CN105400535A

CN105400535A - Coal Tar Distillation Process Of Coal And Device For Its Implementation

Info

Publication number: CN105400535A
Application number: CN201510558151.3A
Authority: CN
Inventors: Y·德纳格蒙; L·吉尤
Original assignee: Fives Proabd
Current assignee: Fives Proabd
Priority date: 2014-09-04
Filing date: 2015-09-02
Publication date: 2016-03-16
Also published as: FR3025523B1; FR3025523A1

Abstract

The invention relates to a coal tar distillation process comprising a primary distillation. The invention is characterized in that the process comprises the following steps: a flash distillation of a mixture of dehydrated coal tar and pitch is carried out to obtain flashed vapors at the top of column and pitch at the column bottom; a portion of the pitch obtained during the flash distillation is used in the starting mixture of the dehydrated coal tar and the pitch; after the flash distillation, stripping and rectification of flashed vapors are immediately carried out to obtain a carbon black oil and a wide naphthalene distillate, and the device for its implementation is related.

Description

The method of Doak Tar Oil and the equipment of enforcement the method

Technical field

The present invention relates to the method for Doak Tar Oil, its objective is direct generation three kinds of hydrocarbon-fractions in primary distillation: naphthalene wide fraction (naphthalenicwidefraction), carbon black oil and pitch, wherein latter two cut is containing the alkali added.

Background technology

Coal tar is the mixture of mononuclear aromatics and polycyclic aromatic hydrocarbons.It is by obtaining afterwards in the process of the condensation of oven battery exit and decant coal and anthracitic pyrogenic steam.The organic phase reclaimed after decant is coal tar.According to estimates, coal tar is above the complex mixture [H.-G.Franck] of 10000 kinds of different compounds.Some of them exist in a large number, such as naphthalene, anthracene, phenanthrene or comprise heteroatomic compound, as carbazole or quinoline.The heaviest compound that normal boiling point exceedes about 360 DEG C is generically and collectively referred to as pitch.Pitch accounts for the about 45%-55% of tar by mass.Due to its very high molecular weight, its high boiling point and its tending to the reactivity under the temperature action making it be polymerized, it does not such as distill by traditional means and it is earlier fractionated into different cuts.

The compound comprised according to them derived from the various hydrocarbon-fractions of tar defines:

– light oil (LO) or BTX, be rich in benzene, toluene and dimethylbenzene;

– carbolic oil (CO), phenol-rich, cresols, indane and cumarone;

– naphtalene oil (NO), primarily of naphthalene and small amount xylenol composition;

– washing oil (WO), especially comprises methylnaphthalene;

-carbolineum (AO), comprises anthracene, carbazole and phenanthrene.This cut can be divided into two kinds of cuts sometimes, and namely different average normal boiling point is respectively carbolineum I and II of about 280 DEG C and about 340 DEG C.

– heavy oil (HO), be sometimes called when it is rich in (chrysene) in the wrong and bend oil, its average normal boiling point is about 350-360 DEG C;

– coal-tar pitch, its comprise the compound of all high molecular and normal boiling point more than 360 DEG C.The feature of coal-tar pitch is, it is made up of different resins (α, β and γ) more or less solvable in selective solvent.The ratio forming often kind of resin of coal-tar pitch is a kind of quality standard.Coal-tar pitch is reactive mixture.When it stands to exceed the temperature of about 350-360 DEG C, it trends towards the form spontaneous polymerization reacted with " reformation " or " from reforming ".This reaction trends towards particularly by the ratio of increase α resin the distribution changing resin.Exceed certain balance between the α resin of certain content and β and α resin, it is underproof that the quality of coal-tar pitch (is included in the main application of to produce for Primary Aluminum Industry in anode) for some working specification.For these application, the coal-tar pitch of about 100-120 DEG C Mettler or higher must be obtained.The pitch of this quality is by using the oily bitumen of modification or unmodified 80-95 DEG C Mettler to obtain, to correct the balance between resin.Must pay special attention to term " pitch ", in fact it is general, and its product with different properties and composition of obtaining do not describe the different carbon-based material of pyrolysis processing with having preference after.Although this term is identical, the character of the pitch obtained is different.

The name of above-mentioned various oil can change according to the application of coal tar naphtha refinery and type:

– carbon black oil (CBO) is the wide fraction usually comprising carbolineum and heavy oil.It can also comprise a part of washing oil and oily bitumen.This oil usually with specific specification, as standard C OST1126 is correlated with;

The summation of all oil of – from carbolic oil to heavy oil is sometimes called as wide fraction oil (WFO);

– or, be combined with from washing oil until the cut of heavy oil fraction can be called creosote (CRO).

All these titles can change between each refinery according to local usage, especially by introducing the concept of " head " cut or the attribute etc. of " gently " or " weight " that characterize continuous normal boiling point scope etc.

Describe and employed the scheme of various distillation tar.For example, historic method Wilton, AbderHaldenouNewton-Chambers [FR933385A] can be mentioned, heads removes [US2679833], there is the modern times of " tower bottom flow " distillation [FR1311305] and many flash distillations [CN101139527, CN1986735].Often kind of distillation scheme is corresponding to the specific production object about target fraction quality and quantity, or the selection made due to the technical limitation existed when they are developed.

The oldest scheme of continuous still battery tar is described to Wilton method (Fig. 1) or AbderHalden method [Romovacek] in the literature.It is made up of three treatment steps:

1. primary tar is dewatered, produce dehydrated tar (also will notice, this dehydrating step is the preliminary treatment of primary tar common in all continuous tar distillation methods);

2. by dehydrated tar flash distillation rectifying, produce several hydrocarbon-fraction: one or both chemistry oil, creosote and oily bitumens;

3. according to some specific embodiments, then oily bitumen heated and be retained in polymerization reactor or ripening tank (maturingvessel), thus the polymerization schedule in a controlled manner by controlling pitch changes its character.

With the Wilton variant difference of under atmospheric pressure carrying out, AbderHalden variant is that it with the addition of steam stripped (steamentrainment).It provides the control of better pitch dilution and better inwardness.Particularly, for the final softening temperature of identical pitch, colder than in Wilton structure at the bottom of the tower in AbderHalden structure, this can limit the spontaneous and not controlled polymerization of pitch.These two kinds of Wilton with AbderHalden methods are carried out usually on identical distillation plant.Their advantage is simple and powerful, but throughput can not meet dehydrated tar per year over the requirement of about 100000 tons.In addition, the cut quality of collection is not best with reclaiming output; Particularly, the quality of naphthalene cut is no more than 70%m/m usually.This qualitative limitation is relevant with the standard of these methods, and wherein the standard of these methods does not comprise boiling again of any stripping stage or any oil.Except producing the clean cut of negligible quantity, lacking boils again also makes these methods not produce to meet the carbon black oil distillate of common specification.

Describe other variants of Wilton method, such as, comprise the Newton-Chambers method [FR933385] of boiling again.Although there are some differences or improvement of distinguishing these methods, they all have identical its generation that do not allow and meet expection specification, such as, according to the shortcoming of the carbon black oil cut of standard GOST1126.

When object is not main generation chemistry oil, the simplification variant of these methods can be used.(topping) method that those skilled in the art's reference term " goes to top ".In these embodiments, be simplify distillation after dehydration, its sole purpose is separated mutually light and heavy phase.For the tar that phenol content is few, H.G.Franck describe under steam stripped at recovered overhead naphthalene and " go top " (Fig. 2) reclaiming tar heavy oil at the bottom of tower.Then tar heavy oil is used as fuel.Describe in [Krik], the distillation unit implanted in Canadian Hamilton can " going to push up " under vacuo be that the oiliness cut of all compounds of 140 DEG C of-Yue 340-350 DEG C is separated (Fig. 3) with the oily bitumen at the bottom of tower by combining normal boiling point between working life.Oiliness cut is used as such as, the carbon geochemistry fuel suitable with the fuel of FA to the FE classification according to standard NFEN14156.Can softening temperature be regulated by taking to remove middle clean cut and remove the character that a small amount of heavy oil regulates oily bitumen.This clean cut accounts at most the 1%-5% of tar charging by mass.After aging in ripening tank/reformation, then a part of oily bitumen is recycled in the charging of distillation tower.The clean product of this unit is left in the representative of all the other oily bitumens.

