DD212159A3 - METHOD FOR PRE-RUNNING AND / OR MAIN-RUN AND RUN-OFF SEPARATION FROM MULTIPLEX AND MULTIPURPOSE MIXTURES - Google Patents

Abstract

The invention relates to a method for flow and / or main run u. Trailing separation with minimal energy and material consumption from in particular multi-component and multi-substance mixtures, as well as temperature-sensitive substances. The invention has for its object to act on the evaporation and condensation process and on the media properties so that the separation of substances is accelerated and completely carried out on a short path with internal energy exchange u. thermal fission products are also secreted. According to the invention, the object is achieved by evaporating from a degasified and dewatered crude mixture, to which the condensate from a first condensation phase is added as the circulation amount, in a first partial evaporation beyond the phase equilibrium, all feedstocks and in a second partial evaporation under lower pressure a first main run u. in a third partial evaporation a lag evaporation u. Rueckstandsabtrennung takes place, whereupon the tamps of the first and third partial evaporation are combined u. these muffs in d. first condensation phase on outer surfaces d. rectifying evaporation d. Lead portions and separation of a second main run from the condensate from a second condensation phase of these tamps by twice partial re-evaporation on inner surfaces causes u. d. second condensation phase, d. again takes place on the outer surfaces, the evaporation of the first main run from the raw mixture, that causes the second partial evaporation, on inner surfaces.

Description

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Title of the invention

Process for flow and / or main run and tail separation from mixed and multi-substance mixtures

Field of application of the invention

The invention relates to a process, in particular for flow, main and tail separation from thermally sensitive split fatty acids of plant and animal origin.

In addition, the process may find application where the precursor and residual pressure separations need to be subjected to rectification conditions, such as. B. in the distillation of caproiactam, essential oils.

synthetic fatty acids, tall oil, amines, fatty alcohols, etc.

Characteristic of the known technical solutions

The crude fatty acids obtained by cleavage of vegetable oils and animal fats contain water in addition to dissolved air and in the subsequent thermal workup due to thermal decomposition or 'and Aucoxydation resulting, non-condensable at atmospheric pressure low-boiling organic compounds. Autoxidation may cause further fission products during storage and hydrolytic cleavage of the fats which greatly influence the odor, color, heat resistance and chemical properties of the split fatty acids. The thermal workup of the degassed and dehydrated raw material acids must be such that the distillation proceeds under such conditions, under which a thermal or autoxidative damage is avoided as far as possible with renewed formation of separate and heavy spaite products. The all required today Ausoeute to destiilieroaren fatty acids with the highest quality leads, especially when processing low-quality raw materials as a result of de ^r contained in the jerk Standen high boiling dye carrier and other organic contaminants to zusatzlichem apparatus and process technical effort.

The large-scale distillative work-up of canned fatty acids takes place in the processing stages degassing / dewatering, feed separation, main run and after-run separation. For degassing / dehydration and Voriaufaotrennung it is possible to use an ApDaratur consisting of an 8m long Durchiauf-Fallfilmverdamofer as Abtnebsteil and a 5m long packed column or tray column with 10 bubble cap as amplifier part. At the top of the column SiCN is a separator in which the water іга from the fatty acids deposited л / and is given to the column, the predominant ~ eii de ^r 'Eichten -ettsäurephase as RücKiaur. 3 distillation column is 13300 Pa and the temperature in the stripping section is between 180 and 220 ° C. The reflux ratio is in the range of 40 to 200 ⁰ C e'ngerege. "Siage, 4th fats, soaps, paints 32, Jg. 9, p.338-339) DE-OS 23528S9)

The main and Nacnlaufabtrennung carried out in succession by moving Geradeausstu ^f s. In the main stage, up to 90% of aerostable fractions are evaporated; and η de * - final stage to about -0% distillate. ! Stage, H .: fats, soaps. Paints, Jg.76, 197 1S74 p. 250) To avoid any entrained undesirable components, such as color carriers and unsaponifiable constituents, these columns are provided with acousne preparations and the effective steam velocities are measured in the range from 3 to max. In addition, it is customary for the product flowing from the degasification / dehydration stage to flow into a relaxation space. ^; n soft the steam velocity is kept slightly below 1 m / s comparable air velocity, to ladder, the nichtverriamofta proportion arranged in the lower left part of the expansion space Hauptfümveroamcfer another Verdamofung and the unevaporated portion is fed to a, the relaxation space right arranged falling film evaporator for residual evaporation , In order to avoid mechanical entrainment of clogged liquid particles or of the residue which has a higher corrtenate flow through the fatty acid vapors flowing from the expansion space to the condensation zone, the stemming apart from the inclusion of low vapor velocities at the droplet cutter

Featured "euroformao cutter".

