The method of extraction and removal of mononuclear and polynuclear aromatic by-products formed in the reaction zone a hydrocarbon dehydrogenization

 

(57) Abstract:

The invention relates to the extraction and removal of by-products, representing a multi-core aromatic organic compounds from a stream of steam flowing from the reaction zone dehydrogenization normally gaseous hydrocarbon. Polynuclear aromatic compounds (PNA's), obtained as by-products in the area of dehydrogenization hydrocarbons, is recovered and removed by mixing resulting from dehydrogenization thread with a loop recycled stream containing mononuclear aromatic organic compounds (MNA's), and contacting the resulting mixture with an adsorbent to reduce the concentration of MNA's and to obtain a stream containing dehydrogenation hydrocarbons and dehidrirana hydrocarbons. The spent adsorbent extracted from stage adsorption and containing MNA's, regenerate by contact with the hot enriched hydrogen gas to extract at least part MNA's and PNA's and consequently the regeneration of the spent adsorbent. Resulting from the stage of regeneration of the hydrocarbon stream is then separated into a stream containing MNA's, and a stream containing PNA's, and, at least in part on what blasto application, to which the present invention is the extraction and removal of by-products, representing a multi-core aromatic organic compounds from a stream of steam flowing from the reaction zone dehydrogenization normally gaseous hydrocarbon.

Prior

Dehydrogenate hydrocarbons is an important industrial process for the conversion of hydrocarbons due to the existing and growing needs dehydrogenating hydrocarbons for the manufacture of various chemical products, such as detergents, high octane gasoline, saturated with oxygen high-octane components of gasoline, pharmaceutical products, plastics, synthetic resins and other products well known to specialists. One example of this process is dehydrogenate isobutane to obtain isobutylene, which can be polymerized to obtain reagents, giving a viscous bonding, which reduces the dependence of viscosity on temperature additives for motor oils and imparts impact resistance and anti-oxidation additives for plastics. Another example of the growing demand in the isobutylene is poluchennymi to reduce air pollution due to automobile emissions.

Specialists in the field of conversion processing of hydrocarbons are well known to produce olefins by catalytic dehydrogenization paraffin hydrocarbons. It was also published numerous patents that have been studied and discussed dehydrogenate hydrocarbons in General practice. For example, in patent US-A-4430517 described this process of dehydrogenization.

Despite the fact that dehydrogenase paraffin hydrocarbons is well known, the broader application of this process and greater rigor to the existing industrial equipment has highlighted the problem with the location in the area of product recovery process dehydrogenization. This problem is a result of trace amounts of single-core and multi-core compounds of the aromatic series. Multicore aromatic organic compounds are not only unwanted impurity, but also pose a serious operational problem, because they condense and are deposited with the formation of deposits on the colder surfaces of the installation, which leads to harmful consequences. These deposits multinuclear aromatic compounds of a number of hard to learn the application dehydrogenation compounds in subsequent processes unexpected release of multi-core compounds of the aromatic series in deriving dehydrogenation stream can contaminate products, received in subsequent processes. The presence of multi-core compounds of the aromatic series changes the color purity of the products and significantly reduces the value or suitability for product sales.

Summary of invention

The present invention therefore relates to the decision regarding the management of multi-core compounds of the aromatic series (PNA's) formed in the area of dehydrogenization hydrocarbon. According to the method of the present invention arising from dehydrogenization hydrocarbon stream is mixed with recirculated loop stream containing mononuclear aromatic organic compounds (MNA's), and provide contacting the mixture with an adsorbent selective for MNA's and PNA's, to obtain a stream containing dehydrogenation hydrocarbons and dehidrirana hydrocarbons. Provide the possibility of contacting the spent adsorbent containing mononuclear and polynuclear aromatic organic compounds and extracted from the adsorption stage, with hot, enriched with hydrogen gas to remove at least part MNA's and PNA's and regenerating as a result of the spent adsorbent. Then share received is PNA's. At least part of the stream containing MNA's, then recycle to the stage of displacement, thus providing the necessary management solution.