[US2673833] describes another kind and " goes to push up " embodiment.Wherein, go to withstand in two successive stage and carry out.First stage can carry out dewatering and reclaiming lightweight oil simultaneously.Subordinate phase can the tar heavy oil removed at the bottom of the tower of first stage of flash distillation, is separated different oil distillates with from pitch.The naphtalene oil reclaimed is in about 46-65 DEG C crystallization.This corresponds to the naphtalene oil composition of 46%-74% by mass.In subordinate phase, oil normal boiling point being greater than 235 DEG C concentrates.The oil mass reclaimed accounts for 1/3 to 3/4 of vaporizing oil.This irreducible oil comprises the naphthalene of 15%-25% by mass.The softening temperature of the pitch collected is 87-123 °F, i.e. about 30-50 DEG C of R & B.These two information can be summed up out, and the oil produced by this method is not carbon black oil, but are intended to apply to the transparent creosote of dipping sleeper.Although transparent creosote and carbon black oil have identical initial normal boiling point, the distillation range of transparent creosote is 262 DEG C of end, and the distillation range of carbon black oil is until 350-360 DEG C.The pitch produced at the bottom of tower is " melting (fluxed) " pitch, its softening temperature is significantly lower than the softening temperature required by routine application (especially for the production of aluminium melting anode), and only allow the application described in [US2673833], i.e. road paint or gasket coating.

When hydrocarbon-fraction to be recycled quantity increase and when recovery output or higher quality imperative time, tar distillation unit develops into more complicated system.Original method that is that use in Clairton (Fig. 4) and that describe in [Kirk] is the example of this Evolutionary Type.After dehydration, the separation column of several series connection carries out continuous still battery.Each tower can reclaim specific hydrocarbon-fraction, and its quality especially can be regulated by the degree of back flow controlling each distillation tower.Then will deliver to next tower at the bottom of tower, wherein make it stand extra distillation to reclaim next cut, by that analogy.Hydrocarbon-fraction reclaims with the order corresponding to the normal boiling point increased.After continuing through each water distilling apparatus, in the end pitch is reclaimed in the bottom of a tower.Therefore, described pitch has the relatively long residence time, and stands to promote it spontaneous and the thermal history of not controlled fusion.In order to limit relevant thermal stresses, various equipment under reduced pressure runs, this can reduce column bottom temperature and alleviate (can only partly) pitch from reforming.In fact this alleviation from reforming is part, because it is by the impact of distillation cellular manufacture capacity variation: be the polymerization reactor reclaiming pitch at the bottom of tower.When the throughput of described unit reduces, the residence time at the bottom of tower mechanically increases.Therefore, the pitch under underproductivity is reformed more than the pitch under high productive capacity.Therefore when adjusting carrying capacity, can not keep the quality of pitch and the quality of oil, the interests in order to other need compromise quality and productivity of sacrificing some product/cut simultaneously.This distillation type is described to " bottom cycle distillation " [Romovacek] usually in the literature.[FR1311305] describes the another kind of variant by the method for circulation distillation tar at the bottom of tower.Contrary with the method described by [Kirk], the method does not adopt the distillation under decompression.The method uses steam stripped to instead of distillation.The method can produce the naphtalene oil that fluxing point is 70 DEG C, this is merely able to by carrying out extra process to improve with sodium hydroxide, makes its titre reach maximum value 90% by mass, on the other hand, do not have the extra washing of described sodium hydroxide, its titre by mass maximum value is 92%.The method is not used to production carbon black oil; In order to produce carbon black oil, oil may be necessary to mix, and this may cause extra energy expenditure.

In order to overcome the shortcoming of bottom cycle distillation, adopt the alternative strategy (Fig. 5-[H.-G.Franck]) be made up of flash distillation or many flash distillations technology.In such method, being first time " primary distillation " flash distillation after dehydration, is then the strict fractionation more or less of oil.Primary distillation can in the method as early as possible by oily bitumen more or less and oiliness fraction seperation.For the distillation example implanted in Hamilton, the transparent cut for reclaiming a small amount of carbolineum II or heavy oil can regulate the character of the pitch collected at the bottom of tower.The heavy oil that generation may be similar with carbon black oil is removed in the middle of this.But tonnage is still very low: these cuts are actually " cleaning " cut, be merely able to-add in asphalt quality clean difference (netdifferentiation), particularly by the content reducing residual volatile oil.Therefore, these " clean " cut and only account for the considerably less per-cent of tar charging (by mass 1%-5%), and for producing the tar distillation of carbon black oil, and its production object is by mass about 20%.Then by the oil at collected overhead by fractionation process, various cut can be reclaimed.According to circumstances, primary distillation is as under atmospheric pressure carried out described in patent CN102161901B, under reduced pressure carrying out [Ullmann] or as undertaken by steam stripped in AbderHalden continuous still battery scheme.The distillation strategy be used under decompression or steam stripped can reduce the thermal stresses of pitch.

After the distillation under steam stripped, by the oil wash of collected overhead, condensation dewatering, simultaneously by aqueous condensate stripping.These various operations are carried out simultaneously, thus can:

– reclaims the corrosives in aqueous condensate, therefore compared with the work-ing life of replaceable technology, adds the work-ing life of equipment for distillate oil and tower;

– reclaims very easily water-soluble organic substance, therefore, it is possible to prevent the significant production loss produced owing to contacting with organic phase with aqueous phase;

Organic phase is dewatered by –, thus can not cause any extra production loss at the top of the downstream column for distillate oil owing to forming the volatility azeotrope of water/tar compounds.

Then in one or more reforming reactors of series connection, under controlled temperature, pressure and residence-time conditions, by the pitch polymerization of reclaiming at the bottom of tower, thus its character can be regulated.

It is and then fractionation after the primary distillation carried out under decompression.The distillation that this distillation use is made up of several towers of connecting with primary distillation arranges (distillationtrain) and carries out.Vapor phase is directly sent in tower.By controlling to reflux to the recirculation of upstream column at the bottom of downstream column.Because do not reclaim corrosives before fractionation, at the bottom of these towers, water cooling and washing must be used.This will cause backflow wetting.Because some tar compounds and water form azeotrope, the in the end leakage of the water from steam of a top of tower causes the production loss relative to distilling under steam stripped.Oil reclaims with its normal boiling point descending.In the scheme that [H.-G.Franck] or [Ullmann] proposes, vacuum source diffuses to first primary distillation tower from last separation column.Due to the pressure-losses in whole tower, the resulting pressure bottom primary tower may be low not, make pitch dilution can not with such as, the pitch dilution obtained during the primary distillation with steam stripped is suitable.Then the pitch produced may than required heavy wool a little more.And according to destination properties, may be proved to be necessary by the unit carrying out extra downstream dilution of extra flash distillation.Or for the primary distillation under steam stripped, the pitch collected at the bottom of tower may experience extra reformation process.

