A way of separating olefins from saturated hydrocarbons

 

(57) Abstract:

Usage: petrochemistry. Essence: spend contacting a feedstock containing olefins and saturated hydrocarbons with a linear polyaromatic compound under conditions effective to form a reaction mixture containing adducts of linear polyaromatic compound - olefin and saturated hydrocarbon. The resulting adducts are separated with getting the stream of saturated hydrocarbons and flow adducts of olefins. This was followed by a dissociation of adducts with obtaining linear polyaromatic compounds and compositions of olefin may emit linear polyaromatic compounds. Effect: increase the efficiency of the process.7 C.p. f-crystals, 2 tab.

The invention relates to a method of separation of olefins from saturated hydrocarbons, and more specifically to a method of separation of olefins from saturated hydrocarbons in the stream of the Fischer-Tropsch (FT).

In many industrial processes receive streams of olefin/saturated hydrocarbons, which are a mixture of olefins, saturated hydrocarbons and oxygenates. Olefins are often used when obtaining polymers, such as polyethylene, kacestveno. In some industrial processes receive the threads of olefins by oligomerization of ethylene over a catalyst to obtain alpha-olefins with the formation of mixtures of alpha - and nikocevic olefins with a wide range of number of carbon atoms in the molecule. However, the use of data streams based on the use of ethylene as a feedstock, which significantly increases the cost of production of olefins. On the other hand, FT-process starts with a low-cost feedstock, the synthesis gas, typically derived from natural gas, coal, coke and other carbon compounds, obtaining oligomers consisting of olefins, aromatic compounds, saturated compounds and oxygenates.

However, CFT-way has a very high selectivity for olefin production. While the reaction conditions and the catalysts can be selected in such a way as to obtain in the stream of FT product stream enriched in the desired compounds, a large percentage of FT-stream contains other types of connections, which must be separated from the olefins, the olefins cleaned and then sell them in different markets. For example, a typical commercial FT-stream will contain a mixture of n is karbonovye acid, alcohols, ethers, esters, ketones, aldehydes and small amounts of aromatic compounds. All of these compounds must be separated from the raw (untreated) PB-flow before specific composition can be offered commercially. To further complicate the operations division FT-stream contains compounds with a wide range of number of carbon atoms in the molecule, as well as a wide variety of olefins in the range FROM2-C200connections, linear non-end olefins, linear alpha olefins, branched non-end olefins, branched alpha-olefins and cyclic olefins, many of which have similar molecular weight. Separation and isolation of these compounds is not an easy task. Commonly used methods of distillation often can not be applied for the separation of compounds with similar boiling points.

Different ways were suggested for effective separation of the various compounds in PB-flow with a degree of purity sufficient for a particular composition would be acceptable for its intended use. These methods highlight different compounds in PB-flow include the use of molecul, which is more limited in comparison with a composition containing a wide range of medium quantities of carbon atoms in the molecule in the range FROM5-C20, the use of exchange resins, the use of superfractionation columns, often working under high pressure, and the use of catalysts for the oligomerization or methods of esterification to change the boiling points of the compounds in the FT thread. However, in many reactive methods of separation of compounds in PB-flow cannot be selective reaction with olefins while ignoring the reaction of paraffins.

It would be desirable to perform the operation of division PB-flow so that the activity and lifetime of the separating agent did not decrease would be due to the presence in the flow of impurities such as oxygenates; so the agent remains active and in the case of compounds with a wide range of medium quantities of carbon atoms in the molecule in the range of C5-C20and distinguished in the FT thread olefins and paraffins.

U.S. patent No. 4946560 describes the allocation method nikocevic of olefins, alpha-olefins by contacting the feedstock with a connection leading to the formation of the adduct, the same is on under the action of heat with getting anthracene and composition of olefins, enriched with alpha-olefins, and the allocation of anthracene from alpha-olefins. This reference does not suggest the desirability or the use of anthracene during the operation of the separation of saturated hydrocarbons and olefins.

US - A - 4579986 describes a method of obtaining a linear olefins having at least 10 and not more than 20 carbon atoms per molecule. Experiment cracking (6) in the above-mentioned document describes a light liquid fraction essentially consisting of linear C5-C20- olefins. It is reported that the olefin content is 95 %, and the content-olefins equal to 90%.

The present invention relates to a method for separating olefins from saturated hydrocarbons in a feedstock, including:

a) contacting a feedstock containing olefins and saturated hydrocarbons with a linear polyaromatic compound under conditions effective to form a reaction mixture containing adducts of linear polyaromatic compound - olefin and saturated hydrocarbon;

b) Department of adducts of linear polyaromatic compound - olefins from saturated hydrocarbons in the reaction mixture to obtain a stream of saturated hydrocarbons is - the olefin with obtaining linear polyaromatic compounds and compositions of olefin; and optionally

d) isolation of the linear polyaromatic compounds formed in stage (C), from the composition of olefins;

the concentration of olefins in the olefin composition is increased compared with the concentration of olefins in the feedstock.

The flow of the treated feedstock contains at least olefins and saturated hydrocarbons. The class of saturated hydrocarbons, as used in the description, include, at a minimum, the paraffin. The class of saturated hydrocarbons may also include other molecules such as cycloparaffin.

Olefin means any compound containing at least one double bond in the carbon - carbon bonds. The olefins may be linear, branched, paired, can contain multiple double bonds in any position along the chain can be substituted, unsubstituted, and may contain aryl or alicyclic group, or contain heteroatoms.

