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1.
Biodiesel production from abundant bio-sources has drawn the attention of the academic as well as the industrial communities in recent years. However, one of the most serious obstacles for using biodiesel as an alternative fuel is the complicated and costly purification processes involved in its production. The difficulties involved in the separation of glycerine and other un-reacted reactants and by-products necessitate the development of new competent low cost separation processes for this purpose. In this work, a low cost quaternary ammonium salt-glycerine-based ionic liquid is proposed as a solvent for extracting glycerine from the transesterification biodiesel product. The separation technique was tested on palm oil-based produced biodiesel with KOH as a reaction catalyst. The study investigated the effect of DES:biodiesel ratio and the DES composition on the efficiency of the extraction process. The lab scale purification experiments proved the viability of the separation technique with a best DES:biodiesel molar ratio of 1:1 and a DES molar composition of 1:1 (salt:glycerine). The purified biodiesel fulfilled the EN 14214 and ASTM D 6751 standard specifications for biodiesel fuel in terms of glycerine content. A continuous separation process is suggested for industrial scale application. 相似文献
2.
Patricia Quinlin Herman J. Weiser Jr. 《Journal of the American Oil Chemists' Society》1958,35(7):325-327
Summary Monoglyceride concentrates are quantitatively separated into mono-, di-, and triglyceride components on silica gel columns
by an adsorption chromatographic technique. The separated glycerides are determined gravimetrically. The adsorption on silica
gel is dependent on the number of hydroxyl groups in the molecule, and the influence of unsaturation and chain length is minimized.
Combinations of benzene and ethyl ether are used for elution, thus preventing isomerization, which frequently results when
polar solvents such as alcohols are used.
The procedure for the chromatographic separation is simple and straightforward. The equipment used is easily obtainable. The
silica gel adsorbent requires only adjustment of its water content before use.
Mixtures of both saturated and unsaturated glycerides and those having different fatty acid chain length have been separated.
Known mixtures have also been analyzed. For a known mixture containing 15% tripalmitin, 45% distearin, and 38% monopalmitin
the average deviations from the calculated values were 0.4%, 0.2%, and 0.6%, respectively 相似文献
3.
Coal slimes from coking coal with an average ash content of about 45% and difficult separation characteristics have been studied. Investigations have also been carried out on two artificial mixtures of gangue and coal of low ash content. Two kinds of agitation have been tested: mechanical—rotational (with an impeller mixer) and vibroacoustical (with vibrating band) at a frequency of 50 Hz and an amplitude of 1 – 2 mm. Vibroacoustical agitation was much more efficient than mechanical-rotational. Second-degree orthogonal-central-compositional planning was used for studying slimes of appropriate size (−0.063 mm). In the most successful test with natural slimes, an efficiency of separation of 34.41% was obtained with the following technological parameters: yield of concentrate 27.93%, ash content of concentrate 22.00%, yield of refuse 72.07%, ash content of refuse 54.30%, the ash content of the run-of-mine coal being 45.28%. These results are close to the best ones obtained with the same slimes by fractional analysis in a liquid of density 1500 kg/m3. In this case, an efficiency of separation of 39.18% was obtained with yield of concentrate 35.04%, ash content of concentrate 24.01%, yield of refuse 64.96%, and ash content of refuse 56.01%.
The experiments on selective agglomeration have been carried out using kerosene at 14.8% consumption with respect to solids. The investigations are of a preliminary character. 相似文献
4.
Frank C. Magne Evald L. Skau Andrew F. Freeman 《Journal of the American Oil Chemists' Society》1954,31(3):113-114
Conclusions Data obtained on the solubility of hydrogenated peanut oil in refined peanut oil and the behavior of the mixtures on cooling
indicate that freedom from oil separation on storage is largely determined by the nature as well as the amount of solid crystals
present in the oil. The results suggest that the best procedure for prevention of oil separation would involve shockchilling
the molten mixture to produce the finely divided metastable crystalline modification followed by tempering at such a temperature
as to permit transformation of the crystals into the more desirable higher-melting form without changing the finely divided
state necessary for improved palatability.
The data imply that under controlled conditions any amount of the high-melting modification of the hard fat incorporated in
peanut oil above the solubility temperature in excess of 2% should produce a mixture free from oil separation under average
storage conditions. The choice of the actual concentration of the hard fat, above the minimum amount, would depend upon the
degree of plasticity desired. Ambient temperature to which the mixture is likely to be subjected will influence to a considerable
extent the selection of the hard fat content. The information obtained is of fundamental importance in connection with the
problem of oil separation in peanut butter.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献
5.