, Stage, H .. Fats, soaps, paints 32, Jg.9, 1S8C pp 34.5-346) (DE - OS 2736357) Also known is a method with apparatus according to DD-PS 91 800, where the degassing / dehydration in a single-stage or multi-stage falling film countercurrent apparatus is performed and runs the main run and Nachiaufao separation in a nacngescnaiteten apparatus. In this plant, high-yielding natural fatty acids are distilled at vapor velocities of up to 6 m / s, with farpstacile distillates being obtained without additional precipitators.

wasserGutwasser, H. Voß, 3rd.: Chem. Technik November 19811 If necessary, the stripping distillates are subsequently freed by rectification of undesirable precursors and low-boiling fatty acids in the mainstream. In the known, Verfanren to Hauptlauf- and caster aotrennung an energy requirement of 100% based on the single evaporation, oenotigt.

For the Voriaufaotrennung the Energieoeoarf η dependence increased from the Rongemiscreigenscnaften and the separation method used by 20 to 30%, based on the unique Ve ^r damDfung.

The deposition of transferred color bodies and other impurities as well as the germge steam velocity in the pedestrian column room Pedingen in all these Ve-drive complex Apoaraturen and internals.

The desired high yield, especially for poor quality raw materials, can only be achieved with a reduction in quality of the final products.

For the rectification of weir and Vielstoffgemiscnen has already been proposed that only influencing the condensate to be evaporated refluxing condensates are recycled and obtained by multiple partial reevaporation of an end product as a distillate and a bottom product free of Leicnten shares. However, this Reictifikationsverfahren is only economically feasible for the recovery of existing only in small amounts of individual components of poly- and multi-component mixtures.

Object of the invention

The aim of the invention is to provide a process for flow and / or Hauptiauf- and tailing separation, which ensures the maximum yield of color distillates distillates in good quality and reduces the energy and equipment expense.

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Explanation of the essence of the invention

The invention involves the Aufgaoe on the Verdampfurgs urd condensate onsprozeß sow e effect on the media properties so that the separation is accelerated and completely on a short way rrit nternem energy exchange takes place urd thermal cleavage products are also separated Erfindungsgerraß the task is solved by that from the degassing and dewatered mixture of rons, to which a partial condensate flows in a conventional manner as a circular volume, in a first evaporation, a main run containing all the precursors, and in a second evaporation, a first main volume, and in a third evaporation, a first evaporation. Then the residue is separated and the steams of the first and third evaporations are brought together and these steams are contacted in countercurrent with the circulating partial condensate. Thereafter, the steams are totally condensed and a lint is emitted over the Phase equilibrium hinaLS / potting The unevaporated Ante I is withdrawn as a second main stream The steams containing the precursor are condensed From this polycondensate, a precursor is rectified, partly as an end product and partly as the condensate from the first and third evaporation in a similar manner supplied as a circulating amount E ^ fmdungsgemaß schrieben the fact that from the raw mixture to the precursor-free from eirer soater described condensation phase originating condensate is seen as KreisiauTgem η one or more falling film or thin-film evaporator *! with external heat supply in a first v'erdamp'urg a main run with all Vorlaufarteilen under a pressure of 380 to 420Рз vaporized jrd below a soeziel'en Koiorne zugeTuhrt werder The unverdampfte Rohgermscn is the inner surfaces of a downstream heat exchanger fed η those in a second Part The evaporation of a first main run under a pressure of ¹ OO or 200 Pa and a flow rate of 20 to 40 m is effected in condensed form. The rest of the flow is now η a further or mehrerei to 420Pa to the third or following evaporation and to the residue was evaporated with external energy oeneizten Falifilm or thin film evaporator ^ oei 380 the vapor of the third evaporation of the spezieilen column is also supplied to the bottom and the residue runs from the vapor de ^r first and third Partialverdamof ung η be the particular column in a first Kondersationsphase with hone ^r Stromungsgeschwnd gke tm ^ Bere'ch on 30 to 5Om ⁷ S to outer "Warmetausci = rflacher upwardly guided OÖN from the special Коюппе neraus and eoenfails above the outer surfaces of the / Varmetauscners zugeruhrt D supplies> e sRSte condensation phase the energy ^f for the later described bekanrte itself twice rectification the aolautende voriauffreie condensate is as circulation quantity of the first evaporation ζ "gegeoen> m outer Warm Swap ^r takes place Dere ts erwannte two ^f e Kordensatiorsphase of the vapor on the outer ^el acnen the second Partiaiverdarrotung ^b on the rneren F'ac en of the ⁿ // armetausc e ^r s causes the Damof Kcnae ^r sa * mixture wira jnten aogezogen from the heat exchanger and tctai Kondersie ^

