Way catalytic oxychlorination process of ethane to vinyl chloride
(57) Abstract:The invention relates to the production of the monomer is vinyl chloride from ethane. The method is based on the reaction of the oxychlorination process by the interaction of ethane, oxygen and a source of chlorine in the reactor for the oxychlorination process in the presence of a catalyst for the oxychlorination process. The catalyst includes copper salt and a salt of an alkali metal deposited on an inert carrier. Preferably the catalyst contains copper, potassium and cerium based 1,3:3,4:0,74 wt.%. The process is carried out in excess of gaseous hydrogen chloride at 400-550°C. Then separate vinyl chloride from the reaction products, and side-unsaturated chlorinated products hydronaut in the presence of a hydrogenation catalyst at from 20 to 250°C and recycle to the reactor for the oxychlorination process. The process is characterized by a high conversion and a significant reduction in waste. 8 C.p. f-crystals, 1 Il., 6 table. The present invention relates to a catalytic method for producing a vinyl chloride monomer (VCM) from ethane by oxychlorination process last.In most industrial methods of production of ACM as raw materials are ethylene and chlorine. In General, chlorinated ethylene in contact with chlorine and catalogbrowser VCM and hydrogen chloride. The use of ethylene as a starting material is substantial in value received VCM. In General, significant cost reduction can be achieved only at the expense of savings, the known methods are almost at maximum efficiency.Another disadvantage of the use of ethylene as a feedstock is that the dehydrochlorination of the intermediate 1,2-dichloroethane leads to the separation of hydrogen chloride. Disposal of the latter is usually achieved by the catalytic oxychloination ethylene additional stage with obtaining 1,2-dichloroethane.On the other hand, a method of obtaining VCM, which includes the use as feedstock ethane. The use of alternative hydrocarbon original substances from which ethane is the primary consideration, directly solves the problem of the high cost of ethylene by replacing the cheaper raw materials. In addition, the chemistry of receipt of ACM using alternative hydrocarbons can give several advantages. For example, the production of VCM can be made one.There are three known chemical method of converting ethane to VCM. These include Gazavat the FDS, based on oxychloination:
C2H6+ Cl + O2---> C2H3Cl + other products + H2O.The source of chlorine can serve as Cl2, HCl or chlorinated hydrocarbons. If the source of chlorine is used, hydrogen chloride, you can use one of the intermediate products for the production of VCM from ethylene.The production of VCM from ethane has no commercial success. Made several attempts to implement this method in the industry, but used methods had serious flaws that, making some inconvenience in the laboratory, in the implementation process on an industrial scale was unacceptable.A number of catalysts for carrying out catalytic oxychlorination process ethane.The most promising catalysts, as it turns out, are the catalysts of the fluidized bed copper-based. Brit. the patent 1492945 (BP) describes such catalysts containing the chlorides of copper, potassium and cesium, plotted together with the chloride of cerium in the process of evaporation to the media on the basis dioxide aluminum. However, the patent does not follow from the evidence that the specific formulation used in the patent BP, % nitrogen, that is not feasible in industrial applications, and are not presented all the results. On most of the side products of the reaction oxychlorination process did not pay attention. In addition, use high temperature (530oC).In patent SU 567714 also revealed copper/potassium catalyst for ethane oxychlorination process. However describes one specific used formula, which is effective at temperatures above 550oC, and up to 62.4% unreacted ethane are not consistent with the specified there range of products.Brit. the patent 2009164 (firm Monsanto) is described, along with others, copper/potassium catalyst. But used the exact recipe, as it turns out, is not effective at temperatures below 500oC. moreover, the results aren't helpful, because it may seem that the formation of ethylene or ignored or mistaken for the education of ACM. Conversion to VCM is not given.From the above description of the prior art shows that the selectivity of the reaction oxychlorination process to VCM is not 100%. This fact is largely the source of the inefficiency of the process of oxychlorination process.aboutsa in the oxidation of hydrocarbons, for example, ethane, with the formation of mainly CO2. These products are the losses of raw materials. However, they have not been studied in the works of the preceding level. No attempt has been made to reduce the formation of these byproducts, except attempts associated with the reformulation of the catalyst, which, as is evident from consideration of the work of the previous level, has its limitations.Another reason for the inefficiency of ethane oxychlorination process due to the formation of side products, which are not products of combustion. Such by-products are mainly chlorinated hydrocarbons and, in some cases, can be turned into VCM. However, such by-products were also excluded from consideration in the work of the previous level.For example, in Brit. the patent 1256245 (Princeton Chemical Research, Inc.) other chlorinated materials were formed at the level of approximately one tenth of the yield of vinyl chloride. Brit. the patent 1256245 no suggestions as to what to do with such by-products. However, you can see that these by-products make up a considerable part of the total output reacts chlorinated hydrocarbons, such as trichloroethane, trichloroethylene, tetrachlorid and similar compounds. It is assumed that such by-products are burned, resulting in the loss of their value as raw