The olefins may contain in the same connection aryl units together with aliphatic or cycloaliphatic link, or they can consist solely of alifatic the situation. Preferably, the olefin is aliphatic compound.

The olefin may be branched or linear. Examples of branching include alkyl, aryl or alicyclic chain branching. The number of sites of unsaturation along the chain is also not limited. The olefin may be mono-, di-, tri -, etc. - unsaturated olefin, optionally paired. The olefin may also contain unsaturation acetylene type.

The alpha-olefin is an olefin, in which the double bond is located both on-and on-carbon atoms. -carbon atom is any terminal carbon atom regardless of how long is the chain relative to the lengths of the other chains in the molecule. The alpha-olefin may be linear or branched. Branching or functional groups can be located on the carbon atoms forming the double bond, the carbon atoms adjacent to the carbon atoms forming the double bond, or anywhere else along the main carbon chain. The alpha-olefin can also be polirom, which has two or more sites of unsaturation can be anywhere along the molecule to until at least one domoina link is located anywhere along the carbon chain, with the exception of any terminal carbon atom. Reconcavo olefin may be linear or branched. The location of the branching or the substituent on the non-end olefin is not limited. Branching or functional groups can be located on the carbon atoms forming the double bond, the carbon atoms adjacent to the carbon atoms forming the double bond, or anywhere else along the main carbon chain.

The olefin can also be substituted reactive chemical functional groups. Examples of chemically reactive functional groups are carboxyl, aldehyde, keto, thio, a simple ester, hydroxyl and amine groups. The number of functional groups in the molecule is not limited. The functional group can be located anywhere along the main carbon chain.

The feedstock is typically receive in commercial processes, such as the oligomerization of ethylene, optionally with subsequent isomerization and disproportionation. Alternative raw materials can be obtained in the Fischer-Tropsch process, the raw material usually contains a large amount of paraffin. In the way Filequery chain. Other methods of obtaining raw materials, which may contain a mixture of olefins and paraffins include the dehydrogenation of paraffins, such as obtained by means Pacol from UOP, and the cracking of waxes. The most preferred feedstock is the raw material, which is obtained during the synthesis of Fischer-Tropsch (FT).

FT-catalysts and reaction conditions can be selected so that the stream of reaction products to obtain a specific mixture of compounds. For example, a particular catalyst and reaction conditions may be selected so that the flow to increase the amount of olefins and to reduce the amount of paraffins and oxygenates. Alternatively, the catalyst and reaction conditions may be selected so that the flow to increase the number of paraffins and to reduce the amount of olefins and oxygenates.

Generally, reaction conditions will vary depending on the type of equipment used. The temperature of the FT-reaction ranges from 100 to 500°C, the gas pressure at the inlet of the reactor ranges from atmospheric to 10.3 MPa (1500 psig) and the ratio of H2/WITH ranges from 0.5 : 1 to 5 : 1, preferably from 1.8 : 1 to 2.2 : 1, and average speed p the traditional vessel, including a fluid (held) layer, a fixed layer and the suspended layer. The temperature in these layers may be selected by a person skilled in the art in such a way as to optimize the formation of PB-products, including hydrocarbons, particularly olefins and olefins. As an illustration, without limitation, a fluid (held) layers (layer), the reaction temperature, usually high - for example, in the range from 280 to 350°C., preferably 310 to 340°C. If you will use a reactor (reactors) with a fixed layer, as a rule, the reaction temperature will be in the range from 200 to 250°C., preferably from 210 to 240°C, and if you will use a reactor (reactors) with suspended layer, as a rule, the reaction temperature will be in the range from 190 to 270°C.

The catalyst used in the FT-method, is any catalyst known in this area, but preferably it is chosen from molybdenum, tungsten and compounds of group VIII, including iron, cobalt, ruthenium, rhodium, platinum, palladium, iridium, osmium, and combinations of the above components, combinations with other metals, and each of these Ggogo connection either in the form of a salt. Catalysts based on iron and cobalt have found wide commercial application, and ruthenium has gained importance as the metal catalyst, which in the conditions of high pressure stimulates the formation of high-melting waxy compounds. The person skilled in the art will understand, what are the catalysts and combinations will help to produce the desired compounds in the composition of the products of FT reaction. For example, as catalysts for FT synthesis known molten iron containing a promoter such as potassium or oxides on the carrier on the basis of silicon dioxide, aluminum oxide, or silica - alumina. Another example is the use of metallic cobalt. The use of cobalt has the advantage of obtaining during the synthesis of the smaller amount of methane in comparison with earlier catalysts based on Nickel, and cobalt is formed with a wide range of compounds. With proper selection of media, promoters, and other combinations of metals such cobalt catalyst may be adapted to obtain a composition enriched in the desired compounds. Other catalysts, such as catalysts based with the x process.

The catalysts can be processed or deposited or sintered, cemented, impregnated, mixed with a suitable carrier or fused with him.

The catalysts may also contain promoters for promotion activity, stability or selectivity of the catalyst. Suitable promoters include alkali or alkaline earth metals in free or combined form, such as the oxide, hydroxide, salt or combinations thereof.

FT-stream typically contains almost no sulfur or nitrogen, which can have a negative impact on other catalysts, which receive the derivatives of olefins, or that catalyze the reaction of olefins in other processes of oligomerization or polymerization. However, regardless of the used method CFT-way has a high selectivity in respect of the receipt of specific compounds and using it to get a composition with a wide range of compounds.

