SA92120442B1 - Separation of the aldehyde product mixture by distillation - Google Patents

Abstract

Abstract: The present invention relates to a method for distilling a crude aldehyde product mixture consisting of branched-chain and straight-chain aldehyde aldehydes in a single distillation column to obtain, simultaneously, three product streams separated from each other, i.e. to obtain a purified branched-chain aldehyde stream and two different streams Purified straight-chain aldehyde.

Description

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By distillation aldehyde Separation of a product mixture of aldehydes Full Description Background of the invention Raw from aldehyde This invention is directed toward a method for refining a product mixture of aldehydes in order to recover both a branched-chain aldehyde and a straight aldehyde The chain of it at once and separately. This invention was directed; better way; towards distillation of a crude oe aldehyde product mixture consisting of branched and straight chain aldehydes in a single distillation column to yield streams of three products separated into one J; That is, obtaining a purified branched-chain aldehyde stream and two different purified straight-chain aldehyde streams. Methods for producing aldehydes by hydroformylation of an olefinically unsaturated organic compound with carbon monoxide and hydrogen (usually referred to as syngas) in the presence of a rhodium-phosphorous complex catalyst rhodium-phosphorus and a free phosphorus ligand known as lua in art; as he watches; For example; by the basic low-pressure oxo hydroformylation process described in US Patent No. 7577486095 and the rhodium-catalyzed ve hydroformylation processes led by gas-liquid recycling described in US Patent No. 6 41524887 SEVEVEAT aldehyde The resulting mixtures consist of aldehyde and aldehyde products. 4097171 Regular (straight-chain) and iso aldehyde (branched-chain) match the raw material of olefin and result from the addition of a formyl group (-CHO) formyl at one of the YL carbon atoms Ac sana carbon The ethylenic (eg -CH=CH:-) of an olefin e.g. the hydroformylation of propylene results in the butyrate aldehyde oq.

. Normal butyraldehyde [CH,CH,CH,CHO] and iso-butyraldehyde [CH;CH(CHO)CH,]. In general, these hydroformylation processes are designed; Preferably to produce aldehyde products rich in the normal (straight-chain) isomer.

° Moreover; These continuous hydroformylation processes inherently produce “secondary high-boiling liquid aldehyde condensates” eg dimers. trimers and tetramers that may act as a solvent for hydroformation

chydroformylation 0 in addition to the heavy, liquid products (AY) and so forth. There is a small amount of these consistently high-boiling compounds (Logo) in the crude aldehyde product mixture obtained immediately after separation of the primary aldehyde product For its light compounds a) carbon monoxide (ccarbon monoxide) hydrogen (¢ hydrogen) unreacted alkylene and byproduct of alkane (calkane etc.) as in the case of a continuous hydroformylation process in which a gas is recycled or after Separation of the primary aldehyde product from its light compounds and the solution containing the catalyst, as in Alla, a continuous hydroformylation process in which a liquid is recycled. In fact, even after separating a low-boiling branched-chain aldehyde from its normal high-boiling straight-chain aldehyde counterpart in order to obtain a purified branched-chain aldehyde Ye (Da iso-butyr aldehyde) Leaving straight-chain aldehyde (e.g., normal butyr aldehyde ual), the product of normal aldehyde may still contain a higher amount of these heavy organic compounds than that desired for its end use. The traditional industrial technique up to this time in refining Yo and separating the branched-chain aldehyde product from the straight-chain aldehyde product in such crude aldehyde product mixtures as a result of the cq hydroformalization processes.

¢ Continuous hydroformylation catalyzed by such conventional rhodium by a two-step distillation method which includes the use of two separate distillation columns. For example, (Jal) a branched-chain aldehyde (Sie (iso-butyr aldehyde wall, for example) is first separated from the crude aldehyde product mixture by distillation in a primary distillation column, and then the aldehyde is refined aldehyde | 0 normal (straight chain) (eg galebutyr aldehyde) left over is further refined or purified from A remaining high-boiling by-products by a second distillation carried out in a second distillation column.

However, there are two major penalties associated with the commercial refining of the crude aldehyde product mixture using the Jie double distillation method. The first is the very high energy cost required to operate these dual distillation methods on a commercial scale. Secondly, a significant amount of aldehyde is lost due to its transformation at the reaction site into such heavy compounds during these distillation methods as a result of the use of high temperatures to recover the largest possible amount of straight-chain aldehyde from the aforementioned heavy organic compounds. Indeed; It has been estimated that up to LY to LY by weight or more of the straight-chain aldehyde Galatia Ty ve reaction site to ALS compounds is clearly a large amount in any commercial operation; Like the hydroformylation processes described cf

Which may produce hundreds of millions of kilograms of aldehyde per year. In a pre-commercial process carried out more than a year prior to the filing of this application at a plant in the United States owned and operated by the assignee (cad) the patent applicant conducted tests using a single distillation © column; Whereas, a purified branched-chain iso-butyr aldehyde was obtained by distilling some of the upper distillates and basically collecting all the normal straight-chain butyr aldehyde as distilled gas from a bottom side orifice of the same distillation column. However; As with conventional two-stage ld distillation procedures involving two distillation columns, the distillation temperature required to obtain essentially all normal butyr aldehyde a vo the side aperture of a single distillation column was essentially the same as the high distillation temperature (approx. 101°C (degrees Celsius) to about 5007°C) traditionally used in distilleries

