KR101421187B1 - Preparation method for dimethyl carbonate by using greenhouse gases - Google Patents

Abstract

The present invention relates to a process for producing a gas mixture of carbon monoxide (CO) and hydrogen (H ₂ ) obtained through a reforming reaction of carbon dioxide (CO ₂ ) and methane (CH ₄ ) The excess amount of carbon monoxide used in the synthesis of methanol stoichiometrically during the methanol synthesis process is used to prepare dimethyl carbonate and to separate the carbon monoxide remaining therefrom to provide dimethyl carbonate ≪ / RTI >

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing dimethyl carbonate from a greenhouse gas,

The present invention relates to a process for producing a gas mixture of carbon monoxide (CO) and hydrogen (H ₂ ) produced through the reforming reaction of carbon dioxide (CO ₂ ) and methane (CH ₄ ) The excess amount of carbon monoxide used in the synthesis of methanol stoichiometrically during the methanol synthesis process is used to prepare dimethyl carbonate and to separate the carbon monoxide remaining therefrom to provide dimethyl carbonate More particularly, the present invention relates to a method of reforming a mixed gas of carbon dioxide and methane to obtain carbon monoxide and hydrogen; Synthesizing methanol using carbon monoxide and hydrogen obtained in the reforming step; And synthesizing dimethyl carbonate by using an excess amount of carbon monoxide supplied in the step of synthesizing methanol. The present invention also relates to a process for producing dimethyl carbonate using a greenhouse gas.

The cause of global warming has not been elucidated yet, but greenhouse gases are considered to be the main cause of global warming. Carbon dioxide, methane and water vapor in the atmosphere caused by human activities are representative greenhouse gases. In particular, Freon gas, which has started to be used in modern times, has the greatest greenhouse effect. Gases that cause this greenhouse effect are called greenhouse gases. Among these greenhouse gases, there is water vapor, which can not be seen as a greenhouse effect, since it reflects sunlight in the form of clouds. Therefore, it can not be regarded as a greenhouse gas that causes global warming, but it is the fact that it has the greatest influence on the spontaneous greenhouse effect.

In this way, global warming causes radiant heat to be released to the atmosphere by the heat energy transmitted from the sun. Some of this radiant heat escapes into space, but some of it is trapped by the greenhouse gases in the atmosphere, leading to a greenhouse effect on the planet. Greenhouse gas concentrations remained constant before the Industrial Revolution, but the concentration of greenhouse gases in the atmosphere increased due to increased use of fossil energy after the Industrial Revolution. This greenhouse gas is expected to become more frequent and severe due to floods, droughts, colds, and heatwaves, as the result of raising the temperature of the atmosphere by interfering with the emission of radiant heat into space, and also the change of temperature and precipitation pattern Have increased the likelihood of disturbing forests and marine ecosystems and adversely affecting the supply of food and water, leading to the spread of tropical diseases such as malaria.

Among the various greenhouse gases, carbon dioxide and methane are described as follows.

In the case of carbon dioxide, once the carbon dioxide is released, it will stay in the atmosphere for a long time. About 56% of the atmospheric carbon dioxide is released in the 20th century. Since carbon dioxide is the main cause of global warming, it does not mean that it has the greatest ability to hold the heat energy among the greenhouse gases. The ability to hold thermal energy is weaker than other greenhouse gases, but it is said to be the main reason for its abundance in the atmosphere, above 370 ppm.

Experts view 80% of the global warming effect as carbon dioxide, directly or indirectly. In addition to industrialization, the gas that has increased in atmospheric concentrations is carbon dioxide, which is caused by the increase in the amount of carbon dioxide in fossil fuel-based power plants, petroleum refineries, steel mills, cement and chemical plants. When the earth is in a sick state it is sick.

In the case of methane (CH ₄ ) in the greenhouse gas, carbon dioxide is the next most important greenhouse gas. Methane is a gas that is generated by microorganisms living in an oxygen-free environment or from garbage that rotates. Even as our farts and trims contain methane, the rate of methane in the atmosphere is very small at 1.5 ppm, but doubled over the centuries. The increase in methane concentration is related to the increase in population. Methane is much shorter in the atmosphere than carbon dioxide, but its capacity to hold heat energy is 60 times larger than that of carbon dioxide. , Which is estimated to be 15 ~ 17% after carbon dioxide. Therefore, the problem of global warming is an important homework for humanity. For humanity, the way to protect the global environment must be research and development. Reforming is needed to contribute to green growth by high value added carbon dioxide. have.

