Dehydration Technology Research Articles

Technology of Deep Dehydration of Excess Active Sludge Based on the Use of the Effect of Elastic Vibrations

Methodological approaches to the development of technology of deep dehydration of wastewater precipitates and excess active sludge are presented. It is established that the effect of ultrasound positively affects the physical properties of cellulose materials, and the moisture percentage in the initial material is reduced. The ultrasonic effect is also widely used in adjacent branches of science and technology to intensify the separation of emulsion solutions. Main regularities of the influence of the degree of dehydration and neutralization of waste from municipal treatment facilities on time and intensity of the effect of elastic vibrations emitted by means of ultrasonic dispenser are investigated. The technology of deep dehydration of the mixture of wastewater precipitate and excess active sludge, which is implemented by means of modernizing the standard dehydration scheme of waste existing at the most of enterprises of the municipal complex, is proposed.

Deformation and breakup of aqueous drops in viscous oil under a uniform AC electric field

Electric coalescence in alternating current (AC) electric fields is an important electrical dehydration technology. The deformation and breakup of water drops are crucial to the application of this process. In this study, these procedures were examined experimentally in an AC electric field using a high-speed camera. The deformation and breakup of drops depend on the intensity and frequency of this field. Deformation is aggravated by the increase in frequency under a constant electric field strength. Furthermore, the electric strength of breakup weakens as the frequency increases. Thus, understanding the deformation process can help advance electrocoalescencer design.

Evaluation of the environmental performance of alternatives for polystyrene production in Brazil

The global demand for polystyrene is supposed to reach an overall baseline of 23.5milliontons by 2020. The market has experienced the effects of such growth, especially regarding the environmental performance of the production processes. In Brazil, renewable assets have been used to overcome the adverse consequences of this expansion. This study evaluates this issue for the production of Brazilian polystyrene resins, general-purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). The effects of replacing fossil ethylene with a biobased alternative are also investigated. Life Cycle Assessment is applied for ten scenarios, with different technological approaches for renewable ethylene production and an alternative for obtaining bioethanol, which considers the export of electricity. The fossil GPPS and HIPS show a better performance than the partially renewable sources in terms of Climate Change (CC), Terrestrial Acidification (TA), Photochemical Oxidant Formation (POF), and Water Depletion (WD). The exception is Fossil Depletion (FD), a somewhat predictable result. The main environmental loads associated with the renewable options are related to the sugarcane production. Polybutadiene fails to provide greater additional impact to HIPS when compared to GPPS. With regard to obtaining ethylene from ethanol, Adiabatic Dehydration (AD) technology consumes less sugarcane than Adiabatic Dehydration at High Pressure (ADHP), which leads to gains in TA and POF. In contrast, ADHP was more eco-friendly for WD because of its lower water losses and in terms of CC because of the advantageous balance of fossil CO2eq at the agricultural stage and the lower consumption of natural gas in ethylene production. The electricity export is an auspicious environmental opportunity because it can counterbalance some of the negative impacts associated with the renewable route. According to a “cradle-to-grave” perspective, the partially renewable resins show a more favorable balance of carbon. This difference increases when sequestration and biogenic carbon emissions are considered.

Research on Screw-Extrusion Dehydration Technology and Equipment in Recycling Process of Urban Garbage

As new and efficient dehydration technology and equipment needs to be applied to the recycling of Chinese urban garbage urgently, this study discusses the differences and similarities between spiral-extrusion and screw-extrusion physical model on dehydration technology. Based on the research on screw-extrusion dehydration technology, the factors that affect dehydration production volume and efficiency of urban garbage’s recycling have been analyzed. Using screw-extrusion theoretical model, the paper further discusses the influence of some parameters such as operation factors, geometric structure and urban garbage’s material performance. Finally, experiment research is made to examine the screw-extrusion theoretical model. The results show that appropriate screw speed can balance the production volume and dehydration efficiency. The main factors of geometric parameters are screw diameter, screw groove depth and helix angle, and all of these three factors can influence dehydration output and efficiency.