The linear polyaromatic compound used in the method of the present invention, particularly well suited for the separation in the FT-stream of olefins and saturated hydrocarbons in the presence of oxygenates, PQS shall/P>Although reference is made to the FT-stream, you must understand that a suitable feedstock for the method of the present invention is any flow in any way, which contains olefins and saturated hydrocarbons. Almost all raw FT-streams contain from 5 to 95 wt.% olefins, the rest are saturated hydrocarbons containing paraffins and cycloparaffins, and optionally other compounds such as aromatic compounds, optionally containing saturated or unsaturated alkyl chain branching, and oxygenates relative to the weight of all ingredients in the flow of raw materials for the method of the present invention.

The preferred amount of olefins present in the FT-stream is in the range from 15 to 70 wt.% relative to the weight of all ingredients in the feedstock. The number of linear alpha olefins in the FT thread is not limited, but preferably it is in the range from 15 to 60 wt.% relative to the weight of all ingredients in the feedstock. A number of other olefins, including branched alpha-olefins and nikocevic olefins, both linear and branched, also is not limited, but preferably it is in the range of 1 to 55 wt.the amount of paraffin in most FT-streams is in the range from 5 to 95 wt.%. In some PB-flow FT-catalyst selected so as to increase the concentration of olefins and to reduce the concentration of paraffins. In these streams the number paraffins, typically is in the range from 5 to 65 wt.% of the total flow. In other CFT-flows, in which FT-catalyst choose to increase the amount of paraffins, the amount of paraffins in the stream is in the range from 65 to 99 wt.%. A number of other compounds in PB-flow, such as oxygenates and aromatic compounds make up most of the remainder of the FT-stream and, usually present in amounts in the range from 5 to 30 wt.% relative to the weight of all ingredients in the feedstock. In most FT-streams may be present minor amounts of other by-products and impurities in amounts less than 5 wt.%.

The feedstock can be processed CFT thread that you want to remove from the raw stream of some portion of paraffins, high - and low-molecular compounds and oxygenates was subjected to fractionation and/or purification using commonly used distillation, extraction or other methods of separation. If splitting operation carried out by distillation of the reaction mixture containing as the average number of carbon atoms in the molecule in the range of C5-C20and where olefinic compounds predominate in the feedstock, fell in the range FROM5-C20inclusive. The linear polyaromatic compound effectively separates the saturated hydrocarbons from olefins, if the average number of carbon atoms in the molecule in the feedstock and in the prevailing levels of olefinic compounds is within this range, inclusive. If the average number of carbon atoms in the molecule in the feedstock exceeds20then adduct polyaromatic compound - olefin boils at a lower temperature compared with many connections in20+ -composition of the feedstock, thus, these high-boiling compounds will remain in Neogene reaction mixture containing adduct. Accordingly, specific polyaromatic compound and the specific composition of the feedstock must be selected so that the composition of the adduct of linear polyaromatic compound - olefin in the reaction mixture boils at a higher temperature compared to the amount of unreacted paraffin compounds in the feedstock, which is desirable to separate. Therefore, the flow of the feedstock preferably I is, what more preferably from 6 to 18, and where the prevailing olefinic compounds are in these ranges are inclusive. These types of FT threads, usually handled by one of the methods listed above, to essentially remove the fractions containing the ingredients below or above the range of C5-C20.

When it is desirable to use raw materials outside the range of C5-C20to highlight the adduct of unreacted reaction mixture can be used other methods of separation, including the choice of more high-boiling aromatic compounds and/or other separation techniques such as liquid-liquid extraction or crystallization. These techniques can of course be used also in relation to feedstock in the range FROM5- C20inclusive.

The linear polyaromatic compound used in the method of the present invention to education in the flow of raw materials adduct with olefins. As used in the description, “linear polyaromatic compound” refers to a linear polyaromatic compound having at least three condensed aromatic rings, the Oia adduct, as the unsubstituted molecule, and mixtures thereof. Linearity must extend over all three condensed rings, if the connection is used with three condensed rings, and on at least four consecutive condensed cyclic ring, if the connection is used with four or more condensed rings. The linear polyaromatic compound also relates to mixtures of compounds containing as one of their ingredients linear polyaromatic compound, including, but not limited to, coal tar, anthracene oil, and any crude mixture containing fraction separated from naphthalene. The linear polyaromatic compound includes aromatic molecules connected to each other via a bridging group, such as a hydrocarbon chain, an ether bond or a chain containing a ketone group, as long as there are at least three condensed rings in a linear arrangement; and aromatic molecules containing a heteroatom, which prevents separation of olefins from saturated hydrocarbons.

The linear polyaromatic compound has the preferred select with other olefins and at least with paraffins, in respect of which the connection under all operating conditions outside of the conditions of the cracking reactivity practically does not possess. Select the linear polyaromatic compound, the selectivity of which in relation to linear alpha-olefins compared with other olefins higher than 1 : 1 mol, preferably 2 : 1 or more preferably 4 : 1.

