Showing papers on "Raffinate published in 2014"

Production of clean pyrolytic sugars for fermentation.

Abstract: This study explores the separate recovery of sugars and phenolic oligomers produced during fast pyrolysis with the effective removal of contaminants from the separated pyrolytic sugars to produce a substrate suitable for fermentation without hydrolysis. The first two stages from a unique recovery system capture “heavy ends”, mostly water-soluble sugars and water-insoluble phenolic oligomers. The differences in water solubility can be exploited to recover a sugar-rich aqueous phase and a phenolic-rich raffinate. Over 93 wt % of the sugars is removed in two water washes. These sugars contain contaminants such as low-molecular-weight acids, furans, and phenols that could inhibit successful fermentation. Detoxification methods were used to remove these contaminants from pyrolytic sugars. The optimal candidate is NaOH overliming, which results in maximum growth measurements with the use of ethanol-producing Escherichia coli.

Subcritical water extraction of steviol glycosides from Stevia rebaudiana leaves and characterization of the raffinate phase

Abstract: The objectives of this work were to obtain steviol glycosides of S. rebaudiana leaves, possessing natural and noncaloric sweetener properties, using subcritical water extraction; to assess optimum extraction conditions; to determine biological activities of Stevia extracts and to characterize the raffinate phase. A Box–“Bhenken” statistical design was used to evaluate the effects of various values of temperature (100–150 °C), time (30–60 min) and flow rate (2–6 ml/min) at a pressure of 230 bar applying a solid/liquid ratio of 1:10 (m:v). The most effective parameter was temperature (p

Method of producing aromatics and light olefins from a hydrocarbon feedstock

Abstract: The present invention relates to method of producing aromatics and light olefins from a hydrocarbon feedstock comprising the steps of: (a) subjecting the hydrocarbon feedstock to a solvent extraction process in a solvent extraction unit; (b) separating from the solvent extracted hydrocarbon feedstock obtained in step (a) a raffinate fraction comprising paraffins and a fraction comprising aromatics and naphtenes; (c) converting said fraction comprising aromatics and naphtenes in a hydrocracking unit and separating into a high content aromatics fraction and a stream high in light paraffins;; (d) converting said raffinate fraction in a steam cracking unit into light olefins.

Hybrid Process for o- and p-Xylene Production in Aromatics Plants

Abstract: A new hybrid process for the production of o- and p-xylene is proposed to replace the traditional plant of aromatics in refineries. The proposed process comprises a simulated moving bed (SMB) unit and two crystallizers. The SMB technology as the first unit of the suggested process is applied for the separation of xylene isomers and was investigated by simulation of an industrial size unit, using experimentally measured adsorption equilibrium data on MIL-53(Al)-shaped material. The separation of p-xylene from o-xylene with m-xylene as desorbent is the key characteristic of this method. An industrial-scale SMB unit could provide extract and raffinate streams with very high purities.

Method for preparing high-purity vanadium from heteropolyacid impurity in amine extraction mode

Abstract: The invention relates to a method for preparing high-purity vanadium from heteropolyacid impurities in an amine extraction mode. Generally an ordinary vanadium solution is doped with impurities such as chromium, silicon, phosphorus, tungsten, molybdenum and arsenic, if acid is added into the solution, heteropolyacids such as phosphorus tungsten, phosphorus vanadium tungsten, silicon tungsten, phosphorus molybdenum tungsten, silicon molybdenum tungsten, molybdenum vanadium arsenic and tungsten arsenic can be formed, the impurities in the solution are removed by carrying out compounding synergic extraction on the heteropolyacids in the ordinary vanadium solution by using amines and a synergist so as to obtain a purified vanadium-containing raffinate, subsequently the vanadium-containing raffinate is evaporated and concentrated to be the concentration that each liter of the solution contains 40g vanadium, ammonium salt is further added into the concentrated liquid to obtain ammonium metavanadate solid, vanadium pentoxide with the purity greater than 99.9% is obtained through washing in pure water, drying and calcining in an oxygen atmosphere, the organic phase after the heteropolyacid is extracted is subjected to reverse extraction by using an alkali solution so as to form a heteropolyacid water phase, and the organic phase is recycled and circulated. The method has low requirement on equipment, and is simple to operate, key extraction agents are good in thermal stability and not sensitive in acid and alkali, and a recycling and circulating method is simple and easy to be industrialized.