Among the carbon dioxide conversion technologies, the synthesis of dimethyl carbonate is considered to be inexpensive in terms of recycling carbon dioxide, which is the main cause of global warming, and the existing toxic process of synthesizing dimethyl carbonate (DMC) from phosgene, and its use as carbon dioxide which is less corrosive and less toxic . The formula for dimethyl carbonate is (CH ₃ O) ₂ CO, a colorless transparent liquid, also called carbonic diether, carbonic acid ester. Dimethyl carbonate has a melting point of 227 and a boiling point of 363.3 K, a specific gravity (d ²⁰ ₄ ) of 1.07, and a viscosity of 0.625 cP (20). Its physical properties are similar to those of water. The solubility of dimethyl carbonate is 13.9 g DMC / 100 g H ₂ O and 4.2 g H ₂ O / 100 g DMC. It dissolves slightly in water and dissolves well in most organic solvents. It is also soluble in polar solvents such as esters, ketone ethers and alcohols. It is resistant to pyrolysis and stable up to 623 K.

In recent years, with the rapid growth of the electronic communication parts market and the development of the automobile industry, environment friendly dimethyl carbonate synthesis process is being developed, and the demand is rapidly increasing. It is a non-toxic, biodegradable, environment-friendly chemical that is used for the introduction of methyl and carbonyl groups. It is used as a main raw material for producing aromatic polycarbonate which is a transparent polymer. It contains phosgene or methyl group which is highly toxic and highly corrosive. And dimethyl carbonate is also used as a conductive solvent for a rechargeable lithium battery.

Particularly, since dimethyl carbonate has an oxygen content of 53% and is well diluted with gasoline and is not harmful to water and can not be dissolved in water, it can be used as an octane number improver to reduce the pollution of the internal combustion engine. Thus, the harmful MTBE (methyl tertiarybutyl ether), as well as the production of polycarbonate and polyurethane resins, the synthesis of intermediates for medicines and pesticides, the development of the electronic components industry, and the fine chemical and automotive industries, The demand for friendly DMC is also rapidly increasing.

The commercially available dimethyl carbonate can be prepared by a liquid phase methanol oxidation method (Enichem, Italy), a methyl nitrite method (Ube, Japan), an ester exchange method (Bayer, Germany), a gas phase methanol oxidation method (Dow, USA) are in the commercialization stage. Methanol carboxyation method and methanol carbon dioxide direct synthesis method are being studied. Among the processes using carbon dioxide, there is a reaction between urea and methanol. In this process, dimethyl carbonate is produced via an intermediate methyl carbamate (MC), and ammonia produced together during the reaction is recycled to form carbon dioxide . Although a lot of research has been carried out on the reaction of carbon dioxide directly with methanol, efficient catalysis has not been found so far, which is a field that needs further development. This method is economical and eco-friendly and development is expected.

Main manufacturing methods and mechanism for producing dimethyl carbonate (DMC) are shown in Table 1 below.

In addition, the prior art of the process for producing dimethyl carbonate by the simultaneous process of the reaction separation, which has been studied and developed in connection with the present invention, is as follows.

U.S. Patent Application Publication No. 2005-0033080 discloses a process for producing a dialkyl carbonate and a method for using a dialkyl carbonate in the process of producing a diaryl carbonate and a polycarbonate. In the cited invention, a dialkyl carbonate, The present invention relates to a method for converting dialkyl carbonate into a dimethyl carbonate using a greenhouse gas in order to prevent global warming while a mixture containing mate, hydrochloric acid, water and carbon monoxide is produced by a catalytic reaction comprising copper chloride It can be understood that the invention of the cited invention and the technology of the present invention are completely different from the purpose of the invention.

U.S. Patent No. 5,387,708 discloses a product of dialkyl carbonate using a copper catalyst. As a result, since a copper-based catalyst is used to produce the dimethyl carbonate of the present invention, it can be judged that the composition of the dialkyl carbonate is somewhat similar However, in this case, a mixed gas of carbon monoxide (CO) and hydrogen (H ₂ ) generated through the reforming reaction of carbon dioxide (CO ₂ ) and methane (CH ₄ ) (DMC) by using an excess amount of carbon monoxide which is used stoichiometrically in the synthesis of methanol during the synthesis of methanol, which is completely different from the method for producing dimethyl carbonate (DMC).

U.S. Patent No. 7,253,304 discloses a carbonylation process in which a mixture of dialkyl carbonate and a halogen compound is contacted with carbon monoxide in the presence of a metal (catalyst) selected from Group VIII of the Periodic Table, However, in the case of the present invention, a catalyst composed of copper group or another metal group of group 11 is used. In this case, a catalyst composed of methane and carbon dioxide is used as a catalyst for the carbonylation process. It is shown that the technology structure is totally different due to the proposed integrated process for DMC conversion.

U.S. Patent No. 7,799,940 discloses a method of forming a dialkyl carbonate by allowing a catalyst to be contained in a reactor and eliminating or reducing the separation equipment and the transfer line, And a catalyst in a reactor having an upper space of the gas and a liquid body space, wherein the reactor is operated under conditions including a dialkyl carbonate and moisture, the product is a dialkyl carbonate, Water, and the residual reactant is removed from the upper space of the reactor and flows into the cyclone together with the water stream. On the other hand, in the present invention, the gas mixture of carbon dioxide and methane is reformed by carbon monoxide Hydrogen is produced, and methanol and dimethyl carbonate are produced without any separation process. An integrated process technology for the configuration as well as it can be seen that the end product differences at all.

