Economic comparison of pressure driven membrane processes to electrically driven processes for use in hydraulic fracturing

Hydraulic fracturing has become a reliable source for oil and natural gas, yet widespread use has led to significant issues with water consumption and sustainable sourcing. Research into the reuse of produced water and flowback water have focused on mitigating water demand in this industry through membrane separation technology. In general, nanofiltration and reverse osmosis have been thought to be more economically viable for the treatment of produced and flowback water at high flowrates. However, electrodialysis and electrodeionization are generally more flexible for production of produced water and brackish water for reuse in fracturing operations when contaminant concentrations in produced water and flowback water are low. Electrodialysis and electrodeionization can also significantly reduce wastewater produced from water treatment, decreasing the amount of water that must be disposed by deep well injection. Thus, there are many cases where electrically driven processes compete well with pressure driven processes due to high water recovery and each case must be analyzed in terms of water quality variability and overall desired water treatment rate. This paper finds that at low ion concentration of inlet water, electrodialysis and electrodeionization are energy-efficient, cost-effective attractive technologies for water recovery.     

Colloidal aspects of precipitation processes

In precipitation processes a chemical reaction produces a sparingly soluble product which starts to precipitate as a solid via nucleation and growth. As a rule, the newly precipitated primary particles are in the nanometer size range. The behaviour of colloidal particles in this size range is governed by interfacial forces. Therefore, in most case the final product particles are secondary particles, which are built by aggregation from the fine primary ones. The final product morphology results from the action of aggregation, rheological behaviour of the suspensions and the shear rates present in the precipitator. Precipitation technology is concerned with the design and operation of such precipitators. In this paper the relevance of fundamental kinetic, collidal and rheological phenomena on precipitation technology are reviewed and discussed.     

Kinetic aspects of dyeing processes

The dyeing of textiles was classified into two main categories: reactive and adsorptive dyeing. A mathematical model for each case was developed on the basis of a pore model concept. The validity of the proposed models was confirmed by comparison with existing experimental data on dyeing of reactive dyes in cellulose and acid dyes in nylon. It was further desired that the proposed models be checked by experimental results in high fixation regimes. The overdyeing phenomenon may be simulated by intrafiber diffusion with simultaneous multimodal adsorption.     

Novel membrane separation technologies and membrane processes

Membrane-based separation technologies have received increasing attention attributing to lots of advantages such as the low energy consumption,easy operation,an...     

Economic aspects of wood-burning installations

Economic data were obtained from 15 industrial wood burners. The capital cost was correlated by: Cost = $7870 (kW)^0.59. Operating cost varied between $ 0.64 and $ 2.65 per kWhr output, payback times between 3.5 and 11 years and internal rates of return between 6.3% and 28%. Using average values of economic parameters, these results were recalculated on a common basis as a function of wood and electricity costs.     

Chemical aspects of nuclear fuel fabrication processes

Processes used by British Nuclear Fuels plc for the conversion of uranium ore concentrates to uranium metal and uranium hexafluoride, are reviewed. Means of converting the latter compound, after enrichment, to sintered UO₂ fuel bodies are also described. An overview is given of the associated chemical engineering technology.     

Mechanical aspects of ceramic membrane materials

Interest in ceramic transport membrane materials has increased significantly leading also to questions with respect to mechanical reliability and robustness, hence, requiring knowledge of the mechanical properties. The current review focuses on the mechanical properties of such ceramics, emphasizing in particular relationships between mechanical properties, non-elastic effects, phase changes and materials’ stability. Room and elevated temperature application is considered with a main emphasis on elastic and creep deformation as well as fracture. Consideration is given to dense membranes as well as porous substrate materials for advanced asymmetric concepts. Properties are summarized for selected oxygen and proton conductors. Furthermore, mechanical properties of some selected porous ceramic and metallic substrate materials are given. In addition to the failure probability associated with the Weibull distribution of fracture stresses, creep rupture of dense materials and enhanced creep deformation of porous materials are aspects that need special consideration in the application of these materials in gas separation systems.     

膜法提溴过程的研究与对比

利用疏水性聚偏氟乙烯(PVDF)中空纤维膜及组件,对膜吸收法浓海水提溴过程进行了研究.首先考察了膜丝寿命,结果表明,浓海水浸泡123天后,膜的孔径和强度未变,透水压力未降低.将该膜应用于浓海水提溴过程,并比较了直接接触式膜吸收法(DCMA)、减压膜吸收法(VMA)和鼓气膜吸收法(ABMA)的提溴效果.实验结果表明,ABMA中溴脱出速率最快,且设备简单;DCMA操作方便,易于控制;VMA中溴的脱出最慢.因此,探讨了ABMA浓海水提溴系统中鼓气强度、吸收液浓度、吸收液温度、吸收液高度和吸收液附加鼓气等因素对工艺的影响.     

新型膜分离过程

介绍渗透汽化、膜萃取和充气膜过程等新发展的膜过程,简要说明它们的原理、研究现状、操作特点及其应用与发展前景。     

Modern aspects of quantum theory of charge-transfer processes

Recent results in quantum mechanical theory of the elementary act of charge-transfer processes are reviewed. They involve nonadiabatic and adiabatic reactions of electron, proton and atom group transfer. Effects of stochastic motion along the reaction coordinate and fluctuational preparation of the potential barrier are discussed.     