Butyr aldehyde is an ordinary heavy organic compound in a second distillation column and thus causes essentially the same type of aldehyde-damaging loss resulting from the formation of heavy compounds at the reaction site as would normally occur in a second distillation column. It has now been discovered that it is not necessary to use such high distillation temperatures© in order to separate and obtain both purified branched-chain aldehyde and purified straight-chain aldehyde simultaneously from a product mixture of crude aldehydes using a single distillation column . Thus these disadvantages hitherto associated with the conventional distillation process for the refining of crude aldehyde product mixtures can be overcome or at least significantly reduced by the process of this invention which are explained more fully below. General description of the invention Therefore, one of the objectives of this invention is to provide a new method for refining a crude aldehyde product mixture containing branched-chain and straight-chain aldehydes; Which includes obtaining and separating a purified branched-chain aldehyde and a purified straight-chain aldehyde simultaneously by distilling the aforementioned crude aldehyde product mixture ve using a single distillation column. Accordingly; A general aspect of this invention may be described as a process for refining a mixture of crude aldehyde product liquid consisting primarily of about 795 to about 799.55 by weight of straight-chain and branched-chain aldehydes selected from the group of aldehyde having ¢ atoms carbon and aldehydes having “carbon atoms” on the basis of the total weight of said product mixture; The remainder consists mainly of ALS organic compounds, and the aforementioned process includes adding the raw material represented by the aforementioned liquid crude aldehyde product mixture to a distillation column and distillation of the aforementioned liquid crude aldehyde product mixture in the aforementioned distillation column at a temperature at the base ranging from about 1 C to about TO C above the normal boiling point of the straight vo-chain aldehyde present in the aforementioned liquid aldehyde product mixture as the starting material in order to simultaneously obtain: (i) product stream Aldehyde is a liquid aldehyde taken from apex or AL from

The top of the distillation column and consists mainly of purified branched-chain aldehyde and (i) a volatile aldehyde product stream consisting mainly of straight-chain aldehyde purified in an amount not exceeding about Ye by weight of the amount of aldehyde The straight-chain present in the aforementioned liquid crude aldehyde product mixture as the starting material; and less than 777 by weight of the 0 amount of heavy organic compounds present in the aforementioned liquid crude aldehyde product mixture as the starting material; and (ii) where the aldehyde residual lye consisting primarily of straight-chain aldehyde is recovered from the bottom or near the bottom of the distillation column and where the amount of heavy organic compounds present in the recovered lye aldehyde is less than about 1) By weight of the total amount of aldehyde fed to column 0 . distillation plus about 7197 by weight at least the amount of heavy organic compounds present in the liquid crude aldehyde product mixture as the starting material. BRIEF EXPLANATION OF DRAWINGS The attached figure is a process flow diagram according to the present invention illustrating the embodiment of a distillation column (01) for distillation of a crude aldehyde product mixture (line 1) to cause 1. instantaneous recovery of the aldehyde liquid yield Purified branched-chain aldehyde (A ha) at or near the top of the column and the purified straight-chain aldehyde as vapor stream (VY line from pend side) and the second purified aldehyde product (line (VE) at or near the bottom of the column. Detailed Description of Preferred Embodiments The crude aldehyde liquid product mixture used herein can be obtained from any Y. Conventional metal-catalyzed hydroformylation (preferably rhodium complex) Carried out in the presence of a free organic phosphorus ligand These (0x0) exo-processes and their conditions are well known in the art as shown by the continuous gas-liquid recycling processes in US Patent Nos. CEYEVEAT 415871 097177 and US Patent Application Serial number 70805 dated YY Yo Jun 9841 CE current US Patent No. 00077785 filed March 19 ca) 490 all data of which are incorporated herein for reference. Hydroformalization processes include cq.

this hydroformylation; in general; Production of aldehyde rich in its regular straight-chain isomers by reacting an olefinically compound with hydrogen and carbon monoxide in a liquid reaction medium containing aldehyde product catalyst superimposed rthodium-phosphorus organic rthodium-phosphorus “ld” phosphorus© free ligand and high-boiling secondary aldehyde condensate. And of course; It should be understood that the specific manner in which the hydroformylation reaction is carried out and the specific hydroformylation reaction conditions used are not critical to the present invention; They can be changed over wide ranges and configured to meet individual requirements and to produce the desired specific aldehyde product. le Ye The olefinically primary reactants for the hydroformylation process from which the raw materials for the raw liquid aldehyde product of this invention can be derived contain? or; Carbon atoms, illustrative examples of olefins include olefins, propylene, cl-butene, netweb-1 “propylene 7-butene-2-butene (adjacent (cis) or opposite (trans)) and 7-methylpropene propene 2 (isobutylene Vo) Of course, it is understood that mixtures of olefinically different starting materials can be used as desired. For example, it is sometimes common to use mixtures of 1-butene and 7 ?-butene 2-butene as the primary olefin 0 and the best olefin of all is propylene .propylene and methyl; any conventional catalyst can be used from rhodium-phosphorus complex © Moqantastam These catalysts and methods of preparing them, Lad, are well known in industrial technology. These catalysts may include rhodium-phosphorus complexes, i.e. organic thodium-phosphorus complexes, such as rhodium-phosphine catalysts. Organo or organo-rhodium-phosphite provided so far for such hydroformylation processes. Of course, Yo mixtures of these catalysts can also be used as desired. Furthermore. It is clear that the amount of catalyst of the superoxide present in the reaction medium of a given process should be the minimum amount needed to provide oq.