Optimal Design of Solvent Blend and Its Application in Coking Wastewater Treatment Process

Abstract: One of the key steps of coking wastewater treatment is phenolic and tar removal via extraction. However, the high loss of the extractant, i.e., methyl isobutyl ketone (MIBK), leads to the high cost of the process. The adoption of a novel solvent or solvent blend is considered as an efficient way to address this problem. In this paper, seven solvents (benzene, toluene, m-xylene, ethylbenzene, 1, 3, 5-trimethylbenze, cyclohexane, and octanol), selected as candidate diluters for MIBK according to operating requirements, are studied with a nonlinear programming (NLP) model based on ideal counter-current extraction. The results, verified with experiments, suggest toluene is the most promising candidate. Further investigation of this solvent blend reveals that both Dblend (the distribution coefficient of phenol between solvent blend and water) and mMIBK (the MIBK concentration in raffinate) increase with xMIBK (the molar fraction of MIBK in blend). The trade-off between the extraction performance and MIBK loss ...

Separating and recycling method of nickel, cobalt, copper manganese and zinc in electroplating sludge

Abstract: The invention provides a separating and recycling method of nickel, cobalt, copper manganese and zinc in electroplating sludge. The method comprises the steps that acid leaching is performed on the electroplating sludge to obtain leaching agents for fractional extraction, organic phases and nickel-rich raffinate are obtained, four steps of reverse extraction are performed on the organic phases by sequentially adapting hydrochloric acid, vitriol, the vitriol and the hydrochloric acid, and four kinds of corresponding strip liquor are achieved; then follow-up recycle is performed on the nickel-rich raffinate and the four kinds of strip liquor, and separation and recycle of the nickel, the cobalt, the copper manganese and the zinc are completed. According to the method, the complete extraction mode is adopted, the nickel, the cobal, calcium, magnesium, the copper, manganese and the zinc are sequentially extracted step by step and then recycled respectively, a technology procedure is short, production efficiency is high, the equipment investment is small, operation cost is low, the environment is protected, recycling of the nonferrous metal is achieved, and good social benefits and economical benefits are obtained.

Method for extracting rubidium salt and cesium salt

Abstract: The invention relates to a method for extracting rubidium salt and cesium salt. The method comprises the steps of 1) regulating a high-salinity solution to obtain an alkaline solution which has a pH value of 11-14; 2) extracting rubidium ions and cesium ions from the alkaline solution obtained from the step 1) in a centrifugal extractor through an organic extracting agent, thus obtaining a loaded organic phase (I) and raffinate; 3) washing the organic phase (I) obtained from the step 2) through washing water to obtain an organic phase (II) and a washing solution; 4) implementing reverse extraction to the loaded organic phase (II) through reverse extraction acid (I) to obtain a rubidium salt reverse extraction solution and an organic phase loaded with cesium ion; and 5) implementing reverse extraction to the organic phase loaded with the cesium salt obtained from the step 4) through reverse extraction acid (II) to obtain a cesium salt reverse extraction solution and a blank organic phase. The extraction method disclosed by the invention is simple and easy to implement, and can be matched with comprehensive development and utilization of a high-salinity medium to produce a rubidium salt and cesium salt product of preset type.

Supercritical Carbon Dioxide Fractionation of Anhydrous Milk Fat

Abstract: Supercritical carbon dioxide was used to fractionate anhydrous milk fat. Six fractions were produced at 40, 50 and 60 °C using pressure values of 10, 20, 25, 30, 33 and 36 MPa. The fractions were analyzed for fatty acids, thermal behavior, iodine and color values. Composition and yield of fatty acid methyl esters were evaluated at different fractionation conditions in relation to the original milk fat values. Short chain fatty acids (C4–C8), medium chain fatty acids (C10–C14) and total saturated fatty acids were decreased from fraction obtained in the order of 10–36 MPa, while long chain fatty acids (C16–C18:2) and total unsaturated fatty acids were increased. Fractions obtained in the raffinate stage of the fractionation exhibited higher melting behavior that obtained at the low CO2 pressures. The higher iodine value of raffinate fraction indicated that fraction was richer in oleic acid. Fractions produced at low pressures had lower melting behavior than those obtained at high pressures. Yellowness Index and b* values increased in raffinate fraction due to concentration of carotenoids.

