Method for the production of methanol and installation for the production of methanol

 

(57) Abstract:

The invention relates to a method for the production of methanol by gas-phase oxidation of hydrocarbon gas at initial temperature up to 500C, pressure up to 10 MPa and the oxygen content not exceeding 8% vol. in the reaction zones of the reactor. In the mixing zone of the reactor separately served successively compressed and heated hydrocarbon gas and compressed oxygen-containing gas. The process includes an additional supply of oxygen-containing gas in the subsequent mixing zone, cooling the reaction mixture, separation of methanol from the cooled reaction mixture, the flow of exhaust gases in hydrocarbon source gas, or combustion. Moreover, the reaction mixture is cooled at 70-150C before each subsequent stage of oxidation and quenched in the last reaction zone, reducing the temperature of the reaction mixture not less than 200C. for a time which is less than 0,1 time of her stay in the reaction zone. Exhaust oxygen-containing liquid products after separation of the methanol fed to the first mixing zone of the reactor. Plant for production of methanol contains a source of hydrocarbon gas, the compressor and the heater, individual and and reaction zones with pipelines, recuperative heat exchanger, a cooler-condenser, a separator, a pipe for supplying exhaust gases. And recuperative heat exchangers installed at the output ends of all of the reaction zones of the reactor piping. The plant is equipped with a pipe for supplying the waste liquid oxygenated products in the first mixing zone of the reactor. This increases the degree of conversion of the hydrocarbon gas and yield of methanol. 2 s and 5 C.p. f-crystals, 1 Il.

The invention relates to the field of organic chemistry, in particular to a technology for production of methanol by direct oxidation of hydrocarbon gas (natural gas and others), and can be used in chemical and gas industry.

Natural gas reserves are large, it is an environmentally friendly fuel, but the direct use of the gaseous heat carrier in many cases, in particular in transport, inconvenient. The problem solves turning natural gas into a more universal liquid fuel, such as methanol, which besides the original product of many chemical plants.

The number of known ways of converting methane to methanol. The wide industrial application has parova is Arabaev M M, Leonov, C. E. and others "Technology of synthetic methanol".- M: "Chemistry", 1984, S. 72-125), but this process has some significant drawbacks: complexity of the equipment, high demands on the purity of the gas, and the high cost of energy for the production of synthesis gas and its treatment, a large number of intermediate stages of the process, the lack of profitability of small and medium enterprises with a capacity of less than 2000 tons/day.

Currently, the greatest interest is direct, bypassing the stage of synthesis gas production, gas-phase oxidation of methane to methanol at high pressures. The process is carried out at pressures up to 10 MPa and temperatures of 400-450oC in a tubular reactor with a relatively low initial concentrations of oxygen, followed by cooling gas-liquid mixture and separation of liquid products, of which the rectification into methanol (Arutyunov B. C., Krylov, O. C. "Oxidative conversion of methane".- M.: Nauka, 1998, S. 130-145). However, the low degree of methane conversion per pass through the reactor does not exceed 3-5%, and accordingly, the low yield of methanol hinder the practical implementation of the method for producing methanol by direct oxidation of methane.

A known method of producing methanol, comprising separate feeding pre-heat the optimum camera the next stage partial oxidation of methane with oxygen concentration of 1 - 4% vol. with the addition of reagents (metal oxide catalyst, the higher gaseous hydrocarbons or oxygen-containing compounds, cold oxidant in the reaction zone of the reactor, cooling the reaction mixture in the heat exchanger, separation of methanol from the liquid reaction products in the separator, the flow of exhaust gaseous reaction products at the reactor inlet (EN, 2049086 C1, C 07 C 31/04, 27.11.1995). The disadvantage of this method is the need for a catalyst or additional reagents and strong heating of the reacting gases, resulting in reduction of the yield of methanol and increase the likelihood of sooting.

A method of producing methanol, comprising separate feeding into the mixer hydrocarbon gas (natural gas or methane) and oxygen-containing gas (air or oxygen), the subsequent filing of the mixture in an inert reactor, gas-phase partial oxidation of hydrocarbon gas in the reactor under a pressure of 1-10 MPa for 2-1000 with at a temperature of 300-500oC in the absence of catalyst, the oxygen content of 2-20 vol.%, the allocation of methanol in the condenser of the reaction products section is containing a series of gas in the first reactor or the second reactor, sequentially connected to the first reactor (GB, 2196335 A, C 07 C 31/04, 27.04.1988). The disadvantage of this method is the high response time, the performance-limiting reactor methanol.