The primary distillation under atmospheric pressure carried out can not obtain the separation of level identical with primary distillation under steam stripped or under reduced pressure: the pitch collected at the bottom of tower is light, has narrower boiling spread at the oil of overhead collection.This oil distillate stops (comprising the cut of methylnaphthalene) at washing oil place, and the compound with three or more aromatic rings stays (anthracene, anthracene homologue and heavier product) in pitch.Can be similar with tar heavy oil at the bottom of the tower of primary distillation tower.Therefore, in order to produce pitch according to specification, second time flashing operation (Fig. 6 and 7) is needed.Patent CN102161901 will be called term " carbon black oil " at the bottom of this tower; This " carbon black oil " comprises the pitch of about 60% in this case.Then it is under reduced pressure distilled to collect pitch (Fig. 6 a) at collected overhead heavy oil at the bottom of tower.But term used " carbon black oil " is misleading, because its usage with those skilled in the art and adopt its industrial specification not conform to.In fact, the oil identified thus should meet to be strictly regulated, and especially (is assessed by BMCI index (mineral bureau's close-burning index)) in their close-burning power.BMCI value is estimated as 30% when exceeding certain asphalt content, BMCI value affects (penalized) by asphalt content.The method described in CN102161901 is only finally a kind of modified version of " going to push up " method, which increases the separating unit not providing any routine that is remarkable especially or non-obvious performance factor extra.Therefore, CN102161901 describes a kind of enforcement (as shown in Figure 7-[Romovacek]) of old concept, namely by carrying out those skilled in the art's amendment easy to know to it.

Other variants of many flash distillations are described in, such as CN101139527 or CN1986735.CN10139527 describes and combines suitable method with prior art (" Clairton " method and [H.G.Franck] method) the middle principle existed.But the difference of the method is, it is introduced through sodium hydroxide washing and receives phenol back and forth between the primary distillation and fractionation of oil.But CN10139527 directly can not produce " carbon black oil ", and this will must be at least mix carbolineum cut and heavy wash oil fraction just getable result subsequently.Now, this mixture will not meet and will be used as " carbon black oil ", this is because will leave abundant residues sodium salt due to the operation of reclaiming phenol and be found in heavy washing oil.

CN1986735 describes a kind of tar distillation method, and it can produce three kinds of products: pitch, phenol mixed fraction and the wide fraction oil as fuel No.5.This production is by obtaining in conjunction with three kinds of operations to dehydration raw material well known by persons skilled in the art:

1. go to top to be separated with heavy compound ethereal oil in 240 DEG C;

2. with sodium hydroxide extraction phenolic compound (or tar acid), subsequently with the water-based cut of the acid treatment sodium phenylate of gained thus, thus the phenols cut that regeneration is separated;

3. flash distillation weighs compound, heavy oil separation and pitch under vacuo.

Although this refinements seem with prior art in exist suitable for those of Doak Tar Oil, its difference is the different in kind of handled raw material.The tar of CN1986735 process has the distillation very different from coal tar and composes: coal tar is made up of the pitch of 45%-55% by mass, and in contrast, when CN1986735, pitch is 24.8% by mass.The described raw material of remarkable small amount implies that this method does not process coal tar.

In order to the corrosion of limiting device composition material, before described various methods utilize interpolation neutralization bases to process primary tar or some oil distillate.Neutralization bases generally used according to preferred sequence is: sodium hydroxide, sodium carbonate, potassium hydroxide, salt of wormwood or calcium carbonate.Depend on that the type of method is different, different methods is adding at difference.These sodium salt, sylvite or calcium salts formed after adding are not volatile.Then, they tend in last running concentrated.If these cuts have the approval upper limit according to its specification, so the maximum of neutralizing agent is limited.Particularly, exempt quantities does not allow by processing oil and reclaims phenol, and neutralization is limited in part and mineral acid material, such as only a part of muriate." bottom cycle " type method for continuous still battery tar requires to add in charging tar.Therefore, salt is concentrated in pitch.Because pitch is for the restricted specification of maximum acceptable amount (maximum 500ppm, general 250ppm) of sodium, therefore the salt amount comprising sodium ion that can add is limited.In addition, tar comprises sodium, and this slightly lower the amount allowing the neutralizing agent added further.In fact, in this operation scheme, neutralization can not be completely.In many sudden strains of a muscle scheme under reduced pressure, neutralize in the reflux (reflux by " washing oil " fractions consisting) to first time separation column and carry out.As described above, this will cause introducing the water causing production loss.In addition, the method can not process all corrosivess because introduce separation column, the vaporizing oil that causes producing naphtalene oil with the amount of can not ignore, the material that can cause selective corrosion the temperature range of 180-220 DEG C.Therefore, neutralization is part.Finally, because sodium is not volatile, therefore can not excessively introduce.Particularly, sodium tends to become concentrated in the condensation mutually of flowing back to carbolineum cut I, II and pitch.In many sudden strains of a muscle production decision under steam stripped or normal atmosphere, neutralization carries out at the completely concentrated wide oil distillate from primary tower recovered overhead.Therefore, owing to only having processed oil, the pitch produced in these production decisions has not added sodium.On the other hand, the more last running being derived from fractionation is added into wide fraction oil handling hint: the existence being called the sodium in carbolineum, creosote or heavy oil according to name used.If these oil are used as carbon black oil, then the existence of sodium, potassium or calcium becomes crucial, the specification being 50ppm according to GOST1126 to the maximum than pitch strictly up to ten times.Therefore, the heavy oil total amount of collection can not be directly used in preparation carbon black oil: heavy oil partial must pass through Distillation recovery, and carbon black oil cut rests on carbolineum II cut.Therefore sodium is eliminated in heavy oil, but the carbon black oil of gained is comparatively light thus, thus in specification, especially boiling spread and coking aspect of performance are good not.

The production of carbon black oil represents the interests beginning of coal tar distillation industry.Consider the structure mentioned, if object produces this oil while being to produce pitch, then simple unit, the bottom recirculation that such as [Romovacek] introduces seems to be particularly suitable for.But it might not realize chemistry oil, correct economic balance between pitch and carbon black oil, because the profitability of the method only realizes by chemistry oil.Optimum balance is realized by following methods: it can produce the pitch with stability property, and for the scalable chemical product of the method, namely mainly the recovery degree of naphthalene is maximum, allows to form carbon black oil in the restricted limit of relevant regulations simultaneously.

Therefore, in those methods of document description, the sudden strain of a muscle method more than two kinds under decompression or under steam stripped is most suitable.But they all can not reach optimum performance:

– is owing to using neutralization method, and the method under steam stripped brings the loss of the heavy oil containing a large amount of salt, can not promote to form carbon black oil;

– part reduced pressure method can not bring best naphthalene to reclaim output, just in case in and washing oil reflux during excessive or too much shift sodium, carbolineum cut I and II can be polluted by sodium, causes the result identical with the heavy oil in the method under steam stripped.

In addition, have nothing to do with the processing scheme considered, must carbon black oil be formed: this means that it will obtain after the cut mixing fore-distillation.From energy, therefore the energy consumed during distillation is wasted, and the extra consumption relating to reconstruct mixture will be necessary.Have nothing to do with method described and used, seeming not have to describe can continuously and simultaneously with the preferred plan of three kinds of cuts below the yield production per year over 100000 tons of dehydrated tar equivalents on unit:

– retains the pitch not adding sodium of its script character;

The carbon black oil not adding sodium of – maximum production;

The chemistry oil of – optimum yield, such as, comprise naphthalene.

Therefore, in order to produce the coal tar distillation of the pitch, carbon black oil and the naphthalene wide fraction that are fractionated into independent cut subsequently simultaneously, just need to use the method for particular design to meet specification and the product overcoming above-mentioned shortcoming to produce.Present inventors have developed this special method, it is basis of the present invention.

Principle of the present invention is specify that the coal tar primary distillation of wherein coupling flash distillation effect and ethereal oil rectifying, thus produces three kinds of polycyclic aromatic hydrocarbons cuts and without any thermal ageing effect simultaneously, and not be used in charging to add and comprise alkali-metal salt.Consequent three kinds of cuts remain derived from raw materials used inherent nature, and do not experience any less desirable aging effect or add the non-volatile salt of any concentration for pitch and carbon black oil.Primary fractionation does not add alkali and alkaline earth metal ions.