Non-limiting examples of linear polyaromatic compounds include anthracene, 2,3-benzanthracene, pentacene and exact. Suitable examples of substituents in the substituted linear polyaromatic compounds include, but are not limited to, lower alkyl, for example methyl, ethyl, butyl; halogen, for example chlorine, bromine, fluorine; nitro; sulphate; sulfonyloxy; carboxyl; Carbo-(lower alkoxy), for example, carbomethoxy, carboethoxy; amino; mono - and di-(lower alkylamino), for example methylamino, dimethylamino, methylethylamine; amido; hydroxy; cyano; lower alkoxy, for example methoxy, ethoxy; lower alkanoyloxy, for example acetoxy; monocyclic arily, for example phenyl, xylyl, tolyl, benzyl and the like. The specific size of the substituents, their number and their location should be chosen in such a way, cadduct Diels-alder reaction. Suitable substituted linear polyaromatic compounds can be determined in the ordinary course of the experiment. Examples of suitable linear polyaromatic compounds include 9,10-dimethylanthracene, 9,10-dichloroanthracene, 9-methylanthracene, 9-acetylanthracene, 9-(methylaminomethyl) anthracene, 2-chloroanthracene, 2-ethyl-9,10-diethoxyanthracene, antrain and 9-antistreptolysin. Preferred linear polyaromatic compounds are anthracene and 2,3-benzanthracene.

The reaction of formation of adduct Diels-alder reaction is conducted in the usual manner in the reaction zone. An example of a suitable reaction zone is a flow reactor with a stirrer configured in a single reactor, or reactors, installed in parallel or sequentially, where the olefin and linear polyaromatic compound is continuously fed into the reactor with a stirrer for education by heating the liquid reaction mixture, and the reactor agitator continuously divert the reaction mixture. Alternative reaction can be carried out in a bubble column or in a batch reactor, actions, or to use the scheme of the reaction in the reactor with reciprocating thread.

The reaction of formation of the adduct is usually providepractical from 240 to 265°C. Pressure is not critical and typically are in the range of from atmospheric to 100 atmospheres. The reaction can be carried out in the gas phase under vacuum, or in the liquid phase or in a mixed gas-liquid phase depending on the volatility of raw materials, but, as a rule, the reaction is carried out in the liquid phase.

For the formation of adducts can be used in the stoichiometric ratio or an excess of either the olefin or the linear polyaromatic compounds. The molar ratio of olefins in the feedstock to the number of linear polyaromatic compound is preferably in the range from 0.25 : 1 to 10 : 1. The residence time represents a period of time sufficient for the formation of the desired adduct number of linear polyaromatic compounds and olefins. Typical times of stay can range from 30 minutes to 4 hours with periodic carrying out of the reaction.

In the reactor to dissolve the olefin feedstock, or linear polyaromatic compounds, or both may be used an inert solvent. The preferred solvents are the hydrocarbon solvents which are liquids at those the linear polyaromatic compounds. Illustrative examples of useful solvents include alkanes such as pentane, isopentane, hexane, heptane, octane and nonan; cycloalkanes such as cyclopentane and cyclohexane; and aromatic compounds such as benzene, toluene, ethylbenzene and diethylbenzene. The amount of solvent can vary within wide limits without negative impacts on the response.

However, preferably the formation of adducts in the feedstock, and in particular the formation of adduct linear polyaromatic compound - olefin is carried out in the absence of solvent to increase the rate of reaction and to avoid the use of additional equipment and additional stages in the process for separating the solvent.

After the formation of the adduct of linear polyaromatic compound - olefin, the reaction mixture flows into the container for separation, effective for the separation of saturated hydrocarbons from the adduct of linear polyaromatic compound - olefin with receiving a stream of saturated hydrocarbons and flow adduct of olefin. Due to the large differences in molecular weight and in the structure between the adduct of linear polyaromatic compound - olefin, nasawiya unreacted saturated hydrocarbons. For example, not formed adducts of compounds can be removed in the upper chase or fractions by using vacuum distillation or single equilibrium distillation of the reaction mixture, resulting adduct linear polyaromatic compound - olefin and unreacted linear polyaromatic compound remains in the form of liquid nedogona. Not formed adducts of compounds that are removed include saturated hydrocarbons, aromatics, and oxygenates, such as alcohols, ketones, acids together with nekozumi and branched olefins, which do not form adducts with a linear polyaromatic compound.

Alternative adduct of linear polyaromatic compound - olefin produce cooling of the reaction mixture up until the adduct will not crystallized, followed by filtration or centrifugation to remove unreacted olefins.

In most cases, any unreacted linear polyaromatic compound is released from the adduct of linear polyaromatic compound - olefin in the flow of the adduct of olefin. In the flow of the adduct of olefin can be other ingredients, such is Levinov and branched olefins.

The next step in the method of the present invention is the dissociation of the adduct of linear polyaromatic compound - olefin. The process of dissociation can be controlled flow adduct of olefin in the capacity for dissociation, where the flow of the adduct of olefin is heated or subjected to pyrolysis at a temperature effective for the dissociation of the adduct of linear polyaromatic compound - olefin, typically in the range from 250 to 500°C., preferably from 300 to 350°C. This pyrolysis releases olefins from the linear polyaromatic compound.

The linear polyaromatic compound then separated from the mixture by any of the commonly used methods, the selection can be made simultaneously with the holding of pyrolysis, such as by vacuum distillation or single equilibrium by distillation olefins, together with any impurities at temperatures of pyrolysis, and removing the linear polyaromatic compounds from the dissociation of the adduct in the form of nedogona. Other separation techniques include filtration and centrifugation. The linear polyaromatic compound can be recycled back into the reaction zone receiving the adduct.

