146 results about "Relative volatility" patented technology

The invention discloses a method for separating a methyl acetate-methanol mixture by ionic liquid intermittent extractive rectification, which is realized in a way that: a rectifier of an extractive rectification tower is adopted, an ionic liquid 1-ethyl-3-methyl imidazolyl acetate is used as an extractant, and the operation is carried out intermittently, so the top of the extractive rectification tower sequentially produces a methyl acetate product of which the mass content is up to 98-99.9%, a methyl acetate-methanol transitional fraction and methanol of which the mass content is 97-99%; and finally, the extractant of which the mass percent is 99% is left in the heating kettle. The invention has the following advantages: the extractant is adopted to enhance the relative volatility of the methyl acetate-methanol system, the purity of the separated methyl acetate product is high, and the ionic liquid used as the extractant is easy to recover and does not pollute the environment; and only one single tower needs to be operated, so that operation is flexible and the equipment investment is low.

The invention discloses a process for producing hexamethylol melamine, belonging to the field of production and preparation of hexamethylol melamine. The process comprises the steps such as mixing, reaction and crystallization, centrifugalization, evaporation and the like, wherein evaporation auxiliary formate is added when in evaporation so as to change the relative volatility of formaldehyde and water. Furthermore, the process for producing the hexamethylol melamine together with a formaldehyde device can also be used for co-production, so that the concentration of the produced formaldehyde solution is improved to 45wt%-55wt%. The produced hexamethylol melamine provided by the invention has the advantages of small amount of waste water and low formaldehyde content, namely, if 1 ton of hexamethylol melamine is produced, 1 ton of waste water containing 0.84wt% of formaldehyde is discharged. After the process provided by the invention and the formaldehyde device are used for co-production, the formaldehyde production cost and transportation cost are reduced, and the comprehensive cost is 10% less than that of other processes.

A system and method for evaluating the effectiveness of a medical treatment and predicting future medical issues is provided. A digital set of biometric data comprising a plurality of biometric data points is received and stored in a digital database. The digital set of biometric data is analyzed to determine its relative volatility. The relative volatility is then evaluated to help determine the effectiveness of a medical treatment and predict future medical issues.

A method of structuring a guaranteed financial product on a risk asset using a computer comprising: a) introducing a reference asset being another risk asset having a secondary derivative market which is better developed and more liquid than said secondary derivative market of said risk asset; b) analyzing and comparing the volatility level of said risk asset and of said reference asset over a predetermined time period; c) applying an asset adjustment when said volatility level of said risk asset exceeds a predetermined level defined by said volatility level of said reference asset; and d) removing said asset adjustment when said volatility level of said risk asset falls below said predetermined level defined by the volatility level attained in c).

The present invention is C4 hydrocarbon mixture extracting and separating process. Ionic liquid additive is introduced to form one new type of composite extractant for extracting and separating C4 hydrocarbon mixture with 1, 3-butadiene as the main component. Introducing the ionic liquid additive into the extractant can increase the total dissolubility of C4 hydrocarbon mixture in the extractant, raising the hydrocarbon selectivity and relative volatility, and thus raise the extracting and separating effect obviously. In addition, the added ionic liquid has very low vapor pressure and high boiling point, and thus convenient recovery and reuse.

The invention creates and provides a method for refining petrobenzene and thiophene by using an ionic liquid complex solvent. Coking crude benzene is pretreated to form crude benzene in a pretreatment procedure, crude benzene is extracted and rectified twice in the ionic liquid complex solvent during a benzene refining procedure to form a 99.99% benzene product and crude thiophene, a thiophene product with purity of more than 99.7% is also obtained by extracting and rectifying crude thiophene twice with the ionic liquid complex solvent in the thiophene refining procedure, yield is more than 97%, and all the ionic liquid complex solvent is recycled after being refined and recycled through a recovery tower. In the method, the quality of the benzene product reaches A-level standard of petrobenzene national standard, the benzene product can substitute petrobenzene in use, meanwhile, thiophene is recycled efficiently, and the economic benefit increased therefrom is more than 50%; the ionic liquid has good thermal stability, low vapor pressure and high polarity, the complex solvent formed by the ionic liquid has high selectivity, relative volatility among the constituents is increased, dosage of an extraction agent is reduced, and process energy consumption and production cost are respectively reduced by 25% and 40%, so that energy-saving effect is remarkable.

The invention discloses a method for separating m-ethyltoluene and p-ethyltoluene by extractive distillation. The extractive distillation solvent adopted by the method is a nitrogenous compound, preferably cyanobenzene or benzyl cyanide, and more preferably benzyl cyanide. The method comprises the following steps: introducing an m-ethyltoluene/p-ethyltoluene mixture from the middle of the extractive distillation tower, and introducing an extractive distillation solvent from the tower top; and after carrying out extractive distillation, discharging the m-ethyltoluene from the top of the extractive distillation tower, discharging the rich solvent containing rich p-ethyltoluene from the tower bottom, sending the rich solvent into a solvent recovery tower, discharging the p-ethyltoluene from the top of the recovery tower, and recycling the extractive distillation solvent discharged from the bottom of the recovery tower. The invention has the advantages of low operation energy consumption and high product purity; and the solvent adopted by the method can obviously improve the relative volatility between m-ethyltoluene and p-ethyltoluene, is easy to recycle, and has high chemical thermal stability.