materials. Even if the resulting hydrogen chloride can be distinguished, the carbon contained in by-products, is lost.It is established that there is an opportunity to significantly improve the efficiency of the reaction oxychlorination process by solving problems that were previously excluded from consideration.In accordance with this invention proposes a method for the catalytic oxychlorination process ethane to VCM, which includes a mixture of ethane and chlorine in the reactor for the oxychlorination process in the presence of a catalyst for the oxychlorination process, and reaction conditions are selected so as to reduce the impact oxychloride form of the catalyst, separating the resulting VCM from the products and recycling of by-products of the reaction in the reactor.The formation of the products of combustion when the test oxychlorination process promoterwise oxychloride form of the catalyst. Found that the choice of reaction conditions under which decreases the concentration of this form and, consequently, reduces its impact, decreases ATOR can be reduced, for example, increasing the reaction temperature. However, this solution is disadvantageous because, for example, will require a large amount of energy for heating the reactor, which will increase the cost of production.Preferably, the impact oxychloride form of the catalyst decreases as the creation of conditions for its rapid interaction with reagents.Found that some sources of chlorine react with oxychlorides form of the catalyst very quickly, therefore decreases the amount of combustion products formed during the reaction. Thus, it is preferable that the impact oxychloride form of the catalyst is decreased by use of a suitable source of chlorine in excess of the required stoichiometric on chlorine number.The preferred source of chloride is HCl.Hydrogen chloride in the reaction oxychlorination process may be the only source of chlorine. On the other hand, it may be submitted together with the second source of chlorine such as chlorinated hydrocarbons or chlorine itself. All the need for chlorine may also be provided a second source of chlorine.In General, the larger the excess podast reaction oxychlorination process. In those cases, when there is no need for hydrogen chloride, with all of the necessary amount of chlorine is provided by an alternative form, any added amount of hydrogen chloride will have a positive impact.The molar ratio of HCl used in the reaction of the ethane is preferably in the range from 0.1 to 10, preferably in the range from 0.5 to 3.As in the reaction is consumed not all hydrogen chloride, it will leave the reactor together with the reaction products. Preferably an excess of hydrogen chloride to return to the reactor.The selection of hydrogen chloride and its return to the reactor can be accomplished in any known in this field by the way.The reactor and means for mixing ethane and chlorine source is well known in this field. For example, the conditions of this reaction are described in the prior art mentioned earlier.It is preferable, however, that the catalyst contained salt and copper salt of an alkali metal deposited on an inert carrier. Preferably, copper and alkali metal present in an atomic ratio of 2:8.As the alkali metal mo The specified atomic ratio of copper and potassium corresponds to 1.3 and 3.4 wt. %.As an auxiliary component may be used in salt lanthanide. The preferred lanthanide is cerium, which can be used when the atomic ratio of 0.1-5. It is preferable that was used to 0.74 wt.% cerium, which corresponds to an atomic ratio of 0.5.On the other hand, as an auxiliary component can also be used alkaline earth metals. Preferred alkaline earth metals are magnesium and calcium.Inert carrier for catalyst may be selected from those known in the field of media that is easily accessible. For example, you can use devices such as alumina, silica gel, aluminum silicate, magnesium silicate, bauxite, titanium dioxide magnesium, silicon carbide, titanium oxide, zirconium silicate, and other similar media.A preferred carrier is alumina. Preferred is alumina having a low value of the specific surface. Preferably this value is less than 5 m2/g and more preferably 1 m2/,The catalyst may be used in the form of a stationary layer or in the form of psevdoozhireniem average size of about 90 microns.Metal salts used in the catalyst are preferably the chlorides of the metals. But it can also use nitrates, carbonates and hydroxides, which under the reaction conditions oxychlorination process will be converted into chlorides, oxides or oxychloride.Source ethane used in the reactions oxychlorination process may have a high degree of purity, or may contain appreciable quantities of other hydrocarbons, such as ethylene or methane, which is usually for ethane industrial or technical origin.The oxygen may be supplied in the form of gaseous oxygen or oxygen-enriched air, or mixtures thereof.The proportions in which the various components are mixed, the reaction mixture may be determined empirically. Preferably the ratio of ethane to oxygen is in the range from 1:0.25 to 1:1,4, and more preferably from 1:0.75 to 1:1. The ratio of ethane to chlorine is preferably from 1:0.5 to 1:5. All ratios are molar ratios.The catalyst of the present invention can operate in the temperature range from 400 to 550oC. the Preferred range of operating temperatures, atnaciet to work at a pressure in the range from 0 to 30 bar (29,62 ATM), preferably in the range from 1 to 10 bar (0,99-9,9 ATM).The contact time of the reactants with the catalyst is preferably from 1 to 60 seconds, and more preferably from 5 to 25 seconds.It is established that the recycling of by-products of the reaction oxychlorination process in the reactor leads to less waste of raw materials. In the preferred embodiment, this method really may reduce raw material wastage to zero, except for the part that is lost in the form of products of combustion