Accompanying drawing explanation

Fig. 1 is the scheme according to prior art, shows the standard construction of the tar distillation according to Wilton method.

Fig. 2 is the scheme according to prior art, and display basis removes the standard construction of the tar distillation of top method.

Fig. 3 is the scheme according to prior art, shows the standard construction of the tar distillation according to the Hamilton method for the production of pitch and carbon geochemistry fuel used.

Fig. 4 is the scheme according to prior art, the standard construction of " bottom cycle " tar distillation that display Clairton is used.

Fig. 5 is the scheme according to prior art, is presented at the standard construction of the tar distillation of many sudden strains of a muscle type of the upper neutralization oil of washing oil backflow.

Fig. 6 is the scheme according to prior art, shows the standard construction of the tar distillation according to CN102161901B.

Fig. 7 is the scheme according to prior art, and display is supplemented with the standard construction of " bottom cycle " tar distillation of pitch flash distillation.

Fig. 8 is the schematic diagram that the equipment carried out according to the inventive method is described.

Fig. 9 illustrates the replaceable equipment schematic diagram carried out according to the inventive method.

Summary of the invention

The present invention proposes a kind of method of tar distillation, it produces three kinds of logistics in single primary distillation step: pitch, carbon black oil and naphthalene wide fraction oil.Described method can produce by its organizational structure the basic metal (carbon black oil of such as sodium (Na) or potassium (K) or alkaline-earth metal (such as calcium (Ca)) not adding any kind.The amount of carbon black oil produced according to the present invention reaches the amount that obtains with the prior art tar distillation being supplemented with the mixing platform prepared for carbon black oil quite or larger tonnage.Method of the present invention can control separation point between pitch and carbon black oil to regulate the character of pitch.Described method can also be produced by its organizational structure does not add the basic metal (such as Na or K) of any kind or the pitch of alkaline-earth metal (such as Ca).Regulate according to market demand and do not use the method for the hydrocarbon-fraction mixing fore-distillation, it can change the productivity of produced three kinds of cuts (pitch, carbon black oil and chemistry oil).In addition, method of the present invention can condensation chemistry oil vapour, and neutralizes them subsequently thus avoids polluting the chemical oil product having utility value and the production loss caused thereof.

Therefore, the present invention relates to a kind of coal tar distillation method comprising primary distillation, it is characterized in that it comprises:

1. by the mixture flash distillation of dehydrated coal tar and pitch, to obtain flash steam and pitch;

2. after flash distillation, carry out stripping and the rectifying of described flash steam immediately, thus the naphthalene wide fraction oil obtaining quality controllable carbon black oil and with maximum production, the naphthalene comprised in charging tar is concentrated,

A described pitch part obtained during flash distillation is used in the starting mixt of dehydrated coal tar and pitch.

Do not add alkali and alkaline earth metal ions and carry out primary distillation.

According to a specific embodiment, method according to the present invention comprised the step of being dewatered by coal tar before primary distillation.

According to another specific embodiment, described method comprise successively after primary distillation condensation, in and and the step of fractionation naphthalene wide fraction oil, thus obtain various chemistry oil.

The invention still further relates to the equipment for aforesaid method distillation dehydration coal tar, the system wherein for primary distillation comprises:

– flash zone;

– rectification zone and stripping zone;

– heating system.

System for primary distillation can be made up of the equipment that two pieces is independent, and the flashing tower be such as connected and rectifying and stripping tower are best collaborative to allow between each district, or incorporate flash zone by single-piece, the equipment of rectification zone and stripping zone forms.

Also vacuum condensation equipment can be comprised in rectifying and stripping tower downstream according to equipment of the present invention.

It also can comprise coal tar dehydration tower in flashing tower upstream.

Following description describes a specific embodiments of the present invention, wherein distinguish four staples:

– coal tar dewaters, for removing the water and generation dehydrated tar that comprise in charging tar;

– primary distillation tar, for producing pitch, carbon black oil (CBO) and combine the naphthalene wide fraction oil being commonly referred to carbolic oil, naphtalene oil and washing oil fraction in single cut simultaneously;

In – and primary distillation during condensation naphthalene wide fraction oil;

– condensate fractionation and neutralization naphthalene wide fraction oil, for reclaiming the independent cut of carbolic oil, naphtalene oil and washing oil.

Use assorted component distillation, carry out dehydration of tar with light oil as dewatering agent.The water comprised in tar is mixed with light oil, forms the azeotrope preferentially distilled at low temperatures.Then by the condensation of this gaseous azeotropic thing.Because it is heterogeneous, then by it by being layered as being separated mutually of two kinds of forms: organically light oil phase and aqueous phase.Therefore, the light oil of gained is the result of dewatering agent reconstituted form, described dewatering agent be optionally supplemented with exist in tar and be contained in light oil composition in benzene, toluene and xylene compounds.Then the light oil of this regeneration can be used as dewatering agent again.Retain remaining light oil for purposes subsequently in unit.This dehydration can by water content in tar by mass at most the form of about 7% limit carry out.Beyond this content, first by centrifugal mechanical separation the water content in tar must be reduced to and be less than 7m% by mass.

Be that the dehydrated tar of 0.5m% mixes with the recirculation pitch produced in flashing tower by maximum water holding capacity.This when leaving flashing tower be heat and can by heating system keep mixture between the dehydrated tar of heat and pitch can:

– first, dehydrated tar charging is preheated make its temperature reach in flashing tower with the temperature needed for all compounds of normal distillation temperature preferential evaporation being more than or equal to 350-360 DEG C;

Secondly –, dilutes volatile matter in proportion and makes the cut of evaporated volume not have enough energy pitch to be carried secretly flash steam distillation tower to directly connecting with flashing tower in non-volatile pitch barretter (ballast).

Pitch can be remained on temperature lower than 360 DEG C not cause the short contact of coal-tar pitch Quality Down and the residence time by heating system.

Determine the amount of the pitch being added into dehydrated coal tar, thus its energy is increased to enough levels by heating system, makes the mixture of dehydrated tar and pitch in flash zone reach the feeding temperature allowing flash distillation to occur, and be no more than the temperature higher than 350-360 DEG C.

The dehydrated tar processed by this way is obtained: it does not comprise in interpolation and material, such as sodium hydroxide or potassium hydroxide at the bottom of dehydration tower.

Flash zone is directly connected with the import between rectification zone and stripping zone.Carry out this connection with the charging of permission vapor phase.But in order to promote that the evaporation of heavy substance does not need to have in the bottom of flash zone excessive temperature, this assembly runs under vacuo.Therefore, according to one wherein three differentiations be distributed in the embodiment between flashing tower, rectifying and stripping tower and its condenser, they run under vacuo.Therefore, the temperature at the bottom of flashing tower is remained on one enough high with allow good separation but also enough low do not cause pitch from reform temperature.Excessive pitch is emptying at the bottom of flashing tower.Three single towers being designed for division flash zone and rectifying and stripping zone of district's composition.These districts are connected by pipeline, and thus this assembly forms the tower that can run under vacuo.Therefore, the temperature at the bottom of flashing tower is remained on one enough high with allow good separation but also enough low do not cause pitch from reform temperature.Excessive pitch is emptying at the bottom of flashing tower.According to the last specification of needs and the character of raw material, then pitch can be made in special purpose reactor to carry out controlled reformation and/or the adjustment of softening temperature according to the obtainable common rule of those skilled in the art and method.

