THE PEBBLE HEATER—A NEW HEAT-TRANSFER APPARATUS*

This paper describes a new type of apparatus capable of use for heating gases above the operating temperatures permissible in metallic heat interchangers. The principle involved consists of heating refractory pellets by means of high-temperature gases and then passing a gas to be heated through a permeable bed of the heated pellets. Details of the refractory constructions are described and performance figures are given for some operating units. Some applications for the use of this pebble heater in the ceramic and metallurgical fields are also given     

Correlation aspects of the selective gas permeabilities of polymeric materials and membranes

Although the solubility and diffusivity of each gas in each polymer are temperature- and may be pressure-dependent properties of every system nevertheless regular trends are noted when either many gases are studied in a single polymer or a single gas is studied in many polymers. Several empirical though scientifically based correlations of such data have been proposed which are at best semi-quantitative. In this paper improved correlations are described to correlate data on diffusivities D and the related energies of activation, and solubilities S and related heats of solution of gases in polymers. The procedures rely on determining an effective Lennard-Jones force constant and molecular diameter for each gas, which parameters hold in all polymers above T_g and, with slightly smaller diameters for the multiatomic gases, in all polymers below T_g. Each polymer is characterized by four temperature-dependent parameters, two for diffusivity and two for solubility, which hold with all gases. Rules are given for determining these parameters. It is demonstrated that D is correlated to within ±20% and S to ±30%. The procedure described may be used to predict D and S, and hence permeabilities, in cases where data do not already exist. The values and ratios of the predicted permeabilities are a valuable guide when seeking polymers for separating gas mixtures by membrane processing.     

Evaluation of capital cost data: Drives

Capital cost correlations are given for electric and gasoline motors, steam, gas and combustion-gas driven turbines, power transmission units and power converters. Correlations available in the literature and current data are compared on a consistent basis. Thirty-eight graphs show the relative magnitudes of the different correlations and the recommended correlation for each type of equipment is summarized in a table.     

Solubility of supercritical gases in polymers—a review

Processing of polymers is greatly affected by the presence of dissolved gases. Analysis of the effect of dissolved gases requires two types of information: equilibrium thermodynamic data and predictive correlations as well as diffusion rate data and analyses. We review here the state-of-the-art knowledge of the equilibrium thermodynamics of gases dissolved in polymers. The published data are presented and analyzed. Also, we review the latcst theories and predictive correlations for gas solubility in polymers.     

COLD CLEAN ARTIFICIAL GAS AND A DISCUSSION UPON THE GENERAL PROPERTIES OF GASEOUS FUELS1

This paper ² 2 This paper is destined for ultimate use as one of the chapters in a treatise on the Glass Industry, by Prof. Alexander Silverman, University of Pittsburgh, to be published by The Chemical Catalog Company, Inc. Its presentation here is by the courtesy of The Chemical Catalog Co.
is written for the benefit of glass house people whose training has included no particular study of gas as a fuel. The ad vocation of some departure from the common practice, in the light of good and sufficient reasons, ought to be met in a receptive attitude. Warnings are given as to the acceptance of non-standard processes, and apparatus proposed by those of precarious financial backing and questionable familiarity with the technicalities of gas supply and application. There is a brief survey of the field to be covered, followed by a discussion which shows how various gases may be classified. There is a pronounced difference in quality between the various kinds of producer gas, and other standard gases. The heat content per unit volume of theoretically perfect air-gas mixture is shown to be approximately equal for all high grade gases. This value plus the reaction temperature form two important considerations in the comparison of gas fuels. The importance of high “thermal head” in relation to rapid heating, and the economies of rapid heat transfer are pointed out. The fitness of high grade gas fuel for attainment of highest efficiency is shown. Theoretical flue gas heat losses are given. A standard of 1.000.000 B.t.u. is proposed as a conversational basis for approximate comparison of gases as regards cost and volumes required. The merits of regeneration or recuperation are obvious for large scale, high temperature heating, but there are many reasons for adopting direct fire heating units for small operations. This emphasizes the value of high grade clean gas. The use of muffles in leers when clean sulphur-free gas is the fuel is ridiculous. The cost of a method forms the general determining factor in selection when results to be gained are equal. Technical schools ought to give more training on the subjects of fuels and combustion. Apparatus, methods, materials, yields, properties, and application of coal gas, water gas, mixed coal and water gas, and coke producer gas to the glass industry are discussed briefly and illustrations are given. A table of comparison of these gases is given and is followed by the demonstration of the method of obtaining the results given.     