and which is lost in the purge. This is because the by - products of chlorinated hydrocarbons can be converted to VCM in the subsequent process of oxychlorination process.Chlorinated by-products formed in the oxychloination ethane to VCM, usually divided into saturated, unsaturated compounds and combustion products.Saturated compounds include ethyl chloride, 1,1-dichloroethane, 1,2-dichloroethane and 1,1,2-trichloroethane. Products of combustion include carbon tetrachloride, chloroform and dichloromethane. Unsaturated compounds are 1,1-dichloroethylene, CIS-1,2-dichloroethylene, TRANS-1,2-dichloroethylene, trichloroethylene and perchloroethylene.Midrange the project. Although this would provide some positive effect, the total conversion of by-products in ACM would be low.This is because the reactions that take place when carrying out the reaction oxychlorination process, it is impossible transformation of unsaturated chlorinated hydrocarbons in VCM. In addition, many saturated chlorinated hydrocarbons will become unsaturated chlorinated hydrocarbons as the result of dehydrocorydaline, and, therefore, cannot be turned into VCM.Therefore, preferably unsaturated chlorinated hydrocarbons to turn in saturated form on the stage of the hydrogenation.Saturated chlorinated hydrocarbons are converted by dehydrochlorinating and, if necessary, by further hydrogenation of unsaturated hydrocarbons and, ultimately, in BMX. The drawing shows reactions that occur in the reactors oxychlorination process and hydrogenation used in the present invention.When recycling unsaturated by-products turn phase hydrogenation of all chlorinated hydrocarbon side reaction products oxychlorination process can be selected and their value as source materials the house through the catalyst bed at elevated temperature and pressure. Appropriate catalysts are platinum, palladium and rhodium, which are preferably at a temperature of from 20 to 250oC, mostly from 50 to 150oC, in a reactor with a moving bed. It is preferable to use a large excess of hydrogen. However, any acceptable catalyst known in this field can be regarded as a catalyst for the method of the present invention under appropriate operating conditions.Unsaturated chlorinated hydrocarbons can be fed to the hydrogenation reactor in almost pure form. However, in the preferred implementation of the present invention they are in the raw form with saturated chlorinated hydrocarbon by-products and combustion products from the reactor for the oxychlorination process. This eliminates the need for phase separation to separate saturated by-products from unsaturated by-products and combustion products.Saturated hydrocarbons such processing non-sensitive, although under certain conditions they are hydrodechlorination, which leads to the formation of ethane. The combustion products also remain hydro-dechlorination with about mponent, listed above in the indicated molar relationship: - Min. Max.1,1-dichlorethylene - 0; 10
CIS-1,2-dichlorethylene - 0; 10
TRANS-1,2-dichlorethylene - 0; 20
trichloroethylene - 0; 10
perchlorethylene - 0; 10
chloride ethyl - 0; 20
1,1-dichloroethane - 0; 10
1,2-dichloroethane - 0; 90
1,1,2-trichloroethane - 0; 30
carbon tetrachloride - 0; 20
chloroform - 0; 20
dichloromethane - 0; 10
SIM-tetrachlorethane - 0; 5
Raw materials may also contain relatively small amounts of other materials, such as chlorinated butane, chlorinated BUTADIENES and other chlorinated materials, as well as hydrocarbons such as ethane and ethylene.The invention is illustrated in the following examples with reference to the drawing, which shows a diagram of the reactions in the reactors oxychlorination process and hydrogenation.Examples 1 and 2.By evaporation of an aqueous solution of metal chlorides to prepare a catalyst containing at 1.3% copper and 3.4% of potassium on the media - dioxide aluminum. To 250 cm3deionized water is added 20 g of CuCl2H2O and 35 g of KCl. The resulting solution was added in several portions to 500 g of the catalyst carrier (type SAHT-99, Production Chemicals LTD). The resulting paste of katalizatorov. It was found that after preparation of the catalyst has a specific surface area of 1 m2/g and average particle size of 90 microns.The catalyst loading 400 cm3placed in a fluidized bed reactor with a diameter of 50.8 mm, receiving fluidized bed length of approximately 40 cm Conversion and selectivity of the catalyst is determined using a gas chromatograph installed in the line. The reactor is heated by an electric current to the desired operating temperature and filled with a gas mixture of ethane, chlorine, nitrogen and oxygen. Get the results, presented in table. 1, the example 1. The experiment is then repeated, except that replace chlorine hydrogen chloride and use a higher flow of oxygen to provide the necessary high stoichiometric amount of oxygen. The results are presented in table. 1, the example 2. The use of hydrogen chloride instead of chlorine leads to a higher rate of combustion and a lower rate for the conversion of ethane at a somewhat lower rate of conversion of oxygen.Example 3-5.Cook another catalyst loading described above. In addition, a similar method of preparing a sample of a catalyst containing copper, Kali is hydrogen chloride, oxygen and nitrogen. This experiment is then repeated, with the use of Cu/K-Ce catalyst. The results of both experiments are presented in table. 2, example 3. Comparison of conversion and selectivity of these two catalytic formulations repeat for two versions of other conditions for different ratios of feed (table. 2, examples 4 and 5). In all three embodiments, the reaction conditions, the introduction of cerium in the catalytic formulation leads to a significant positive effect: the rate of combustion is reduced and the rate of conversion of ethane increases.Examples 6-22.When using Cu/K/Ce-catalyst obtained by the method described in example 2, the reactor serves a mixture of ethane, oxygen, 1,2-dichloroethane and nitrogen. In table. 