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the concentration of rhodium metal to be used; which will provide the basis for at least that catalytic amount of metal rhodium needed to catalyze the specific hydroformylation process desired. In general; The LH concentrations of rhodium shall be in the range from about 01 ppm to about 0001 ppm; Calculated on a free metal basis, it is sufficient for most hydroformalization processes “below 90:00000. It is generally preferred; The use of concentrations ranging from about 01 to Veo ppm of rhodium and most preferably from Yo to 500 ppm of rhodium calculated on the basis of the free metal. As indicated above; Hydroformylation takes place in the presence of a free rhodium ligand; meaning; Non-overlapping ligand with phosphorus rhodium overlay catalyst Ve used. However; While it is generally preferred that all phosphorus 5 be the same phosphorus ligand for the rhodium-phosphorus complex catalyst, this is not necessary and different ligands can be used in a particular process as desired. Accordingly; As in the case of the organic rhodium-phosphorus complex catalyst; Any conventional organic phosphorus ligand can be used as the free ligand; And such laces; Also, the methods of its preparation are well known in industrial technology. These free phosphorus ligands could include any of the organo-phosphine or organo-phosphate ligands presented so far for these hydroformylation processes. And of course; Mixtures of these ligands can be used as desired. Thus, the phosphorus process can be carried out using any excess amount of hydroformylation Y- phosphorus an amount of not less than one mole of the phosphorus ligand (JE) for every mole of rhodium metal The amount of free phosphorus ligand used depends, in general, on the desired aldehyde product and only on the olefin and the composite catalyst used. The free radicals present in the reaction medium, which range from about ? to about or more per mole of rhodium present, are bound to most objects.

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For example, in general, quantities of a triarylphosphine ligand (Da 3 a triarylphosphine ctriphenylphosphine Sa greater than 0 © mol or

The best is more than 100 moles of free ligand per mole of rhodium to achieve satisfactory results in terms of catalytic activity and/or catalyst stabilization while phosphorous ligands may help

phosphorus ° “sal on Jy eg” membership; ligands of alkyl arylphosphines, alkyl cycloaryl phosphines, and/or organophosphates provide acceptable catalytic stability and catalytic efficacy without inhibition.

Change (Da) the rates of conversion of some olefins to aldehydes when

The amount present of the free ligand in the reaction medium is low Jie an amount ranging from 1 to 001

0 mol, preferably 15 to 1 mol per mole of rhodium present. Specifically. Examples of catalysts for rhodium-phosphorus complexes and illustrations of free phosphorus ligands include; For example; those that are detected

About it in the American patents, No. 8, 7 AD; MF SEYEVEAT v0 EA 67 .44 41 CONTACT REQUIREMENTS EVYTYO Le ¢€TTATOY

EAACE VY Nick Tac EVITA ¢ EVEATYTY RAMAL s 1 EAT 910/9 yo and the international patent application according to the Patent Cooperation Treaty (Publication No. August 9801 AD). Among the ligands and catalysts of the complexes, 71 (published in 10

The most preferred that can be mentioned on (JE dae) triphenylphosphine Ji ligand and rhodium-triphenylphosphine complex catalysts

614,088,760, US Patents Nos. 7,877,864 and triphenylphosphine | 0 and alkylphenylphosphine ligands alkylphenylphosphine ¢£YEVEAT and rhodium- and catalysts for cycloalkylphenylphosphine rthodium-phosphine J 8 and rhodium-cyclo-alkylphenylphosphine ¢€, YAY,01Y mentioned in US Patent No. cycloalkylphenylphosphine

Organic rhodium- and phosphate complex catalysts and phosphite ligands Organic Yo 1177 US Patent Numbers organophosphite

oq.

Ye

Marra NB (£VIVYVO 7/7/4751 Matthew 5 LEVEAYTY The best ligand of all is triphenylphosphine (TPP) (pind) while the preferred catalyst is a catalyst

rhodium superimposed TPP—thodium LS also noted above; Jeli performs hydroformylation in the presence of a so condensed high-boiling secondary aldehyde. One of the nature of these continuous hydroformylation reactions is the production of high-boiling secondary aldehyde products such as Sle, dimers, trimers and tetramers. (tetramers) at the reaction site during the hydroformylation process as explained in greater detail; for example, “Jad in Qed 0 US Patent Nos. 8 4415/4487 7474487 and/A 04717 and US Patent Application Serial No. 2708686 dated YY Jun a) AAT These aldehyde by-products provide an excellent carrier for a liquid recycling catalyst. Indeed; while one can use any suitable solvent” as desired; when starting a continuous process (preferably aldehyde compounds matching the desired aldehyde products); vo the primary solvent at the end will usually include both aldehyde products and secondary high-boiling aldehyde condensates due to the Jota nature of these continuous processes. And of course; CAS aldehyde products (ody gi) aldehyde can be produced as desired; and use it accordingly. It is also evident that the amount of these secondary high-boiling aldehyde 08 products present in the reaction medium may vary over wide ranges and is generally limited only by the constraints of the equipment and the particular aldehyde product to be produced. and for example; The hydroformylation reaction can first be carried out in the absence or presence of small amounts of high-boiling secondary aldehyde condensate as a solvent for the rhodium composite catalyst “Ph0” or the reaction can be carried out in the presence of more than 0 by weight or up to 79560 by weight and more than the by-product condensate oda on a vo basis on the total liquid reaction medium. In general; The ratios of aldehyde byproducts to high-boiling aldehyde condensate byproducts are within the range of about cq.