Study on F lammulina Velutipes Ready-to-Eat Snacks Prepared by Microwave Vacuum Osmotic Dehydration Combined with Hot-Air Drying

Flammulina velutipes ready-to-eat snacks are not commonly known. Response surface methodology was employed to optimize the process parameters in making ready-to-eat snacks. The optimum dehydration condition was found at a sucrose concentration of 30%, a vacuum pressure of −40 ± 1.5 kPa, an osmotic time of 165 s and a microwave intensity of 65 W/g. These parameters resulted in water loss, solid gain and sensory evaluation values of 39.15%, 6.96% and 7.87, respectively. The water diffusion rate and solid gain diffusion rate were 1.55 × 10−9 and 1.29 × 10−9 m2/s, respectively, when employing the optimum microwave vacuum osmotic dehydration (MVOD) parameters. When F. velutipes mushrooms were dried for 180 min by hot-air drying, the water content of the ready-to-eat snack was 9.8 ± 0.5% and the water diffusion rate was 1.14 × 10−11 m2/s. Both the MVOD and the hot-air drying stages were consistent with the Page model. Practical Applications Osmotic dehydration technology combined with other drying technologies, such as hot air, can improve the use value and economic benefits of fruits and vegetables. The two correlations developed by modifying second-order polynomial equations were adequate to predict the responses for the Flammulina velutipes samples. The water and solid effective diffusion rates were calculated at different microwave vacuum osmotic dehydration times and different hot-air drying times for F. velutipes mushrooms. The Page model could be used to illustrate the water loss and solid gain for these two drying stages. The F. velutipes mushroom snacks made using these conditions had good color, high gloss and a moderately soft texture, with a sweet and sour flavor. The developed mathematical models can be considered precise for the prediction and optimization of process parameters in experimental and industrial applications.

The Research of Grading Dehydration Technology on Slurry Pipeline Grade Conveyor

To solve the confusing problem of different grades of slurry in the grades pipeline, this paper presents a new technology for slurry sizing dehydration. The method realizes the grading treatment by making full use of dehydrating station agitation tank and thickener buffer storage capacity. Research has shown that the method can effectively solve the grading dehydration process after the arrival terminal dehydration station in different grade slurry, and ensure the multi-grade mineral classification sequence transportation process completed successfully.

Design of an optimal process for enhanced production of bioethanol and biodiesel from algae oil via glycerol fermentation

In this paper, we optimize a process that integrates the use of glycerol to produce ethanol via fermentation within the simultaneous production of biodiesel and bioethanol from algae. The process consists of growing the algae, determining the optimal fraction of oil vs. starch, followed by oil extraction, starch liquefaction and saccharification, to sugars, oil transesterification, for which we consider two transesterification technologies (enzymes and alkali) and the fermentation of sugars and glycerol. The advantage of this process is that the dehydration technologies are common for the products of the glucose and glycerol fermentation. Simultaneous optimization and heat integration is performed using Duran and Grossmann’s model. The fermentation of glycerol to ethanol increases the production of bioethanol by at least 50%. The energy and water consumptions are competitive with other processes that either sell the glycerol or use it to obtain methanol. However, the price for the biofuels is only competitive if glycerol cannot be sold to the market.

Основы расчета геотекстильных контейнеров из тканевых материалов высокой прочности

The problem of processing, warehousing and a burial place
 of a various kind of a waste is considered. The analysis of the reasons
 of occurrence of degradation of the small rivers and its consequence
 has been made. The new economic innovative technology of dehydration
 and a burial place of a waste on the basis of containers from
 textile material is offered. Methods of calculation of geotextile containers
 are developed.

Challenges in Fuel Ethanol Production

Fuel ethanol production still represents many technological challenges, due mainly to the implicit complexity and costs of feedstock and other inputs. However, this process has been implemented at different scales, including the commercial one, through tax exemptions or subsides, which seek to lower production costs. In this article main feedstocks for ethanol production are discussed considering their production, advantages and drawbacks. The importance of conditioning and pretreatment as decisive process steps for conversion of feedstocks into ethanol is highlighted. Main methods for conditioning and pretreatmen are presented as well as the enzymatic procedures for starch hydrolysis. The need of pretreatment of lignocellulosic biomass is analyzed considering the complexity of this type of raw material. Several methods for pretreatment and detoxification of biomass are briefly described. The difficulties related to the enzymatic hydrolysis of cellulose are analyzed considering the enzyme complexes employed and the presence of solid particles in the reaction mixture. Main fermentation and concentration technologies for ethanol production are discussed. Ethanol dehydration technologies, including the most perspective, are disclosed as well. Finally, some environmental aspects of ethanol production are highlighted

Energy Integration of Bioethanol Production Process Topology from Microalgae Biomass: Evaluation of SSCF, SSF, Acid Hydrolysis and Product Purification Alternatives