B.H. Dijkink 《Powder Technology》2007,172(2):113-119
Milling and air classification is a well-known procedure to obtain protein and starch enriched fractions from cereals and grain legumes. Adhesion of small protein particles to larger starch granules adversely affects the separation efficiency during air classification. To gain insight into this phenomenon the dispersion of bimodal mixtures of starch granules and fine protein particles in an air stream was studied.Using a method to correct for the number of small starch particles in the protein fraction, the dispersability of protein/starch mixtures was determined. The type of protein and, particularly, of starch may affect dispersability. The effect of starch type is not only caused by differences in granule size; likely other properties such as roughness are also involved. Increasing protein content enhances dispersability but does not seem to have an effect on the adhesion between starch and protein particles itself. An increase in adhesion by relative humidity of 90% results in a decreased dispersability.The dispersability of the mixtures was related to their performance upon air classification. Both the separation efficiency and tau were strongly related to dispersability (R2 = 0.86 and 0.88 respectively). Hence, the dispersability, which can easily be measured, is a powerful tool to predict the air classification performance for separation of starch and protein. 相似文献
6.
Manuel Carmona Anna Lech Antonio de Lucas Angel Pérez Juan F. Rodriguez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(8):1130-1135
BACKGROUND: Equilibrium studies were carried out with the aim of finding the basic design parameters for ion exchange plants using a glycerol phase obtained from biodiesel production. The uptake of sodium and potassium ions on a strongly acidic ion exchanger, Amberlite IR‐120, in the proton form from glycerol/water mixtures has been studied. The effect on the selectivity towards sodium of the percentage of water in glycerine/water mixtures on the macroporous resin Amberlite 252 has been analyzed. Finally, chloride removal by a strongly basic anionic‐exchange resin Amberlite IRA‐420 at three different temperatures has been studied. RESULTS: The strongly acidic ion exchanger Amberlite IR‐120 exhibits higher selectivity for potassium versus sodium ions. The ideal mass action law model was able to fit the experimental equilibrium data. The equilibrium data obtained at different percentages of water in the glycerine/water mixture indicate that as the water content increased the resin selectivity for sodium uptake is reduced. The selectivity of the anion exchange resin Amberlite IRA‐420 for chloride ions decreases with temperature. The ideal mass action law was accurate enough to fit the equilibrium data of the three systems and allowed the equilibrium thermodynamic properties to be obtained. CONCLUSIONS: These results confirm that macroporous resin Amberlite 252 could be a good choice to remove sodium ions from glycerol/water solutions with a high salt concentration and also that a strongly basic anionic‐exchange resin could be used for chloride removal. Copyright © 2009 Society of Chemical Industry 相似文献
7.
Nicolae Sdrula 《Desalination》2010,250(3):1070-1072
Biodiesel is a clean burning biofuel produced from renewable resources (straight vegetable oil, animal oil/fats, tallow and waste cooking oil), which can be blended at any level with petroleum diesel to create a blend of biodiesel.The EU has adopted a series of directives to promote and to represent some of the most important renewable energy sources out of biofuels also covering biodiesel as well.The main processing stages currently applied for biodiesel technology are represented by transesterification, neutralization of mixture, phase separation, biodiesel and glycerine purifications. The reaction, generally occurring in a two-stage mixer-settler unit, arises some difficulties for clear cut separations.A new alternative technology, using hydrophobic porous membranes, can be used to prevent bulk mixing of the two phases and facilitate contact and mass transfer of species between the two phases.The glycerine side stream (roughly representing 10% of biodiesel) typically contains a mixture of many components, which are generally difficult to separate. Current methods for glycerine purification are complicated and conducted with higher costs.In this case, the new technology provides an economical solution for the purification of crude glycerine stream combining the high efficiency of electro-dialysis and nano-filtration processes.A comparative cost approach based on available information is sketched. Also, some examples sustain the aim of the study. 相似文献
8.