11 by weight should suffice for most purposes. Similarly, it is necessary 1:01 to about 11 to understand that slight amounts of other conventional organic co-solvents are present as desired. Within wide hydroformylation ranges, while the conditions of the hydroformylation reaction may vary in general; Run the process at a total gaseous pressure of hydrogen (Junaid) from Wiel as explained © and the unsaturated olefinic elemental carbon monoxide carbon monoxide chydrogen kg / cm' (+100 psi absolute) and preferably Less than 015,* less than olefinically

YE kg/cm' (£00 lb/in' absolute) and most preferably less than about 70.6 lb/in' absolute). The minimum total pressure of the reactants is not particularly critical (YO) ' kg/cm and is determined primarily only by the amount of reactants necessary to obtain 0 preferably the partial pressure of carbon monoxide ST the desired reaction rate. Specifically, according to this invention, from about hydroformylation in the process of carbon monoxide hydroformylation (pounds per inch (VY) (kg/cm) AEE (pounds per inch' absolute) to about 1 (g/cm' YoYHY

TY g/cm' (¥ lbs/in' absolute) to about 701.97 at); the best is from about kg/cm' (90 lbs/in' absolute) while the partial pressure of hydrogen is preferably ve kg/cm' 11.76 lbs/in' absolute) to about 10 Tafa VT's of about 11 tapa (1,000 lbs/in' absolute) hydrogen (Ble lbs/in' absolute) or better than about (VT) in pounds per inch' absolute). In general, the ratio may vary (100 (kg / cm) 7,071 to about from about gaseous carbon monoxide to hydrogen carbon monoxide, the molarity of hydrogen, and the most preferred is that the molar ratio ranges from hydrogen Jel or :001 to about 1:01 x ion of about 1 to about carbon monoxide to carbon monoxide hydrogen In addition, as mentioned above, the hydroforming process may be carried out at a temperature of reaction ranges from about 0 °C to about hydroformylation at hydroformylation 0 °C However, in general, hydroformylation processes are preferred (£0 and most preferably from about 5 We C to about 0 °C reaction temperatures Ranging from about Ye M. 111 Lam to about Ye

VY

Thus, as stated in this statement, “the raw aldehyde liquid product mixtures used as the raw materials in this invention consist mainly of aldehydes and heavy organic compounds, and possibly some of the free organic phosphorus ligand used in the hydroforming process ¢hydroformylation The mixtures obtained after separating the primary aldehyde product from its light compounds (compounds with boiling points lower than those of the aldehyde product compounds in the case of continuous hydroformylation) are preferred. In which the gas is recycled or after separating the primary aldehyde product from its light compounds and the solution containing the catalyst, as in the case of the continuous hydroformylation process in which the liquid is recycled. The raw aldehyde product mixture used here on the raw material of olefin for the hydroformylation process from which the aforementioned product mixtures are derived. Such aldehyde may contain; Or © carbon atoms Jia ccarbon Four- and five-carbon aldehydes derived from propylene and butylenes, respectively. Furthermore; It is understood that vo aldehydes are produced as mixtures of normal (straight chain) aldehyde and iso aldehyde (branched chain). Thus illustrative examples of aldehyde products include four-carbon aldehyde mixtures of normal butyraldehyde (normal butanol), iso-butyraldehyde (iso-butanol) and mixtures of aldehyde five carbons of normal valeraldehyde asl (2-branched chain isomeric pentanal; i.e. “normal”-methyl-butyraldehyde pentanals) and Y. pentanal and/or bivaldehyde 3-methyl butyraldehude butyraldehyde Litham-0 methyl butyraldehyde mentioned have molar ratios of aldehyde and mixtures of aldehydes may contain pivaldehyde up to 1:1 BCH ranging from about normal aldehyde to aldehyde aldehyde or higher; neither The upper limit of aldehyde compaction 1:00 about Jie determines the high percentage aldehyde that provides the hydroformylation aldehydes product mixture except by hydroforming the raw Yo as the feedstock. oq.

VY

Similarly, the heavy organic compounds contained in the crude aldehyde product mixtures that may be used herein include any organic solvent and organic by-product having boiling points higher than those of the straight-chain aldehyde compounds of lee hydroformylation derived Including mixtures of product, Shall overburdened aldehyde condensation products, aldehyde | 0 Secondary liquid (dimers, trimers, tetramers, etc.) discussed above.” eg in US Patent No. 51,484,876 and another common high-boiling byproduct” eg the corresponding alkanol. Of course, it is understood that these crude aldehyde product mixtures may also contain small amounts of residual light a compounds (eg unreacted olefin and an organic phosphorus by-product Ss alkane). Jie is a free organic phosphorus ligand and/or its corresponding oxide; phosphorus compounds bearing an alkyl substituent that may exist as a result of their formation at the reaction site or as a result of their intended use in the hydroformylation of the crude liquid aldehyde Aldehyde product mixtures “JB” and for example vo hydroformylation as feedstocks which can be used here can be derived from a hydroformalization process involving gas recycling such as those described in the foregoing patents illustrated and the reference article in EY 5,974,485 detailed in US Patent No. “(Davy McKee) International Journal of Davy McKee VY 187/1947 Indications Published by YA Department of Public Affairs to Ye and pg. p. 1 of Ye England The mixture oad (Davy Corporation) of Davy Corporation used here can similarly be derived from a catalytic process to recycle the aldehyde crude liquid (Say) as described in the aforementioned and preferably described patents; At US Patent No. 45,497,177 for example; Primary Reactor System in Figure, Canadian Patent No. 1,707,777, US Patent Application Returning to Assignee Yo, Existing US Patent ca) AAS Juni YY Filed with Serial Number 77078505 of 09d.