Supercritical production and fractionation of fatty acid esters and acylglycerols

Abstract: The production of biodiesel or fatty acid esters (FAE) from lipids with supercritical methanol (scMeOH) has gained interest in the last decade because it allows the direct transesterification of crude oils and fats. The reaction should be carried out above 593 K in order to achieve complete conversion. When milder conditions are set, also monoglycerides (MG) and diglycerides (DG), together with glycerol, are obtained as byproducts of the transesterification process. Acylglycerols are common food emulsifiers and surface active agents in many industrial cleaning products. The main goal of this work is to study the fractionation of FAE and acylglycerols by using CO2 as a green solvent. Mixtures of FAE, MG and DG were produced by partial transesterification of sunflower oil with scMeOH in a temperature range of 556–605 K and using different methanol to oil molar ratios (between 20 and 50). Then, experimental data on phase equilibria of reaction products + CO2 were measured at 298 K and 313 K in a variable volume cell with windows. The measured data were used to test the predictive capability of the Group Contribution with Association Equation of State (GCA-EoS). The acylglycerols can be purified by near critical extraction of the FAE with CO2. The simulation of the extraction process working with CO2, in liquid or supercritical state, gives a concentration of acylglycerols higher than 99.8 wt.% in the raffinate phase with a concentration of FAE above 97 wt.% in the extract phase.

Application of neutral phosphamide extracting agent to Ce extraction and separation

Abstract: The invention relates to an application of a neutral phosphamide extracting agent shown in a general formula I to Ce extraction and separation, and a method for extracting and separating Ce by using the neutral phosphamide extracting agent shown in the general formula I According to the method, a neutral phosphamide extracting system containing the neutral phosphamide extracting agent shown in the general formula I and Ce -containing material liquid are mixed and extracted so as to obtain cerium-containing extract liquid and cerium-free raffinate The method has the advantages that the separation cost of cerium can be reduced, the yield of cerium reaches 99%, and the purity of the cerium reaches 9999%

Factorial design in optimization of the separation of uranium from yellowcake across a hollow fiber supported liquid membrane, with mass transport modeling

Abstract: The extraction and stripping of uranium(VI) from other impurity elements in yellowcake was performed simultaneously in one stage by a hollow fiber supported liquid membrane. Uranium ions were selectively extracted from yellowcake using TBP as the extractant, while thorium and some rare earth elements were rejected in the raffinate. The optimization method was carried out using 32 factorial design. The concentration of nitric acid in the feed solution and the concentration of TBP in the liquid membrane were regarded as factors in the optimization. A mass transport model focusing on the boundary layer of the extraction side was also applied. The model can predict the concentration of uranium in the feed tank at different times. The validity of the developed model was statistically evaluated through a comparison with experimental data, and good agreement was obtained.

Method for recovering vanadium, potassium and silicon from waste vanadium catalyst

Abstract: The invention discloses a method for recovering vanadium, potassium and silicon from a waste vanadium catalyst. The method comprises the following steps: firstly, leaching the waste vanadium catalyst in water, and leaching in a reductic acid, wherein the total leaching rate of vanadium is greater than or equal to 95.0%, separating the silicon from vanadium and potassium transferred to a leaching solution in a form of a leaching slag; preparing liquid sodium silicate to recover silicon from the leaching slag by alkali dissolution; separating the vanadium from potassium in the leaching solution in an extraction manner; preparing potassium sulphate to recover potassium from a raffinate phase in an evaporative crystallization manner; and preparing vanadium pentoxide from an extract phase by the procedures of re-extraction, molybdenum precipitation, calcination and the like. Meanwhile, the vanadium in the extract phase and the raffinate phase is larger in distribution ratio, and does not react with other metal impurities such as iron and the like due to excellent selectivity of an extraction agent TOA on vanadium, other metal impurity ions such as iron and the like do not need to be removed in advance, and the vanadium can be directly extracted. Thus, a part of edulcoration procedures are reduced, the raw material consumption is saved, and a high-purity product of vanadium can be directly prepared. By adopting the method disclosed by the invention, not only can the vanadium, potassium and silicon in the waste vanadium catalyst be comprehensively recovered, but also the targets of turning the waste into treasure and protecting the environment are achieved.