The concentration of olefins in the compositions is ion area for formation of the adduct, and the concentration of saturated hydrocarbons in the olefin composition is reduced compared to their concentration in the feedstock. Similarly, when saturated hydrocarbons are separated from the adduct of linear polyaromatic compound - olefin in the separation vessel in a stream of saturated hydrocarbons, the concentration of saturated hydrocarbons in the stream of saturated hydrocarbons is increased compared with the concentration of saturated hydrocarbons in the feedstock is fed into the reaction zone for the formation of the adduct, and the concentration of olefins in the stream of saturated hydrocarbons compared with the concentration of olefins in the feedstock is fed into the reaction zone to form adduct decreases. And composition of olefins and a stream of saturated hydrocarbons can be separated and recovered for use in other applications or as intermediates in the other reaction processes.

For the purposes of measuring the percentage decrease in the content of compounds in stream concentration of the considered compound or series of compounds in the product stream, is subtracted from the concentration of the considered compound or series of compounds in the feedstock, passing the rhenium % enrichment thread compound concentration connection or series of connections, taking place in the flow of raw materials, is subtracted from the concentration of the considered compound or series of compounds in the product stream, the difference is then divided by the concentration of the same compounds in the flow of raw materials, and multiply by 100. For the purposes of summation series of compounds by addition of the received total content of the series in the flow of raw materials, and then adding received total content of the compounds in the product stream. Total content in the product stream was then compared with the total content in the flow of raw materials to determine whether increased or decreased the total content of the series in the flow of products compared with total content in the flow of the feedstock. Corresponding to the above-mentioned calculation is then used depending on whether decreased or increased content of the series in the product stream.

The method of the present invention is to increase the total concentration of olefins, will increase the concentration of linear alpha-olefins and to reduce the concentration of saturated hydrocarbons, each, in the composition of olefins compared to the concentration of all olefins, linear alpha-alevebuy to increase the concentration of saturated hydrocarbons, taking place in the stream of saturated hydrocarbons, compared with the concentration of saturated hydrocarbons in the stream of the feedstock. Concentration nikocevic olefins and branched olefins in the stream of saturated hydrocarbons, and in the composition of olefins compared to the concentration of these ingredients in the flow of raw materials, can be increased or decreased in each of the streams for the reasons explained below.

The concentration of all olefins in the stream of saturated hydrocarbons resulting from the use of the method of the present invention preferably is reduced in comparison with the concentration of all olefins in the feedstock for only one run of at least 15 %, more preferably at least 30%, most preferably at least 40%.

Since the linear polyaromatic compound has a greater selectivity for the formation of adduct with linear alpha olefins in comparison with other olefins, the concentration of linear alpha olefins in the stream of saturated hydrocarbons compared with the concentration of linear alpha olefins in the stream of the feedstock, preferably reduced in one pass, the PNA 50%.

The number of redundant linear polyaromatic compounds present in the reaction zone receiving the adduct, time and temperature will influence the number of adducts formed from nikocevic or branched olefins and linear polyaromatic compounds and, consequently, the amount nikocevic or branched olefins, which are not reacted and moved into the stream of saturated hydrocarbons. While the linear polyaromatic compound preferably forms an adduct with linear alpha-olefins, in the presence of a large excess of polyaromatic compounds in relation to the amount of linear alpha olefins present in the feedstock, in combination with large sometimes stay will be accompanied by the appearance not formed adducts of linear polyaromatic compounds, which are free to be able to form adducts with nekozumi and branched olefins, thereby increasing reducing the data content of olefins in the stream of saturated hydrocarbons compared with the concentration of these olefins in the stream of the feedstock. Concentration nikocevic olefins in the stream of saturated hydrocarbons, predoctor raw materials.

With regard to the concentration of branched olefins, the change of their concentrations in the stream of saturated hydrocarbons, typically is in the range from a slight decrease to increase in relation to the concentration of branched olefins in the feedstock. The concentration of branched olefins compared to the concentration data of branched olefins in the feedstock, can be reduced only at 1-30%, or to increase by 1-30%, or remain unchanged.

The concentration of saturated hydrocarbons in the stream of saturated hydrocarbons compared with the concentration of saturated hydrocarbons in the stream of the feedstock increases. The concentration is preferably increased at least 5%, more preferably at least 20%, and it can be increased by 100-400%, in particular, when the concentration of saturated hydrocarbons in the feedstock is low. As a rule, the degree of enrichment of the stream of saturated hydrocarbons saturated hydrocarbons varies in antiphase with the concentration of saturated hydrocarbons in the feedstock.

The concentration of saturated hydrocarbons in the olefin composition in Rasul saturated hydrocarbons in the feedstock for only one run, at least 80%, more preferably at least 90%, even more preferably at least 95%, and most preferably 100%.

As described above, the percentage reduction or increase in the content of branched olefins and nikocevic olefins in the olefin composition depends on the number of linear polyaromatic compounds, temperature and residence time of the feedstock in the reaction zone receiving the adduct. Preferably the concentration of branched olefins in the olefin composition in comparison with the concentration of branched olefins in the feedstock is reduced. Preferably the concentration nikocevic olefins in the stream of olefins compared to the concentration nikocevic olefins in the feedstock increases. The degree of increase of the content of nikocevic olefins in the stream of olefins is preferably in the range from 10 to 250%.