Manfred Kaiser 《Propellants, Explosives, Pyrotechnics》1997,22(6):321-325
High performance liquid chromatography (HPLC) is used in a large extent for environmental analysis. In this field many components have to be determined at the same time, but it is difficult to find the optimum separation conditions. Therefore, retention times of explosives and propellant components were determined at different solvent compositions of methanol/water and different temperatures on a column with an octadecyl phase. From the data constants were calculated for solvent and temperature dependence. With the determined data different column conditions were simulated by computer and the separation was optimized. The optimal separation was verified experimentally and compared with the calculated values. The deviation from calculated and experimental retention times lies as a rule below 2% and has a maximum of approximately 3.3%. Thus, separation of substance mixtures can be optimized by determination of column constants for temperature and solvent dependence. 相似文献
9.
Manuel Carmona José L. Valverde Angel Pérez Jolanta Warchol Juan F. Rodriguez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(5):738-744
BACKGROUND: In this study, equilibrium and kinetic data of the ion exchange of sodium from glycerol–water mixtures on the strong acid resin Amberlite‐252 were obtained. Basic parameters for the design of ion exchange units for the purification of the crude glycerol phase from biodiesel production have been determined. RESULTS: Equilibrium uptake of sodium ions with the strong acid ion exchanger Amberlite‐252 was studied at three temperatures. The Langmuir equation and the mass action law model were used to fit the experimental equilibrium data. Equilibrium constants and thermodynamic parameters were obtained at each temperature. Kinetic experiments were carried out to evaluate the effective diffusion coefficients of sodium on the resin Amberlite‐252 in glycerine–water media. CONCLUSIONS: Equilibrium results indicate that this process is favourable and also that its selectivity decreases with temperature increase from 303 to 333 K. Both models were able to fit the experimental equilibrium data. Kinetic experiments showed that the rate of mass transfer in this binary system is high. An Arrhenius type equation allowed the correlation of effective diffusion coefficients and temperature. The results indicate that the macroporous resin Amberlite‐252 could be useful for removal of sodium ions from glycerine/water solutions with a high salt concentration. Copyright © 2008 Society of Chemical Industry 相似文献
10.
两性淀粉的取代度与吸湿保湿性能关系的研究 总被引:3,自引:0,他引:3
以淀粉为母体,3-氯-2-羟丙基三甲基氯化铵和氯乙酸为改性剂,通过清洁的半干法工艺合成出不同羧甲基取代度高的水溶性两性淀粉,并对其吸湿、保湿性能进行研究。结果表明,两性淀粉的吸湿、保湿性能均随着羧甲基取代度的增加而增强。当RH为81%,阴离子取代度大于0.08时,两性淀粉的吸湿性与甘油相当,而保湿性在RH81%和RH38%下均优于甘油;两性淀粉的吸湿速率随着羧甲基阴离子含量增加而提高。初步探讨了两性淀粉的吸湿动力学,水分子在两性淀粉中的扩散属于non-Fickian类型。 相似文献
11.
Galactose is an aldohexose, which has commercial uses in the pharmaceutical and food industries. Since monomeric galactose is not a freely occurring compound, it must be produced from galactose‐containing hydrolysates. This paper reports the results of experimental studies of the chromatographic separation of galactose in aqueous solutions by ion exchange resins on an industrial scale. Until now, galactose has only been determined from various solutions by liquid chromatography (HPLC) on an analytical scale. Chromatographic separation of galactose from carbohydrate mixtures was studied with strong acid cation exchange resins in Na+, Ca2+ forms and strong base anion exchange resin in SO42– form. The feed solutions were hydrolysates from three possible galactose sources: lactose, gum arabic and hemicellulose in spent sulfite liquor. The main monosaccharide impurities in these raw materials were glucose, arabinose, and xylose. It was demonstrated that large scale liquid chromatography can be used effectively for galactose separation from complex carbohydrate mixtures such as plant hydrolysates as well as lactose hydrolysate. 相似文献
12.
Ya‐lei Zhang Min Zhang Zheng Shen Jing‐fei Zhou Xue‐fei Zhou 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2013,88(5):829-833
BACKGROUND: Glycerine, a main by‐product of the biodiesel manufacturing process, has potential to be an important biorefinery feedstock with the rapid increase in biodiesel production all over the world. Hydrothermal experiments with glycerine were carried out at 250 °C using H2O2 as an oxidant. RESULTS: Glycerine was converted into formic acid with a yield of 31.0% based on the starting mass of carbon in glycerine. A possible oxidation pathway for the formation of formic acid from glycerine is proposed. In the proposed pathway, glycerine may first be oxidised and then decomposed into formic acid and oxalic acid. Oxalic acid was indirectly attributed to the increase of formic acid production from glycerine, but it instead acts as a retardant to prevent further oxidation of formic acid. However, when an alkali was added to the experimental conditions, the yield of formic acid was not greatly improved, reaching only 34.7%. CONCLUSION: The present work should help to facilitate further studies to develop a new green process for the production of formic acid from renewable biomass. © 2012 Society of Chemical Industry 相似文献
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14.