3 presents the results of a series of experiments at different temperatures and ratios of supply of raw materials and specified interval conversion to ethane and oxygen, as well as data on the selectivity of the reaction. The best results are achieved at high temperature when using a lower rate of oxygen (example 13).Examples 23-25.Again use Cu/K/Ce-formulation described in example 2. In the reactor serves a mixture of ethane, oxygen, 1,2-dichlorethane load half of the normal loading of the catalyst and a half of pure carrier for catalyst. The transfer catalyst in the fluidized state by means of nitrogen and maintained at 470oC for 8 h, and then serves a mixture of ethane, oxygen, 1,2-dichloroethane, ethyl chloride and nitrogen. The results obtained are presented in table. 4, example 24. The method is repeated, except that the use of a catalyst which contains only 25% of the initial loading of the catalyst and 75% of the net medium. The results are presented in table. 4, example 25.The results of this series of experiments show that the effect of the conversion of raw materials and the selectivity can be measured only at concentrations of metal in the catalyst is between 25 and 50% of the initial concentration.Example 26.By evaporation of an aqueous solution of metal chlorides to prepare a catalyst containing at 1.3% copper and 3.4% of potassium on the media - dioxide aluminum. To 250 cm3deionized water is added 20 g of CuCl2H2O and 35 g of KCl. The resulting solution was added in several portions to 500 g of the catalyst carrier (Type SAHT-99, Production Chemicals LTD). The resulting paste of the catalyst is dried at 120oC for 24 h, and then before using sieved to break up the agglomerates. It was found that after preparation of the catalyst has a specific surface area of 1 mipadin layer with a diameter of 50.8 mm, getting a fluidized bed height of approximately 40 cm Conversion and selectivity of the catalyst is determined using a gas chromatograph installed in the line. The reactor is heated by an electric current to the desired operating temperature and filled with a gas mixture of ethane, chlorine, nitrogen and oxygen. Data on raw materials and the results obtained are presented in table. 5, example 26.Example 27.Use the same catalyst and operating conditions, as example 26. The differences are that increase the feed rate of hydrogen chloride and does not serve the nitrogen. The results are presented in table. 5.In example 27 fed an excess of hydrogen chloride does not participate in the reaction oxychlorination process, as all the oxygen is consumed at a lower feed rate of hydrogen chloride, as shown in example 26. From the results shown in the table, you can see that when increasing the feed rate of hydrogen chloride in the reactor exit of products of combustion (mainly CO2) decreases with 8,44 to 7.27% based on unreacted ethane.Example 28.Using the catalyst of the same composition as in example 26, and mixed chlorophenothane raw materials. The impact of the expansion of the form a catalyst of the same composition, as in example 20, and mixed chlorophenothane raw materials. The effect of increasing the feed rate of hydrogen chloride, but at a higher temperature than in example 28, shown in the table. 6, examples 29A-29C.Example 30.Again using the catalyst of the same composition as in Example 20, and mixed chlorophenothane raw materials. The impact of increased feed rate of hydrogen chloride, but at a higher temperature than in example 28, and a lower rate of oxygen supply, are presented in table. 6, examples 30A-30C.From table. 6, it is seen that when the three combinations of temperature and feed rate of oxygen increase the feed rate of hydrogen chloride leads to a decrease in the rate of combustion of ethane. Moreover, the efficiency with which the conversion of ethane in the reactor, increasing the feed rate of hydrogen chloride in the reactor also increases.Example 31.In the fluidized bed reactor serves the following components:
Ethane - 1,0
Oxygen - 0,85
The products of direct chlorination:
Ejh - 0,35 (0,35 feed chlorine)
Oxides of carbon - 1,1
Chloride ethyl - 0,37
EJH - 0,78
1,1-Dichloroethane - 0.02
1,1,2-BR>Hydrogen chloride - 0,1
The above molar ratio are stationary working feed rate of the reactants into the reactor. Chlorine enters the process in the form of elemental chlorine supplied directly to the chlorination reactor.Ethane is mixed with recycle hydrogen chloride and fed into the reactor below the plates supporting the catalyst. In the air chamber it is mixed with evaporated recycle hydrogenation and products of direct chlorination. The combined streams have a temperature of 150oC and a pressure of 5.5 bar (5,43 ATM).The mixture passes through a supporting grid to bring in the fluidized state of the catalyst, which operates at a temperature of 450oC. Oxygen raw material is fed through a gas distributor, which is located directly above the supporting grid. The residence time in the reaction zone is 12 seconds and the reaction temperature is maintained constant by removal of heat of reaction through heat exchange coils submerged in the bed and chilled circulating hot salt. Range of products based on raw materials specified above conforms to the following:
Ethane - 0,24
EJH - 0,78
Dichlorethylene - 0,05
Trichloroethylene - 0,01
1,1,2-trichlorethane - 0.02
Perchlorethylene - 0,01
Carbon tetrachloride - 0,03
Hydrogen chloride - 0,1
Water - 1,31