The concentration of linear alpha olefins in the olefin composition in comparison with the concentration of linear alpha olefins in the stream of the feedstock increases. The concentration of linear alpha olefins in the olefin composition, compared with the concentration of linear alpha-or more preferably, at least 40%, most preferably at least 60%.

The concentration of all olefins in the olefin composition in comparison with the concentration of all olefins in the stream of the feedstock increases. The degree of increase of the content of olefins varies in antiphase with the concentration of olefins in the feedstock. Preferably the concentration of all olefins in the olefin composition is increased by at least 40%, more preferably at least 60%.

Threads Fischer-Tropsch contain a large variety of difficult to separate compounds including saturated hydrocarbons, aromatics, oxygenates, nikocevic olefins, branched olefins and linear alpha olefins. The advantage of the stream of the Fischer-Tropsch is that it contains a mixture of compounds with an even and odd number of carbon atoms in the molecule and in the method of the present invention receive a stream of olefinic compounds with even and odd number of carbon atoms in the molecule when the content of saturated hydrocarbons in the range of very low to zero, with a high concentration of linear alpha-olefins. The method of the present invention also m the olefins, and linear alpha-olefins at low contents of saturated hydrocarbons.

In one embodiment of the method of the present invention provides the composition of the Fischer-Tropsch containing olefins with odd and even numbers, and the composition is characterized by an average number of carbon atoms in the molecule in the range FROM6-C18or optionally in the range FROM6- C12containing:

a) at least two linear alpha olefin with different lengths of carbon chains;

b) each of the two most prevalent (on a molar basis) of linear alpha-olefins of the above, at least two linear alpha-olefins is in the range FROM6-C18inclusive;

c) mentioned the two most predominant linear alpha olefins present in the amount of at least 20 wt.%, preferably, at least 30 wt.%, more preferably at least 40 wt.% relative to the weight of the olefins in the composition;

d) total full content of linear alpha olefins present in the composition in the above-mentioned range, inclusive, is at least 40 wt.%, preferably, at least 60 wt.%, more predpochtitelney olefins with odd numbers, falling in the above range, present in amount of at least 10 wt.%, preferably, at least 20 wt.%, more preferably at least 30 wt.% and even 40 wt.% or more in total; and

f) the total content of aromatic compounds, saturated hydrocarbons and oxygenates, equal to 5 wt.% or less, preferably 2 wt.% or less, more preferably 1 wt.% or less, most preferably 0.5 wt.% or less, each relative to the weight of the composition.

Processed composition of the Fischer-Tropsch process may optionally contain branched olefins in the amount of at least 5 wt.% and even 10 wt.% or more relative to the weight of the olefins in the composition. Alternatively, or in addition to branched olefins, the composition may contain non-end of the olefins present in amounts in the range from 5 to 20 wt.%. Such flows of raw materials can be advantageous from a cost perspective in some processes, such as processes hydroformylation that are not very sensitive to the position of double bonds in the feedstock, to obtain the primary alcohols.

The above composition preferably contains as one of the two molecule.

In another embodiment of the present invention offers the processed composition of the Fischer-Tropsch process, which is characterized by the average content of carbon atoms in the molecule in the range FROM6-C18containing at least two linear alpha olefin with different lengths of carbon chains that fall in the above range, inclusive, in the amount of at least 50 wt.% from linear alpha olefins, where the composition contains the most predominant olefin containing n carbon atoms, where the next most predominant olefin contains either n + 1 or n - 1 carbon atoms; and where said composition contains 2 wt.% or less of saturated hydrocarbons.

Preferably said composition comprises 1 wt.% or less of saturated hydrocarbons. The above composition preferably further comprises a branched olefins in the amount of at least 5 wt.% and/or non-end olefins in the amount of at least 5 wt.%.

The method of the present invention mainly provides a stream of olefins, which has a high concentration of olefins, where the concentration of olefins in the olefin composition may comprise at least 90% and up to 100% purity of the solid fuel component of drilling muds, to interact with elementary sulfur with getting sulfatirovannykh products as an agent for creating ultra-high pressures in liquids for metal processing, useful as comonomers for polymerization of polyethylene, an intermediate connection when receiving poly-alpha-olefins (PAO), used as a lubricant, as glorieuses flow to obtain polychlorinated hydrocarbons in applications for PVC, for interaction with hydrogen sulfide to obtain primary and secondary mercaptans as pharmaceutical intermediates and as additives for modifying the properties of rubber, as solvents and as a precursor to obtain a plasticizer alcohols and alcohols detergent range and surfactants, which can be obtained derivatives in the form of sulfates or alkoxylate detergent range for liquids for washing and washing powders, powders and liquids for washing dishes, bulk Soaps, shampoos, liquid Soaps for hands and cleaners for hard surfaces.

The ranges and limitations specified in this description and in the claims, such that it is considered, that is in the scope of the present invention includes other ranges and limitations which allow essentially the same way to perform essentially the same function to achieve the same or essentially the same result. The present invention will be further illustrated by reference to the following examples:

EXAMPLE 1

As a source of raw materials used, the flow of Fischer-Tropsch consisting of compositions presented in table 1. FT-composition obtained by passing synthesis gas over FT-catalyst, followed by distillation of the products in the range of boiling points from hexyl to underimplemented. The composition was used as feedstock. The highest content was7-C10-hydrocarbons.