U.S. Patent No. 7,803,961 discloses a process for producing dimethyl carbonate. The process for forming a dialkyl carbonate in the cited invention is a process for producing a diaryl carbonate having an alkanol, a residual dialkyl carbonate and a residual aromatic compound, And the by-product stream is configured to flow into the distillation column to produce the best alkanol stream and the best dialkyl carbonate stream, wherein the best alkanol stream comprises oxygen, carbon monoxide and a stream of In the present invention, a gas mixture of carbon dioxide and methane is directly used for methanol synthesis without producing any carbon monoxide and hydrogen to form a secondary dialkyl carbonate, Surplus work remaining in A method for preparation of dimethyl carbonate, the carbon dioxide can be seen the difference at all invention and technology configuration and spirit of the invention.

In ST King, Catalysis Today 33 (1997), 173-182, a study has been conducted on the oxidation carbonylation to form dimethyl carbonate by a solid ion-exchanged CuY type catalyst. In this paper, The authors of this paper have confirmed that chlorides are indispensable even if there is no chloride present in the zeolite catalyst if the catalyst is properly prepared. , And ExLZ-20M catalysts in which Zeolite Y was ion-exchanged with an aqueous solution of copper nitrate (Cu (NO ₃ ) ₂ ), and the catalysts for the gas phase oxidation carbonylation of methanol were examined. It can be seen that the purpose of the invention, as well as the technical composition and ideology are completely different.

Cu ⁺ X and Cu ⁺ ZMS zeolites prepared by the solid-phase ion exchange method were used for methanol / water mixture of methanol and methanol for the production of dimethyl carbonate in Steven A. Anderson, Thatcher W. Root, Journal of Molecular Catalysis A: The investigation of the carbonylation of Cu ⁺ zeolite and carbon monoxide is focused on the interaction between carbon monoxide and carbon monoxide. It is judged that the technology is different from the integrated process for the conversion of dimethyl carbonate using greenhouse gas.

In a paper cited in Steven A. Anderson and Thatcher W. Root, Journal of Catalysis, 217 (2003), 396-405, an infrared spectroscopy (FTIR) study on vapor phase carbonylation of methanol using copper- As a result of the dynamic study, the present invention is similar to the catalyst for producing the dimethyl carbonate of the present invention by carrying out a dynamic study of methanol carbonylation using Cu ⁺ X zeolite prepared by a solid phase ion exchange method However, in this paper, we have investigated the dynamic study of carbonylation of methanol using Cu ⁺ X zeolite. In this paper, however, we have attempted to modify the carbon dioxide (CO ₂ ) and methane (CH ₄ ) without any separation process, a gas mixture of the generated carbon monoxide (CO) and hydrogen (H _2), directly to the methanol synthesis through use, and methanol synthesis process The excess amount of carbon monoxide used in the synthesis of methanol stoichiometrically relates to an integrated process for preparing dimethyl carbonate (DMC) and separating the remaining carbon monoxide as a starting material for other uses, It can be seen that the purpose of the invention is of course very different from that of the technology.

In a cited paper by Wang Yanji, Zhao Xinqiang, Yuan Baoguo, Zhang Bingchang and Cong Jinsheng, Applied Catalysis A: General 171 (1998), 255-260, the gas- In this paper, the catalysts prepared according to the experimental conditions were evaluated in terms of their properties and reactivity, and catalysts in the course of the synthesis of dimethyl carbonate using catalysts composed of different active carbon supports and catalyst components having different specific surface areas The present invention can be included in a part of the present invention by examining the conditions of the reaction of dimethyl carbonate according to the components of the support, the alkali metal promoter and the reaction conditions. However, when comparing the purpose of the present invention with the overall constitution of the present invention, Able to know.

If greenhouse gas emissions continue to increase to the present level due to ever-increasing greenhouse gas emissions, it will lead to huge chaos in global ecosystems due to climate change as well as astronomical economic losses worldwide. It is essential that greenhouse gas conversion technology for reduction projects or resources is indispensable.

For example, recently landfill gas from landfills has been recycled under the background of energy substitution effects, global warming gas reduction, and economic utilization of landfills. Landfill gas is a by-product of the decomposition process of organic wastes. Main components are methane (CH ₄ ) and carbon dioxide (CO ₂ ). If you use it as energy, it will reduce the use of fossil fuel, so it can save resources. So far, steelmaking companies that consume large amounts of fossil fuels, including landfill gas, can produce electricity from gas engines, gas turbines, steam turbines, etc., Many methods such as fuel, greenhouse fuel, methanol production, hydrogen production, and conversion to liquefied natural gas have been developed or are being studied. However, an integrated process for producing dimethyl carbonate from a mixed gas of carbon dioxide and methane as in the present invention is not yet known It is not possible to make a significant contribution to the conversion technology for reducing greenhouse gases.