Y¢

0017975 as well as the concurrently filed US Patent Application Serial No. 101 entitled: “An Improved Hydroformylation Process” which ay towards a New Method for the Separation of Light Compounds from a Product Mixture of Caldehyde and the data for these applications are fully incorporated into This statement is for reference. The crude aldehyde ° liquid product mixtures used herein are preferably derived from catalytic hydroformylation processes involving liquid recycling. Further, as noted from the aforementioned prior art, as is the case with recycling processes Gas It is preferable to remove at least most of the light compounds from the aldehyde product mixture from a liquid recycling catalyst process before separating the branched-chain aldehyde isomer from the high-boiling straight-chain 0 aldehyde. Regardless of the type of purification steps used to separate light compounds and/or impurities of organophosphorus compounds from the mixture of crude aldehyde products obtained from a liquid recycling catalyst process, it is preferable to pass the raw aldehyde product dada through Stabilizer such as that shown in Column 1 of the drawing on page YY of the Indicators article mentioned above before using the aldehyde product mixture

raw Vo aldehyde as the liquid feedstock in the process of this invention. Thus the mixture of the crude aldehyde liquid product which can be used here may consist mainly of about 745 to about 794.95 by weight; It is preferred from about 747 to about 799.90 by weight of caldehyde based on the total weight of the aforementioned liquid product mixture. The remainder of the aforementioned liquid product mixture consists mainly of organic compounds.

And accordingly, with reference to the attached drawing, which schematically shows the invention (coal), the refining process of this invention may be carried out in any suitable distillation column that has two side openings to withdraw the liquid and the evaporating currents from the aldehyde product. Thus, the mentioned distillation column includes any distillation column or A packed column or other suitable evaporating apparatus (01) in which vo distillation of the present invention may occur. See for example the "Handbook of Chemical Engineering"; edited by Perry and Shelton; 5th ed.; OPT p. Fig. OT Page VF oq.

Yo©; As well as the book “Operational Units in Engineering 0-1 and page 1-18, Figure 04

LEA page GAN ed. (Smith) and Smith (McCabe) McCabe Al dl gal Chemical” The actual type of gaskets or trays in the shaft is not a critical part of this invention; It may use any kind of trays or fillings. In addition the number of trays or stages

Jail separation used shall be non-critical and shall be sufficient only to conduct operations 0 liquid crude as the desired aldehyde feedstock. Thus, the mixture of similar aldehydes in degrees of isomers is introduced into the distillation column in the usual manner to separate the isomers (Y) line on a normal diso-butyraldehyde and the butyraldehyde isobutyre butyraldehyde i.e. by boiling it For example, at a point some distance from the top and bottom of the column; preferably somewhere at the aldehyde in the middle of the column. Again the exact point of introducing the aldehyde product mixture 0 as the feedstock is a non-critical issue of the invention and can be determined as such Preferred; with the usual engineering practice. Liquid crude as the starting material to remove the aldehyde and then distill the product mixture of normal aldehyde branched chain purified liquid aldehyde and iso-aldehyde both iso-aldehyde compounds withdrawn (JU) purified straight-chain as well as light compounds thereof, for example evaporated light ve aldehyde (i.e. substances having a boiling point lower than that of aldehyde etc.) in the form of unreacted calkane upper product; branched-chain olefin alkane; Olefin-like (VY) and partially or fully condensed (collecting vessel (V0) (line); where it can be cooled (water coolant; Non-condensate is removed (line 1) and the condensate is recovered; in addition, if desired some overhead condensate may be returned to the column (by line 7)* Ye. to act as a reflux. The purified BCH (which is lighter; i.e. has an iso-aldehyde and the regular straight-chain iso-aldehyde may be removed) at or near the top of the aldehyde has a lower boiling point than that of the branched-chain aldehyde mentioned as a current Either side of the iso-aldehyde distillation column, it is preferable to remove the iso-aldehyde liquid aldehyde (line 8), somewhere above the feed point of the vo 0d aldehyde product mixture.

liquid raw. The exact point is not critical and the preferred point is determined by normal engineering practice. The evaporated, purified, straight-chain aldehyde is simultaneously removed as a vapor-side stream (VY line) somewhere below the feed point of the 0-product liquid crude aldehyde mixture. Again, the determination of the point The minute of such removal is not critical; the preferred point may be determined by common engineering practice.If also desired a vapor draw separator (not shown in the drawing) may be used to return any liquids from the evaporated straight-chain aldehyde stream to the column however Any drawing separator is unnecessary or essential to embody the process according to this invention. The Ve aldehyde and the remaining purified liquid (VE line) are recovered from the bottom or near the bottom of the column. As desired a portion of the aldehyde may also be heated. straight chain that leaves the bottom of the column in a reboiler (01) and returns it to the column. The aldehyde purified liquid recovered 1 is less than about 71 by weight of the total amount of aldehyde fed to the distillation column plus at least about TY by weight of the amount of heavy organic compounds present in the crude aldehyde product mixture liquid as the raw material. Distillation of the liquid crude aldehyde product mixture as the starting material in the refining process of this invention may occur under conditions such as temperature at the bottom of a column. distillation ranges from about 1 C to about ° C and preferably from about 10 C to © av above the normal boiling point (i.e. at 0.,17785 kg/cm' VEY lb/in) absolute ) of the straight-chain aldehyde in the liquid crude aldehyde product mixture as the starting material; and at a pressure at the top of the distillation column within the range from about 1,006 kg/cm 1 (lb/in standard) to about REL 7301 kg/cm (lb/in standard) and preferably From ve about 1 014 kg/cm (1 lb/in' standard) to about 7.04 "ofan 10 lb/in' standard). The conditions (such as temperature, pressure, rewind rate, etc.) are .oq