In an autoclave were placed 0.24 mol (42.2 g) anthracene with a purity of 95% and 150 g of raw material. Full olefins in the downloadable source raw materials was equal to about 0.5 mol (55,9 g). The autoclave was tightly closed and then was purged with nitrogen. The contents of the autoclave were heated to 255°C for four hours to obtain the adduct Diels-alder reaction of olefin and anthracene. During the heating of the contents of the autoclave were stirred.

After completion of the reaction the autoclave was cooled to 20°C. the Mixture of products perrhenate was removed by distillation. The substance remaining in the flask, (18,2 g) consisted of a certain number withheld saturated hydrocarbons, unreacted anthracene and anthracene adduct - olefin. Then for the dissociation of the adduct with getting anthracene and product As described in the following table 1, the flask and its contents were heated to a temperature in the range of 310-350°C. the Product was isolated and extracted from anthracene by distillation. The compositions of each stream products were analyzed using gas chromatography.

As can be seen from table 1, the product And significantly increases the content of alpha-olefins and full olefins compared to the concentration of alpha-olefins and total olefins in the stream of the feedstock. The product And the content of alpha-olefins increased by 205%, and that for the full content of olefins, it is the product And increased 155% ([(86,5+8,9)-(28,3+9,0)]/(9,0+28,3)X100).

In addition, the concentration of saturated hydrocarbons (excluding the oxygenates in the product flow was significantly reduced by 91%. The presence of saturated hydrocarbons in the product And due to their incomplete removal during the distillation of unreacted compounds from the adduct before stage dissociates place in the feedstock, decreased only marginally.

The product is a stream of saturated hydrocarbons selected from the reaction mixture in the upper pursuit of distillation columns. As can be seen from table 1, the product enriched In saturated hydrocarbons by 38% compared with the concentration of saturated hydrocarbons in the stream of the feedstock. The concentration of alpha-olefins in the stream of saturated hydrocarbons compared with the concentration of alpha-olefins in the feedstock was reduced by 67%.

EXAMPLE 2

FT-stream with the composition shown in table 2, were treated with anthracene. This FT thread was obtained by passing synthesis gas over FT-catalyst, followed by distillation and collection of the products in the range of boiling points from pencil to nonyl- (C5-C9)hydrocarbons.

In the autoclave of 300 ml were placed 0.6 mol (112 g) anthracene with a purity of 95% and 96 g of the feedstock. The autoclave was tightly closed and then was purged with nitrogen. The contents of the autoclave were heated to 255°C for seven hours to obtain adduct Diels-alder reaction of olefin and anthracene. During the heating of the contents of the autoclave were stirred.

After zaversheniya, saturated hydrocarbons and unreacted oxygenates were removed from the reaction mixture by distillation. The substance remaining in the flask was heated to a temperature in the range of 300-350°C for the dissociation of the adduct with getting anthracene and product As described in the following table 2. The product was isolated and extracted from anthracene by distillation. The compositions of each stream products were analyzed using gas chromatography.

As can be seen from table 2, the product And significantly increased the content of alpha-olefins and full olefins compared to the concentration of alpha-olefins and total olefins in the stream of the feedstock. The product And the content of alpha-olefins increased by 579%, as for the full content of olefins, the product And it increased by 348%. Purity olefins in the stream of olefins product And was 100%. Concentration nikocevic olefins in the product flow As compared with the concentration nikocevic olefins in the feedstock, increased by 163%.

1. Method of separating olefins from saturated hydrocarbons in a feedstock, characterized in that it comprises (a) contacting a feedstock containing savania reaction mixture, containing adducts of linear polyaromatic compound - olefin and saturated hydrocarbon, (b) the Department of adducts of linear polyaromatic compound - olefins from saturated hydrocarbons in the reaction mixture to obtain a stream of saturated hydrocarbons and flow adducts of olefins, c) dissociation of adducts of linear polyaromatic compound - olefin obtaining linear polyaromatic compounds and compositions of olefins and optionally, (d) the selection of the linear polyaromatic compounds formed at the stage (C), from the composition of olefins, and the concentration of olefins in the olefin composition is increased compared with the concentration of olefins in the feedstock.

2. The method according to p. 1, characterized in that the feedstock is in contact with a linear polyaromatic compound at a temperature in the range from 150 to 290°C.

3. The method according to p. 1 or 2, characterized in that the dissociation of the adduct of linear polyaromatic compound - olefin carried out by heating the adduct of linear polyaromatic compound - olefin to a temperature in the range from 250 to 500°C.

4. The way PP.1, 2 or 3, characterized in that the feedstock contains a stream obtained in proaire contains from 15 to 70 wt.% olefins relative to the weight of all ingredients in the feedstock.

6. The method according to any of the preceding paragraphs, characterized in that the feedstock contains paraffins in an amount of 5 to 95 wt.% relative to the weight of all ingredients in the feedstock.

7. The method according to any of the preceding paragraphs, characterized in that the average number of carbon atoms in the compounds of the feedstock is in the range of C5-C20and the prevailing olefins in the feedstock is in the range FROM5-C20inclusive.

8. The method according to any of the preceding items, wherein the linear polyaromatic compound contains anthracene or benzanthracene.

 

Same patents:

The invention relates to a method of separation of linear olefins with internal double bonds from branched olefins with internal double bonds

The invention relates to the production of hydrocarbons

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The invention relates to the production of catalytic compositions for the Fischer-Tropsch synthesis

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The invention relates to a method of manufacturing a synthesis gas, intended for use in the synthesis of gasoline, methanol or dimethyl ether

The invention relates to a Fischer-Tropsch synthesis from carbon monoxide and hydrogen with obtaining alcohols and olefins

FIELD: hydrocarbon manufacturing.