An increasing interest exists in the use of ethanol as substitute of fossil fuels which can be obtained from renewable resources, microalgae are a promising source for third generation bioethanol due to the high percentage of carbohydrates/polysaccharides presents in some species and thin cellulose walls. Ethanol can be produced from either microalgae biomass before lipid extraction or from microalgae cake after cell disruption and oil extraction. Second option gives the interesting possibility of producing both biodiesel and ethanol from the same biomass. Energy analysis can be used for evaluation of the performance and efficiency of a process based on the first law of thermodynamics. In this work, third generation bioethanol production process was evaluated using the methodology of energy integration with the software Aspen Plus, the microalgae genera used was Chlorella sp. and technologies evaluated were Simultaneous Saccharification and Co-fermentation SSCF, Simultaneous Saccharification and Fermentation SSF, and Separate Saccharification and Fermentation using acid hydrolysis (SHF). Results shows that technology of Simultaneous Saccharification and Co-fermentation SSCF (route 1) presents the highest bioethanol yield 24.1 %, and the lowest energy requirements after energy integration. Separated hydrolysis and fermentation SHF (route 3) presents the lowest efficiency, ΔTmin was defined in 9 °C for SSCF, 4 °C for SSF, and 8.5 °C for SHF, the use of molecular sieves technology for bioethanol dehydration represents lower energy requirements respect to extractive distillation.

Dehydration and Upgrading of Lignite with Microwave

For solving the problems of high energy consumption and high capacity of water-absorption, microwave dehydration technology of lignite was studied in this paper. A self-developed microwave system was used for the experiment on dehydration of lignite from eastern Inner Mongolia. It was proved that the condition of moisture migration was improved and microwave dehydration had a unique mechanism. By analyzing the effects of microwave powers, coal particle sizes, and lignite qualities on drying characteristics, it was found that the moisture decreased when the microwave power increased. it was found that the higher the power was, the faster the moisture decreased; the smaller the particle size was, the faster the moisture decreased; the less the lignite was, the faster the moisture decreased. Through the scanning electron microscope analysis, it was concluded that microwave had no significant effect on the smooth particles, and the fibrous particles and clusters particles tended to be smooth under the effect of microwave. Therefore, the interface of lignite was relatively stable, and not easy to reabsorb water after microwave.

Analysis of Coke Oven Gas Dehydration Technology for Vehicles

Coke oven gas is an alternative hydrogen-rich fuel for vehicles, the water vapor in it will result in corrosion and seal damage of the engine combustion chamber. The paper describes the method and principle of COG dehydration, through the analysis of gas dehydration technology, determines the program of coke oven gas dehydration, and implements it in the coke oven gas stations. The result shows the coke oven gas after dehydration meets automotive requirements.

Technology of dehydration and transformation of silicic acid

The technology that silicic acid was pressurized under high temperature in order to dehydrate and transform was investigated in the paper. The effects, such as the ratio of liquid to solid, pressure, temperature, and reaction time on the dehydration rate and volume shrinkage rate, were researched. The experimental results show that the dehydration rate of silicic acid is up to 41.20 %, accompanying with the volume shrinkage rate of 40.37 % after silicic acid is pressurized under high temperature in the high-pressure kettle. The results of silicic acid tested by SEM indicate that the metasilicate acid molecules and water molecules are closely arranged, and there are almost no gaps before pressure reaction. There are many gaps accompanying with formatting lamellar structure after pressure reaction. The experimental results indicate the effect that silicic acid is dehydrated and transformation is obvious under high temperature and pressure.

Study on Biological Materials with the Dehydration Technology and Equipment of Banana Stems

The dehydration processing of banana stems was carried out to obtain plant fiber, and some structure characteristics were tested. An experimental design with different equipment that was studied to discover the effect of the dehydration rate of banana stems. We are trying to extract natural fibers from Hainan immense resources of biological materials. The paper also relates to an equipment for slicing the banana stem into elongated strips and pressing the strips. The result shows that the dehydration rate of banana stem which pressed by Sugarcane Mill (SM) was 57.0%(roots), 58.0% (central) and 51.0% (sheath) respectively. The samples which pressed by Open Roll Mill (ORM) have a lower level of dehydration rate (29.3% of roots, 12.1% of central, 13.5% of sheath, respectively).

Enhanced mass transfer of osmotic dehydration and changes in microstructure of pickled salted egg under pulsed pressure

Pulsed pressure osmotic dehydration (PPOD) technology is much more effective than the traditional pickling for salted egg. This study was designed to compare the changes of water and salt in salted egg under five pressures and five pulsation frequencies in saturated brine solution (⩾25% NaCl (w/w)). Results showed that moisture content of both egg white and yolk significantly decreased with concomitant increase in salt content compared to traditional pickling. PPOD caused increases in water loss and salt gain of eggs and the optimal pressure and pulsation frequency were 160kPa and 7.5min/15min. Moreover, hardening ratio of egg yolk increased as pickling time and storage time increasing. About 2.92–15.63 fold diffusivity was found for the egg under PPOD compared to traditional pickling over the same time period. Environmental Scanning electron microscopic study revealed that yolk granule was aligned closely and became increasingly smaller after pickling.