In addition, as described in the above cited invention and cited articles, the conventional methods for producing dimethyl carbonate using a gas mixture of carbon dioxide and methane can cause harm to the human body due to toxic gas during the manufacturing process, And the manufacturing process is complicated or requires a lot of energy because the integrated process is not known. Thus, the economical efficiency is greatly reduced.

It is an object of the present invention to provide a process for producing dimethyl carbonate, which is a substitute for methyl halide or dimethyl sulfate in fine chemical and automobile industries, and other chemical substances whose demand is increased all the time, by using a greenhouse gas such as carbon dioxide or methane gas, Manufacture of dimethyl carbonate using greenhouse gas that can contribute to green growth by high value added while protecting the global environment caused by accelerated global warming as a high-efficiency conversion of dimethyl carbonate while maintaining harmless environment due to gas emission Method.

In order to achieve the above-mentioned object, there is provided a method for producing carbon monoxide, comprising: modifying a mixed gas of carbon dioxide and methane to obtain carbon monoxide and hydrogen; Synthesizing methanol using carbon monoxide and hydrogen obtained in the reforming step; And synthesizing dimethyl carbonate by using an excess amount of carbon monoxide supplied in the step of synthesizing methanol. The present invention also provides a process for producing dimethyl carbonate.

In one embodiment of the present invention, the process for producing dimethyl carbonate according to the present invention comprises the steps of: separating carbon monoxide remaining in a product of dimethyl carbonate synthesized in the step of synthesizing dimethyl carbonate, separating the separated carbon monoxide as a starting material in a different process The method comprising the steps of:

In one embodiment of the present invention, the step of separating the carbon monoxide remaining in the product of the synthesized dimethyl carbonate is preferably carried out by separating the carbon monoxide by the organic or inorganic film or the bypass method.

A mixture of greenhouse gases such as carbon dioxide (CO ₂₎ and methane (CH ₄₎ carbon monoxide (CO) and hydrogen (H ₂₎ generated by the reforming reaction of the gas when using the production process of dimethyl carbonate with a greenhouse gas of the present invention The gas is directly used for the synthesis of methanol without any separation process, and the excess amount of carbon monoxide used in the synthesis of methanol stoichiometrically during the methanol synthesis process is used to produce dimethyl carbonate, and the remaining carbon monoxide is separated Can be provided as a starting material for use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a process for producing dimethyl carbonate using a greenhouse gas according to the present invention. FIG.
FIG. 2 is a photograph of the batch reaction system (FIG. 2 (A) and the fixed bed reaction system (FIG. 2 (B)) used in the embodiment of the process for producing dimethyl carbonate according to one embodiment of the present invention.
3 is an integrated process diagram for explaining an embodiment according to the present invention.

Hereinafter, the method for producing dimethyl carbonate of the present invention will be described in detail.

First, a mixed gas of carbon dioxide and methane is reformed to obtain carbon monoxide and hydrogen.

In the process for producing dimethyl carbonate according to the present invention, the reforming reaction step uses carbon monoxide (CO) and hydrogen (H ₂ ), which are starting materials, for converting the final methanol and dimethyl carbonate, which are the object of the present invention, (CO ₂ ) and methane (CH ₄ ), which are greenhouse gases, are introduced into a fixed bed type reactor by a flow meter capable of controlling the flow rate of the gases, In order to maximize the conversion rate of the gas, a catalyst is formed in the reactor, and the heating temperature and the heating rate of the reactor are arbitrarily adjusted. The overall process of the present invention is configured to be operated by a controller.

At this time, the inflow amount of the carbon dioxide and the methane gas is not limited so much, and the inflow amount may be changed according to the size of the reactor or other processes required for the reaction. , Pressure, and space velocity.

As shown in Table 2, when the reaction temperature is lower than 500 ° C, dissociation of the feed reactant does not occur and reaction does not proceed. When the temperature exceeds 1200 ° C, the active metal, It is preferable to select the reaction temperature in the temperature range suggested in Table 1, since the reaction does not proceed. In addition, since a high pressure for maintaining the pressure at the pressure of 5 MPa or more is required at the reaction pressure, high initial installation cost may be a problem, and since the retention time of the catalyst and the reactant is long, It may be desirable to perform the reforming by the reaction pressure proposed in Table 2. In addition, at a space velocity of less than 500 mlg ^-1 hr ^-1 , the carbon deposition is easy due to the long residence time of the catalyst and the reactant, which makes it inactive easily. At a space velocity exceeding 300,000 mlg ^-1 hr ^-1 , It is preferable to carry out the reforming under the reaction conditions as shown in Table 2 since it has a disadvantage of having a short activation time and a short activation time.