SUBSTANCE: natural gas is brought into reaction with vapor and oxygen-containing gas in at least one reforming zone to produce syngas mainly containing hydrogen and carbon monoxide and some amount of carbon dioxide. Said gas is fed in Fisher-Tropsh synthesis reactor to obtain crude synthesis stream containing low hydrocarbons, high hydrocarbons, water, and unconverted syngas. Then said crude synthesis stream is separated in drawing zone onto crude product stream containing as main component high hydrocarbons, water stream, and exhaust gas stream, comprising mainly remained components. Further at least part of exhaust gas stream is vapor reformed in separated vapor reforming apparatus, and reformed exhaust gas is charged into gas stream before its introducing in Fisher-Tropsh synthesis reactor.

EFFECT: increased hydrocarbon yield with slight releasing of carbon dioxide.

7 cl, 3 dwg, 1 tbl, 5 ex

FIELD: petrochemical process catalysts.

SUBSTANCE: fischer-Tropsch process catalyst constituted by cobalt deposited on aluminum metal may additionally contain promoters selected from oxides ZrO2, La2O3, K2O and metals Re, Ru, Pd, and Pt.

EFFECT: increased heat conductivity and selectivity.

2 cl, 2 tbl, 2 ex

FIELD: petrochemical processes catalysts.

SUBSTANCE: fischer-Tropsch process catalyst constituted by cobalt deposited on granulated halumine may further contain promoters selected from oxides ZrO2 and HfO2 and metals Ru, Pd, and Pt.

EFFECT: increased selectivity and productivity.

2 cl, 3 tbl, 2 ex

FIELD: petrochemical process catalysts.

SUBSTANCE: cobalt-based catalyst precursor is prepared by impregnation of porous catalyst carrier particles with cobalt salt followed by partial drying and subsequent calcination of impregnated carrier, after which calcined product is partially reduced, impregnated with cobalt salt, partially dried and finally calcined. Preparation of Fischer-Tropsch catalyst comprises similar preparation of precursor thereof and reduction of the latter.

EFFECT: increased catalytic activity.

12 cl, 3 dwg, 1 tbl, 2 ex

FIELD: cobalt-based catalysts used in Fisher-Tropsh reaction in reactors with gas-liquid-solid agent fluidized bed.

SUBSTANCE: diameter of particles of cobalt-based catalyst applied to carrier is measured by means of Coulter LS230 in interval of from 70 to 250 mcm, area of surface exceeds 175 m2/g and volume of pores exceeds 0.35 cm3/g as measured by BET method. Specification contains also description of Fisher-Tropsh method in reactor with gas-liquid-solid agent fluidized bed. This method includes chemical interaction of CO with H2 for obtaining C5+ hydrocarbons in presence of said catalyst.

EFFECT: enhanced activity of catalyst; facilitated procedure.

8 cl, 3 dwg, 10 tbl, 6 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing mainly C5+-hydrocarbons. Method involves contacting carbon monoxide with hydrogen at temperature 180-270°C and under increased pressure in the presence of catalytic composition comprising as measure for the total mass of catalytic composition from 5 to 30 wt.-% of cobalt, from 0.01 to 5 wt.-% of manganese and at least from 0.01 to 0.9 wt.-% of rhenium and/or ruthenium on a carried made of titanium dioxide. Invention provides reducing amount of carbon dioxide evolved in the process of hydrocarbons synthesis by Fisher-Tropsh to the level 2% vol./vol., not above, but preferably to 1% vol./vol., not above, and without reducing C5+-selectivity.

EFFECT: improved preparing method.

7 cl, 2 tbl, 4 ex

FIELD: petrochemical processes.

SUBSTANCE: hydrocarbons are produced via contacting synthesis gas with catalytic composition consisting of mixture of iron-containing Fischer-Tropsch synthesis catalyst and acid component at elevated pressures and temperatures and specified iron-containing catalyst reduction conditions. Specifically, said iron component is a mixture of neodymium and cerium silicates at weight ratio between 1:9 and 9:1 and weight ratio of acid component to iron-containing catalyst ranges from 1:1 to 6:1.

EFFECT: increased selectivity and productivity of catalyst and reduced level of aromatic hydrocarbons in product.

3 cl, 1 tbl, 15 ex

FIELD: chemical industry; conversion of synthesis gas into alcohols and hydrocarbons.

SUBSTANCE: proposed catalyst contains the following constituents, mass-%: active component in terms of CO; promoter-fluorine, 0.1-1.0; the remainder being carrier-aluminum oxide.

EFFECT: enhanced conversion of CO.

1 dwg, 2 tbl, 6 ex

FIELD: petroleum chemistry, organic chemistry, chemical technology.

SUBSTANCE: method involves contacting a mixture of carbon monoxide and hydrogen at increased temperature and pressure with a catalyst comprising manganese and cobalt on a carrier wherein cobalt, at least partially, presents as metal and catalyst comprises also inorganic phosphate in the amount at least 0.05 wt.-% as measure for elementary phosphorus relatively to the catalyst weight. Also, catalyst can comprise vanadium, zirconium, rhenium or ruthenium additionally. Method provides selectivity in formation (C5+)-hydrocarbons and decrease in formation of CO2.

EFFECT: improved preparing method.

7 cl, 1 tbl, 2 ex

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