Found that when the content of hydrogen chloride in the gases leaving the reactor ethane oxychlorination process goes to a very small level (almost full completion of the reaction, the amount of ethane, which turns into the combustion products increases dramatically. While maintaining an excess of hydrogen chloride combustion reaction can be reduced with 20% (no HCl in the exhaust gas) to 3% (10% HCl in flue gases). Also found that it is possible to reduce the operating temperature in the reactor to 450oC, while maintaining acceptable conversion of raw materials and selectivity by increasing the residence time in the reaction zone from 2 to 12 seconds. This is very significant, as is known industrial metals at temperatures above 470oC largely susceptible to corrosion/erosion.The reaction mixture described above is divided into a stream of anhydrous hydrogen chloride stream of dry light components (all components easier VCM), the flow of pure VCM and the flow of heavy pasochnitsa results in the aqueous phase HCl, phase wet organic liquid and wet vapor phase. The aqueous phase is mixed with a solution of calcium chloride and then distilled to obtain the head of anhydrous hydrogen chloride, which is recycled to the reactor. The main product is taken in the form of a side of the steam flow, which is condensed with the formation of uncontaminated water flow. The flow of calcium chloride recycle in the raw column. Wet liquid phase is subjected to azeotropic drying in distillation columns. Wet the top product is recycled to the stage of phase separation, whereas the dry main product is pumped to the separation by distillation. Wet pair dried by contact in countercurrent flow with a 20% solution (weight/weight) HCl, cooled to -20oC. To maintain the material balance is the product of this thread on a column of calcium chloride.Compressed steam products and a stream of dried organic liquids are served together on the distillation column (column of light components), in which ethane is used as a light shoulder strap, and VCM as heavy. After heat exchange in the commodity column steam product interacts with the chlorine with the formation of ejh from ethylene, priyono liquid-phase reactor.A vapor-phase fluidized bed XLERATOR direct chlorination is preferred to conduct this reaction, since the heat of reaction can be abstracted with the flow and there is no contamination of the product, for example, iron, which affects the environment. The reactor operates at a pressure of 6 bar (5.92 to ATM) and a temperature of 200oC. the off-gas recycle to the reactor for the oxychlorination process, but is a small purge stream in order to balance the content of carbon oxides. Ejh is removed from the purge flow through the absorption layer of coal. Containing a small amount of impurity gas is burned.The main stream from the column of light components distilled (VCM column) for separation of ACM in the form of the head of the product. The main product is reacted with hydrogen in a reactor with a moving bed. In this reactor, any olefinic compounds (e.g., dichloroethylene, trichloroethylene and perchloroethylene) become saturated analogues. The reaction proceeds and o adiabatically at a pressure of 10 bar (9,87 ATM) and at a temperature of 75oC with a 10-fold excess of hydrogen. The flow of saturated compounds is then vaporized and recycled to the reactor for the oxychlorination process, where saturated compounds, for example, is transformed into VCM. 1. Way catalytic oxychlorination process of ethane to vinyl chloride, including the interaction of ethane, oxygen and a source of chlorine in the reactor for the oxychlorination process in the presence of a catalyst for the oxychlorination process, including salt and copper salt of an alkali metal deposited on an inert carrier, wherein the process is carried out in an excess of HCl, separate vinyl chloride from the effluent from the reactor stream and recycle by-products in the reactor.2. The method according to p. 1, wherein the catalyst further comprises a salt of lanthanide.3. The method according to p. 2, characterized in that the catalyst contains copper, potassium and cerium based 1,3 : 3,4 : 0,74 wt.%.4. The method according to any of paragraphs.1 to 3, characterized in that the metal salts are the chlorides of the metals.5. The method according to any of paragraphs.1 to 4, characterized in that the process is conducted at temperatures of 400 - 550oC.6. The method according to p. 5, wherein the process is conducted at temperatures of 450 - 470oC.7. The method according to any of paragraphs.1 - 6, characterized in that the recycled by-products are subjected to hydrogenation prior to feeding into the reactor for the oxychlorination process.8. The method according to p. 7, characterized in that nanosystem, what stage hydrogenation is carried out in a hydrogenation reactor in the presence of a catalyst containing platinum, palladium or rhodium at a temperature of 20 - 250oC.
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing vinyl chloride monomer. Method involves generating outlet flow from reactor by catalytic interaction in common ethane, ethylene, oxygen and at least one source of chlorine taken among hydrogen chloride, chlorine or chlorohydrocarbon wherein the mole ratio of indicated ethane to indicated ethylene is in the range from 0.02 to 50. At this stage of catalytic interaction method involves using a catalyst comprising component of rare-earth material under condition that catalyst has no iron and copper practically and under additional condition that when component of rare-earth material represents cerium then catalyst comprises additionally at least one more component of rare-earth material being except for cerium. Indicated outlet flow from reactor is quenched to form flow of crude product that doesn't comprise hydrogen chloride practically. Flow of crude product is separated for vinyl chloride monomer flow and light fractions flow and the latter flow is recycled for catalytic interaction in common with indicated ethane, indicated ethylene, indicated oxygen and indicated chlorine source at the indicated generating stage. Also, invention proposes variants of a method in producing vinyl chloride. Invention provides the complete extraction of hydrogen chloride from the reactor outlet flow after conversion of ethane/ethylene to vinyl (chloride).
EFFECT: improved producing method.