Plant for production of methanol contains successively installed and connected by pipelines mixing chamber connected to separate sources of hydrocarbon gas and air or oxygen, the reactor from an inert material with heating elements for partial oxidation of methane in the mixture fed to the reactor under pressure, a condenser and separator for the separation of methanol from the reaction products, the capacity for recycled gaseous reaction products by pipeline to serve them in the original hydrocarbon gas or mixing chamber (GB, 2196335 A, C 07 C 31/04, 27.04,1988). Method and installation provide a high yield of methanol and 5-15% methane can react with each pass through the reactor. However, a high residence time of the reactants in the reactor is not possible to achieve a high performance setup.

A known method of producing methanol by separate feed and oxidation of hydrocarbon gas to oxygen gas is actionnow mixture to 330 - 340oC the introduction into the reactor of methanol (SU, 1469788 A1, C 07 C 31/04, 20.11.96) or by cooling the reaction mixture without intermediate condensation and separation of up to 380-400oC interstage heat exchangers installed in the reactor, after which the reaction mixture flows on 2-3 consecutive stages of oxidation (SU, 1336471 A1, C 07 C 31/04, 27.09.96). The disadvantage of this method is the need for additional flow and re-allocation of methanol, because of its inevitable losses, or the installation of additional cooling circuits of circulation in additional cooling agent.

The closest technical solution is the method of production of methanol and installation for its production. The method includes separate feeding successively compressed and heated hydrocarbon (natural) gas and compressed air or oxygen in the mixing zone (mixing unit) reactor, sequential stepwise oxidation of hydrocarbon gas at initial temperature 325-500oC, a pressure of 3-10 MPa and the oxygen content of 1.5 to about 8. % in two reaction zones of the reactor with an additional supply of oxygen or air in the subsequent mixing zone, cooling the reaction mixture, selected the containing gas (pipeline) or incineration.

Plant for production of methanol contains installed and connected to a source of hydrocarbon gas compressor, regenerative heat exchanger and fire heater to compress and heat the hydrocarbon gas, a separate source of oxygen or air, is connected to the compressor, reactor with two mixing and reaction zones with separate pipelines for the supply of hydrocarbon gas and air or oxygen in the mixing zone, successively installed and connected to the reaction zone of the reactor tubular recuperative heat exchanger for cooling the reaction mixture and heating of cold hydrocarbon gas, refrigerator capacitor, the separator for the separation of methanol from the gas-liquid cooled reaction mixture and the pipe for supplying exhaust gases from the separator into the pipeline hydrocarbon gas or digester (EN, 2057745, C07C 31/04, 29/50, 10.04.1996). The known method and the installation does not provide a sufficiently high methane conversion in a single pass gas through the reactor. Effective recirculation of gases almost inevitably requires the use as an oxidizer oxygen, which increases the th self-heating of the reaction mixture reduces the yield of the target product and promote intensive sazheobrazovanie, complicating the operation of the process equipment and reduce the quality of the obtained methanol.

The technical result of the proposed method of production of methanol and installation for its production is to increase the degree of conversion of the hydrocarbon gas and the increase in the yield of methanol, preventing soot formation and the environmental improvement process.

This technical result is achieved by the fact that the proposed method of producing methanol includes separate feeding successively compressed and heated hydrocarbon gas and compressed oxygen-containing gas in the mixing zone of the reactor, the subsequent gas-phase oxidation of a hydrocarbon gas at initial temperature to 500oC, pressure up to 10 MPa and the oxygen content not exceeding 8% vol. in the reaction zones of the reactor with an additional supply of oxygen-containing gas in the subsequent mixing zone, cooling the reaction mixture to 70-150oC before each subsequent stage of oxidation and quenching the reaction mixture in the last reaction zone by lowering its temperature not less than 200oC for a time which is less than 0,1 time of their stay in the reaction AOR is levonorgesterel the exhaust gas and oxygen-containing liquid reaction products after separation of the methanol in the first mixing zone of the reactor; additional cooling of the reaction mixture before each of 2-5 degrees of oxidation of the lead through the wall of the flow of cold hydrocarbon gas; exhaust high-boiling liquid oxidation products is served in the subsequent mixing zone and at the output end of the last reaction zone to the quenching of the reaction mixture; use the original hydrocarbon gas selected from the group of: natural gas, associated petroleum gas, refinery gas, LPG (wide fraction of light hydrocarbons, gas condensate; gas-phase oxidation is carried out at the initial temperature 280-450oC and a pressure of 0.5 to 10 MPa.

