire composition range are measured for the five binary systems formed by 1,2-dimethylbenzene with 2-propanol, 1-butanol, 2-butanol, 2- methylpropan-1-ol, and 2-methylpropan- 2-ol. A Swietoslawski - type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

BUBBLE TEMPERATURES OF THE BINARY MIXTURES OF 1,2-DIMETHYLBENZENE WITH 2-PROPANOL, 1-BUTANOL, 2-BUTANOL, 2-METHYLPROPAN-1-OL AND 2-METHYLPROPAN-2-OL AT 95 kPa

Bubble temperatures at 95 kPa over the entire composition range are measured for the five binary systems formed by 1,2-dimethylbenzene with 2-propanol, 1-butanol, 2-butanol, 2- methylpropan-1-ol, and 2-methylpropan- 2-ol. A Swietoslawski - type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

EXCESS GIBBS ENERGY FOR THE BINARY MIXTURES OF NITROBENZENE WITH SOME HYDROCARBONS AT 94.95KPA

Bubble point temperatures at 94.95 kPa, over the entire composition range, are measured for the binary mixtures of nitrobenzene with: cyclohexane, n-hexane, n-heptane, n-decane, and o-, m-, and p-xylenes, using a Swietoslawski-type ebulliometer. Liquid phase composition versus bubble point temperature measurements are well represented by the Wilson model. Computed values of the excess Gibbs energy are presented and discussed.     

BOILING POINT TEMPERATURES OF THE BINARY MIXTURES OF 1,3-DIMETHYLBENZENE WITH METHANOL, 1-PROPANOL, OR 2-PROPANOLAT 95 kPA

Boiling point temperatures at 95 kPa over the entire composition range are measured for the three binary systems formed by 1,3-dimethylbenzene with methanol, 1-propanol, and 2-propanol. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

BUBBLE POINT MEASUREMENTS FOR TERNARY SYSTEMS CONTAINING NITROGEN AND METHANE WITH PROPANE, n-BUTANE, OR n-PENTANE

Bubble Point measurements were made for the following ternary systems: nitrogen-methane-propane, nitrogen-methane-normal butane, and nitrogen-methane-normal pentane. The temperature range was 122 to 205 K and the pressure range was 0.34 to 5.37 MPa. Bubble point pressures were reproducible to within ±0.007 MPa.     

THERMODYNAMIC PROPERTIES OF BINARY LIQUID MIXTURES OF ETHANE AND ETHYLENE WITH METHANE AND THE RARE GASES

Two series of binary liquid mixtures containing either ethylene or ethane have been investigated, at one or more temperatures (usually at the triple-point temperature of the component with the higher melting-point). In the ethylene series liquid-vapour equilibrium and liquid density studies were carried out for mixtures with methane, krypton and xenon; the heats of mixing were also measured for the ethylene + krypton mixtures. In the ethane series, which comprised mixtures with methane, argon, krypton and xenon, all three properties were measured except for the ethane + methane and ethane + argon systems where the enthalpies of mixing were already known. The ethylene + ethane system was also investigated at 161.39 K.

The results have been used to estimate the thermodynamic excess functions G^E , V^E and H^E . The G^E values decrease, within each series, as one moves from the lighter to the heavier rare gas, the values being lower in the ethane series. For the ethane + xenon mixtures both G^E and H^E are negative, showing a weak attraction between the two molecules. The V^E values for the mixtures of hydrocarbons suggest the probable formation of interlocking structures between the two components.

The values of the thermodynamic excess functions have been interpreted in the light of the model of Frisch-Longuet Higgins-Widom for the liquid state.     

碳化硅基复相陶瓷的高温氧化及其对强度的影晌

本文系统地研究了引入第二相非氧化物粒子TiC,TiB_2,ZrB_2和氧化物粒子Al_2O_3后SiC基复相陶瓷的氧化行为和规律,以及它对SiC基复相陶瓷强度的影响。实验结果发现,引入第二相非氧化物粒子后SiC基复相陶瓷的抗氧化性能大大降低,会在较低的温度下发生灾难性快速氧化,出现灾难性氧化的温度与引入的第二相非氧化物粒子的种类有关而与添加量无关,在出现灾难性氧化前的100～150℃,强度会发生大幅度下降现象;引入第二相氧化物粒子Al_2O_3的SiC基复相陶瓷,其抗氧化性不发生踢显变化,高温强度也不出现大幅度降低的现象;各种SiC基复相陶瓷的抗氧化能力次序为:SiC-Al_2O_3>SiC-TiC>SiC-TiB_2>SiC-ZrB_2。     

用鼓泡平衡釜测定高温汽液平衡数据及对总压测定的探讨

本文用改进了的鼓泡平衡釜测定了均三甲苯-偏三甲苯体系在411.4K、424.2K、437.0K三个温度下,以及甲苯-正丁醇体系在353.5K及373.2K二个温度下的汽液平衡数据,所得数据均通过热力学一致性检验,实验数据用Wilson方程进行了关联,两个二元体系的计算值与实验值的偏差|△Y|<0.005,△Ymax<0.01。文中还就鼓泡平衡釜总压确定问题进行了探讨。     