The invention provides a treatment technology of waste water containing fluoride and ammonia nitrogen. The technology is used for treating waste water containing fluoride and ammonia nitrogen in tantalum-niobium hydrometallurgy. The technology is characterized in that the relative volatility difference between ammonia and water is utilized; an ammonia-water separating technology in which high-efficiency distillastion is treated as the main technology core is carried out and combined with a pre-treatment technology to perform defluorination-calcium removing-strong dissolving and complexing-molecular distilling, so as to realize the removal of fluorine and ammonia; the drained water obtained after treatment reaches national primary emission standard; meanwhile, high-purity ammonia water with concentration being equal to or greater than 15% is recovered for production. According to the technology, the ammonia is recycled, so that the balance of payments of the treatment cost of the ammonia containing waste water can be achieved; the requirement on comprehensive utilization of the resource can be met; the technology brings a certain economic benefits.

The invention relates to a method, a process and an apparatus for separation of ethylene glycol and 1,2-butanediol. The method includes, (1) subjecting ethylene glycol and 1,2-butanediol to reaction through acetal/ketal to produce acetal/ketal liquid product mixture correspondingly, (2) separating the acetal/ketal liquid product mixture containing ethylene glycol and 1,2-butanediol by a series of rectifying columns, (3) separating different acetal/ketal products by rectifying according to difference of boiling points of acetal or ketal, (4) respectively hydrolyzing the acetal/ketal products to obtain an ethylene glycol primary product and a 1,2-butanediol primary product, and (5) purifying the ethylene glycol primary product and the 1,2-butanediol primary product respectively by rectifying to obtain an ethylene glycol product and a 1,2-butanediol product. The purity of the ethylene glycol product can be up to 99.9% and the recovery thereof can be up to 99.5%; the purity of the 1,2-butanediol product can be up to 98.5%. By a reversible-reaction conversion method, the difficulty in separating ethylene glycol and 1,2-butanediol which are of similar boiling points and low relative volatility and are azeotropic is changed into the problem about separation of acetal/ketal products which are easy to separate relatively.

The invention relates to a separation method, technique and device of ethylene glycol and 1,2-butanediol. The method comprises the following steps: reacting a diol mixture and aldehyde or ketone in a reaction rectification tower by acetal or ketal reversible reaction to generate an acetal/ketone mixture, rectifying to separate the acetal/ketone mixture, and carrying out reaction, rectification and hydrolysis to obtain the high-purity ethylene glycol and 1,2-butanediol products. By using the technique for separation and purification, the purity of the main product ethylene glycol can reach 99.9% or above, the recovery rate can reach 99.5% or above, and the purity of the 1,2-butanediol product can reach 98.5% or above. By using the reaction rectification method, the difficulty in separating azeotropic ethylene glycol and 1,2-butanediol with approximate variable boiling point and low relative volatility becomes the problem of separation of the separable acetal/ketone product, thereby effectively implementing the high-efficiency separation on the ethylene glycol and 1,2-butanediol.

THe invention provides a method for separating acetic acid and water by complexation, extraction and rectification process. Said invention utilizes the acting force between organic alkali and acetic acid, which is stronger than that of water, and greatly raises the relative volatilities of acetic acid and water so as to separate them. In the fractionating recrtifying tower with 10-50 theoretical plates it adopts tertiary amine organic alkali as complexation extracting agent, under the condition of normal pressure (or reduced pressure), its solvent ratio is 0.5-5 and refluxing ratio is 0-5, the water whose mass fraction is greater than 99.7% can be obtained from tower top, and in the solvent recovering tower with 5-40 the oretical plates, under the condition of reduced pressure and refluxing ratio of 0.5-5 the acetic acid whose mass fraction is greater than 95.0% can be obtained.

The invention discloses a process for separating an acetonitrile-water azeotrope system by adopting ionic liquid extraction distillation. According to the process, an ionic liquid azeotropic agent is adopted, so that the relative volatility of acetonitrile in the acetonitrile-water system can be enhanced, the solvent ratio can be reduced, and the concentration of acetonitrile in a vapor phase is increased along with the increment of the mass percent of ionic liquid; ionic liquid cations are imidazolium cations or pyridine cations, and ionic liquid anions are halogen anions, acetic acid anions, bistrifluoromethylsulfimide anions, hexafluorophosphoric acid anions, dibutyl phosphate anions or trifluoromethanesulfonic acid anions. When the mass percent of the ionic liquid is 15%-60%, an acetonitrile-water azeotropy point can be disappeared. When the mass ratio of the ionic liquid to acetonitrile-water binary azeotrope is 1 : 4, the extraction distillation can be well carried out to obtain more than 99% of acetonitrile, and the ionic liquid is environment-friendly and recyclable.