The problem is solved also by the fact that the installation for the production of methanol contains a source of hydrocarbon gas, the compressor and the heater to compress and heat the hydrocarbon gas, a separate source of oxygen-containing gas with a compressor, reactor sequentially alternating mixing and reaction zones with the supply pipe hydrocarbon gas and oxygen containing gas into each of the mixing zone and installed at the output ends of the reaction zones recuperative heat exchangers for cooling the reaction mixture through the wall of the Ho the fir products followed by separation of the methanol, the supply line of the exhaust gases in the hydrocarbon source gas and the supply pipe exhaust oxygen-containing liquid products in the first mixing zone of the reactor; the installation further comprises up to five reactors installed in series with chillers-condensers and separators, each of the reactors connected by piping to the separator previous reactor, and the corresponding separator connected to the first mixing zone of the subsequent reactor; the plant is equipped with additional pipelines to supply the waste liquid products of the reaction in the subsequent mixing zone and to the output ends of the last reaction zone of the reactor.

The proposed method and installation provide the process with step-wise oxidation, each stage of which heating of the reaction mixture does not exceed 70-150oC, prior to each subsequent stage of the oxidation reaction mixture is cooled by an amount approximately equal to its heat at the previous stage of oxidation, and at the end of the oxidation - hardened by cooling through the wall of the cold hydrocarbon gas, while it is heated. In addition, the use of up to five follower is of aktov oxidation between them with subsequent supply of exhaust gases to the hydrocarbon source gas allows more time to improve the overall conversion of hydrocarbon gas to methanol, and applying to the input of the mixing zones of the first stages of oxidation reactors side liquid oxygen-containing oxidation products separated in the allocation of methanol, allows to reduce the initial temperature of the process, which also helps to increase the yield of methanol.

If the "dry" natural gas are oxidized by air, then diluted with nitrogen is less than 35% emerging hydrocarbon gas has a sufficiently high calorific value for effective use in power burner and devices of almost any kind. For full utilization of hydrocarbon exhaust hydrocarbon gas recycle.

Proposed installation installed at the output ends of all of the reaction zones of the reactor regenerative heat exchangers cooled by the flow of cold hydrocarbon gas prior to its submission to the heater, provides cooling of the reaction mixture at 70-150oC and quenching of the reaction products, i.e., cooling the reaction mixture to not less than 200oC for a time not exceeding 0,1 residence time of the reaction mixture in the reaction zone and the flow of exhaust oxygen-containing liquid products of distillation columns in the first smesiteli, disrupting the work of the reactor and pollutants produced methanol, and to avoid accumulation of liquid wastes containing such problematic from the point of view of ecology products, as formaldehyde and formic acid.

The drawing shows the setup diagram for methanol production. The apparatus comprises a source 1 of hydrocarbon gas, the compressor 2 and the heater 3, a separate source of oxygen-containing gas (not shown) together with the compressor 4, reactors 5 and 51with sequential mixing zones 6, 6', etc. and reaction zones 7, 7', and so on line 8 hydrocarbon feed gas from the heater 3 in the first mixing zone 6 and the pipe 9 feeding oxygen-containing gas from the source to the compressor 4 in each mixing zone 6, 6', etc. of the reactor 5, 51, recuperative heat exchangers 10, 10', etc. for cooling the reaction mixture and heat through the wall of the cold carbon-containing gas supplied through pipelines 11 installed at the output ends of the reaction zones of the reactor 5 and is supplied by a pipeline 12 for supplying heated in heat exchanger 10, 10', etc. carbon-containing gas in the heater 3, and line 13 to hearth the separators 15, 151for the Department of exhaust gases and liquid products pipelines 16, 161for feeding the liquid reaction products in a collection of 17 and then to distillation column 18 with the Department of methanol through the pipeline 19 to the warehouse (not shown), water pipeline 20 and liquid high boiling oxygen-containing oxidation products through the pipeline 21 in the collector 22 with the pipe 23 for supplying the waste liquid oxygenated reaction products in the first mixing zone 6 of the reactor 5, 51; pipe 24 for supplying exhaust gases from the separator 151to the input of the compressor 2 in the original hydrocarbon gas or the combustion in a power plant (not shown).

Installation can contain up to five (the drawing shows one), installed additional reactors 51and so refrigerators-capacitors 141and so on, the separators 151and so on with the pipes 25, 12 and 8 for the exhaust gases of the previous reactor 5 and so on through the recuperative heat exchangers 10, 10', etc. subsequent reactor 51and so on, and the heater 3 in the first mixing zone 6 subsequent reactor 51and pipelines 23 and so on for the exhaust oxygen-containing liquid product is going liquid oxygenated reaction products to the output ends of the last reaction zone 7' reactors 5, 51and so on quenching.