This Konoensa 'w ll now at the head aer spezie'len Kolorre η а "to oeKannter way to the inner surfaces of a first partial vViederverdarrofung aufgegeoen η de ^r the Vorlau' at a honing Damofgeschwindigkeit from 30 to 50 rr s rektifizierend ube ^r the Phasengleichgewic ^ th is ausgedamptt naus and ^ n / erdampfte Kondersat as vo ^r iajf "e he Expires zwe'ter r-auotlau * on the ground de ·· first / Viederverdamorung D <= r Daript 3us aer prsten W ede ^r verdam3 ^T urg vvird konaens he abandoned * and on top of the second oart e ien / V Ede ^r verda ~ pctung surfaces on nnreren ^P Ir of zwe th Wiederverdampt "ng aampft rectly vulnerability curves ^r erd of the flow enriched from is condensing ert and a Теп aer the amount of Ie 'jna judges parts from the third ^D artialverdamoTurg entsoric ^b t discharged to arde ^r s part of the condensate from the second Kondersa +' Want """enes in Rongemiscn and gamma newly formed onsphase ais Kre'slauimenge zugefu ^ r Ten from the zwe / Vieder / erdanDfurg ^ ntsn ar ^ ailende Kordensat ng -oe ⁿ ta 'э aem condensate of zwe fen condensate onsphas? zugerriscnt as ^<r e'slauTrnenge

Эг fikatjon the RA the η le'sn - _a cns ^r occurs rr Gegenbtromphasenkontakt woDei from the first inner Flacne oei an effective DamptgeschwindigKeit 30 ois 5Om ⁷ S of the flow via the ^D hare equilibrium nmaus is erdamoft / and the second held ^r e Flat as actual ReKtmkationsstu ^ e - due to the circuit performance - d'ert the vorteilhaftesten pressure and Gesc ^b windigKeitsverha'trisse of DampTes in de ^r first and second Kcndensationsphase г and the first and second W'ede have / erdampfjrg ^ with ^p = Da ^{1 3} Da4 = ⁼ Da5 ~ 400 ^D a ura

^v Da1 = ОаЗ = 'Da5 ~ 45m / s nerausgestellx The Drijck and speed ratios η of the second partial Verdamprung the raw mixture Hegen preferably at ^a _3a ^ - 113Pa and Ѵ _Эa2 ~ 30m / s The from the Rettabtrennurg out äs ™ second " ^c ailfiim- or thin-film evaporator possibly durcn ^ ermiscne Umiagerungen newly formed eicnts edenden Arteue pass through the Kre slau ^ uhruig aes Koroensates from aer arranged outside aer column outer surfaces on dia first nternal surface η of the column for Vo ^r iaufabtrennung and not funren consequently rur deterioration of Hauotdestillate the from the residual vaporization with the steam high-boiling color carrier and org impurities, such as unver B unsaponifiable constituents, are attacked on the outer surfaces with little rectification

It entspncnt the nature oer Erindung л / епп <a Vorlaufarteile are vorharden or are not taken soller that then the condensates from the first partial evaporation and Restverdarrpfung outsid ^r half of the column, NAC ^h abgerührt the heat exchanger as end products and the vapor from the nreren ⁼ 'acne the heat exchanger outside the column separately condensed and ejected