Lal

at the apex portion of the distillation zone where vaporized light compounds are removed and the All-branched aldehyde is limited to non-critical; It depends only on the explicit process conditions necessary to achieve the desired result of removing these light compounds and obtaining a bypass of said liquid aldehyde which is essentially 0 1.44 . at least by weight of branched chain aldehyde and less than about #9 by weight of the amount of heavy organic compounds present in the crude aldehyde product mixture (JL) as the starting material. Furthermore; Preferably, the amount of branched-chain aldehyde in the liquid obtained in this way should be essentially  glue; The amount of branched-chain aldehyde present in the liquid crude aldehyde product mixture as the starting material. Of course, it is 0 > to understand that the amount of heat needed to distill aldehyde compounds may be provided by any conventional heat exchanger. like that; It should be understood that while the optimal conditions for the Gy process of the present invention necessary to achieve the best desired results and efficacy depend on one's experience using the Gag process of the present invention; A certain amount of experimentation is necessary to ascertain those conditions which are ideal for a given situation; This shall be within the knowledge of ve those skilled in the art and ideal conditions can be easily attained by following the most favorable aspects of this invention as I have explained herein and/or by simple repeated experimentation. for example; high distillation pressures are required; in general; High distillation temperatures are required

Low distillation pressures Low distillation temperatures. In general; It is preferable to find a reciprocal relationship between the conditions of temperature and pressure, Ye, at the base in the process of this invention, so that the amount of purified volatile straight-chain aldehyde obtained by the aforementioned side stream does not exceed about Ye of the amount of aldehyde. The straight-chain present in the liquid crude aldehyde product mixture as the starting material and where the aforementioned selected volatile straight-chain aldehyde contains less than about LTT by weight of the amount of heavy organic compounds present in the Ye aldehyde product mixture Liquid crude as the raw material. 5 eagle It is preferable to associate adverbs of the base so that dun ty is removed from no less than about * to no more than 270

YA aldehyde straight chain present in the aldehyde product mixture aldehyde by weight of aldehyde evaporated straight chain aldehyde raw liquid as the raw material by way of the aldehyde stream find a reciprocal relationship between the conditions mentioned in a manner Lad must (Jilly The aforementioned side. It is preferable that the aforementioned purified straight-chain aldehyde 26 obtained by this method ranges from zero to about +77 by weight of the amount of heavy organic compounds 0 present in the liquid crude aldehyde product mixture as the substance And the most detailed is that the aforementioned purified straight aldehyde (ALL) obtained by this method contains less than about 701 by weight of the amount of heavy organic compounds present in the liquid crude aldehyde product mixture as the starting material. 1 The remaining purified liquid aldehyde product may be removed and easily recovered as a liquid stream from the bottom of the distillation column and consists mainly of straight-chain aldehyde in a proportion ranging from about (IF about 795 by weight of the amount of straight-chain aldehyde present in the liquid crude aldehyde product mixture as the starting material; the amount of heavy organic compounds present in said recovered liquid aldehyde is less than about 1 vo by weight of the total amount of aldehyde fed to the distillation column plus not less than about 7797 by weight and preferably not less than about 7980 os by the amount of heavy organic compounds present in the aforementioned liquid crude aldehyde product mixture as the feedstock.The refining process of this invention is in fact unique in its kind Whereas Ye not only saves some amount of the very high energy cost Tolan to omit the traditional dual distillation procedures described above to this time; Load eliminates or at least significantly reduces the above CAE in aldehyde Due to the transformation of some of it at the reaction site into heavy organic compounds associated with previous distillation processes; It also ensures recovery of the streams of three different purified aldehyde products from a single distillation column.

And of course; The aldehyde products that have been hydroformed have several known uses, Tas, and are primarily traditional. It is best to use aldehyde products

These are also traditionally used to produce alcohols and other useful solvents. The following examples illustrate the present invention and do not limit it at all. It must be understood that it expressed all parts and proportions referred to in this statement and in the attached claims of weight, unless otherwise indicated; According to the amount of rhodium given on the basis of