Have nothing to do with embodiment, for the rectifying of flash steam and the combination of stripping zone, no matter it is made up of special carbon black oil rectifying tower or forms by by the compartment being exclusively used in stripping and rectifying carbon black oil in the larger tower of this function and flash distillation pitch/dehydrated tar mixture coupling, make it possible to controlled specification carbon black oil and and naphthalene wide fraction oils like chemistry oil lighter fraction between realize the separation point of clear and definite.This naphthalene wide fraction oil comprises carbolic oil, naphtalene oil and washes oil fraction.Due to the dilution effect relevant to the existence of carbolic oil and wash oil fraction, its naphthalene purity is lower than the naphtalene oil of rectifying.In order to control the quality of the oil produced, bottom stripping zone, adopting controlled boiling again, and adopt controlled backflow at top, rectification zone.Such as, then the energy that boils is by forming heating system, and the system of boiling again of the integral part of the economizer network of such as recovery furnace cigarette energy provides.Backflow can by returning a part at the chemistry oil of top, rectification zone condensation or control by the structure that fractionator is integrated into assembly, and described assembly forms carbon black oil rectifying tower and maybe will be exclusively used in the compartment of stripping and rectifying carbon black oil in the larger tower of this function and flash distillation pitch/dehydrated tar mixture coupling.

According to a specific embodiment, heating system is made up of one or more radiant-type furnace, each radiant-type furnace is equipped with the one or more economizer sections on the single spiral winding for the fluid to be heated that circulates and flue gas, described economizer section for reclaim obtainable energy thus for carbon black oil rectifying tower maybe by this function and flash distillation pitch/dehydrated tar mixture, preheat dehydrated tar charging, preheat stove combustion air, produce the compartment being exclusively used in stripping and rectifying carbon black oil in the larger tower of the couplings such as steam the energy that boils again is provided.

Vacuum condensing system is had low-loss interchanger to the completely concentrated pressure leaving the evaporation chemistry oil at carbon black oil rectifying tower top formed by what connects.This system uses the heat-transfer fluid of one or more closed loop cycle with recovered energy and uses it for the elsewhere of refinery, and such as in fractionating system, the first rectifying tower upstream preheats and to be supplemented with in light oil and naphthalene wide fraction oil.Collect condensation product in a reservoir.Kept under vacuo by whole piece equipment chain, vacuum is applied to cold oil collection container and adverse current spreads until at the bottom of flashing tower.

Then in two-phase contactor and cold oil.In and period, organic phase, namely cold oil fully mixes with the aqueous phase comprising neutralization bases.Then by sedimentation by two-phase laminated flow, by distillation process organic phase.Aqueous phase itself then mixes with the process water from pending dehydration of tar.In this and period, the corrosives comprised in oil (such as muriate, fluorochemical, sulfocyanate, thiocyanate-etc.) is caught by the basic metal that provided by alkali and/or alkaline-earth metal and water-soluble.One its be coal-tar middle oilly rich in the specific embodiments of tar acid (naphthenic hydrocarbon material and phenol derivatives), carry out neutralizing to attack the organic labile hydrogen of these corrodibility with more concentrated alkali.Then water-soluble salt is formed, such as sodium salt (as sodium phenylate).In this case, in and at the end of the process water collected process with separating available from process water dewater, especially in order to by means of supplementary water technology recovery aldehydes matter.

In this and afterwards, the oil distillate that decant can be gone out carries out fractionation.Before distillation, the shortcoming with water saturated neutralization oil is provided (will the formation of azeotrope to be caused during distilling in order to overcome, thus cause naphthalene to reclaim the loss of output), consider in this and the limited solubility of W/O, neutralization oil is supplemented with the unnecessary light oil collected in dehydration in proportion, thus only can form the assorted azeotrope of water+light oil.Because the distillation temperature of this assorted azeotrope lower than in and the lightest organic compound that comprises in oil distillate, output can not suffer a loss.

Then according to standard principle, the neutralization oil being supplemented with light oil is carried out fractionation.According to the trap-to-trap distillation cut increasing normal distillation temperature.The heads of first tower can reclaim carbolic oil.Head condensation be part, with make water+light oil mix azeotrope keep vapour phase.Therefore the first condensation product collected is carbolic oil.Then the total condensation point will the steam of condensation not had under these conditions to be cooled to assorted azeotrope.Enriched material is delivered to the decanting vessel of dewatering period to reclaim the light oil as dewatering agent.

Then, the bottom of first tower is distilled in second tower, to produce concentrated naphtalene oil at top and to produce washing oil in bottom.For any distillation, the degree controlling to boil and reflux can control the quality of discharging logistics.These boil and to carry out according to the obtainable technology of those skilled in the art.Similarly, those skilled in the art according to circumstances can revise the operational condition of these Distallation systms by known technology; Particularly, the type etc. of the type of column internals, stress level, equipment amount, heat exchange and condenser system.Depend on the circumstances, because the randomness implemented embodiment concrete grammar of special circumstances, such as, can use the character of cooling fluid, and need these to revise.

With reference to figure 8, the detailed description according to coal tar distillation method of the present invention of carrying out in the device in accordance with the invention will be provided below.

The coal tar 101 of the water comprising maximum 7% is by mass mixed with the light oil 102 that the mixture by benzene, toluene and dimethylbenzene forms.Become with benzene, toluene and dimethylbenzene to produce water in proportion with the amount of light oil composition Accurate Determining light oil according to the water content of tar, make the amount of benzene, toluene and dimethylbenzene for exist all water be enough, thus with these compound formation azeotropes.These ratios are controlled by the law of thermodynamics.Then the mixture 103 of preparation is preheated to the temperature of the azeotropic compound flash distillation in dehydration tower 10 making water+light oil compound.

In dehydration tower 10, water added the azeotrope steam raising of benzene, toluene and dimethylbenzene and discharge with the form of steam 104.Then by any suitable these steam of heat exchange system condensation.Therefore, in a common embodiment, cold fluid can be used such as to carry out condensation for the water coolant of condensation azeotrope steam by shell-tube exchanger.In another interchangeable embodiment, atmospheric condenser (aerocondensor) condensation azeotrope steam can be passed through.Then decant the steam of separating and condensing.Organic phase reused, a part mixes again with tar 101, and a part mixes with naphthalene wide fraction oil 302, and excessive discharges in unit exit.Aqueous phase is discharged in unit exit, then processes in Industrial cleaning facility factory.

Then mix at the dehydrated tar of dehydration tower 10 bottom collection with the hot-fluid 212 of oily bitumen.Then this mixture 201 is sent into flashing tower 20.This flashing tower 20 is connected with carbon black oil rectifying tower 22, vacuum cooler-condenser 24 and collection container 25.Kept under reduced pressure by the equipment of vacuum system by this group series connection.Vacuum is put on collection container 25, and adverse current spreads to condenser 24, carbon black oil rectifying tower 22 and flashing tower 20.This vacuum system by, such as liquid ring pump composition, the fitting of fluids in ring is for having low-steam pressure and compatible with polycyclic aromatic organic compound with aromatics organic compound.The oil defining the washing oil type of object for the present invention is especially applicable.Vacuum can also be produced by screw-type compressor or cam (" Roots ") pump.Vapo(u)r blasting or spouting of liquid vacuum system (" Hi-jet ") can also be used.In a first scenario, medium-pressure or high pressure steam is used.In the case of the latter, use has low-steam pressure and the liquid compatible with polycyclic aromatic organic compound with aromatics organic compound.For " Hi-jet " application, this liquid can be, such as, define the oil of the washing oil type within implication, carbolineum or heavy oil in the present invention.Other embodiments substituted also are possible, such as, combined by the liquid ring pump using the steam injector of low pressure or middle pressure steam and wherein liquid to be made up of water or the cooling condensation thing that is derived from injector.These various embodiments are nonrestrictive, and those skilled in the art can change vacuum system.