An advantageous yerfahrersweise also bestent that the Ronprodukt η e'nerr Piesele ^r hitzer with the Heizrredierablauf from the f-allfnm- or Dunnscnichtverdamp ^ ern vorgeneziz up to boiling temperature and at a pressure or 3990 bts 13300Pa preferably 5320Pa degassed and dewatered

The solution according to the invention has the advantage that 20% to 30% energy compared to conventional e'ngespart reduced, the equipment cost by 50% and a high yield with very good quality is achieved even with inferior feed products necessary'ge in known processes 8m hone exchange pool reduces me to 3 m

_3- 244 001 6

embodiments

The method will be explained in more detail below with two examples.

Fig. 1 shows schematically the main run, caster and flow separation

Fig. 2 shows schematically the main run and follower separation without flow separation

example 1

From a dehydrated and degassed oil fatty acid with a fatty acid component of reien ^c = 96%, a flow amount of 2% and a main deck to be separated of 94%. The raw mixture F _n is fed to a trickle heater 1, which is heated with the heating medium outlet from the thin-film evaporator 2, and passes further into the thin-film evaporator 2, where about 50% of the Zulauforoduktes be evaporated at about 400Pa. The exiting vapor Da ₁ flows upwards at an effective vapor velocity of 45 m / s on the outer surface 3, which has a height of 3 m, in column I Dei 400 Pa and becomes at the top the outer surface of the outside of the column I arranged heat exchanger 4 supplied. The portion X ₁ not evaporated in the thin film evaporator 2 is supplied to the inner surface of the heat exchanger 4, which is under a pressure of 133Pa. By the heat exchange in the apparatus 4 at an effective steam velocity of 30 m / s, about 35%, based on the Rohgemischzuiaufmenge evaporate. This vapor Da ₂ condensed τη capacitor 5 and taken as finished product F ₁₂ (first Hauotlauf).

The non-evaporated from the interior of the heat exchanger 4 ^c Smile Friend fraction x ₇ is supplied to a second, arranged at the lower part of the column I falling film evaporator. 6 The unevaporated portion of about 4%, drawn on the Rohgemischzuiaufmenge, is set out as a residue F, ₃ . The after-run Da ₃ vaporized in the thin-film evaporator 5 with an amount of about 11%, based on the raw mixture addition amount, flows together with the steam on the outer surface 3 in the column! and is fed above the column I to the outer surface in the heat exchanger 4. The not yet koncensierte on the outer surface of the heat exchanger 4 Damof Da ₁ . Since ₃ , condenser 7 is condensed and all this condensate F _{4 is} fed to the first reevaporation on inner surfaces 8, which acts as a pure stripping column and therein a pressure of 400 Pa is maintained. Due to the temperature difference at the outer outer surface 3 and the inner surface 3, the partial vaporization Da _a of about 20% of the discontinued fibers F _{4 occurs} . This vapor Da ₁ is condensed in the condenser 9 and given up on a second heat / evaporation on internal surfaces 10, which acts predominantly as an amplifier column. Here about 10% evaporate. The amount of DaS is condensed in the condenser I ¹ and the condensate F ₁₅ is partly taken to about 2%, based on the Rchgemischzuiaufrrenge, as hocnangereiche'tes feed product F ₆ and partially admixed to the condensate F ₄ as a light cycle amount F ₇ . De ^r from the second inner F'äche 10 not vaporized and partially reduced to flow shares fraction F- ₈ of about 10% is also the condensates F ₁₄ and F ₇ admixed and now abandoned together on the first nnere surface 8 of Koionne I.

The vaporized Judges from the first inner surface 8 unc / on Vcriaufbestanateiien f-eie proportion F ₉ of about 59% is obtained as a finished product (2nd main run).

