Summary of the invention
The purpose of this invention is to provide a kind of method that from oil product, removes and reclaim naphthenic acid, it can remove the sour composition in the oil product easily, again can efficient recovery naphthenic acid product that wherein mainly comprise, high added value, it may further comprise the steps: select the double solvents that comprises C2-5 saturated alkoxides, ammoniacal liquor and emulsion splitter for use, pending oil product is mixed with double solvents, between 30~70 ℃, be heated to many 60 minutes, isolate solvent phase behind the standing demix, and this solvent phase of acidification, isolate the naphthenic acid phase.
In the method for the invention,, can also comprise the flocculation agent that is selected from the plurality of inorganic salt class in the described double solvents, be preferably and be selected from ammonium sulfate, volatile salt, sodium-chlor and the Repone K one or more for shortening above-mentioned separation time.The weight percentage of described flocculation agent consumption is 0.1%~2%.
In the oil product by the inventive method processing, acid constituents is mainly naphthenic.They are the chemical intermediates with higher-value.
The C2-5 saturated alkoxides that the present invention uses can be ethanol, propyl alcohol, butanols and other low-molecular-weight alcohols, preferred Virahol.
Emulsion splitter described in the present invention can be selected from one or more in alcohols polyethers, polyethylene polyamine block polyether, phenolic resin type, the PEP-101, also can be the small molecules emulsion splitter.
By the inventive method, can adopt concentration is 15% ammoniacal liquor, and Virahol: the volume ratio of ammonia volume is 1: 2~1: 4; The consumption of emulsion splitter is 50~100ppm, and the agent of double solvents and oil in the mixing/oil volume is than between 0.2~1, preferably between 0.5~1.
Acidification solvent phase described in the present invention is that the pH value with solvent phase is adjusted to below 2.
Oil product described in the present invention can be a crude oil with high acid value, can be light ends oil also, comprises diesel oil and kerosene that naphthenic acid content is higher.
The present invention can adopt the oil product phase and the solvent phase that contains the acid of deviating from after the method for natural sedimentation or electric field separates is separated depickling.
In the methods of the invention, described type of heating can adopt steam heating, electric heating or other ordinary method.The general agitator in the pot type operating process is used in described mixing, or uses the extraction tower countercurrent liquid-liquid operation of operate continuously process.Can adopt the method for natural sedimentation or electric field separates separate after the depickling oil product mutually and contain the solvent phase of the acid of deviating from.The neutral oil that is mixed with in the isolated solvent phase can adopt a kind of the extracting in benzene,toluene,xylene, sherwood oil, 90~180 ℃ the liquid hydrocarbon, to improve the thick acid number of naphthenic acid.Add hydrochloric acid or sulfuric acid and regulate the pH value of the solvent phase behind wash-out or make it heating, make system separate out the naphthenic acid layer, can get the naphthenic acid product after the layering.Can recycle and separate the depickling solvent that obtains.
If described oil product is crude oil, then described being separated in the refinery desalting unit carried out, and obtains the former oil phase after the depickling and contains the solvent phase of naphthenic acid salt.
The present invention uses the double solvents of ammoniacal liquor and C2-5 saturated alkoxides, preferred Virahol to remove that its main component is the sour composition of naphthenic acid in crude oil and the distillate thereof, its mechanism is believed: by ammonia with the neutralization reaction of naphthenic acid and utilize the extracting effect of the salt that alcohol in the solvent produces neutralization, naphthenic acid in the oil is transferred in the solvent, oil product and the demixing of solvents that contains naphthenic acid also are separated, reach the purpose that removes naphthenic acid in the oil product.Its advantage is, the solvent safety of use can effectively suppress the generation of emulsion in the extractive process, make the layering of solvent extraction process very fast; The naphthenic acid that obtains is to exist with purer state; Solvent is recycled easily.Also the sulphur of mercaptan can be removed in the lump simultaneously, to reduce the sulphur content of oil product.
The following specifically describes some detail operation stepss of the inventive method.