Free metal weight. EXAMPLE 1 The following computer (computed) experiment illustrates the present invention. According to the drawing; 0 Feed about AYALY kg/hr (VAT (lb/hr) of a raw mixture of normal butyraldehyde and iso-butyraldehyde containing about 70.7 by weight of lighter constituents than iso- butyraldehyde and about 4 by weight of constituents heavier than normal butyraldehyde in the form of a stream 7 to the sixty-one theoretical tray calculated from the bottom of the distillation column in which there are 110 theoretical trays. The vo light impurities were removed along with some aldehyde branching from the top of the column. partly condensed by cooler 10 and collected in a collection vessel .117 and some of the resulting liquid stream was returned to the column for reflux as stream 7; About 84.04 kg/hr Yoo (lb/hr) was removed from the system in the form of two waste streams? and 1. A side liquid stream at a rate of about 4.4 97 kg/hr 7001 (lb/hr) was taken from theoretical tray 01 calculated from the bottom as Y. iso-butyraldehyde (stream of (A). A side vapor stream at a rate of about Yeo, kg/h (4 VY lb/hr) from the third theoretical tray calculated from the bottom was taken as the product of normal high-purity butyraldehyde (Hes stream ( VY this vapor stream was passed through a small intake separator (not shown in the drawing) to remove any suspended liquid from the vapor stream.A liquid stream at a rate of about 9001lb/h (9001lb/h) was removed from the bottom of the column as vo Purified ordinary butyraldehyde wall (VE) and the temperature at the base of the distillation column was about 44 C and the pressure at the top of the distillation column was about 1.74 kg/cm" (01)

0 in iso-butyraldehyde sidestream (lb/in) standard). The aldehyde isobutyrate content was about 744.9 by weight; The content of heavy compounds in the upper butyrate aldehyde (A) stream is about 70.97 by weight; The ratio between the concentration of normal lower butyraldehyde (VY) heavy compounds (VE) in the feed stream to the concentration of heavy compounds in the lower vapor sidestream was essentially equal to about VE of about 1:700. The content of heavy compounds in stream 0 was about 0.1 by weight of ad lime yall by weight of the content of heavy compounds in 0

The content of the aldehyde mixture in the current.

Yes? We provide the following actual operating data from a commercial system to illustrate the present invention. 0 and according to the drawing; Feed about AYA 0.0001 kg/hr (lb/hr) of a crude mixture of normal butyraldehyde and iso-butyraldehyde containing about 0.601 by weight of lighter components than iso-butyraldehyde and approx. 7 by weight of components heavier than ordinary butyraldehyde in the current form? to the sixty-first theoretical tray from the bottom of the distillation column in which there are 015 theoretical trays. ve and light impurities along with some branched-chain aldehyde were removed from the Aad column; Partially sieved by refrigerant V0 and collected in the collection vessel VY and some of the resulting liquid returned to the column for reflux as stream©; About 89.04 kg/hr (Yo) was removed from the system in the form of the two waste streams? and +. A side liquid stream at a rate of about 768.7 kg/hr (TIVE lb/hr) was taken from theoretical tray No. VY from the bottom of the distillation column as iso-butyraldehyde (+ stream). A side vapor stream of YYYT kg/hr (00 lb/hr) was taken from the third theoretical tray from the bottom as normal high-purity butyraldehyde (Tes (VY). This vapor stream was taken through a small intake separator (not shown in the drawing) to remove any suspended liquid from the vapor stream A liquid stream at a rate of about 070.7 kg/hr (17775 lb/hr) was removed from the bottom of the column as the second purified normal butyraldehyde Yo (stream (VE and the temperature at the base of the distillation column was about 5100°C and the pressure at the top of the distillation column was about 1.1 kg/cm” AS) 09d.

The iso-butyraldehyde content in the upper side stream (A) was about 749.7 by weight; the content of heavy compounds in the lower normal butyraldehyde (VE) stream was about 7007. by weight; the ratio between the concentration of heavy compounds in the feed stream to the concentration of heavy compounds in the lower side vapor stream (VF) was about 1:76 0. The content of heavy compounds in the stream (VE) was essentially equal to about 70,000 By weight of the content of compounds ALE in the stream (Y) adding al about 70.04 by weight of

The content of the aldehyde mixture in the current (Y).

example? The following (computed) experiment illustrates the present invention. call Why Feed 0 approximately ASV 18450 kg/hr (lb/hr) from a raw mixture of normal butyraldehyde and iso-butyraldehyde containing approximately 70.7 by weight of lighter constituents than isobutyrate aldehyde, iso-butyraldehyde and about 77.7 by weight of the JE components of the normal butyraldehyde in the form of a current? to the sixty-first theoretical tray from the bottom of a distillation column containing 01 theoretical tray. Light impurities were removed along with some ve aldehyde branching from Add column; Partially condensed by refrigerant 10 and collected in the NY collection vessel some of the resulting BL stream was returned to the column as tema ALY stream and approximately 01.825 kg/hr (YE lb/hr) was removed from the system as The drain currents Y and +. A liquid stream of ils at a rate of about 917.7 kg/hr (050 lb/hr) was taken from theoretical tray No. 017 from the bottom as iso-butyraldehyde (stream (A |) and a side steam stream was taken At a rate of 00.8 YY kg/hour (00 YY lb/hour) from theoretical tray No. © from the bottom as a product of pure Je sole butyraldehyde (stream 11). Day This vapor stream is passed through a small intake separator (not shown in the drawing) to remove any suspended liquid from the vapor stream. A liquid stream at a rate of about 5711.6 kg/h (9674 lb/hr) was taken from the bottom of the column as purified normal butyraldehyde (VE) ob. The temperature vo was at the base of the distillation column about 101 m and the pressure was at the top of the distillation column is approximately 64 kg/cm' 01 (lb/in" standard). The aldehyde isobutyrate content was iso-