The invention discloses a method for purifying silicon tetrachloride of optical fiber grade through total reflux distillation. The method comprises the following steps: after being preheated, silicon tetrachloride waste liquid enters a middle feed opening of a low boiling fraction removal rectifying tower, top steam of the low boiling fraction removal rectifying tower constantly accumulates in a reflux tank after being condensed by a condenser after rectification begins, and the total reflux operation is maintained, so that light components are constantly concentrated at the top of the low boiling fraction removal rectifying tower; when liquid in the reflux tank exceeds the operation liquid level, liquid above an overflow plate in the reflux tank flows into an extraction area to be extracted; tower bottoms, formed by silicon tetrachloride and phosphorus trichloride, of the low boiling fraction removal rectifying tower are discharged from the bottom of the low boiling fraction removal rectifying tower and pumped into a middle feed opening of a silicon tetrachloride purifying tower by a silicon tetrachloride feed pump; overhead fraction of the silicon tetrachloride purifying tower partially refluxes after being condensed by an overhead condenser of the silicon tetrachloride purifying tower, and the other part of overhead fraction is extracted, so as to obtain the silicon tetrachloride product of optical fiber grade. According to the method and the device, after compression, the relative volatility of trichlorosilane and silicon tetrachloride is improved, so that separation becomes easier.

The invention discloses a solvent for separating carboxylic acid mixtures by extraction and rectification. The solvent is mainly composed of ionic liquid. The solvent can be absolute ionic liquid and also can be a mixture of ionic liquid and preparation materials of cations and anions thereof. The cations of ionic liquid are organic amine. The anions are carboxyl groups. The solvent for extracting, rectifying and separating carboxylic acid mixtures can raise the relative volatilities among components, can raise the separation efficiency, and can reduce the production cost.

The invention relates to a composite extractant for separating an azeotrope of acetone and methanol and a use method thereof, belonging to the technical field of separation utilization of industrial waste materials. The composite extractant consists of a main extractant and an additive, wherein the additive is a high-valence cation ionic salt, a compound salt or an ionic liquid. According to the invention, an extraction and rectification tower and a solvent recovery tower are used so as to separate a mixture of acetone and methanol; through introducing the salt additive, the separation capacity of the extractant is effectively improved, and the relative volatilities of the acetone and methanol are increased, thus a high-recovery product is obtained, above 95% acetone is obtained by virtue of primary extraction and rectification of the mixture of acetone and methanol with 40-70wt% acetone, the recovery of the acetone is above 85%, and the concentration of methanol is above 95%; and simultaneously, the salt additive has an extremely-low steam pressure and almost non-volatility, which is convenient for recovery and recycling of the composite extractant.

The invention relates to a method for preparing high-purity hexafluoropropylene oxide by extraction and rectification. The method comprises the following steps: selecting epoxy chloropropane as an extracting agent, wherein the mass ratio of the extracting agent to HFPO-HFP mixture feed is controlled between (1-200): 1; introducing the HFPO-HFP mixture into an extraction rectifying tower, spraying the epoxy chloropropane from the tower top, and separating HFPO from the tower top to obtain HFPO with purity over 99 percent; and discharging HFP and the epoxy chloropropane from the bottom of the extraction rectifying tower to be pressed into a reclaiming tower once again, separating the HFP from the top of the reclaiming tower, and discharging the epoxy chloropropane from the bottom of the reclaiming tower to be pumped once again to return a spraying port on the top of the extraction rectifying tower for cycle use. The method selects the epoxy chloropropane as the extracting agent to make relative volatility of the HFPO and the HFP reach 1.5 to 3.7, so that the HFPO and the HFP can be well separated; meanwhile, the number of column plates required for rectification can be reduced, and investment cost can be reduced.

The invention relates to a rectification separation method, and concretely relates to a new technology for separating isopropanol-isopropyl ether azeotrope by using ionic liquids. The new ionic liquids [emim]<+>[BF4]<-> and [bmim]<+>[BF4]<-> (with the structures shown in figure 1) are adopted in the invention as extractants, and the isopropanol-isopropyl ether azeotrope is separated through adotpign a continuous rectification method. Rectifying towers adopted in the technology comprise an extraction rectifying tower, a solvent recovery tower and other auxiliary devices. The technology comprises the following steps: adding the isopropanol-isopropyl ether azeotrope into the central portion of the extraction rectifying tower, recovering the ionic liquids in the solvent recovery tower, pumping the ionic liquids into the extraction rectifying tower through using a pump in order to realize cycle use, and controlling different temperatures and reflux ratios of the above two towers in order to realize continuous production. The technology breaks use of a traditional solvent glycol as an extractant, improves the relative volatility of isopropanol-isopropyl ether, avoids the problem of poor solubility of traditional glycol as the extractant, and has the advantages of convenient operation, large operation elasticity and continuous production.