30 cl, 5 dwg, 9 tbl, 30 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing vinyl chloride monomer from ethane and ethylene. Method involves generating the outlet flow from reactor by catalytic interaction in common of ethane, ethylene, oxygen and at least one chlorine source taken among hydrogen chloride, chlorine or chlorohydrocarbon wherein the mole ratio of indicated ethane to indicated ethylene is in the range from 0.02 to 50. At the indicated stage of catalytic interaction method involves using a catalyst comprising component of rare-earth material under condition that catalyst doesn't comprise iron and copper practically and under additional condition that when component of rare-earth material represents cerium then catalyst comprises additionally at least one more rare-earth material but not cerium. Indicated outlet flow from reactor is cooled and condensed to form flow of crude product comprising the first part of hydrogen chloride and flow of crude cooled hydrogen chloride comprising the second part of indicated hydrogen chloride. Then method involves separation of indicated flow of crude product for vinyl chloride monomer as the flow product and flow of light fractions comprising the indicated first part of indicated hydrogen chloride. Then indicated flow of light fractions is recycled for catalytic interaction in common with indicated ethane, indicated ethylene, indicated oxygen and indicated chlorine source at indicated generating stage. Also, invention proposes variants of a method for producing vinyl chloride from ethane and ethylene. Invention provides preparing vinyl (chloride) from ethane and ethylene by the complete extraction of hydrogen chloride from the reactor outlet flow.
EFFECT: improved producing method.
40, 9 tbl, 3 dwg, 31 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing vinyl chloride monomer and to a catalyst sued in catalytic preparing vinyl chloride monomer from flows comprising ethylene. Method for preparing vinyl chloride from ethylene is carried out by the oxidehydrochlorination reaction. Method involves combining reagents including ethylene, the source of oxygen and chlorine in the catalyst-containing reactor at temperature 350-500°C and under pressure from atmosphere to 3.5 MPa, i. e. under conditions providing preparing the product flow comprising vinyl chloride and ethylene. Catalyst comprises one or some rare-earth elements under condition that the atomic ratio between rare-earth metal and oxidative-reductive metal (iron and copper) is above 10 in the catalyst and under the following condition: when cerium presents then the catalyst comprises additionally at least one rare-earth element distinctive from cerium. Ethylene is recirculated from the product flow inversely for using at stage for combining reagents. Invention proposes a variant for a method for preparing vinyl chloride. Also, invention proposes variants of a method for catalytic dehydrochlorination of raw comprising one or some components taken among ethyl chloride, 1,2-dichloroethane and 1,1,2-trichloroethane in the presence of catalyst. Catalyst represents the composition of the formula MOCl or MCl3 wherein M represents a rare-earth element or mixture of rare-earth elements taken among lanthanum, cerium, neodymium, praseodymium, dysprosium, samarium, yttrium, gadolinium, erbium, ytterbium, holmium, terbium, europium, thulium and lutetium. The catalytic composition has the surface area BET value from 12 m2/g to 200 m2/g. Invention provides simplifying technology and enhanced selectivity of the method.
EFFECT: improved conversion method.
61 cl, 8 tbl, 32 ex
FIELD: petrochemical processes.
SUBSTANCE: invention relates to oxidative halogenation processes to obtain halogenated products, in particular allyl chloride and optionally propylene. Process comprises interaction of hydrocarbon having between 3 and 10 carbon atoms or halogenated derivative thereof with halogen source and optionally oxygen source in presence of catalyst at temperature above 100°C and below 600°C and pressure above 97 kPa and below 1034 kPa. Resulting olefin containing at least 3 carbon atoms and halogenated hydrocarbon containing at least 3 carbon atoms and larger number of halogen atoms than in reactant. Catalyst contains essentially iron and copper-free rare-earth metal halide or oxyhalide. Atomic ratio of rare-earth metal to iron or copper is superior to 10:1. In case of cerium-containing catalyst, catalyst has at least one more rare-earth element, amount of cerium present being less than 10 atomic % of the total amount of rare-earth elements. Advantageously, process is conducted at volumetric alkane, halogen, and oxygen supply rate above 0.1 and below 1.0 h-1, while diluent selected from group including nitrogen, helium, argon, carbon monoxide or dioxide or mixture thereof is additionally used. Halogenated product is recycled while being converted into supplementary olefin product and olefin product is recycled in order to be converted into halogenated hydrocarbon product. Optionally, allyl chloride and ethylene are obtained via interaction of propane with chlorine source in presence of catalyst.
EFFECT: increased productivity of process and improved economical characteristics.
26 cl, 1 tbl
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to processes for the oxidative halogenation reaction of hydrocarbons, in particular, for synthesis of haloidmethanes, their following processing to value chemical compounds. Method involves contacting methane, halogenated methane or their mixture with halogen source and oxygen source in the presence of catalyst to yield halogenated C1-hydrocarbon having more amount of halogen substitutes as compared with the parent hydrocarbon, Process is carried out at temperature above 200°C but less 600°C and under pressure 97 kPa or above but less 1.034 kPa and at the volume rate of raw feeding above 0.1 h-1 but less 100 h-1. Catalyst comprises rare earth metal halide or oxyhalide no containing iron and copper. The atomic ratio of rare-earth element to iron or copper exceeds 10:1 under condition that if catalyst comprises cerium in the amount less 10 atomic percent of the total amount of rare-earth components then catalyst comprises also one additional rare-earth element. Reacting hydrocarbon is chosen from the group consisting of methane, chloromethane, bromomethane, iodomethane, dichloromethane, dibromomethane, diiodomethane, chlorobromomethane and their mixtures. The molar ratio of hydrocarbon to halogen is above 1;1 but less 20:1 and that to oxygen is above 2:1 but less 20:1. The reaction mixture comprises additionally a diluting agent as nitrogen, helium, argon, carbon monoxide or dioxide or their mixtures. Formed methyl chloride or methyl bromide can be fed to the hydrolysis step to yield methyl alcohol or used in process of catalytic condensation to form light olefins and/or gasolines. It is possible contacting methyl halide with the condensation catalyst to form ethylene and the following preparing vinyl halide monomer, for example, vinyl chloride or acetic acid under carbonylation conditions. Invention provides enhancing output of the process at the expense of using the effective modified catalyst based on rare-earth elements.