YY

butyraldehyde in the upper sidestream (A) is about 799.8 wt; The content of heavy compounds in the normal lower butyraldehyde stream (V8) is about 5.1 by weight; The ratio of the concentration of heavy compounds in the feed stream to the concentration of heavy compounds in the lower vapor sidestream (VY) was about YT and the heavy compound content in the VE stream was essentially equal to about 7001 by weight of the heavy compound content in stream Blas to about 70.46 by weight of the aldehyde mixture content in stream 7. EXAMPLE > The following (computed) experiment illustrates the present invention. According to comma ll he fed about 9887.4 kg/hr 777001 (lb/hr) of a raw mixture of regular and branched-chain pentanals 0 containing about 0.1 by weight of lighter components than the branched pentanals and about 70.7 by weight of constituents heavier than ordinary pentanal in the form of a stream 1 to the sixty-one waiting tray from the bottom of a distillation column having a Veo theoretical tray. Light impurities were removed along with some aldehyde branching from the top of the column; partly condensed by refrigerant 106 and collected in collection vessel IY and some of the resulting liquid vo-stream was returned to the column for reflux as ©-stream; Approximately 4 81.0 kg/hr (01 lb/hr) was removed from the system as two drain streams * and +. A side liquid stream (A stream) at a rate of about YAAY, A kg/h (7700 lb/hr) was taken from theoretical tray No. 013 from the bottom as a branched aldehyde product (mainly 7-methyl 2-methyl butyrate aldehyde (butyraldehyde). A side steam stream was taken at a rate of about VAVEY kg/h (00 EY © | lb/h) from the third theoretical tray from the bottom as a product of Je sale pentanal. Purity (Dey stream 11.) This vapor stream was passed through a small intake separator (not shown in the drawing) to remove any suspended liquid from the vapor stream. A liquid stream was removed at a rate of about AY, kg/hr (VY eet) lb/ h) from the bottom of the column as a second purified normal pentanal (VE) and the temperature at the base of the distillation column was about 7491 °C; and the pressure at the top of the distillation column was about 1.7 kg/cm. 01 (lb/in standard).. The branched aldehyde content in the upper sidestream (A) was about 794.8 by weight; the content of heavy compounds in

YY

about 7007 by weight; The ratio between the concentration of (V6) normal lower pentanal heavy compounds in the feed stream to the concentration of heavy compounds in the lower steam side stream was essentially equal to 16, and the content of heavy compounds in the stream was NYE about (VY) 1.0.09 about ad) Glas ¥ by weight of the content of heavy compounds in stream 7001 to about m by weight of the content of the aldehyde mixture in stream 7. It will become apparent to one skilled in the art that several Modifications and modifications of this invention; It should be understood that these modifications and modifications are within the scope of this fag and the scope of the accompanying safeguards.

Claims (1)

Y¢ Protection Elements 1-1 process for refining a mixture of aldehyde product, crude aldehyde, consisting mainly of about Y5 to about 794,558 by weight of straight-chain and branched-Y-chain aldehydes chosen from the group consisting of aldehyde aldehydes. It has four carbon 3 atoms and the aldehyde has five carbon atoms based on the total weight ° of the aforementioned product mixture; The remainder consists mainly of organic compounds ALE and 1 the aforementioned process includes adding the aforementioned liquid crude aldehyde product mixture v as the starting material to a distillation column; And the distillation of the aforementioned liquid aldehyde crude product mixture A in the aforementioned distillation column at a temperature at the base ranging from about 1 C to about a Fe higher than the normal boiling point of aldehyde “1” straight chain in The aforementioned liquid aldehyde product mixture as 11 raw material to obtain in one OF: (i) liquid aldehyde product stream VY taken from Ad or near the top of the distillation column and formed as purified primary branched-chain aldehyde Vw and (i) a volatile aldehyde product stream consisting principally of straight-chain aldehyde Ve-aldehyde purified to an amount not exceeding about #70 wt. straight-chain aldehyde vo aldehyde present in the aforementioned liquid crude aldehyde product mixture Vi as the raw material and less than 777 by weight of the amount of heavy VY organic compounds present in the aforementioned liquid crude aldehyde product mixture YA as the feedstock; and (i) where the aldehyde the remaining purified liquid 4 consisting primarily of straight-chain aldehyde is recovered from the bottom or near the bottom 0 of the distillation column; Whereas, the amount of organic compounds (ALE) contained in the recovered purified (Jill) aldehyde 71 is less than about 09 by weight of the total amount of aldehyde YY fed to the distillation column in addition to about 717 by weight at least of YY the amount of organic compounds Heavy aldehyde in the crude aldehyde product mixture Ye liquid as the raw material. : Yo : =v \ process of claim Cua 1 The distillation takes place at a base temperature Y from about 10 °C to about 5 °C above the normal boiling point of aldehyde 1 and said straight chain. 1 *- A process according to the protection element Cua oF aldehyde aldehyde in the aforementioned raw aldehyde Y aldehyde product mixture used as the raw material is butanal Jb su ¥ normal and iso-butanal JUL en . 1 ;- A process according to the protection element oF where the aldehyde in the aforementioned raw aldehyde Y aldehyde product mixture used as the raw material is ordinary pentanal Jt Ay and branched-chain pentanals. 1 0— process according to claim 1 wherein the distillation takes place at a pressure at the top ranging from about 0.014 kg/cm'' 1 (lb/in' standard) to 3.147 kg/cm' (Vo) Y psi" standard). (psi” standard) to Tafa aS 0.15 (10 psi” standard). inch” standard) to 7.04 kg/cm 1 (kg/cm’ 0.014 from approx. 7 Yaa yf Jha \ 0) cq.