One of the variants of the present invention may be characterized as a method of controlling by-products, which represents a mononuclear and polynuclear aromatic organic compounds formed in the area of dehydrogenization hydrocarbon, comprising the following stages: (a) mixing resulting from the reaction zone dehydrogenization hydrocarbon stream containing dehydrogenation hydrocarbons, dehidrirana hydrocarbons and trace amounts of single-core and multi-core compounds of the aromatic series, with loop recycled stream containing mononuclear aromatic organic compounds; (b) contacting the mixture obtained from stage (a) with adsorbent selective for single-core and multi-core compounds of the aromatic series, to reduce the concentration of mononuclear and polynuclear aromatic compounds range in the mixture and obtaining a stream containing dehydrogenation hydrocarbons and dehidrirana hydrocarbons; (C) contacting the spent adsorbent holding adsorber is i.i.d. with hydrogen gas to deformirovaniya, at least part of the single-core and multi-core compounds of the aromatic series and thus regenerating the adsorbent; (g) separation of the stream containing hydrogen, mononuclear and polynuclear aromatic organic compounds extracted from stage (C), receiving stream containing mononuclear aromatic organic compounds, and stream containing multinuclear aromatic organic compounds; and (d) recycling at least part of the stream containing mononuclear aromatic organic compounds, separated in stage (g), to obtain a loop of the stream is recycled to stage (a).

A brief description of the drawing

The drawing is a simplified process map process, which is the preferred option of the present invention.

Detailed description of the invention

The present invention is a method of removal and extraction of trace quantities of multi-core compounds of the aromatic series of steam flow resulting from dehydrogenization hydrocarbon. Dehydrogenase paraffin hydrocarbons are well known to experts in the field of processing of hydrocarbons. In accordance with the present invention Prado, propylene and butylene.

In the process of dehydrogenization fresh download of hydrocarbon combined with recycled hydrogen and recycled unconverted hydrocarbons. This results in the reaction stream, which is passed through a layer of a suitable catalyst for dehydrogenization supported required to dehydrogenization conditions, such as temperature, pressure and space velocity, and resulting from the catalytic reaction zone of the flow further treated to obtain a stream containing olefinic hydrocarbons. In accordance with the present invention resulting from the catalytic reaction zone dehydrogenization stream contains unconverted saturated hydrocarbons, olefinic hydrocarbons, mononuclear aromatic organic compounds in an amount of from 100 to 5000 wppm (weight parts per million, 100 - 5000 mg/l = [100-5000] 10-4wt.%) and multi-core compounds in an amount of from 50 to 500 wppm (50-500 mg/l = [50 - 500] 10-4wt.%) For the preferred dehydrogenation hydrocarbons this flowing stream, while withdrawing it from dehydrogenization is preferably in the form of vapour.

Under the loop thread containing mononuclear aromatic organic compounds. The amount of recirculated loop flow mononuclear aromatic compounds of a number is chosen so as to prevent the deposition and accumulation of multi-core compounds of the aromatic series on the inner surface of the installation downstream for the reaction zone dehydrogenization, preferably in amounts of from 0.01 wt.% up to 1 wt.% the weight resulting from the reaction zone of the flow. Then provide the possibility of contacting the mixture resulting from the reaction zone dehydrogenization stream and is recycled to the loop flow mononuclear aromatic series compounds with an adsorbent selective for MNA's and PNA's, to reduce the concentration of single-core and multi-core compounds of the aromatic series and to obtain the resulting purified stream containing hydrogen, dehydrogenation hydrocarbons and dehidrirana hydrocarbons. This is the preferred stream is then compressed and cooled to a temperature in the range from -50oF to -200oF (-45oC to -129oC) for the production of enriched hydrogen gas stream, which, preferably, partially recycle in reactionary. In accordance with the present invention may be selected from any suitable adsorbent, however, the preferred options are selected from the group comprising activated alumina and activated carbon.

The spent adsorbent containing mononuclear and polynuclear aromatic organic compounds, extracted at the stage of adsorption, in contact with the hot enriched hydrogen gas having a temperature in the range of 300oF (149oC) to 700oF (371oC) for deformirovaniya at least part of the contained compounds of the aromatic series. The resulting stream of hydrogen, mononuclear and polynuclear aromatic compounds number is cooled to a temperature in the range of 60oF (16oC) to 120oF (49oC) and injected into a zone of vapor-liquid separation to obtain an enriched hydrogen gas stream, which, if necessary, can be recycled. Enriched with hydrogen gas, preferably, is part of the resulting exhaust stream of hydrogen generated in the reaction zone. The liquid stream containing mononuclear and polynuclear aromatic organic compounds, are also removed from the zone of the liquid-vapor separation and share,and stream, containing mononuclear aromatic organic compounds, at least part of which is used as the above-mentioned recycled loop flow. Since mononuclear aromatic organic compounds formed in the reaction zone of dehydrogenization as by-products from the resulting stream containing mononuclear aromatic organic compounds is removed from the process.