THE EFFECTS OF AIR TEMPERATURE,SPHERE DIAMETER AND PUFFING WITH C02 ON THE DRYING OF POTATO SPHERES

ABSTRACT

An experimental air dryer was used to investigate the effects of air temperature, sphere diameter and puffing with CO₂ on the drying of potato spheres. Accordingly, the experimental results showed only falling-rate behaviour and hence drying completely controlled by internal mass transfer was interpreted on the basis of Fick's diffusional model for non-steady state diffusion. Drying rate increased with increasing air temperature, and also increased with decreasing diameter of sphere. By considering the diffusion coefficients at different diameters, it was established that the drying occurred by a diffusion mechanism as opposed to a capillary mechanism. It was also found that CO₂ puffing had a positive effect on the drying rate.     

DENSITIES AND DERIVED THERMODYNAMIC PROPERTIES OF THE BINARY SYSTEMS OF BENZENE WITH BUTYL METHACRYLATE, ALLYL METHACRYLATE, METHACRYLIC ACID, AND VINYL ACETATE AT 298.15K

Densities of the binary systems of benzene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are positive for the four binaries studied.     

CaSO4氢气下还原分解的热重研究

在ＴＧ－１５１加压热天平上,对常压和加压氢气气氛下ＣａＳＯ４的分解反应进行了研究,并采用ＸＲＤ技术对不同反应条件下的产物进行分析测试,结果表明：在氢气还原气氛下升高温度和压力都导致ＣａＳＯ４还原分解速率快,ＣａＳＯ４分解产物主要是ＧａＳ;在１０００℃时ＣａＳＯ４和ＣａＳ之间可以发生固－固反应生成ＣａＯ。     

载荷、速度及环境温度对聚醚砜酮摩擦磨损性能的影响

利用MM—2000型和THT07—135型摩擦磨损试验机系统考察了载荷、滑动速度和环境温度对含二氮杂萘联苯型聚醚砜酮(PPESUK)摩擦磨损性能的影响，并利用扫描电子显微镜(SEM)观察分析了其磨损表面形貌及磨损机理。研究表明，干摩擦条件下，随载荷增加PPESUK的摩擦系数降低、磨损率增加；在高的滑动速度下，摩擦系数和磨损率都降低；环境温度对PPESUK的摩擦系数影响不大，并且粘着磨损是其主要磨损机理。     

活性炭上NO和SO2的常温吸附特性研究

通过吸附穿透曲线和吸附容量,考察了两种活性炭吸附剂在不同气氛条件下SO2和NO的常温吸附性能.结果表明,无氧条件下,活性炭对NO吸附能力较弱;有氧时,O2可促进NO在活性炭上的吸附转化;无氧条件下,活性炭吸附SO2的性能远远强于吸附NO;O2的存在均可提高两种活性炭对NO和SO2的吸附能力.预吸附NO形成的某些NOx物种可促进SO2吸附.SO2对NO的吸附有明显抑制作用.同时吸附时,SO2和NO不会单独占据同一活性中心,即SO2与NO可能有共同的吸附位,并形成新的吸附态中间产物.且比较两种活性炭的常温吸附性能,椰壳活性炭强于煤质活性炭.     

硅灰与ZrSiO4,SiC微粉中温结合机理的研究

本文研究了ＳｉＯ２微粉及其与ＺｒＳｉＯ４、ＳｉＣ微粉在３５０－１２００℃之间的显微结构，结果表明：ＳｉＯ２微粉所形成的风状锭合是它人具有高中温结合强度的原因。     

THE INFLUENCE OF DRYING MEDIUM,TEMPERATURE, AND TIME ON THE RELEASE OF MONOTERPENES DURING CONVECTIVE DRYING OF WOOD CHIPS

ABSTRACT

The release of volatile organic components (VOC) during the drying of wood chips was studied experimentally. The drying medium was hot dry air with a pressure of 1 bar and velocity of 1 m/s. Four different temperature levels of the drying medium, i.e., 120, 140, 160 and 180°C, and two different materials, Scots Pine and Norway Spruce, were investigated. It was found that the main components released consist of various types of monoterpenes, with α-pinene dominating in each of the two materials. The amount released is time-dependent, showing a maximum at shorter times. The release rate is more intensive at higher drying temperatures. The mass-balance for α-pinene was checked by comparing the amount present in the wood chip before and after drying with the amount obtained by integrating the release curve. A good agreement was obtained. Environmental Scanning Electron Microscope pictures were taken of both the spruce and pine chip in order to investigate differences in the wood structure before and after drying with air at 160°C. No obvious structural change could, however, be observed. The influence of the drying medium on the release rate of monoterpenes (air and superheated steam) was also studied. The results showed that the release rate was faster when drying with superheated steam.     