Described double solvents can followingly be prepared: Virahol: the volume ratio of ammoniacal liquor can be between 1: 2~1: 4.Virahol also can be replaced by ethanol, n-propyl alcohol and propyl carbinol and other low-molecular-weight alcohols.Because the gasification potential of alcohols material is low, boiling point is low, and the energy consumption that reclaims the extract solvent from extract is lower, helps energy-conservation.
Described emulsion splitter can be that (as SPI69, its molecular formula is C to the alcohols polyethers
18H
37-O-(C
3H
6O)
x-(C
2H
4O
y-(C
3H
6O) z-H)), (as AE is two sections block polyethers to the polyethylene polyamine block polyether, AP is three sections block polyethers), in the phenolic resin type (as AR type emulsion splitter, promptly alkylphenol is with EO and PO copolymerization), oxyethane (EO)-propylene oxide (PO) multipolymer (as UD10) one or more.Described emulsion splitter also can be selected one or more in micromolecular ethylenediamine tetraacetic acid (EDTA), lipid acid, aliphatic amide, the negatively charged ion amine etc., to accelerate layered effect; Effect emulsion splitter preferably is SPI69.For some lightweight oils, comprise that crude oil and distillate, flocculation agent may be nonessential.
Described flocculation agent can be selected one or more the mixture in sodium-chlor, ammonium chloride, Repone K, sodium sulfate, ammonium sulfate, vitriolate of tartar, SODIUMNITRATE, ammonium nitrate, the saltpetre for use, and its ratio can be selected arbitrarily.Wherein ammonium salt is best.
Above-mentioned reaction mixture natural subsidence is separated, and system is divided into oil phase and solvent phase two-phase, and the acid number of oil phase can reach below the 0.5mgKOH/g.Utilize the neutral oil in the solvent phase after the depickling of light hydrocarbons wash-out, to improve the thick acid number of naphthenic acid.Add hydrochloric acid or sulfuric acid and regulate below the pH of the solvent phase behind wash-out value to 2, system is separated out the naphthenic acid layer at once, utilizes density difference between naphthenic acid and the solvent phase and immiscible character thereof, and the employing natural sedimentation is told naphthenic acid wherein.Naphthenic acid can wash with water with seawater or general industry earlier mutually, can suitably add emulsion splitter, washes with water with general industry at last, makes the naphthenic acid product.The recyclable utilization of solvent that obtains from delaminating process.
The double solvents amount that the present invention uses and the volume ratio of corresponding crude oil can be between 0.2~1, and be slightly different according to different operating method.
Liquid between agent/oil-liquid contact can be adopted the andnon-continuous operation manner of depickling jar, also can adopt the operate continuously mode of counter-current extraction tower multi-stage solvent extraction.Solvent can prepare the back and add, and adds alcoholic solution and other breakdown of emulsion components again after also can adding basic solution earlier.The adding mode can be the depickling solvent to be joined in the crude oil go, and also crude oil can be joined in the depickling solvent and go.
The method of separating crude oil and solvent can adopt natural sedimentation also can adopt the method for electric field separates.If adopt the latter, can utilize in the refinery existing desalination unit to implement.Can in static mixer, under low-shearing power, mix, to react.
Solvent phase can adopt a kind of washing back in the organic solvents such as benzene,toluene,xylene, sherwood oil, light hydrocarbon to reclaim, and the solvent in the oil phase can distill recovery simply, is recycled.Resistates after the distillation is neutral crude oil, can merge with depickling crude oil.
Depickling temperature of the present invention can be chosen between 30~70 ℃, and preferably between 45~55 ℃, the reaction times is no more than 60 minutes, preferably between 10 minutes~40 minutes.Agent/oil content layer also can carry out under the situation of suitably insulation.
The mode of separating depickling crude oil and solvent can adopt natural sedimentation, and the mixture behind the stirring reaction is left standstill in separating funnel or other separators.Utilize density difference and its immiscible character of crude oil and solvent, the natural subsidence layering.