甘油作陶瓷磨具成型料松散度调节剂的研究 总被引:1,自引:0,他引:1
本文针对固结陶瓷磨具生产中存在的成型料结块现象及机理加以分析。在参考大量文献的基础上选定甘油作为成型料松散度调节剂,对加入甘油后成型料的松散性、流动性进行研究,检测成型料压制出的湿、干坯强度,并对试验产品的各项性能进行分析对比。结果显示成型料添加甘油2-4ml/kg干料后,成型料的松散性、流动性提高50%以上。在生产应用中发现,采用成型料添加甘油的新工艺后,年度组织不均废品率由原来的5.40%降到2.00%左右;年度总废品率由8.87%降到4.00%左右。 相似文献
15.
S. K. Myasnikov A. D. Uteshinsky N. N. Kulov 《Theoretical Foundations of Chemical Engineering》2009,43(3):227-237
The physicochemical fundamentals of the combined processes of distillative crystallization (also called distillation crystallization or distillative freezing) and distillative sweating (also called distillation sweating or distillation melting) are considered. Results of the experimental study of the kinetics of separation of binary and ternary organic mixtures of various forms (liquids, powders, continuous layers, and granules) are presented. The high efficiency of the combined processes that make it possible to rapidly decrease the impurity content by one to two orders of magnitude after a single stage is shown. It is found that these processes can be used for effective separation of the mixtures of a eutectic composition when conventional crystallization is not applicable. Dependences of the important kinetic characteristic—an effective diffusion coefficient—on pressure are determined for a number of mixtures. An empirical formula for estimating its values is proposed. It is found that the kinetic features of the combined processes conducted under nonequilibrium conditions can cause both a decrease and an increase in the efficiency of separation of the mixtures of different types in comparison with calculated values for the equilibrium process. A method is developed that makes it possible to combine distillative crystallization with the granulation of a melt in a semicontinuous or continuous process on a cooled movable belt. The method ensures the additional purification of solidifying granules from volatile impurities. Results of calculating the main characteristics of the combined process for purifying naphthalene granules in the batch and continuous modes are given. 相似文献
16.
V. Finsy L. Ma L. Alaerts D.E. De Vos G.V. Baron J.F.M. Denayer 《Microporous and mesoporous materials》2009,120(3):221-227
Adsorptive separation of CH4/CO2 mixtures was studied using a fixed-bed packed with MIL-53(Al) MOF pellets. Such pellets of MIL-53(Al) were produced using a polyvinyl alcohol binder. As revealed by N2 adsorption isotherms, the use of polyvinyl alcohol as binder results in a loss in overall capacity of 32%. Separations of binary mixtures in breakthrough experiments were successfully performed at pressures varying between 1 and 8 bar and different mixture compositions. The binary adsorption isotherms reveal a preferential adsorption of CO2 compared to CH4 over the whole pressure and concentration range. The separation selectivity was affected by total pressure; below 5 bar, a constant selectivity, with an average separation factor of about 7 was observed. Above 5 bar, the average separation factor decreases to about 4. The adsorption selectivity is affected by breathing of the framework and specific interaction of CO2 with framework hydroxyl groups. CO2 desorption can be realised by mild thermal treatment. 相似文献
17.
G. Rebollar-Pérez E. Carretier N. Lesage P. Moulin 《Journal of Industrial and Engineering Chemistry》2012,18(4):1339-1352
This study deals with the application of vapour permeation on the abatement of air polluted with VOC, from low to medium concentrations. Toluene, butadiene and propylene were chosen as model compounds. On a first part of the study, the permeation of single VOC, binary and ternary VOC/air mixtures was performed at different flow rates and VOC concentrations. The permeate flux, permeance, enrichment factor, separation efficiency and the recovery were determined. The experimental results were compared to those obtained with a mathematical model, allowing the calculation of the membrane area required to eliminate 95% of the feed VOC content. 相似文献
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《分离科学与技术》2012,47(6-7):1393-1409
ABSTRACT Distillation is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE of some binary mixtures is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum. 相似文献