In order to maximize the conversion rate of the greenhouse gas, the catalyst formed in the reactor is composed of a support and a catalyst component. Support of the present invention include alumina (Al ₂ O _3), magnesium oxide (MgO), titanium dioxide (TiO _2), zirconium oxide (ZrO, ZrO _2), calcium oxide (CaO), cerium oxide (CeO _2), strontium oxide (SrO), BaO, Cr ₂ O ₃ , La ₂ O ₃ , MgAl ₂ O ₄ , MgCr ₂ O ₄ , ZnCr ₂ O _4), calcium silicate _{(CaSiO 3, Ca 2 SiO 4} , Ca 2 SiO 5), silica (SiO _2), oxide thorium (ThO ₂₎ and selected to be first used by a catalyst support consisting of at least one inorganic oxide of the And the catalyst component is at least one selected from the group consisting of Ce, Sc, Ti, V, Cr, Mn, Fe, Co, ), Copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), rhodium (Rh) (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir) Rudderpodium (Rf), At least one inorganic oxide selected from dibromide (Db), cybium (Sg), barium (Bh), miter (Mt), diffusstium (Ds), rg (Metal Oxide) may be used alone or in combination. It is preferably constituted by 30 wt% or less based on the support of the catalyst by the impregnation method or the sol-gel method, and the carrier material and the activating material It can be prepared by coprecipitation with the content of the mixed components.

Next, methanol is synthesized using carbon monoxide and hydrogen generated in the reforming step.

The methanol synthesis step of synthesizing methanol using carbon monoxide and hydrogen obtained in the reforming step is directly used in the synthesis of methanol without the separation process of the synthesis gas of hydrogen and carbon monoxide obtained in the reforming step of the greenhouse gas, The objective of the present invention is to directly synthesize carbon monoxide and hydrogen, which are produced in order to prevent the production of substances of low purity, in the synthesis of methanol. In order to synthesize dimethyl carbonate, which is the final product of the present invention, And a step of synthesizing methanol using carbon monoxide (CO) and hydrogen (H ₂ ) gas obtained through the reforming step of the gas.

The mixed gas obtained in the reforming step may generate carbon monoxide, hydrogen and other unreacted substances unnecessary for the production of methanol. Of these, carbon monoxide and hydrogen gas which are not required to be separated are used in the subsequent methanol synthesis process . In this case, in the case of carbon dioxide and methane as the reactants, the conversion rate is set to 100% so that unreacted substances other than the synthesis gas are not emitted. Thus, pure synthetic gas can be produced through the synthesis gas. Therefore, The process is not required, and since methanol can be synthesized through a short process, it has a great advantage that it can prevent a lot of energy consumption for separation of unreacted materials and manufacture of methanol with low purity.

In order to produce dimethyl carbonate according to the present invention, a synthesis gas of carbon monoxide and hydrogen corresponding to 2 moles is produced by the reforming step of the greenhouse gas as shown in Reaction Scheme 1, and this is used in the methanol synthesis step. At this time, as the molar ratio of hydrogen to carbon monoxide is 2: 1 as in the reaction formula 2, 2 mol of carbon monoxide produced in the reforming step is consumed by 1 mol to synthesize methanol, leaving 1 mol of carbon monoxide. It is another great advantage of the present invention that the remaining carbon monoxide is synthesized with dimethyl carbonate without supplying additional carbon monoxide from the exterior during the synthesis of dimethyl carbonate.

[Reaction Scheme 1]

CH ₄ + CO ₂ ⇔ 2CO + 2H ₂

[Reaction Scheme 2]

CO + 2H ₂ ⇔ CH ₃ OH

It is preferable to synthesize methanol under the following reaction conditions by a catalytic reaction in order to inhibit the formation of by-products in the methanol synthesis step of synthesizing methanol using carbon monoxide and hydrogen obtained in the reforming step and to improve the yield of methanol.

Catalysts for the synthesis of methanol at a high yield by the catalytic reaction include alumina (Al ₂ O ₃ ), magnesium oxide (MgO), titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ , ZrO ₂ ), calcium oxide (CaO) (CeO ₂ ), SrO, BaO, Cr ₂ O ₃ , La ₂ O ₃ , MgAl ₂ O ₄ , magnesium chromate MgCr ₂ O _4), zinc chromate (ZnCr ₂ O _4), calcium silicate _{(CaSiO 3, Ca 2 SiO 4} , Ca 2 SiO 5), silica (SiO _2), oxide thorium (ThO ₂₎ at least one member selected from (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni) (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), rhodium (Rh), palladium Ag, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, (Rf), dubium (Db At least one metal oxide selected from the group consisting of Sb, Sb, Bh, Mt, Ds, Rg, and Cm, It may be used alone or in combination, and it is preferably constituted by 12 wt% or less based on the support of the catalyst by the impregnation method or the sol-gel method, By the co-precipitation method.