不同离子膜工艺流程的比较

介绍了离子膜制碱技术的基本流程,并简要比较了不同设计形式的使用情况。     

Recent membrane development for pervaporation processes

Pervaporation has been regarded as a promising separation technology in separating azeotropic mixtures, solutions with similar boiling points, thermally sensitive compounds, organic–organic mixtures as well as in removing dilute organics from aqueous solutions. As the pervaporation membrane is one of the crucial factors in determining the overall efficiency of the separation process, this article reviews the research and development (R&D) of polymeric pervaporation membranes from the perspective of membrane fabrication procedures and materials.     

Determination of membrane areas for ultrafiltration processes

For batch mode ultrafiltration processes a numerical method for calculating membrane area has been devised with flux predicted from Flemmer's model. Erythromycin broth filtrate was used as a model fluid. Experiments at a 20 dm³ scale were used to estimate the parameters involved in Flemmer's equation, from which membrane areas appropriate for operations of 80 metric tons were calculated. Factors such as rejection, concentration ratio, etc, which affect the membrane size for batch operation, are discussed. The calculated results were consistent with experimental data at the 100 dm³ scale. For continuous operation equations for calculating membrane areas have also been established. The minimum membrane area was calculated at the optimum concentration ratios of each stage, usually their values were different at each stages. Comparison between batch and continuous mode in the context of the membrane area required is also discussed. The method could be applicable to other ultrafiltration operations. © 2001 Society of Chemical Industry     

Dynamic behavior and operational aspects of heat-integrated distillation processes

Complex configurations of distillation columns have been shown to consume less energy than simple configurations. These complex configurations mainly results from two considerations: either a feed split, where the condensing vapor from the top of the high pressure column is used to heat the reboiler of the low pressure column, or the overheads from a high pressure column in a distillation train used to reboil a column under lower pressure. Industrial experience shows that very often in these configurations there is still incentive for more energy reduction simply because of inefficient control. The energy integration increases the control loop coupling the system, so that the operating strategy for the columns is no longer apparent. Therefore, the dynamic behaviour and the operational constraints of such systems become very important. The use of rigorous dynamic model of the processes is an essential instruments to pursue the goal of good and reliable process control Such models allow the engineer to realistically simulate the process with the desired control system in place and to analyze the effects of equipment sizing, hest integration, and disturbances. Variable pairing proved is used to illustrate that effective control of energy-integrated distillation columns can be achieved by proper selection of manipulated variables and pairing them correctly with control variables. Hints will also be given, when multivariable predictive control schemes should be used.     

Energetic aspects of turbulence promotion applied to electrolysis processes

This paper presents a simple and rational method for determining how much hydrodynamic factors influence the rate of production in electrochemical systems using turbulence promoters in various alternative flow conditions. Empirical and theoretical data correlations of limiting current densities (or mass transfer coefficients) and pressure drops are presented in unobstructed channels as well as for eddying flow induced by different types of eddy promoters. Based on the dimensional analysis and on the experimental results, it is shown that, within a given range of variations, all the promoters have an equivalent energetic effectiveness. However, when the conversion factor of the reacting species through the electrochemical reactor is near unity (complete transformation), this conclusion is no longer valid and the general methodology presented in this work shows that the rates of production present large differences depending on the system considered, the less sophisticated system (unobstructed channel) being the most effective.     

Approach from physicochemical aspects in membrane filtration

In membrane filtration, solution environment factors such as pH and solvent density are important in controlling the filtration rate and the rejection of the particles and/or the macromolecules. The filtration rate and the rejection in membrane filtration have been investigated from physicochemical aspects. It was shown that the properties of the filter cake formed on the membrane surface play a vital role in determining the filtration rate in mem-brane filtration. It was clearly demonstrated that such filtration behaviors as the filtration rate and the rejection are highly dependent on the electrical nature of the particles and/or the macromolecules. Furthermore, it was shown that the solvent density ρ has a large effect on the steady filtration rate in upward ultrafiltration.     

Study on polybenzoxazinone membrane in pervaporation processes

Poly(benz‐3,1‐oxazinone‐4) was prepared by thermal cyclization of its hydrolytically stable precursor polyamic acid. Both polymer and its precursor were investigated as membrane materials. Thermogravimetric analysis and contact angle measurements were carried out for characterization of peculiarity of membrane compositions and analysis of membrane surface. Pervaporation of water–isopropanol mixture was studied in the wide range of feed composition. To interpret the pervaporation transport properties of the membranes, swelling experiments were performed, kinetic curves of sorption and desorption were plotted, and basic sorption and diffusion parameters were analyzed. It was established that poly(benz‐3,1‐oxazinone‐4) membrane is extremely effective in dehydration of water–isopropanol mixture and shows high separation factor. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4024–4031, 2013     

Ion-Exchange membrane processes for clean industrial chemistry

New uses of artificial selective membranes, particularly ion-exchange membranes, improve on traditional methods of treating liquid mixtures before, during or after chemical or biochemical reactions. With the correct choice of ion-exchange membrane in a membrane reactor, reactions can be performed in such a way that the main product is not contaminated by undesired byproducts. Recent examples, mainly in organic chemistry, are given for eight typical ion-exchange membrane reactors: electrodialysis (ED), electrometathesis (EMT), electro-ion substitution (EIS), electro-ion injection-extraction (EIIE), coupled counter-transport (CCT), electro-electrodialysis (EED), electrohydrolysis with bipolar membranes (EHBM), and catalysis with ion-exchange membrane (IEMC).