EFFECT: improved halogenation method.
33 cl, 1 tbl, 1 ex
SUBSTANCE: invention relates to catalytic methods of processing methane through direct and/or oxidative chlorination. For oxychlorination of methane, hydrogen chloride is taken in volume ratio to methane equal to 0.5-1:1, oxygen is taken in total volume ratio to hydrogen chloride in the range of 0.58-0.68:1 and at the oxidative chlorination step of the process in mass ratio of 3.5-4:1 to unreacted hydrogen chloride. Water is added, through which unreacted hydrogen chloride in the composition of the formed hydrochloric acid is returned into the process to the methane oxychlorination step. The process also includes the following steps: pyrolysis of methyl chloride obtained at the methane chlorination and/or oxychlorination step to obtain lower olefins, mainly ethylene, oxidative chlorination of the obtained ethylene to dichloroethane, thermal dehydrochlorination of the obtained dichloroethane to vinyl chloride. The catalyst for direct and/or oxidative chlorination of methane used is a mixture of copper, potassium and lanthanum chlorides in molar ratio of 1:1:0.3, deposited in amount of 3-30 wt % on a porous support with specific surface area of 1-60 m2/g. Pyrolysis of methyl chloride is carried out in a reactor with a fluidised bed of a silicoalumophosphate catalyst of the SAPO-34 type at pressure of 2-5 atm and temperature of 400-500°C.
EFFECT: design of a chlorine-balanced method of processing natural gas to obtain methyl chloride, lower olefins, mainly ethylene, dichloroethane and vinyl chloride.
7 cl, 1 dwg, 1 ex
SUBSTANCE: method for oxidative halogenation involves bringing C1 reacting hydrocarbon selected from methane, halogenated C1 hydrocarbon or mixture thereof, into contact with a halogen source and an oxygen source in a reactor in the presence of a catalyst. Molar ratio of the C1 reacting hydrocarbon to the halogen source in the raw material for the reactor is greater than 23/1; or molar ratio of the C1 reacting hydrocarbon to the oxygen source in the raw material for the reactor is greater than 46/1; or in both raw materials for the reactor, the molar ratio of the C1 reacting hydrocarbon to the halogen source is greater than 23/1 and the molar ratio of the C1 reacting hydrocarbon to the oxygen source is greater than 46/1. Contact takes place under conditions of the method which are sufficient for obtaining a halogenated C1 product, having at least one extra halogen substitute compared to the reacting hydrocarbon. Conditions of the method include temperature higher than approximately 375°C and lower than approximately 700°C and pressure higher than approximately 14 psia (97 kPa) and lower than approximately 150 psia (1034 kPa); the catalyst contains a halide of a rare-earth element or an oxyhalide of a rare-earth element and the atomic ratio of the rare-earth element to iron and copper is greater than 10/1, provided that when cerium is present in the catalyst, at least one other rare-earth element is also present in the catalyst, where cerium is present in the catalyst in amount less than approximately 10 atomic % of the total amount of the rare-earth components. The invention also relates to a method of producing a halogenated C1 product, involving: (a) feeding a stream of a halogen source into a reactor containing a catalyst, where the catalyst contains a halide of a rare-earth element or an oxyhalide of a rare-earth element, and the atomic ratio of the rare-earth element to iron and copper is greater than 10/1, provided that when cerium is present in the catalyst, at least one other rare-earth element is also present in the catalyst, where cerium is present in the catalyst in amount less than approximately 10 atomic % of the total amount of the rare-earth components; (b) cutting the flow of the halogen source to the reactor; (c) adding a mixture into the reactor, where the mixture contains a C1 reacting hydrocarbon selected from a group comprising methane, a halogenated C1 hydrocarbon or mixture thereof, and an oxygen source, such that the concentration of the halogen source in the said stream is less than 0.5 vol. % and molar ratio of the C1 reacting hydrocarbon to the halogen source is greater than 23/1, under conditions of the method sufficient for obtaining a halogenated C1 product, having at least one extra halogen substitute compared to the reacting hydrocarbon, where conditions of the method include temperature higher than approximately 375°C and lower than approximately 700°C and pressure higher than approximately 14 psia (97 kPa) and lower than approximately 150 psia (1034 kPa); (d) cutting the flow of the mixture containing the C1 reacting hydrocarbon and the oxygen source to the reactor and (e) repeating steps (a) to (d) in a varying way.
EFFECT: high efficiency, complete conversion of a halogen source and an oxygen source, avoiding catalyst deactivation.