The carbon monoxide and hydrogen obtained by the reforming reaction of the greenhouse gas are introduced into the reactor and heated in the reducing atmosphere at the temperature range of 180 to 550 ° C to reduce the carbon monoxide as shown in Table 3, 25 kg / cm ² naejineun reaction pressure of 70 kg / cm ² and 1,000 hr ^-1 mlg ^- the synthesis of methanol takes place in ^one naejineun space velocity of 10,000 hr ^{-1 -1} mlg, dimethyl carbonate using a greenhouse gas of the present invention The synthesis conditions for providing methanol as a pre-stage of the synthesis may vary depending on various production environments and conditions, and it is most preferable to drive the synthesis conditions under the synthesis conditions in which the conversion rate of carbon monoxide is high by the integration process of the present invention Do.

In order to synthesize methanol according to the present invention, a batch or continuous system may be used according to the conditions shown in Table 3. In order to increase the production amount without specifically limiting the purity of methanol, a synthesis method using a continuous system is used In order to synthesize an advantageous and high purity methanol, it is preferable to use a batch synthesis method.

Next, dimethyl carbonate is synthesized using an excess amount of carbon monoxide supplied in the step of synthesizing methanol.

In the step of synthesizing the dimethyl carbonate in an integrated process for converting dimethyl carbonate using a greenhouse gas, dimethyl carbonate is produced by carbo-nitration of methanol in the presence of a catalyst. At this time, in order to synthesize the optimum dimethyl carbonate, the synthesis of dimethyl carbonate represented by the following formula (1) having low methanol conversion and selectivity and low corrosivity is carried out by reacting carbon monoxide, oxygen and methanol under a copper catalyst.

[Chemical Formula 1]

In order to produce dimethyl carbonate according to the present invention, activated carbon, mesoporous silica (MCM-41, and SBA-15), Y type zeolite, X type zeolite, zeolite selected from ZSM-5 type zeolite Support may be used, and the catalyst may be selected from one or more of copper chloride or palladium chloride selected from among CuCl, CuCl ₂ and PdCl ₂ .

The amount of the catalyst according to the present invention is preferably in the range of 2.5 wt% to 30 wt%, more preferably 4.5 wt% or less, relative to the carrier, by the ion exchange method or the loading method, To 25% by weight, and most preferably from 8.5% to 15% by weight. When the content of the catalyst is less than 2.5% by weight, the catalyst does not function as a catalyst and the content of dimethyl carbonate If the content of the catalyst is more than 25% by weight, it can provide high corrosiveness during the process of synthesizing dimethyl carbonate. In addition, when the catalyst component having a high price is coated, the final dimethyl carbonate There is a problem that the unit price for manufacturing the optical fiber is increased and the price competitiveness is lost. It is preferable to bond the catalyst of the suggested concentration to the carrier.

Since the synthesis conditions and results of the dimethyl carbonate may vary depending on the contents of the support and the catalyst, the support and the catalyst may be adjusted to suitably adjust the type of the support and the amount of the catalyst to provide the best yield of dimethyl carbonate It is preferable to select it. For example, in the case of copper-substituted Y-type zeolite, the catalyst is particularly active in the synthesis of DMC. Cu-X type zeolite and Cu-Y type zeolite generally have excellent activity and Cu- Zeolite or Cu-MORD type zeolite has low activity for the synthesis of dimethyl carbonate and has high selectivity for the production of dimethoxymethane (DMM). In some cases, the Cu-X type zeolite is converted into Cu-ZSM -5 < / RTI > type zeolite.

In addition, since the ratio of copper ion to chloride ion in the liquid phase may greatly affect the selectivity and yield of dimethyl carbonate, it is preferable that the Y-type zeolite substituted with copper is mainly carried out in a gas phase reaction, ion bridge hanryang between the cation of the copper ion and Y-type zeolite is there is a limit possible free copper ions using a method for supporting according to that the limit, the reaction with the zeolite in the liquid phase adjustment becomes caused in using the process of CuCl ₂ It is preferable to appropriately change the components of the carrier and the catalyst.

In order to provide dimethyl carbonate (DMC) which provides economy and stability according to the present invention, carbon dioxide (CO ₂ ) and methane (CH ₄ ) gases, which are greenhouse gases, are introduced into a reforming reactor as starting materials for the production of dimethyl carbonate The molar ratio of the gas mixture of methanol synthesized using carbon monoxide and hydrogen obtained by the reforming reaction and carbon monoxide and oxygen stoichiometrically excessively supplied in the step of methanol synthesis is in the range of methanol to 40 to 50% 50%) and oxygen (10 to 30%), and the two materials of methanol and carbon monoxide in the three mixtures are provided by the product obtained during the production of dimethyl carbonate using the greenhouse gas of the present invention And the other oxygen (O ₂ ) is supplied from the outside.