Example 1: Cold dry natural gas (methane content of 98%) of source 1 with a flow rate 7330 m3/h compressed in the compressor 2 to 10 MPa, served piping 11, 12 through the recuperative heat exchangers 10', 10 reactor 5 in the heater 3 where it is heated to 430oC and fed to the first mixing zone 6 of the reactor 5, while the pipes 9 into each of the mixing zone 6, 6' to deliver air from the compressor 4 with a flow rate of 505 m3/h and under a pressure of 10 MPa; the reaction zones 7, 7' of the reactor 5 is gas-phase oxidation of natural gas with an initial temperature of 430oC, a pressure of 10 MPa, the concentration of oxygen of 1.4% vol., response time 1 s, after which the reaction mixture at the outlet of the reaction zone 7 is cooled in the regenerative heat exchanger 10 70oC and enters the mixing area 6' of the next stage of oxidation with the same air supply (only two degrees of oxidation and subsequent tempering at 200oC 0.1 C (0,1 residence time of the reaction mixture in the last reaction zone 7') when passing through the regenerative heat exchanger 10'; leaving the reactor 5 the reaction mixture is fed to the cooler-condenser 14 where it is cooled to temperatures separator 15 through the pipe 16 serves in a collection of 17 and further rectification column 18 with the Department of methanol and its feed line 19 to the warehouse. At the same time there is a selection of water through the pipe 20 and the high-boiling oxygenated products (aqueous solution of formaldehyde and formic acid) through the pipeline 21 in the collector 22, where 25% of the total number of these products on line 23 enters the first mixing zone 6 reactors 5 and 51. Exhaust gases from the separator 15 through the pipe 25 through the heat exchangers 10, 10' and the heater 3 are received in the first mixing 6 subsequent reactor 51. Cooling of the reaction gases between stages of oxidation and hardening are made through the wall of the flow of cold hydrocarbon gas fed into the tube space recuperative heat exchanger 10, 10', are heated to 350oC before it enters the heater 3. The oxidation of lead in four (two of which are not shown) installed in series reactors with two reaction zones each. The total number of produced methanol 625 kg/H. the Remainder (75%) exhaust oxygen-containing high-boiling liquid products pipelines 26 serves to output ends of the last reaction zone 7', quenching of the reaction mixture. Exhaust gases from the last reactor serves on the burning torch (not shown).

Thus, in comparison with the known method achieved a higher degree of conversion of the hydrocarbon gas for passage several times increases the yield of methanol, reduced specific consumption of hydrocarbon gas and decreases the time (or temperature) of the reaction.

1. Method for the production of methanol comprising separate feeding successively compressed and heated hydrocarbon gas and compressed oxygen-containing gas in the mixing zone of the reactor, the subsequent gas-phase oxidation of a hydrocarbon gas at initial temperature to 500oC, pressure up to 10 MPa and the oxygen content not exceeding 8% vol. in the reaction zones of the reactor with an additional supply of oxygen-containing gas in the subsequent mixing zone, cooling the reaction mixture, separation of methanol from the gas-liquid cooled reaction mixture, the flow of exhaust gases in hydrocarbon source gas, or combustion, characterized in that the reaction mixture is cooled to 70 - 150oC before each subsequent stage of oxidation and quenched in the last reaction zone, reducing the temperature of the reaction mixture not less than 200oC for a time amounting to less than 0.1 time her stay vesitalous zone of the reactor.

2. The method according to p. 1, characterized in that the reaction mixture cooled down before each of the 2 to 5 stages of oxidation through the wall of the flow of cold hydrocarbon gas.

3. The method according to PP.1 and 2, characterized in that the waste liquid oxygen-containing oxidation products additionally serves in the subsequent mixing zone and at the output of the last reaction zone to the quenching of the reaction mixture.

4. The method according to p. 1, characterized in that use hydrocarbon source gas selected from the group of: natural gas, associated petroleum gas, refinery gas, LPG (wide fraction of light hydrocarbons, gas condensate.

5. The method according to p. 1, characterized in that the gas-phase oxidation is carried out at initial temperatures of 280 - 450oC and a pressure of 0.5 to 10 MPa.