3 tbl, 4 ex
SUBSTANCE: invention relates to chemistry, specifically to the technology of producing a valuable semi-product - methyl chloride, which is a promising raw material for producing ethylene and other light olefins. Described is a method for selective catalytic oxychlorination of methane to methyl chloride, where a mixture consisting of methane, hydrogen chloride and either oxygen diluted with an inert gas, or air or pure oxygen is passed at temperature not higher than 350°C through a catalyst layer which is a geometrically structured system which contains microfibres of a high-silica support and at least one active element, said element being either in form of a MeOxHaly composite or in form of a NwMezOxHaly composite, where element Me is selected from a group comprising iron, cobalt, nickel, ruthenium, rhodium, vanadium, chromium, manganese, zinc, copper, silver, gold or one element from a group of lanthanum and lanthanides, and element Hal is one of halogens: fluorine, chlorine, bromine, iodine and element N in composite NwMezOxHaly is selected from a group comprising alkali, alkali-earth elements or hydrogen.
EFFECT: high degree of conversion of initial reagents and selectivity of formation of methylchloride.
4 cl, 4 ex
SUBSTANCE: method involves oxidative chlorination of methane, pyrolysis of the methyl obtained from methane oxychlorination, and is characterised by that after extracting chloromethanes from the methane oxychlorination step, the remaining still liquor, which primarily contains methylene chloride and chloroform, undergoes hydrodechlorination at temperature 150°-300°C on a palladium or nickel-molybdenum catalyst on a support, and the obtained stream of reaction gas is split into two fractions. One of said fractions with high-boiling point hydrodechlorination products, which contain unreacted methylene chloride and chloroform, is fed into a chloromethane separation unit for the methane oxychlorination step, and the other fraction with low-boiling point gases from the chloromethane hydrodechlorination process, which contain hydrogen, methane, hydrogen chloride and partially methyl chloride, is merged with the gas stream coming from the methyl chloride pyrolysis step, followed by combined separation thereof into hydrogen, methane, lower olefins and unreacted methyl chloride, which is returned to the catalytic pyrolysis step.
EFFECT: use of present method enables to increase output of methyl chloride and, consequently, light olefins obtained during conversion thereof.
1 cl, 1 tbl, 2 ex, 2 dwg
SUBSTANCE: invention relates to method of oxidising halogenation of methane, which includes contact of flow of supplied material, containing methane, halogen source and oxygen source, with first catalyst in conditions, sufficient for providing flow of product, where first catalyst is selected from group, consisting of solid superacids and solid superbases.
EFFECT: catalyst has great methyl halogenide and carbon monoxide selectivity than methylene halogenide, trihalogen-methane or carbon tetrahalogenide selectivity.
10 cl, 25 ex, 8 tbl
FIELD: chemical industry, in particular method for production of value products from lower alkanes.
SUBSTANCE: claimed method includes passing of gaseous reaction mixture containing at least one lower alkane and elementary chlorine through catalytic layer. Used catalyst represents geometrically structured system comprising microfiber with diameter of 5-20 mum. Catalyst has active centers having in IR-spectra of adsorbed ammonia absorption band with wave numbers in region of ν = 1410-1440 cm-1, and contains one platinum group metal as active component, and glass-fiber carrier. Carrier has in NMR29Si-specrum lines with chemical shifts of -100±3 ppm (Q3-line) and -110±3 ppm (Q4-line) in integral intensity ratio Q3/Q4 from 0.7 to 1.2; in IR-specrum it has absorption band of hydroxyls with wave number of ν = 3620-3650 cm-1 and half-width of 65-75 cm-1, and has density, measured by BET-method using argon thermal desorption, SAr = 0.5-30 m2/g, and specific surface, measured by alkali titration, SNa = 10-250 m2/g in ratio of SAr/SNa = 5-30.
EFFECT: method of increased yield.
3 cl, 4 ex
FIELD: chemical industry, in particular method for production of value monomer such as vinylchloride.
SUBSTANCE: claimed method includes passing of reaction mixture containing dichloroethane vapor trough catalytic layer providing dehydrochlorination of dichloroethane to vinylchloride. Catalyst has active centers having in IR-spectra of adsorbed ammonia absorption band with wave numbers in region of ν = 1410-1440 cm-1, and contains one platinum group metal as active component, and glass-fiber carrier. Carrier has in NMR29Si-specrum lines with chemical shifts of -100±3 ppm (Q3-line) and -110±3 ppm (Q4-line) in integral intensity ratio Q3/Q4 from 0.7 to 1.2; in IR-specrum it has absorption band of hydroxyls with wave number of ν = 3620-3650 cm-1 and half-width of 65-75 cm-1, and has density, measured by BET-method using argon thermal desorption, SAr = 0.5-30 m2/g, and specific surface, measured by alkali titration, SNa = 10-250 m2/g in ratio of SAr/SNa = 5-30.
EFFECT: method with high conversion ratio and selectivity.
3 cl, 2 ex
FIELD: chemical technology, in particular method for vinylchloride production.
SUBSTANCE: claimed method includes fast gas cooling in quenching column followed by separation of pyrolysis products. Quenching and separation are carried out by barbotage through the layer of liquid concentrated by-products of these gases in quenching column cube. Then steam/gas mixture is brought into contact with returning condensate in regular filling layer of rectification tower with simultaneous purification of steam/gas mixture in rectification zone upstream. Liquid concentrated by-products are additionally rectified in vacuum with isolating and recovery of products having boiling point higher than the same for dichloroethane and distillate recycling. Method of present invention also makes it possible to produce perchloroethylene and tricloroethylene.
EFFECT: vinylchloride of high quality; reduced effort and energy consumption.
2 tbl, 4 dwg, 2 ex