Dehydration Technology of Organic Solvent with Inorganic Ordered-porous Membrane

Dehydration Technology of Organic Solvent with Inorganic Ordered-porous Membrane

Dehydration of natural gas using membranes. Part I: Composite membranes

All natural gas must be dried before it enters distribution pipelines, to control corrosion and prevent formation of solid hydrocarbon/water hydrates. Glycol dehydrators are often used for natural gas dehydration, which, however, causes the emissions of hazardous volatile organic compounds (VOCs). In light of increasing concerns about VOC emissions, this study examines the technical feasibility of membrane technology for natural gas dehydration. More specifically, the Part I of this study is focused on the laboratory-scale tests of composite membranes. First, the current state-of-the-art research in membrane materials for H2O/CH4 separation is reviewed. Hydrophilic microphase-separated block copolymers (Pebax®) with promising H2O/CH4 separation properties were identified and made into industrial thin film composite membranes. Second, the composite membranes were extensively tested in a laboratory permeation cell by varying operating parameters including feed gas composition, feed gas flow rate and the flow rate of the dry sweep gas on the permeate. Water vapor permeation was mainly restricted by the microporous support and paper layers of the composite membranes, as opposed to methane permeation, in which the main transport resistance was in the selective layer. Increasing sweep gas flow rate on the permeate side of the membrane decreased the overall membrane transport resistance to water vapor, thus increasing water vapor permeance (up to 2000 gpu) and H2O/CH4 selectivity (up to 1500). Finally, the effect of different layers of composite membranes on water vapor permeance and water/methane selectivity is interpreted using a resistance-in-series model. The Part II of this study will describe a field test of Pebax®-based membranes at a natural gas processing plant and membrane process designs to maximize the membrane separation efficiency.

Microwave Drying of Food and Agricultural Materials: Basics and Heat and Mass Transfer Modeling

Microwave drying is based on a unique volumetric heating mode facilitated by electromagnetic radiation at 915 or 2,450 MHz. The responses of a lossy food product to dielectric heating result in rapid energy coupling into the moisture and lead to fast heating and drying. A significant reduction in drying time in microwave drying is often accompanied by an improvement in product quality, making it a promising food dehydration technology. The need for improvement in engineering design and process optimization for microwave drying has stimulated the development of computer simulation techniques to predict temperature and moisture history and distribution in the product to be dried. In this article, we present the basics of dielectric heating and drying, examine the heat and mass transfer models developed for the simulation of microwave drying processes, and discuss dielectric properties of selected food products as influenced by moisture, temperature, and porosity. In addition, we analyze nonuniform heating caused by the geometry and composition of the product, as well as by the nonuniform distribution of electromagnetic field in a microwave cavity, followed by a discussion on how to improve the microwave heating uniformity. We focus the discussion on heat and mass transfer models developed over the years to simulate microwave drying, including simplified ones, those based on diffusion theory, and coupled heat and mass transfer analysis with the Philip and de Vries theory, Luikov scheme, Whitaker method, and two-region model. In the end, the determination of the heat source term in the energy equation, numerical schemes used to solve the partial differential equations, and the model validation are also discussed.

Pb-227 吸湿剤を用いたバイオディーゼル燃料脱水技術の検討(ポスターセッション2:2.技術,研究発表,(ポスター発表))

Pb-227 吸湿剤を用いたバイオディーゼル燃料脱水技術の検討(ポスターセッション2:2.技術,研究発表,(ポスター発表))

Study on Dehydration Process of Wet Natural Rubber by Single Screw Dehydrator and Properties of Dry Natural Rubber

In this work, one self-invented closed single screw dehydrator was used to dehydrate wet natural rubber, instead of current three opened crepers and one hammer mill at home and abroad. The dehydration technology and the properties of the obtained dry natural rubber were studied. The results show that single screw dehydrator can simplify dehydration process. The water consumption of single screw dehydrator is 20% of current productive technology, meaning a lower wastewater discharge and treatment cost of wastewater. The moisture content of dehydrated natural rubber is lower than 20%, a good dehydration effect. The dry natural rubber dehydrated with single screw dehydrator has an improved thermal-oxidation ageing resistance whether dried by hot-air or microwave. The thermal-oxidation ageing resistance of natural rubber dried by microwave is better than that of hot-air drying, the value of initial plasticity (P0) and plasticity retention index (PRI) are 29.3 unit value and 19.26 unit value greater than that of SCR5 in GB/T 8081, respectively.