Heating value of biomass and biomass pyrolysis products

Studies conducted on the heating value of various types of biomass components and their pyrolysis products such as char, liquids and gases are presented. Heating values of chars are comparable with those of lignite and coke; heating values of liquids are comparable with those of oxygenated fuels such as methanol and ethanol, which are much lower than those of petroleum fuels. Heating values of gases are comparable with those of producer gas or coal gas and are much lower than that of natural gas. It is also found that the heating values of products are functions of the initial composition of biomass; correlations are developed to express these. Also, correlations are developed which explain the influence of ash elements on heating values of the pyrolysis products and on percentage distribution of energy in the products.     

带压氧化尾气能量综合利用研究

提出环己酮装置氧化尾气能量综合利用方案 ,采用膨胀机使高压尾气膨胀到低压 ,从而回收能量 ;而气体膨胀作功的同时又可产生低温 ,通过新型特种翅片管换热器将尾气冷却 ,实现尾气中质量分数 0 .2 %左右的少量有机物的回收。初步计算 ,对于 3万t/a环己酮装置年经济效益达 30 6万元 ,投资回收期不足一年。该氧化尾气能量综合利用研究对于装置中存在带压气体放空、降压以及需要回收尾气中含量很低的有机物的工艺过程均有较大的参考价值     

Gas transport in ethylene-propylene-diene (EPDM) elastomer: Molecular simulation and experimental study

Time lag permeation measurements with ethylene-propylene-diene (EPDM) elastomer have been undertaken in an effort to characterize the gas transport properties of this barrier material. The derived solubility and diffusivity of a series of probe gases including helium, hydrogen, neon, argon, krypton, oxygen, nitrogen, carbon dioxide and methane were measured and compared with molecular simulation predictions. Molecular Dynamics (MD) and Grand Canonical Monte Carlo (GCMC) calculations were performed to provide estimates for diffusivity and solubility, respectively. Agreement between the molecular simulations and experimental data is obtained for simple spherical monatomic probe gases, with greater deviation observed for non-spherical polyatomic gases. Additionally, agreement between semi-empirical correlations based on the effective cross-sectional area of the diffusing species and the effective Lennard-Jones interaction constant of the sorbed species is better than widely used correlations based on gas critical properties. Furthermore, the molecular simulations provide a meaningful representation for the elastomer studied and additionally appear to capture the fundamental principles of sorption and diffusion of the chosen probe gases.     

Evaluation of capital cost data: Offsite utilities (Supply)

Capital cost correlations are given for units supplying utilities: steam, refrigeration, cooling and treated water, electricity. Correlations available in the literature and current data are compared on a consistent basis. Thirty-two graphs show the relative magnitudes of the different correlations, and the recommended correlation for each type of equipment is given. Some factors are given on the costs of installing the package units.     

Gas transport in ring substituted polyanilines

The gas transport properties of polymethoxyaniline (PMANi) and polyethoxyaniline (PEANi), in which the methoxy and ethoxy groups were introduced onto the benzene rings at the ortho position, were studied to determine the effect of substituents. Measurements were carried out at 40 psi from 25°C to 55°C. When compared with polyaniline, the gas permeability increases with the size of substituent because of the increases in the diffusivities while the selectivities remain the same or increase for some gas pairs. Excellent correlations were found between the diffusion coefficients and the molecular diameters of gases and between the solubility coefficients of gases and their boiling points (or critical temperatures).     