Solvent after the depickling can directly be regulated pH to alkalescence, as new depickling solvent recycling.Also can after suitable distillation purification processes, reuse.
Can adopt thermal degradation and directly add acid-treated method the processing of naphthenate, obtain the naphthenic acid product.
The present invention compared with prior art, its advantage is: be applicable to the depickling of distillate and crude oil; Depickling and acid treating, recovery are organically combined, avoided the emulsion of separation and removal process; Reduced the technology cost of whole process; The yield and the acid number thereof of the naphthenic acid that is recovered to after removing are higher.Method is simple, economical and effective for this, and favorable economic benefit and social benefit are arranged.And the yield and the acid number thereof of petroleum acid have been improved.
Embodiment
Embodiment 1
In this embodiment, use the Sudan's crude oil, its acid value for crude oil is 10.8mg KOH/g.At volume is to add 250 gram the Sudan crude oil in the still kettle of 2 liters; In Virahol: the volume ratio of 15% ammoniacal liquor is 1: 2 a ratio preparation double solvents, wherein contains commercially available UD10 type emulsion splitter 80ppm; With crude oil and double solvents is to mix at 1: 1 by volume, is heated to 60 ℃; Under 250r/ minute stirring velocity, mixed 30 minutes, left standstill at least 30 minutes; After treating the abundant layering of crude oil and solvent phase, lower floor's solvent phase is told.Measure acid value for crude oil, acid number is reduced to 3.2mg KOH/g from 10.8mg KOH/g.
The solvent of as above gained is regulated pH value to 14 with ammoniacal liquor or NaOH, adds the UD10 emulsion splitter, with its concentration adjustment to the 80ppm.So far the solvent of gained joined again in the crude oil of depickling go.Under 50 ℃, mixed 30 minutes, and mixed system was transferred to left standstill 30 minutes in the separating funnel; Layering; Record its oil phase acid number and reduce to 0.2mg KOH/g.
The solvent that above-mentioned steps is told with petroleum ether after, add hydrochloric acid and also regulate pH to 2, tell the black oil phase on the solvent upper strata at once. upper oil phase is told.Determine that with infrared spectra and mass spectrum it consists of the naphthenic acid of molecular weight ranges between 100~1000.
Embodiment 2
Take by weighing the Sudan's straight run heavy grease of 450~500 ℃ of cuts of 200 grams, its acid number is higher than 18.2mgKOH/g.It is mixed by 1: 0.5 volume ratio with the depickling double solvents among the embodiment 1, and temperature maintenance is at 40 ℃.Mix 30 minutes in beaker after, the impouring separating funnel adds ammonium chloride 2 grams and makes flocculation agent, and suitably insulation; After treating the solution layering, measure the acid number of distillate, acid number is reduced to 0.5mgKOH/g.With the solvent petroleum ether of telling, use salt acid for adjusting pH value to 2 at last.Tell the naphthenic acid of gained, the thick acid number of measuring naphthenic acid is 154mgKOH/g; Pure acid number 168mgKOH/g.
Embodiment 3
Use Peng Lai, Shandong crude oil (total acid value 3.8mgKOH/g) in this embodiment.Mix with following condition preparation double solvents and with this crude oil and to handle:
It is 25% ammoniacal liquor that double solvents in the present embodiment is selected ethanol and concentration for use, and by ethanol: ammoniacal liquor is that 1: 2 volume ratio is mixed, and adds the alcohols polyether-type SPI69 emulsion splitter of 60ppm; Above-mentioned double solvents is 0.3 with the agent/oil volume ratio of oil; Temperature of reaction is 50 ℃, and the reaction times is 30 minutes.Mixture after treatment separated 10 minutes under DC electric field, strength of electric field 1000V/cm.Divide fuel-displaced, agent two-phase, measuring the oil phase acid number is 0.2mgKOH/g.Use the petroleum ether identical with former oil volume, gained raffinate addition sulfuric acid is regulated pH value to 2, and system is layering at once, obtains naphthenic acid, measures its specification and meets SH00922 acidity scale standard.