Detailed description drawing

According to the drawing normally gaseous dehydrogenative hydrocarbon feedstock is introduced into the process through line 1 and is mixed with recirculated loop flow of hydrogen supplied through line 26, and the resulting mixture is introduced through line 2 into the zone of dehydrogenization 3. Stemming from dehydrogenization 3 the resulting stream containing dehydrogenation hydrocarbons, dehidrirana hydrocarbons and trace amounts of single-core and multi-core compounds of the aromatic series, is transported by pipeline 4 and is mixed with recirculated loop stream containing mononuclear aromatic organic compounds supplied through the pipe 35, and the resulting mixture is transported through a pipeline 5, trubor the concentration of mononuclear and polynuclear aromatic compounds, removed from the adsorption zone 9, is transported through the pipe 10, valve 11, pipe 12 and the pipe 23 and is injected into the area of the liquid-vapor separation 24. Enriched hydrogen gas stream removed from zone vapor-liquid separation 24 through line 26 and recycle, as described above. The resulting stream of gaseous hydrogen is removed from the zone of the liquid-vapor separation 24 through line 40. The stream of liquid hydrocarbon containing dehydrogenation hydrocarbons and dehidrirana hydrocarbons, is removed from the zone of vapor-liquid separation through line 25 and removed from the process. Hot-enriched hydrogen gas stream is introduced through conduit 16 and 17 in a disabled adsorption zone 18. The obtained gas stream of hydrogen containing desorption of single-core and multi-core aromatic organic compounds is removed from adsorption zone 18 through line 19, line 22 and introduced into the heat exchanger 36. The resulting cooled effluent stream from the heat exchanger 36 is transported through line 37 and introduced into the area of the liquid-vapor separation 27. Enriched hydrogen gas stream removed from zone of the liquid-vapor separation 27 through line 38. Liquid p is split 7 through line 28 and introduced into fractionation zone 29. A stream containing multi-core aromatic organic compounds is removed from fractionation zone 29 through line 30 and removed from the process. A stream containing mononuclear aromatic organic compounds, are removed from fractionation zone 29 through line 31 and introduced into the receiver 32. A stream containing mononuclear aromatic organic compounds, are removed from the receiver 32 through conduit 33 and 35 and recycle, as described above. The resulting stream containing mononuclear aromatic organic compounds, are removed from the receiver 32 through conduit 33 and 34 and removed from the process. The pipes 13 and 6 in combination with a valve 14 and the pipes 20 and 39 in combination with the valve 21 is used when the adsorption zone 18 is put into operation to replace the adsorption zone 9 in the process of regeneration of the latter.

Illustrative option

The isobutane stream of initial raw materials in the amount of 100 mass units per hour is introduced into zone dehydrogenization to convert 50 percent by weight loading of isobutane. Recycled loop flow of hydrogen is also introduced into zone dehydrogenization in the amount of 160 STD. m3/m3gas (900 SCFB) of the result arising from dehydrogenization stream, with the multi-core compounds of the aromatic series, based on the hydrocarbon, mixed with recirculated loop stream containing mononuclear aromatic organic compounds in the amount of 0.05 mass units per hour. The mixture resulting from dehydrogenization stream and is recycled to the loop flow is introduced into the adsorption zone containing activated alumina, to restore the level of mononuclear aromatic compounds range to less than 500 ppm (500 mg/l = 500 10-4%) and the level of multi-core compounds of the aromatic series to less than 1 ppm (1 mg/l = 1 10-4%). The result derived from the adsorption zone, the stream is compressed and cooled to a temperature of -130oF (-105oC) and then injected into a zone of vapor-liquid separation to obtain an enriched hydrogen gas stream, which is recycled from dehydrogenization, and the flow of liquid hydrocarbon containing isobutane and isobutylene.

Hot-enriched hydrogen gas stream at a temperature of 600 G (315oC) is injected into the exhaust disconnected adsorption zone containing activated alumina with adsorbed single-core and multi-core compounds of the aromatic series, for the regeneration of the adsorption zone. The resulting stream of hydrogen containing core and the aromatic compound and injected into a zone of vapor-liquid separation to obtain a stream of hydrogen and a liquid stream, containing mononuclear and polynuclear aromatic organic compounds, which are subjected to fractionation to obtain a stream containing multinuclear aromatic organic compounds, and stream containing mononuclear aromatic organic compounds. Part of the stream containing mononuclear aromatic organic compounds, recycle, as described above. The resulting stream containing mononuclear aromatic organic compounds, is recovered and removed from the process.