The three mixtures are introduced into a reactor containing a catalyst, and dimethyl carbonate is synthesized by a batch or continuous method. The reaction temperature for the synthesis of dimethyl carbonate is preferably in the range of 110 to 185 ° C , More preferably in the range of 120 to 170 ° C, and most preferably in the temperature range of 130 to 150 ° C. When the reaction temperature for synthesizing dimethyl carbonate is less than 110 ° C It has a disadvantage in that the activity is insufficient and the yield of dimethyl carbonate is greatly decreased. When the reaction temperature is higher than 185 ° C, the activity is increased and the yield of dimethyl carbonate is relatively increased. However, Not only will the price competitiveness deteriorate, It is preferable that the reaction is carried out within the above-mentioned limited reaction temperature range.

The pressure of the reactor for the synthesis of dimethyl carbonate is preferably 25 to 110 atmospheres. If the pressure of the reactor is less than 25 atm, the corrosiveness of the catalyst is increased by copper chloride catalyst, and the selectivity of dimethyl carbonate There is a problem in that the generation rate is lowered. When the reaction is carried out in a high-pressure reactor exceeding 110 atmospheres, corrosiveness by the copper chloride catalyst is lowered and dimethyl carbonate having a high conversion ratio and high selectivity of methanol is produced. However, There is a problem that a large equipment requiring durability and chemical resistance is required as well as a safety device necessary for operation, so that it takes a lot of initial equipment cost, so it is preferable to produce dimethyl carbonate by the above-mentioned pressure.

Next, after dimethyl carbonate is synthesized, carbon monoxide remaining in the synthesized product of dimethyl carbonate is separated.

In the process of producing dimethyl carbonate using a greenhouse gas, the separation step is aimed at separating the carbon monoxide remaining in the synthesized dimethyl carbonate product. There is no particular limitation on the method for separating the carbon monoxide in the present invention. Any method can be used for separating the carbon monoxide coexisting with the dimethyl carbonate without providing the physicochemical change of the dimethyl carbonate produced by the present invention. have. For this purpose, a separation method using the difference in condensation or precipitation temperature between dimethyl carbonate and carbon monoxide can be used, and a separation method using an organic or inorganic membrane (organic or inorganic membrane) can be used. In addition, The co-existing carbon monoxide is separated by carbon monoxide by a by-pass method, and then the carbon monoxide is recycled to the process requiring carbon monoxide.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example  One

As shown in FIG. 3, the influent amount of carbon dioxide and methane is introduced into the reactor at a rate of 1 kmol / hr, and the reactant at 10 ° C is introduced into the reforming reactor through a primary heat exchanger before the reaction product of carbon dioxide and methane is introduced into the reforming reactor. The reaction temperature of the reforming reactor was set at 850 ° C, and the conversion rate at this time was set to 100% of the carbon dioxide.

The product obtained through the reforming reactor was set to cool down to 150 DEG C through a primary exchanger. The product of carbon monoxide and hydrogen cooled through the primary heat exchanger is cooled to 0 ° C through the secondary exchanger. The mixture of cooled carbon monoxide and hydrogen is configured to regulate pressure from 1 bar through a compressor to 51 bar for methanol synthesis. At this time, the compressed gas mixture is cooled to 400 ° C. by the exchanger to lower the temperature rise to 755 ° C., thereby lowering the process problems due to the temperature rise. The cooled mixed gas is configured to be injected into a methanol synthesis reactor through a transfer tube. The reaction temperature of the methanol synthesis reactor was 200 ° C, the reaction pressure was set at 50 bar, and the conversion rate at this time was set to 58% of carbon monoxide. Carbon monoxide and methanol are present together in the synthesized methanol. In order to inject methanol and carbon monoxide into the high-pressure reactor for the synthesis of dimethyl carbonate, the synthesized methanol and carbon monoxide are compressed to 81 bar through a compressor.

Methanol and carbon monoxide, which are compressed through the compressor, are injected into the dimethyl carbonate synthesis reactor along the feed pipe. At this time, oxygen is injected through the oxygen transfer tube to participate in the reaction for the synthesis of dimethyl carbonate. At this time, the conditions of the reactor were 140 ° C and 80 bar, and the conversion was set to 61.8% of methanol. The amount of dimethyl carbonate produced through the final dimethyl carbonate synthesis reactor was calculated to be 0.309 kmol / hr. It is possible to obtain the production of dimethyl carbonate about 16% of the carbon dioxide and methane reactant which is the greenhouse gas reactant, and the surplus carbon monoxide can be calculated after the reaction type. Carbon monoxide is about 35% (0.691 kmol / hr) Was produced. This demonstrates the feasibility of the integrated process of dimethyl carbonate using greenhouse gases.