The mixture 201 of flash oil pitch and dehydrated tar in flashing tower 20.During this flash distillation, can evaporating elements 221 with constitute a charging part, the separated from bitumen that remains liquid under the temperature and pressure condition of tower 20.Pitch is collected with the form of logistics 202 in the bottom of tower 20.Logistics 202 is divided into two portions: a part 211 is by heating system 21 recirculation, and rest part exports the discharge of 203 places at unit.Measure by the amount of heating system 21 recirculation, thus its energy is increased to and is enough to make dehydrated tar stream in tower 20 reach the feeding temperature allowing flash distillation to occur by heating system 21, and the temperature that heating system exports 212 places is no more than 350-360 DEG C.Heating system 21 by, such as radiant-type furnace composition, wherein oily bitumen stream circulates in single spiral winding, prevents radiant-type furnace furnace flame superheated boiler tube by hot baffle.The radiant-type furnace that it also can be arranged in parallel by two or more forms.In interchangeable embodiment, heating system 21 is made up of electric furnace.In interchangeable embodiment, the electric furnace that heating system 21 is arranged in series by two or more forms.These various embodiments are nonrestrictive, and those skilled in the art can change heating system.

The organic steam 21 of flash distillation in flashing tower 20 is sent into carbon black oil rectifying tower 22.Carbon black oil rectifying tower 22 can control chemistry oil or the separation between naphthalene wide fraction oil 241 and carbon black oil 222.Separation point is guaranteed with speed of boiling again by controlling backflow.The condensate flow reclaimed in vacuum cooler-condenser 24 exit by returning a part controls backflow dose rate.Reflux very important for the separation point controlled between naphthalene wide fraction oil and carbon black oil.Backflow can guarantee the quality of naphthalene wide fraction oil.In an exemplary embodiment, the equipment that condenser 24 is connected by two pieces forms: the main condenser being arranged on fractional distillating tube on tower 22 or fractionator and being arranged on collector 24.In interchangeable embodiment, the equipment that condenser 24 is connected by two pieces forms: be arranged on fractional distillating tube on storage vessel and be arranged on the main condenser on collector 25, described fractional distillating tube be equipped with guarantee to the overhead reflux of tower 22 dedicated pump or be arranged so that backflow can be undertaken by gravity.In interchangeable embodiment, main condenser 24 is made up of the single main condenser be arranged on collector 25; The top flowing to tower 22 is guaranteed back up through gravitational effect or by dedicated pump.These embodiments each in, system 24 can be made up of the combination of the interchanger in shell-tube exchanger, plate heat exchanger, spiral interchanger or these technology.

By guaranteeing to regulate the thermal load in reboiler 23 to control to boil again speed.Speed of boiling again is very important for the recovery output of naphthalene in the quality of carbon black oil controlling to produce and naphthalene wide fraction oil vapour.In a specific embodiment, reboiler 23 is made up of the heat exchanger of the flue gas economizer type being arranged on radiant-type furnace 21 exit.In interchangeable embodiment, reboiler 23 is made up of radiant-type furnace.In another interchangeable embodiment, reboiler 23 is made up of shell-tube exchanger, and wherein thermal load is provided by the heat-transfer oil heated in generator.These various embodiments are nonrestrictive, and those skilled in the art can change heating system.

Carbon black oil stream 231 from logistics 222 is delivered to reboiler 23.Calculate the amount of transfer, make it possible to reach the required speed and the temperature of reboiler 23 exit carbon black oil can not be increased to above 350 DEG C of boiling again.Excessive carbon black oil 223 is discharged in unit exit.In order to optimize the amount of carbon black oil, according to a specific embodiment, can by excessive 223 and pitch stream 203 on-line mixing shifted.The ratio of mixture of preparation is that the amount of its medium pitch keeps being less than 30% of gained mixture still to meet the specification of carbon black oil, such as, by mass according to standard GOST1126.Because this on-line mixing hot-fluid carries out, slightly make it become viscosity and answered by the column bottoms pump experience Transportation Efficiency for recycle stream 223 and 203, it does not need extra energy input to carry out, and this is contrary with the mixing carried out under storing temp in a reservoir according to prior art.

The naphthalene wide fraction oil 251 collected in collector 25 is delivered to neutralisation unit 30 with the form of logistics 301, contacts with neutralization bases solution wherein.In a specific embodiment, contact and carry out in stirring tower.In interchangeable embodiment, contact and carry out in pulse-column.In another interchangeable embodiment, contact and carry out in decant mixing tank, this decant mixing tank can be made up of static mixer and decanting vessel.In another interchangeable embodiment, contact and carry out in a series of decant mixing tank, described series can comprise, such as 2-5 decant mixing tank.In another specific embodiment, neutralization bases solution spends mineral water and sodium hydroxide preparation.In interchangeable embodiment, the another kind of inorganic neutralization bases of sodium hydroxide, such as potassium hydroxide or sodium carbonate, calcium carbonate or salt of wormwood substitute.These various embodiments are nonrestrictive, and those skilled in the art can change the character of neutralized system or neutralization bases.

The naphthalene wide fraction of neutralization oil 302 is mixed with light oil 401.Amount according to the water content in the naphthalene wide fraction oil of neutralization and light oil composition Accurate Determining light oil produces in proportion to make water and benzene, toluene and dimethylbenzene, make the amount of benzene, toluene and dimethylbenzene to exist all water time enough, thus with these compound formation azeotropes.These ratios are controlled by the law of thermodynamics.Then the mixture 402 of preparation is admitted to rectifying tower 40.

Rectifying tower 40 is from common fractionation apparatus.In distillation tower 40, be separated following three kinds of cuts: the i) vapor phase 421, ii of the composition of light oil and water and water+benzene, toluene and xylene azeotrope) liquid distillate 422 of carbolic oil and iii) other oil collect at the bottom of tower with the form of wide fraction 404.Distillation tower 40 is equipped with return-flow system and system of boiling again.The quality of carbolic oil is controlled by return-flow system.This return-flow system is made up of the fractional distillating tube 42 only for condensation carbolic oil, and the azeotropic mixture 421 of water+light oil can not be condensed by fractional distillating tube 42.In a specific embodiment, fractional distillating tube is directly installed on the shell-tube exchanger on tower 40.Therefore, carbolic oil is condensation in pipe, flows back to tower 40 top by gravitational effect, and wherein a part is discharged with the form of logistics 422.The flow of logistics 422 is controlled by control discharge temperature, and to guarantee for quality needed for carbolic oil 422, tower is at correct operating point.According to this embodiment, the condensation of carbolic oil by carrying out with certain pressure evaporating cold condensate in the shell side of interchanger, and selected pressure to make the temperature of saturation steam higher than the condensing temperature of the least volatile azeotrope of water+light oil compound.Therefore, azeotropic mixture can not condensation by pipe.Then it can carry out condensation according to the situation of dehydration and azeotropic mixture in foregoing embodiments.In interchangeable embodiment, the interchanger that condenser 42 is arranged on collection container by bias forms.This collection container is placed in the mode making condensation product and can be recycled to tower 40 top by gravity part, or is equipped with the lift pump being exclusively used in and partial condensation thing being recycled to tower 40 top.According to this specific embodiment, it is contemplated that any hot swapping.As described above, partial condensation can be undertaken by transpiration cooling fluid.As described above, fractional distillating tube is by water vapor residual in only condensation carbolic oil, vapor phase and naphtha steam.Then these steam is collected according to aforementioned embodiment condensation suitable in dehydration and azeotropic mixture situation.

Boil is that logistics 411 by heating circulation in reboiler 41 is carried out again.In a specific embodiment, reboiler 41 is made up of radiant-type furnace.In another interchangeable embodiment, reboiler 41 is made up of shell-tube exchanger, and wherein thermal load is provided by the heat-transfer oil heated in generator.These various embodiments are nonrestrictive, and those skilled in the art can change heating system.

The oily stream of discharging from logistics 404 is delivered to reboiler.Calculate the amount of transfer so that required speed of boiling again can be realized, and the oil temperature in reboiler 41 exit is not increased to above 350 DEG C.Excessive oil 501 is sent into rectifying tower 50.