DEGRADATION OF AQUEOUS SOLUTIONS OF ALKANOLAMINE BLENDS AT HIGH TEMPERATURE, UNDER THE PRESENCE OF CO2 AND H2S

An experimental study on the degradation of aqueous solutions of alkanolamine blends, under the presence of carbon dioxide and hydrogen sulfide, was carried out. The studied alkanolamines were: diethanolamine (DEA), methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP). Degradation experiments were carried out at a temperature of 200°C. The mass fraction of DEA and MDEA in the studied aqueous solutions was 10% and 35%, respectively. AMP was incorporated into the MDEA-DEA aqueous solutions, with concentrations of (0-8) mass fraction. Partially degraded alkanolamine aqueous solutions were analyzed, after about 90 hours, by gas chromatography.

It was found that in all the studied alkanolamine aqueous solutions the MDEA degrades more slowly than DEA under the same experimental conditions. Degradation of both alkanolamines was found to be almost independent of the AMP concentration. AMP exhibits an intermediate stability; it is more resistant to degradation than DEA but less than MDEA. In addition, thermal degradation of DEA and MDEA is minimal up to 200°C.     

INFLUENCE OF THE PROCESSING TEMPERATURE AND OF THE COMPATIBILIZING AGENT ON THE RHEOLOGICAL BEHAVIOR OF HIGH DENSITY POLYETHYLENE-BASED COMPOSITES CHARGED WITH CALCIUM CARBONATE. II. THE ELASTIC COMPONENT

The paper discusses the results of some ample studies, devoted to the influence of processing temperature and of the amount of compatibilization agent on the elastic component of some high density polyethylene (HDPE)-based composites charged with calcium carbonate. Based on a calculation algorithm of their own, and starting from the output pressure from the rheological nozzle, determined experimentally, the authors realized the rheological characterization of the elastic component of HDPE melts charged with calcium carbonate.

It was demonstrated that the processing temperature influences considerably the elastic component of the analyzed compounds, while the application of a suitable processing temperature, combined with an optimum ratio of compatibilization agent led to the obtention of some thermoplastic composites evidencing the elastic behavior of some thermoplastic alloys.     

高温氧化预处理对B4C—SiC／C复合材料自愈合抗氧化性的影响

考察了未经和经过１２００℃,１ｈ氧化预处理的两种Ｂ４Ｃ－ＳｉＣ／Ｃ复合材料样品ＢＳ２０２０和ＢＳ１５３０在８００℃、１０００℃（干燥气）及１０００℃潮湿空气中的氧化行为。结果表明：经过１２００℃氧化预处理后,除了ＢＳ１５３０在８００℃（干燥空气）氧化过程的自愈合抗氧化性改善程度有限外,ＢＳ１５３０在１０００℃（干燥和潮湿空气）、ＢＳ２０２０在８００℃（干燥空气）和１０００℃（干燥和潮湿空气）氧化过     

ALTERNATIVE GENERATION OF H2, CO AND H2, CO2 MIXTURES FROM STEAM-CARBON DIOXIDE REFORMING OF METHANE AND THE WATER GAS SHIFT WITH PERMEABLE (MEMBRANE) REACTORS

A new process is proposed which converts CO₂ and CH₄ containing gas streams to synthesis gas, a mixture of CO and H₂ via the catalytic reaction scheme of steam-carbon dioxide reforming of methane or the respective one of only carbon dioxide reforming of methane, in permeable (membrane) reactors. The membrane reformer (permreactor) can be made by reactive or inert materials such as metal alloys, microporous ceramics, glasses and composites which all are hydrogen permselective. The rejected CO reacts with steam and converted catalytically to CO₂ and H₂ via the water gas shift in a consecutive permreactor made by similar to the reformer materials and alternatively by high glass transition temperature polymers. Both permreactors can recover H₂ in permeate by using metal membranes, and H₂ rich mixtures by using ceramic, glass and composite type permselective membranes. H₂ and CO₂ can be recovered simultaneously in water gas shift step after steam condensation by using organic polymer membranes. Product yields are increased through permreactor equilibrium shift and reaction separation process integration.

CO and H₂ can be combined in first step to be used for chemical synthesis or as fuel in power generation cycles. Mixtures of CO₂ and H₂ in second step can be used for synthesis as well (e.g., alternative methanol synthesis) and as direct feed in molten carbonate fuel cells. Pure H₂ from the above processes can be used also for synthesis or as fuel in power systems and fuel cells. The overall process can be considered environmentally benign because it offers an in-situ abatement of the greenhouse CO₂ and CH₄ gases and related hydrocarbon-CO₂ feedstocks (e.g., coal, landfill, natural, flue gases), through chemical reactions, to the upgraded calorific value synthesis gas and H₂, H₂ mixture products.