Method for recovering molybdenum from pressurized leaching liquid of molybdenum concentrate

Abstract: The invention relates to a method for recovering molybdenum from a pressurized leaching liquid of molybdenum concentrate. The method comprises the following steps: adding an extracting agent trialkylamine (N235), a phase regulator isooctanol and a diluent to the pressurized leaching liquid of molybdenum concentrate containing molybdenum; extracting molybdenum to an organic phase after mixing and phase separation, and separating from impurities such as copper, zinc, iron, phosphorus, silicon, arsenic and the like left in raffinate; and reversely extracting a molybdenum-loaded organic phase by adopting ammonium hydroxide as a stripping agent, so as to obtain an ammonium molybdate liquid. A method which is economical and simple, quick and effective and friendly to environment is provided for recovering the molybdenum from the pressurized leaching liquid of the molybdenum concentrate, and the impurities such as copper, zinc, iron, phosphorus, silicon, arsenic and the like are removed when extraction and enrichment of the molybdenum in the pressurized leaching liquid are achieved, and the method is short in technological process, and easy to achieve industrialized application.

Method for mixed production of light-weight aromatic hydrocarbon by use of catalytic cracking diesel and C10 distillate oil

Abstract: The invention relates to a method for mixed production of light-weight aromatic hydrocarbon by use of catalytic cracking diesel and C10 distillate oil The method comprises the following steps: firstly mixing the catalytic cracking diesel and the C10 distillate oil with hydrogen, performing a hydrofining reaction to remove sulfur and nitrogen, saturate olefin and appropriately saturate aromatic hydrocarbon; then, extracting a hydrofining product by using an extraction solvent to obtain extract oil containing rich aromatic hydrocarbon and raffinate oil containing rich alkane; using the raffinate oil as a clean diesel oil concoction component, and performing rectification separation on the extract oil to obtain aromatic hydrocarbon extract oil; performing a hydrocracking reaction on the aromatic hydrocarbon extract oil, performing cutting separation on a hydrocracking product, using a distillate oil product greater than 195 DEG C as the clean diesel oil concoction component, feeding the distillate oil product smaller than 195 DEG C as an aromatic hydrocarbon raw material into an aromatic hydrocarbon treatment device to obtain a light-weight aromatic hydrocarbon product and a clean gasoline concoction component By adopting the method provided by the invention, the yield of the light-weight aromatic hydrocarbon is increased, and meanwhile high-quality clean fuel oil is obtained and the high additional value utilization of the C10 distillate oil is achieved

Production of Ethanol as a Renewable Energy by Extractive Fermentation

Abstract: One issue with batch fermentation is that product inhibition causes low yields and ethanol productivity. The objective of this study was to increase the yield and ethanol productivity via continuous fermentation in a packed bed bioreactor with both an integrated extraction process and recycling of the raffinate into the fermenter. Molasses was used as the feedstock, and the immobilized cells were supported by ĸ-carrageenan. This process used n-amyl alcohol, 1-octanol, and 1-dodecanol as solvents. The yield and ethanol productivity increased from 8.79% to 20.03% and 34.54 g/L·h to 118.16 g/L·h for experiments using n-amyl alcohol, 9.05% to 12.67% and 35.59 g/L·h to 74.71 g/L·h, for 1-dodecanol, 8.89% to 13.45% and 34.93 g/L·h to 84.62 g/L·h, for1-octanol by increasing recycle ratio from 0 to 0.5. Based on these results, n-amyl alcohol was the best solvent for the extractive fermentation process.

Separation of high purity gadolinium for reactor application by solvent extraction process

Abstract: A solvent extraction process for the production of nuclear grade Gd2O3 for its applications in pressurized heavy water reactor (PHWR) from a crude concentrate of rare earths containing ~70 % Gd2O3 has been developed and tested on bench-scale and continuous counter-current operations. The separation of gadolinium from other rare earths with similar chemical properties has been successfully accomplished by adopting a dual cycle solvent extraction employing 2-ethylhexylphosphonic acid, mono-2 ethylhexyl ester (EHEHPA) as an extractant. Taking advantage of the extraction order of rare earths with EHEHPA, in the first cycle, heavy rare earths including Tb, Dy and Y were separated in the product strip solution, while gadolinium was separated in the raffinate solution along with samarium and neodymium. In the second cycle, gadolinium was purified to the extent of >99.5 % with respect to other rare earths. Effects of process variables such as aqueous acidity, phase ratio, metal concentration in the aqueous feed, scrubbing and stripping acidity etc. on separation of terbium and other heavy rare earths in the first cycle and upgrading the purity of Gd2O3 in the second cycle have been investigated. The experimental conditions were optimized using computer simulation and validated by bench scale counter-current operations. Under optimized conditions of process parameters, continuous operations of mixer settler yielded kilogram quantity of nuclear pure Gd2O3 which was subsequently converted to gadolinium nitrate for PHWR application. The overall recovery was found to be >98 %.