Rectifying tower 50 is from common fractionation apparatus.In rectifying tower 50, be separated following two kinds of cuts: i) concentrated naphtalene oil 521 and ii) at the washing oil 504 of tower 50 bottom collection.Rectifying tower 50 is equipped with return-flow system and system of boiling again.The amount of naphtalene oil is controlled by return-flow system.This return-flow system is made up of the condenser 52 for condensation naphtalene oil.In a specific embodiment, condenser is directly installed on the shell-tube exchanger on tower 50.Therefore, naphtalene oil is condensation in pipe, flows back to tower 50 top by gravitational effect, and wherein a part is discharged with the form of logistics 521.The flow of logistics 521 is controlled by control discharge temperature, and to guarantee for quality needed for naphtalene oil 521, tower is at correct operating point.According to this embodiment, the condensation of naphtalene oil by carrying out with certain pressure evaporating cold condensate in the shell side of interchanger, and described pressure selection is that the temperature of saturation steam is close with the value lower than the condensing temperature of naphtalene oil.In interchangeable embodiment, the interchanger that condenser 52 is arranged on collection container by bias forms.This collection container is placed in the mode making condensation product and can be recycled to tower 50 top by gravity part, or is equipped with the lift pump being exclusively used in and partial condensation thing being recycled to tower 50 top.According to this specific embodiment, it is expected to any hot swapping.As described above, partial condensation can be undertaken by transpiration cooling fluid.

Boil is that a part of logistics 503 by heating circulation in reboiler 51 is carried out again.In a specific embodiment, reboiler 51 is made up of radiant-type furnace.In interchangeable embodiment, reboiler 51 is made up of shell-tube exchanger, and wherein thermal load is provided by the heat-transfer oil heated in generator.These various embodiments are nonrestrictive, and those skilled in the art can change heating system.

The oil stream 511 of discharging from logistics 503 is delivered to reboiler.Calculate the amount of transfer so that required speed of boiling again can be realized, and the oil temperature in reboiler 51 exit is not increased to above 350 DEG C.Excessive oil 504 is discharged in unit exit.

In interchangeable embodiment, tower 40 and 50 under reduced pressure runs.Partial vacuum alternate embodiment with the assembly be made up of collector 25, condenser 24, carbon black oil rectifying tower 22 and pyrolysis residue flashing tower 20 is placed in vacuum under described those suitable.In interchangeable embodiment, tower 40 under atmospheric pressure runs and tower 50 under reduced pressure runs.Partial vacuum alternate embodiment with the assembly be made up of collector 25, condenser 24, carbon black oil rectifying tower 22 and pyrolysis residue flashing tower 20 is placed in vacuum under described those suitable.According to this embodiment, the boiling again of tower 40 can use auxiliaryly has the radiant-type furnace of convection zone to carry out.Then the deep fat 41 leaving this system is sent into as in the shell side of the shell-tube exchanger of reboiler 51, and the recirculation washing oil stream 211 being derived from logistics 503 is by described pipe.According to this embodiment, boiling again that single stove is two towers 40 and 50 provides institute's energy requirement.Therefore, consider the needs that boil again of two rectifying, regulate the calculating of the work capacity of common stove.

With reference to figure 9, the description according to coal tar distillation method of the present invention carried out in the device in accordance with the invention will be provided below.

According to this embodiment, principle is identical with those presenting in the description of Fig. 8 with function, except following difference.

The mixture 201 of flash oil pitch and dehydrated tar in the flash zone of independent primary tower 601.During this flash distillation, can evaporating elements 603 with constitute a part of charging, the separated from bitumen that remains liquid under the temperature and pressure condition of independent primary tower 601.Pitch is collected with the form of logistics 202 in the bottom of tower 601.Logistics 202 is divided into two portions: a part 211 is by heating system 21 recirculation, and rest part exports the discharge of 203 places at unit.Measure the amount by heating system 21 recirculation, thus its energy is increased to and is enough to make dehydrated tar stream in compartment primary tower 601 reach the feeding temperature making flash distillation occurs in district 602 by heating system 21, and the temperature that heating system exports 212 places is no more than 350-360 DEG C.

The organic steam 603 of flash distillation in the flash zone 602 of compartment primary tower 601 is sent in the compartment 604 that wherein there is carbon black oil rectification zone of compartment primary tower 601.Charging 603 is between the stripping and rectification zone of compartment 604.Carbon black oil rectifying compartment 604 can control chemistry oil or naphthalene wide fraction oil 241 and carbon black oil 222 between separation.This separation point controls with speed of boiling again by controlling backflow.Backflow dose rate controls by returning a part of condensate flow reclaimed in vacuum cooler-condenser 24 exit.Reflux very important for the separation point controlled between naphthalene wide fraction oil and carbon black oil.Backflow can guarantee the quality of naphthalene wide fraction oil.

Speed of boiling again controls by regulating the thermal load in reboiler 23.Speed of boiling again is very important for the recovery output of naphthalene in the quality of carbon black oil controlling to produce and naphthalene wide fraction oil vapour.In 23, the oil 222 of heating is back to below stripping zone but the bottom of the compartment 604 of outlet more than 222.

Logistics 203,223 and exceed 241 other Application elements and embodiment Fig. 8 in those are suitable.

Embodiment

Following examples set forth according to the coal tar distillation unit with 38600kg/h tar processing ability (by butt) of the present invention.Primary tar comprises by the insolubles in the quinoline of butt 1.2% and 50ppm sodium.

The primary tar 101 of water of 3% and Continuous Flow 102 on-line mixing of 6000kg/h light oil will be comprised by mass.Light oil composition be by mass 30% benzene, by mass 30% toluene and by mass 40% dimethylbenzene.Light oil content is excessive a little relative to water balance, with the fluctuation that water content in supplementary tar charging is possible.

The mixture 103 of tar+light oil is preheated with shell-and-tube exchanger.Heat energy is provided with the DowthermA type organic fluid of heat.Flash distillation hot mixt 103 in dehydration tower 10.Dehydration tower 10 is equipped with four pieces of spreader plates (dividingplate).The energy controlling to provide to preheat exchanger is to obtain the dewatered steam 104 of 95 DEG C of temperature.These steam are made up of the azeotrope of water+light oil compound.By the condensation be cooled to 50 DEG C in the shell side of shell-tube exchanger of these steam.The energy of condensation and cooling is provided by the water coolant circulated in exchanger tube.Then by the condensation product decant with assorted Azeotrope compositions.Aqueous phase is pumped into water treatment system.Organic fraction is recycled to tar charging 101, part is recycled to the naphthalene wide fraction oil 302 of neutralization, and excessive can obtaining in unit restriction place.The flow of these recirculation needed for various mixing and exhaustion point carries out.After this process, the tar of tower 10 bottom collection comprise by mass about 0.5% in conjunction with residual water.

Dehydrated tar is mixed with deep fat pitch 212.The temperature of oily bitumen 212 is set to make mixture 201 in pyrolysis residue flashing tower 20 ingress for about 360 DEG C.This corresponds to the flow 300m of pitch 203 ³/ h.Pyrolysis residue flashing tower is made up of flash tank, and described flash tank is used for being separated with remaining liquid portion oily bitumen by the steam discharged during flash distillation under the pressure and temperature condition of tower 20.At the bottom collection oily bitumen of flash tank, and it is distributed in again on one group of 6 pieces of spreader plate.Tower 20 runs under the decompression of-80kPa (g).The pitch 202 collected at the bottom of tower is recycled to two with total flux 211 for 300m ³/ h (i.e. each stove 150m ³/ h) radiant-type furnace 21 that runs parallel.Continuously with 17.6m ³the flow of/h discharges oily bitumen 203.The softening temperature measuring consequent oily bitumen according to standard A STMD3104 is 90 DEG C of Mettler.Quinoline-insolubles that it comprises 2.2% is measured according to standard A STMD2318.The pitch amount of discharging accounts for 54.7% of dehydration charging.The content considering the quinoline-insolubles of tar and the concentrated effect caused by flash distillation, this shows that the pitch produced does not cause forming certainly reforming of secondary quinoline-insolubles through any meeting.The sodium content of the oily bitumen produced is 92ppm.This increase is only relevant to the concentrated effect of the sodium amount contained relative to initial package in charging.