6. Plant for production of methanol containing hydrocarbon source gas, the compressor and the heater to compress and heat the gas, a separate source of oxygen-containing gas with a compressor, reactor sequentially alternating mixing and reaction zones with the supply pipe hydrocarbon gas in the first mixing zone of the reactor and the oxygen-containing gas into each underwater hydrocarbon gas, the cooler-condenser, a separator for separating the exhaust gases and liquid products followed by separation of the methanol and the piping for the exhaust gases in hydrocarbon source gas, wherein the regenerative heat exchangers installed at the output ends of all of the reaction zones of the reactor pipelines for further supplying heated hydrocarbon gas in a heater, the installation is equipped with a pipe for supplying the waste liquid oxygenated products in the first mixing zone of the reactor.

7. Installation according to p. 6, characterized in that it contains up to five consecutive installed additional reactors refrigerators-condensers and separators with the piping for the exhaust gases of the previous reactor through recuperative heat exchangers and heater in the first mixing zone of the subsequent reactor.

8. Installation on PP.6 and 7, characterized in that it is provided with an additional pipelines to supply the waste liquid oxygenated reaction products to the output ends of the last reaction zone of the reactor.

 

Same patents:

The invention relates to the production of catalysts for the process of low-temperature methanol synthesis
The invention relates to the chemical industry and can be used on units of production of methanol

The invention relates to energy-saving methods for the synthesis of methanol from synthesis gas obtained by partial oxidation of natural gas with air enriched with oxygen, air or the flow of oxygen-containing gas with a high content of nitrogen in the energy machines with electricity generation at all stages of production of methanol
The invention relates to chemical technology, more specifically to an improved method of separating methanol from a by-product of the synthesis of 1,4-butandiol (1,4-BID), obtained by the interaction of formaldehyde and acetylene, which finds application in the manufacture of polymeric materials

The invention relates to processes and apparatuses of chemical technology and can be used to implement the exothermic heterogeneous synthesis, in particular in the production of methanol or ammonia from synthesis gas
The invention relates to the field of chemical technology and can be used for chemical and petrochemical plants producing synthetic alcohols, in particular methanol

The invention relates to a combined synergistic method of production of methanol and the production of tertiary butyl esters of lower Akilov partial oxidation of heavy hydrocarbon fractions
The invention relates to a process for the catalytic conversion of hydrocarbons and the production of methanol from synthesis gas

The invention relates to the purification of exhaust gases of high-temperature furnaces and is a device for quenching nitrous gases containing metal block with repeatedly intersecting channels for gases with decreases in the direction of movement of gases in the ratio of 0.5 to 0.9 in diameter and not communicating with them channels for the refrigerant, and the channels for gases made with annular grooves, the diameter of which is D = 1,14-1,17 d, where d is the current diameter of the channels, the width of the grooves z = 0,082-0,085 d, step grooves t = 0,164-0,017

The invention relates to the production of 1,2-dichloroethane (ethylene dichloride , ejh) by introducing ethylene and chlorine in the circulating ejh under vigorous stirring and heat recovery

The invention relates to the technology of vinyl chloride, specifically to a device for input of reagents in the reactor the ethylene oxychlorination process used to obtain dichloroethane

The invention relates to a device for carrying out chemical interactions in gaseous media

The invention relates to a method for producing urea

The invention relates to the technology of production of urea from ammonia and carbon dioxide

The invention relates to the technology of production of urea

The invention relates to a method for producing urea and installations for the production of urea

The invention relates to a device specifically designed for the General chemical interactions in gaseous media, and more specifically relates to devices for pulse compression of gases

FIELD: chemical technology.

SUBSTANCE: invention relates to producing urea from ammonia and carbon dioxide. Method involves preparing products of reaction in the synthesis zone as a solution containing urea, ammonium carbamate and unreacted ammonia. Part of solution obtained in synthesis of urea (preferably 10-60 wt.-%) is fed from the synthesis zone to additionally assembled zone of treatment under mean pressure at 1-4 MPa wherein gas flow is separated and subjected for absorption with ammonium carbamate solution of low pressure supplying from the section for isolation and treatment of urea. As a variant of method the invention proposes to use the combined reactor in the synthesis zone representing vertically installed or combined reactor. Enhancement of output of existing processes in synthesis of urea is achieved by feeding part of urea solution synthesized in the synthesis reactor to additionally installed zone for treatment of mean pressure including the dissociation zone, desorption zone of mean pressure and the condensation zone of mean pressure. Invention provides enhancement of output of unit for producing urea being without modification of section of high pressure.

EFFECT: improved method for producing urea.

10 cl, 4 dwg

Up!