Installations for blowing metal by inert gases

Since the operational characteristics of Russian installations for blowing metal by an inert gas through plugs with a random porosity are outdated, the Shiber joint-stock company in cooperation with the Vnukovo plant of refractory products have developed a technology and organized a production of units for blowing metal with inert gases. The installations are delivered in a gas-tight cover of a stainless metal.     

Evaluation of capital cost data. part 7: Liquid waste disposal with emphasis on physical treatment

Capital cost correlations are given for oil-water separators, equalization basins, primary clarifiers, clarifiers and clarifier mechanisms, reverse osmosis unit, ultrafiltration units, gravity filters and miroscreens. Data are included for raw sewage, intermediate and recirculation pumping stations and for preliminary treatment (or bar screens, grit removal, overflow and bypass chamber and Parshall flume), for grit removal, comminution and gas stripping. The correlations are accurate to ± 30%, expressed in Canadian dollars and adjusted to a Marshall and Swift value of 1000. Details as to what components are included in the cost are given. Data are given for the labour and material costs to create a working process module. For inflation indices, a critique of the Engineering News Record, EPA small city, Marshall and Swift, Chemical Engineering and Southam inflation indices suggested that the Marshall and Swift index is most appropriate for the construction and process equipment studied here. Concerning the currency exchange, for the equipment and processes in this study, equipment costs the same whether expressed directly in US or Canadian dollars. To put the current data into perspective, several hundred sources of cost data were analyzed. The major correlations are compared, on a consistent basis, with current data.     

Recent Developments and Applications of Ionic Liquids in Gas Separation Membranes

Flue gas emissions and the harmful effects of these gases urge to separate and capture these unwanted gases. Ionic liquids due to negligible vapor pressure, thermal stability, and wide electrochemical stability have expanded its application in gas separations. A comprehensive overview of the recent developments and applications of ionic liquid membranes (ILMs) for gas separation is given. The three general classifications of ILMs, such as supported ionic liquid membranes (SILMs), ionic liquid polymeric membranes (ILPMs), and ionic liquid mixed‐matrix membranes (ILMMMs) along with their applications, for the separation of various mixed gases systems is discussed in detail. Furthermore, issues, challenges, computational study, and future perspectives for ILMs are also considered.     

Evaluation of capital cost data: Gas moving equipment

Capital cost correlations are given for gas moving equipment. Correlations available in the literature and current data are compared on a consistent basis. Forty-three graphs show the relative magnitude of the different correlations and the recommended correlation for each type of equipment is summarized in a table. Some data on the costs of installing gas moving equipment are given.     

Effectiveness of operation of sewerage system of mobile complex of thermocatalytic waste treatment

The design and functionality of basic units of a mobile waste processing complex of MPK type is described. Experimental data on the catalytic purification of gases are presented. It is determined that concentrations of toxic compounds in waste incineration flue gas of the MPK complex are much smaller than the values allowed by regulations for emissions.     

Natural gas viscosity estimation using density based models

Accurate value determination of natural gas viscosity plays a key role in its management as it is one of the most important parameters in natural gas engineering calculations. In this study, a comprehensive model is suggested for prediction of natural gas viscosity in a wide range of pressures, temperatures, densities and compositions. The new model can be applicable for gases containing heptane plus and non‐hydrocarbon components. It is validated by the 2011 viscosity data from 18 different gas mixtures. Compared to existing similar models and correlations, its results are quite satisfactory. © 2012 Canadian Society for Chemical Engineering     

Compressibility factor model of sweet,sour, and condensate gases using genetic programming