The steam 221 leaving tower 20 top is transferred to tower 22 by pressure difference effect.Tower 22 runs under the decompression of-85kPa (g).Rectifying tower 22 is equipped with the rectifying part of structured packing.Be positioned at the Stripping section under steam feed 221, this tower is equipped with 20 pieces of slit plates (slitplate).Boil again with vertical shell-tube exchanger 23, in pipe side via carbon black oil ring 231 charging being derived from logistics 222, be used in the DowthermA type hot-fluid heated in the convection zone of stove 21 in shell side side and flow to material.The spiral interchanger of picture fractional distillating tube is equipped with at the top of tower 22.Carbon black oil 223 is discharged continuously with adjustable flow 7720kg/h.It meets the strictest specification and standard, such as GOST1126.

Then the steam 241 not in the normal point condensation of the top interchanger of tower 22 exchanged condensation in the condenser 24 of type and cools under perfect vacuum at spiral, and collecting in buffer pool 25.These condensation products 251 are naphthalene wide fraction oil.Vacuum is applied to buffer pool 25 by cam (" root ") pump.Vacuum pump charging escorts condenser protection by two.Cooling energy is provided by the cold water in the hot water in the first condenser and the second condenser.Optionally by escort at these condensation product collected in interchanger again lead in and 30.Naphthalene wide fraction oil 301 is continuously pumped into neutralizing zone 30.

Neutralizing zone 30 is made up of the stirring tower being equipped with the many blade agitators of staged.Agitator runs with 10rpm.In stirring tower, naphthalene wide fraction oil stream is contacted with the sodium hydroxide solution of circulated in countercurrent.Use the sodium hydroxide of 2%.The amount of the sodium hydroxide of injection is changed according to the chloride content measured in naphthalene wide fraction oil.Sodium hydroxide is preheated to the temperature of naphthalene wide fraction oil charging.Keep the homo(io)thermism of neutralizing tower to avoid any phase in version risk.

Then in decanting vessel be separated in and naphthalene wide fraction oil and water.This organic fraction 302 is mixed with the light fluidizing oil 401 available from dewatering period.The amount of light oil is regulated according to the content of the water dissolved in decant and in naphthalene wide fraction oil.Then this mixed flow 402 is sent into rectifying tower 40.

Rectifying tower 40 is equipped with 35 pieces of single-pass slit plates in rectifying part, is equipped with 32 pieces of bilateral slit plates at Stripping section.Boil again under the assistance of the stove 41 of the logistics 411 of logistics 404 at heating source.Tower 40 and 50 is all with stove 41.Backflow is controlled by right angle setting shell-tube exchanger 42 on tower 40.Divide condensed steam 403 at tube side part, this guarantees backflow.The energy of the interchanger on shell side side and temperature are guaranteed by the generator water of evaporated vapor form under the pressure of 100kPa (g).Be made up of water+light oil azeotrope by the uncondensed vapor stream 421 of interchanger 401.As described above, condensation in shell-tube exchanger also cools these azeotropes, and wherein cooling energy is provided by cold water.By the decanting vessel of condensation product by gravity guiding dewatering unit, wherein they are separated.Carbolic oil is discharged with the form of logistics 422 continuously with regulating flow quantity 640kg/h at top board.The naphthalene wide fraction of neutralization oil is sent into tower 50 continuously with the form of logistics 501, wherein the naphthalene wide fraction of described neutralization oil is gone the impact of pushing up not to be subject to light oil distillate+water and carbolic oil.

Rectifying tower 50 is equipped with structuring filling in rectifying part, is equipped with 40 pieces of bilateral slit plates at Stripping section.There is provided be derived from the assistance of the economizer 51 of the logistics 511 of logistics 503 at hot spots under and boil again.Heat energy is provided by oil 411 at the bottom of the superheated tower in stove 41 exit.Backflow is controlled by right angle setting shell-tube exchanger 52 on tower 50.In pipe side condensed steam 502, this guarantees backflow.The energy of the interchanger on shell side side and temperature are guaranteed by evaporation boiler water under the pressure of 400kPa (g).The concentrated naphtalene oil of 92% is discharged from top board continuously with the form of logistics 521.Discharge continuously with flow 4250kg/h with the form of logistics 504 at the washing oil of tower 50 bottom collection.

Two rectifying tower 40 and 50 run under vacuo under the pressure of-85kPa (g).Vacuum is applied by liquid ring pump, and described liquid is the washing oil of 25 DEG C.

Logistics 203 and 223 is cooled in interchanger their storing temp, their torrid zone to DowthermA deep fat stream is used for adding thermal tar in the charging of tower 10.Excessive heat is used for producing steam under the pressure of 400kPa (g).Logistics 504 and 521 is circulated by heat exchanger, and wherein they are cooled to their storing temp by heating incoming flow 402.

The variant of the implementation detail of this embodiment is possible, as long as they do not deviate from object of the present invention.

reference

[H.-G.Franck]:H.-G.Franck,J.W.Stadelhofer,in“IndustrialAromaticChemistry”,SpringerVerlag,BerlinHeidelberg,1988

[Kirk]:“TarandPitch”in“Kirk-OthmerEncyclopediaofChemicalTechnology”,J.WileyandSons

[Ullmann]:Blümer,G.-P.,Colin,G.and H.2011.TarandPitch.Ullmann'sEncyclopediaofIndustrialChemistry.

[Romovacek]:G.R.Romovacek,LightMetals,1985,pp.793-803

Claims

1. comprise a method for the Doak Tar Oil of primary distillation, it is characterized in that it comprises:

-mixture of dehydrated coal tar and pitch is carried out flash distillation, to obtain flash steam and pitch;

Immediately by described flash steam stripping and rectifying after-described flash distillation, thus obtain carbon black oil and naphthalene wide fraction oil,

Pitch described in the part obtained during flash distillation is used in the starting mixt of dehydrated coal tar and pitch.

2. method according to claim 1, is characterized in that described primary distillation is carried out under partial vacuum, under steam stripped or under the combination of partial vacuum and steam stripped.

3. method according to claim 1, is characterized in that described primary distillation is carried out when not adding alkali and alkaline earth metal ions to described coal tar.

4. method according to claim 1, is characterized in that the softening temperature of the described pitch produced is 85-120 DEG C of Mettler.

5. method according to claim 1, is characterized in that described naphthalene wide fraction oil comprises the tar compounds that normal boiling point is 70-300 DEG C.

6. method according to claim 1, is characterized in that described carbon black oil comprises the tar compounds that normal boiling point is 300-450 DEG C, and not containing the basic metal added or alkaline-earth metal.

7. method according to claim 1, it is characterized in that described method is included in the step by pitch and carbon black oil on-line mixing after primary distillation, the ratio of its medium pitch accounts for the 0-30% of described mixture by mass.

8. method according to claim 1, is characterized in that described method is included in the step of condensation successively after primary distillation, neutralization and distillation naphthalene wide fraction oil.

9. method according to claim 8, it is characterized in that described neutralization be in the step of described condensation and described primary distillation not backflow carry out.

10. use the dehydrated coal tar distillation plant of the method as described in any one of claim 1-6, it is characterized in that the device for primary distillation comprises:

-flash zone;

-rectifying and stripping zone;

-heating system;

-system of boiling again;

-return-flow system.

11. dehydrated coal tar distillation plants according to claim 10, is characterized in that, described in the device of primary distillation:

-described flash zone and described rectifying and stripping zone are integrated in an independent tower, and the top of described flash zone is connected between described stripping and rectification zone.