The liquid condenses which are deposited on the inner surfaces 8 and 10 cause partial condensation of the vapor Da ₁ -Da ₃ on the outer surfaces of about 30%, based on the raw mixture addition amount. This condensate Fi ₁₀ is zugemiscnt as Kreislaiifmenge csm Rongemisch and aufgegeoen the thin film evaporator 2 for re-evaporation. The energy consumption, based on a single evaporation, amounts to about 95% in this case. When processing inferior crude products with a free fatty acid content of about 59%, end products of about F will become available _; = 23%, F ₆ = 2%, F ₃ = 41%, Fi ₉ = 34%, based on the raw mixture additions. The energy consumption in relation to a single evaporation amounts in this case to about 107%.

Example 2

From a dehydrated era degassed Spaitfettsaure with 'reier ^ snsaureanteilen> 96% a Haurjtlauf of 96% is to be separated ao.

After heating the Rongemisches F ₁ at boiling temperature m R eseierhitzer 1 approximately 62% are evaporated to Zulaufrjrodukt at 400 ^p a in Dünnscnichtveraampfer 2. That steam there. flows with an effective vapor velocity of 30m / s in the column space ι and ooerhalD the column is supplied to a heat exchanger 4 arranged outside to the outer Fiacren. The ment evaporated portion x <from the! -Allfilm- or thin-film evaporator 2, the inner surfaces, which are under a pressure of about 133Pa stenen, the heat exchanger 4 is supplied.

Due to the temperature gradient at the outer and 'nneren F'ächen ⁱ rr heat exchanger 4 <cmrrt it to Teiiverdampfung Da ₂ of the' nneren surfaces aufgegeoenen Flussigke'tsmengen. This steam is condensed in the condenser 5 and ^f äiit as finished product _F: on. The slightly evaporated in the heat exchanger 4 Ante ¹ ! x ₂ ^w ' ^r d supplied to a disposed below the Koionre second falling film or thin film evaporator 6. In this about 11%, based on the Rohgemischzuiaufmenge evaporated. As the steam passes ₃ together with DA to the outer F'äcnen aes heat exchanger 4, the condenser 7 resikondensiert uno as a finished product F. ₉ discharged the non verdamofte in Dünnschichtveraampfer 6 content of about 4% F- ₃ .Rückstand! also falls as the final product.

The energy requirement, based on a one-time Verdamofung is about 73%.

If products with a free fraction of fatty acids of about 59% are processed, the quantities are approximately: Da = 38%, Da ₂ = F-, = 15%, Da ₃ = 6%. Since ₁ - Da ₃ = F., = 44% and F- ₃ , 'residue) = 4% The energy requirement, based on a former evaporation is about 35%.

Claims (5)

244 001 6 invention claims 1. A process for the separation of thermally sensitive multi-substance mixtures ^; Vacuum, after degassing and dehydration by distillation and subsequent evaporation and condensation and condensation of condensates, characterized in that the multi-material mixture is separated at a pressure of 380-420Pa in a main run containing the flow and a main stream containing the residue, the Residue-containing main run subsequent rectifying at 100-200Pa in a, representing a final product first main run and separated into a wake and this wake is evaporated to the separable residue, the resulting wake steam together with the flow containing main steam of the first evaporation in countercurrent with a back part condensate from it at a speed of 30 to 50 m / s and contacted under a pressure of 380 ^ 420Pa and then total condensed and from the resulting main condensate with simultaneous rectification a flow over the phase equilibrium out verd vaporizes, the unevaporated portion is recovered as a final product representing the second main run and condenses over the phase equilibrium out of the vaporized lead-containing vapors, circled and partially evaporated at 100-200Pa flow and then separated in a highly concentrated. 2. The method according to item 1, characterized in that in the distillation of a multicomponent mixture without flow components remaining after the recovery of the first main run and the residue remaining vapors are completely condensed as a second Hauptiauf. 3. The method according to the items 1 and 2, characterized in that the residue containing main run of the first evaporation is immediately subjected to a residual evaporation at 300 or 500 Pa, as a result of which the residue is seoarated. 4. The method according to item 1 and 2, characterized in that the exchange height of the arranged in the column outer and inner surfaces (3, 8, 10) is 2 to 5 meters, preferably 3 meters. 5. The method according to item 1 to 4, characterized in that the Rieseierhitzer (1) at the same time works as Entgasurgs-dehydration stage and hierein pressure of 3990-13300Pa, preferably 5 320Pa, upright genaiten. For this two sheets of drawings