Gas compressibility factor (z-factor) is necessary in most petroleum engineering calculations. The most common sources of z-factor values are experimental measurements, equations of state (EOS) and empirical correlations. There are more than twenty correlations available with two variables for calculating the z-factor from fitting Standing–Katz chart values in an EOS or just through fitting techniques. However, these correlations are too complex, which require initial value and longer computations, and have significant error. This work presents a new model for estimating z-factors of sweet gases, sour gases and gas condensates using genetic programming (GP). The z-factor model was developed using pseudo-reduced pressure, and pseudo-reduced temperature. Moreover, two new models of pseudo-critical pressure and temperature were built as a function of the gas composition (mol percent of C₁–C₇₊, H₂S, CO₂, and N₂) and the specific gravity of the C₇₊. The developed new GP-based model yields a more accurate prediction of gas z-factor compared to the commonly used correlations and EOS's.     

Gas transport properties of polyaniline membranes

The transport properties of He, H₂, CO₂, O₂, N₂, and CH₄ gases in solvent cast, HCl doped, and undoped polyaniline (PANi) membranes were determined. Measurements were carried out at 40 psi pressure from 19°C to 60°C. An excellent correlation was found between the diffusion coefficients and the molecular diameters of gases. The solubility coefficients of gases were found to correlate with their boiling points or critical temperatures. The sepa-ration factors for CO₂/N₂ and CO₂/CH₄ are dominated by the high solubility of CO₂. These correlations enable us to predict the permeability, diffusion, and solubility coefficients of other gases. After the doping-undoping process, the fluxes of gases with kinetic diameters smaller than 3.5 Å increased but those of larger gases decreased. This results in a higher separation factor for a gas pair involving a small gas molecule and a larger one. © 1996 John Wiley & Sons, Inc.     

双气头多联产系统的Aspen Plus实现及工艺过程优化(Ⅰ) 模拟流程的建立及验证

通过流程模拟对煤基多联产系统进行过程优化是一种低成本、高效率的研究方法。通过稳态流程模拟软件Aspen Plus建立了二甲醚和电力为主要目标产品并副产甲醇的煤基多联产系统流程。采用气化煤气与焦炉煤气混合气作为气头,以达到利用焦炉煤气中高浓度甲烷、下一步工艺调整氢碳比并实现温室气体减排的目的。模拟流程中包括了空分、煤气化及净化、CH4/CO2重整、产品合成、燃气轮机联合循环发电等多联产系统中的5个主要工艺单元,涉及化学反应的CH4/CO2重整单元和二甲醚合成单元通过嵌入包含特定反应动力学参数的动力学子程序进行模拟。多联产系统综合考虑了化学反应的动力学和热力学,系统总体及各工艺单元物料、能量衡算一致,各个单元模拟数据与文献实验数据吻合。在建立流程的基础上,计算比较了热值加和效率与当量发电效率,发现考虑能量品质的当量发电效率更适合联产液体燃料和电能的多联产系统的评价。     

HYDRODYNAMICS OF SPOUTED BEDS AT ELEVATED TEMPERATURES

A review of the literature reveals little information on the hydrodynamics of spouted beds at high temperature. Most existing correlations are based upon experiments done at ambient conditions; they have not usually been tested with data at higher temperatures. The present study focussed on obtaining data over a temperature range of 20-420°C. Spouting of three sizes of Ottawa sand with preheated air was couducted in a 156 mm diameter stainless steel semi-cylindrical column with a 60° included angle half-conical base. A transparent wire-glass panel on the flat face allowed measurement of parameters which are otherwise difficult to obtain in a full stainless steel column. In addition to air, helium and methane at room conditions were used as spouting gases. With these two additional gases, it became possible to investigate the effect of changing gas density at constant viscosity and the effect of changing gas viscosity at constant gas density. In general, it was found that the range of stable spouting decreased with decreasing gas density and increasing gas viscosity, hence with increasing air temperature. Existing equations for various spouted bed parameters were tested and, where necessary, empirically modified to fit the new data obtained. @KEYWORDS Spouted bed hydrodynamics, High temperature gas spouting, Temperature effect on spoutability