1. Method of removing single-core and multi-core compounds of the aromatic series of product dehydrogenization hydrocarbons containing dehydrogenation and dehydrogenation hydrocarbons and trace amounts of single-core and multi-core compounds of the aromatic series, including the state contacting with adsorbent selective for single-core and multi-core compounds of the aromatic series to reduce their concentration in the above-mentioned product and obtain a stream containing dehydrogenation and dehydrogenation hydrocarbons, stage simultaneous desorption and regenerating the spent adsorbent with an allocation of at least part of the mentioned single-core and multi-core seeding contacting it with the hot enriched with hydrogen gas, followed by separation of the resulting stream, containing hydrogen, mononuclear and polynuclear aromatic organic compounds emitting stream containing mononuclear compounds, forming a loop stream for mixing with the product of dehydrogenization hydrocarbon prior to contacting with the adsorbent.

2. The method according to p. 1, characterized in that the said dehydrogenation hydrocarbons are selected from the group comprising ethylene, propylene and butylene.

3. The method according to p. 1, characterized in that the aforementioned multicore aromatic organic compounds are present in the output from the reaction zone dehydrogenization hydrocarbon stream in an amount of from 50 to 500 wppm (50 - 500 mg/l [50 - 500] 10-4wt.%).

4. The method according to p. 1, characterized in that the stage of adsorption is carried out at a temperature of from 10 to 65C (from 50 to 150F).

5. The method according to p. 1, characterized in that said adsorbent is chosen from the group comprising activated alumina and activated carbon.

6. The method according to p. 1, characterized in that the said loop recycled stream containing mononuclear aromatic organic compounds is from 0.01 to 1 wt.% from the weight mentioned resulting from the reaction zone dehydrogenization Plevo the

 

Same patents:
The invention relates to chemical processing of petroleum products, namely the process of obtaining trademark of gasoline with O. H. 76-PM and organic gasoline with O. H. 92 - EM and benzene highest purification of catalization reforming wide gasoline fractions

The invention relates to methods of producing fuel for marine engines and can be used in the refining industry

The invention relates to the refining and can be used in the petroleum refining catalytic cracking

The invention relates to a method of allocation of organo-sulfur compounds of crude oil from petroleum products (kerosene and diesel oil fractions), in particular adsorption, and can be used in refineries and petrochemical industries

The invention relates to a method of allocation of organo-sulfur compounds of crude oil from petroleum products (kerosene and diesel oil fractions), in particular adsorption, and can be used in refineries and petrochemical industries

The invention relates to a method of selection of organic sulfur compounds from oil and can be used in the refining and petrochemical industry

The invention relates to the field of adsorptive purification of hydrocarbon fractions from sulfur compounds and can be used on gas - and oil refineries for fine purification from mercaptans and hydrogen sulfide, liquefied hydrocarbon gases and other light hydrocarbon fractions

The invention relates to the separation of different substances in connection with the treatment of hydrocarbon oils and, more specifically, to a method and device filtering, degassing, dehydration and removing products of aging in insulation and other petroleum oils

The invention relates to methods for isolating individual components of the oils and can be used in refining and petrochemical industries

The invention relates to the field of adsorptive separation of hydrocarbon mixtures, in particular adsorption methods of purification of liquid paraffins from aromatic hydrocarbons, and can be applied in the refining and petrochemical industry

The invention relates to a method of processing waste absorber Nickel-based

The invention relates to equipment for carrying out processes of purification of oil from wax, and in particular to equipment for carrying out processes of extraction of liquid n-paraffin from crude oil by adsorption

The invention relates to the production of compounds isoalkanes

The invention relates to the field of petrochemicals, in particular for reactors for dehydrogenation of paraffin hydrocarbons

The invention relates to the field of automation of production processes and can be used in the petrochemical industry in the production of styrene by dehydrogenation of ethylbenzene, styrene by dehydration of methylphenylcarbinol, obtaining a-methylstyrene by dehydrogenation of cumene in the production of divinylbenzene by dehydrogenation of diethylbenzene, etc

The invention relates to the petrochemical industry and can be used in the production of isoprene by dehydrogenation of isoamylenes
Up!