Description of the Related Art [0002]
10: reforming reactor 20: heat exchanger
30: air compressor 40: methanol synthesis reactor
50: Dimethyl carbonate synthesis reactor
60: Carbon dioxide and methanol supply
70: dimethyl carbonate product
1: transfer line for injecting the raw material into the reforming reactor
2: transfer line for injecting carbon monoxide and hydrogen generated through the reforming reactor into the heat exchanger
3: Transfer line for injecting carbon monoxide and hydrogen into the compressor
4: transfer line for injecting the material discharged from the compressor into the heat exchanger
5: transfer line for injecting the reactant cooled through the heat exchanger into the methanol synthesis reactor
6: Transfer line for injecting compressed methanol and carbon monoxide into the dimethyl carbonate synthesis reactor through the compressor
7: Transfer line for oxygen injection for dimethyl carbonate synthesis
8: Exhaust line of the final product, dimethyl carbonate
CWCW-3: Cooling water line of each process

Claims (9)

Modifying a mixed gas of carbon dioxide (CO ₂ ) and methane (CH ₄ ) to obtain carbon monoxide (CO) and hydrogen (H ₂ );
Synthesizing methanol (CH ₃ OH) using carbon monoxide (CO) and hydrogen (H ₂ ) obtained in the reforming step; And
Synthesizing dimethyl carbonate using an excess amount of carbon monoxide (CO) supplied in the step of synthesizing methanol (CH ₃ OH);
≪ RTI ID = 0.0 > 1, < / RTI >
The process for producing dimethyl carbonate according to claim 1, further comprising the step of synthesizing dimethyl carbonate and then separating the carbon monoxide remaining in the product of the dimethyl carbonate produced.
3. The process of claim 2, further comprising providing separated carbon monoxide as a starting material in a different process.
The method of claim 1, wherein the reforming step is performed in the step of modifying the mixed gas of carbon dioxide and methane at a reaction temperature of 500 to 1,200 ° C, a reaction pressure of 0.1 to 5.0 MPa, and a space velocity of 500 to 300,000 (mlg ^-1 hr ^-1 ) ≪ / RTI > is carried out by reforming it with carbon monoxide.
The method of claim 4, wherein the catalyst is selected from the group consisting of alumina (Al ₂ O ₃ ), magnesium oxide (MgO), titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ , ZrO ₂ ), calcium oxide (CeO _2), strontium (SrO), barium (BaO), chromium oxide oxide (Cr ₂ O _3), lanthanum oxide (La ₂ O _3), aluminate magnesium (MgAl ₂ O _4), chromic acid or magnesium (MgCr ₂ O _4), zinc chromate (ZnCr ₂ O _4), calcium silicate _{(CaSiO 3, Ca 2 SiO 4} , Ca 2 SiO 5), silica (SiO _2), oxide thorium (ThO ₂₎ one or more selected from kinds of inorganic oxides A catalyst support and a catalyst support of cerium (Ce), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), rhodium ), Cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum Rf), hafnium (Db), hourly A catalyst component of at least one inorganic oxide selected from among Sg, Bh, Mt, Ds, Rg (germanium), and cerium (Cm) ≪ / RTI > is used as the catalyst.
The method of claim 1, wherein the step of synthesizing methanol comprises introducing carbon monoxide and hydrogen obtained in the reforming step into the reactor, heating the mixture in a reducing atmosphere at 180 to 550 ° C in the presence of a catalyst to reduce carbon monoxide, At a reaction temperature of 25 kg / cm ² to 70 kg / cm ² and at a space velocity of from 1,000 ml g ^-1 hr ^-1 to 10,000 g ^-1 hr ^-1 , ≪ / RTI >
The method of claim 6, wherein the step of synthesizing methanol comprises the steps of: synthesizing alumina (Al ₂ O ₃ ), magnesium oxide (MgO), titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ , ZrO ₂ ), calcium oxide cerium (CeO _2), strontium oxide (SrO), barium oxide (BaO), chromium oxide (Cr ₂ O _3), lanthanum oxide (La ₂ O _3), aluminate magnesium (MgAl ₂ O _4), chromic acid or magnesium (MgCr ₂ O _4), zinc chromate (ZnCr ₂ O _4), calcium silicate _{(CaSiO 3, Ca 2 SiO 4} , Ca 2 SiO 5), silica (SiO _2), oxide thorium (ThO ₂₎ is selected from one or more of which A catalyst support and a catalyst support and a catalyst support made of cerium (Ce), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co) Cu, Zr, Yr, Zr, Nb, Mo, Tc, Rh, Pd, Ag, (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum ), Dubium (Db), cybium (Sg) , At least one or more inorganic oxides selected from the group consisting of boron (Bh), miter (Mt), diffusarium (Ds), ruthenium (Rg) and cerium (Cm) ≪ / RTI >
The method of claim 1, wherein in the step of synthesizing the dimethyl carbonate, CuCl, CuCl ₂ and / or CuCl ₂ are added to the support selected from the group consisting of activated carbon, mesoporous silica, Y type zeolite, X type zeolite and ZSM- PdCl ₂ , or a catalyst in which at least one kind of copper chloride or palladium chloride is supported is used as a catalyst for the production of dimethyl carbonate.
3. The process for producing dimethyl carbonate according to claim 2, wherein the step of separating the carbon monoxide remaining in the product of the synthesized dimethyl carbonate is carried out by separating the carbon monoxide by the organic or inorganic film or the bypass method.

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