The method of producing formaldehyde
(57) Abstract:Usage: in the chemical industry. The inventive product is formaldehyde. Reagent 1: natural gas. Reagent 2: air. Reaction conditions: temperature of 300 - 400oC and a pressure of 3 to 10 MPa, natural gas is mixed with air from getting gas mixture containing 1 - 4% vol. oxygen, which is fed into the reactor, and then optionally introducing the air at the site of maximum heating. 9 table. The invention relates to organic chemistry, in particular to methods for formaldehyde, and can be used in the chemical industry.Known methods for producing formaldehyde (FA) as by direct partial oxidation of methane, and by the catalytic oxidative dehydrogenation of methanol oxygen (1). Both methods have disadvantages. Getting FA by catalytic oxidative dehydrogenation of methanol multistage process in which the feedstock (natural gas) sequentially converted into synthesis gas, then in methanol and then in FA. Despite the high selectivity of individual stages of the process requires very high energy costs and complex hardware product is ü methane conversion in FA.The closest technical solution is the method of obtaining the FA and the simultaneous achievement of methanol (2), consisting in a partial air oxidation of methane or mixtures thereof with nitrogen at 300-600aboutC and a pressure of 5-200 bar followed by cooling the reaction mixture and separation of target products.However, the known method (2) has a drawback: low output F (just at the level of 10-19%) due to the low degree of methane conversion.The aim of the invention is to provide a method for obtaining the FA, which allows to increase the output of F (unreacted methane).The solution of this problem is achieved by the proposed method of obtaining the FA, including oxidation of natural gas with air at a temperature of 300-400aboutC and a pressure of 3-10 MPa, followed by cooling the reaction mixture and separation of the target product, in which natural gas is mixed with air from getting gas mixture containing about 1-4. oxygen and fed into the reactor, and then optionally introducing the air at the site of the reactor with a maximum heat coming out of the reactor the gaseous mixture to cool and separate the liquid product is heated to 100-120aboutWith and subjected to oxidative dehydrogenation in at the showed the increased oxygen content in the reaction gas mixture leads to an increase in the degree of methane conversion, not at the same time sharply decreases the selectivity of the process output F and methanol drops. The distributed supply of oxygen along the reactor allows to increase the degree of conversion without significant loss of selectivity of the formation of the desired products. But even under optimal conditions, the main oxidation product is methanol. Known methods for catalytic oxidative dehydrogenation of pure methane in FA (1). However, the liquid product methane oxidation in the proposed process is a complex mixture of alcohols, aldehydes, organic acids and water. Given that the main component of this product (about 50%) is methanol, its translation in F will increase the output F in the process more than three times. As was shown by experiments, the catalytic oxidative dehydrogenation of liquid products obtained in the proposed process by oxidation of methane (without separation of methanol) allows to increase the output F in the process.P R I m e R 1. Natural gas is heated to 350aboutWith the pressure of 10 MPa at a flow rate of 760 nm3/h served in the reaction is t air air consumption 80 nm3/h oxygen Concentration in gas mixture 2. On the site of the reactor with a maximum heating (temperature in the reactor is controlled by thermocouples) impose additional air with the same speed (80 nm3/h). Coming out of the reactor the gaseous reaction mixture is cooled in the heat exchanger and separating the liquid product in the separator. The obtained liquid product has the composition given in table.1.The liquid product of the specified composition is heated to 120aboutC and sent to the catalytic reactor with a silver catalyst, after completion of the reaction, which occurs with heating, the reaction mixture was cooled in the refrigerator.The composition of the liquid reaction product after the catalytic dehydrogenation is shown in table.2.P R I m m e R 2 (comparative). The process is carried out analogously to example 1, but the entire air (air flow 160 nm3/h) is injected in one piece through the mixer.The composition of the liquid product obtained after oxidation of methane is given in table.3.The composition of the liquid product after the catalytic dehydrogenation is shown in table.4.P R I m e R 3. The process is carried out analogously to example 1 but at a temperature of 400aboutC and a pressure of 3 MPa.
FIELD: organic chemistry, in particular formaldehyde production.
SUBSTANCE: claimed method includes oxidation of hydrocarbon-containing gas with oxygen-containing gas at elevated temperature and pressure followed by reaction mixture cooling and separation of target liquid product. As hydrocarbon-containing gas ethane-containing gas is used, including natural and associated gases containing not less than 10 % of ethane. Ethane-containing gas preliminary pressed up to 2-5 MPa and heated up to 280-450°C, and oxygen-containing gas, preliminary pressed up to pressure of ethane-containing gas or more are separately fed into blenders of arranged in tandem reaction zones up to oxygen content of 2-10 vol.%. Reaction mixture is continuously cooled through wall either directly in oxidation process or before feeding thereof in next reaction zone to temperature not more than 450°C. As oxygen-containing gas air, oxygen or oxygen-enriched air are used.
EFFECT: increased formaldehyde yield, simplified process, decreased energy consumption.
2 cl, 4 ex, 1 tbl, 1 dwg
FIELD: organic chemistry, fuel production.
SUBSTANCE: claimed method includes feeding of heated hydrocarbon-containing and oxygen-containing gas in reaction unit, vapor phase oxidation of hydrocarbon-containing gas at 250-450°C and pressure of 2.0-10 MPa under near isothermal conditions; cooling of reaction mixture in heat exchangers, separation of gas and liquid phases of reaction mixture. separation of obtained methanol solution of formaldehyde, C2-C4-alcohols and methanol, methanol and gas phase after separation into reactors; catalytic methanol conversion on zeolite catalyst at 350-450°C and pressure of 3-8 MPa; cooling of produced reaction mixture in heat exchangers; separation of gas and liquid phases of reaction mixture; separation of aqueous fraction and synthetic diesel fuel liquid fractions, including fraction of liquid hydrocarbons, corresponding to motor gasoline having octane number of at least 92.
EFFECT: products of high quality; simplified technology; decreased energy consumption.
5 cl, 1 tbl
SUBSTANCE: present invention relates to a method of producing methanol, involving feeding a first stream of hot hydrocarbon-containing gas into a reactor, feeding an oxygen-containing gas into the reactor, oxidation of the hot stream of hydrocarbon-containing gas in the reactor with oxygen from the oxygen-containing gas to form a stream of products containing methanol and formaldehyde; and transferring heat from the stream of products to the first stream of hydrocarbon-containing gas, extracting methanol from the stream of products and extracting CO2 and formaldehyde from the stream of products to form a reduced stream of products containing hydrocarbons through physical absorption thereof with an absorbent, wherein the first stream contains at least a portion of the reduced stream of products, as well as apparatus (versions) for realising said method.
EFFECT: invention enables to obtain an end product using an efficient and cheap method.
32 cl, 5 dwg
SUBSTANCE: invention relates to a method for direct conversion of lower C1-C4 paraffins to oxygenates such as alcohols and aldehydes, which are valuable intermediate products of organic synthesis and can be used as components of engine fuel and/or starting material for producing synthetic gasoline and other engine fuels. The method involves passing a mixture consisting of a lower paraffin or oxygen, diluted with an inert gas or air or pure oxygen, through a catalyst bed at temperature not higher than 350°C. The catalyst used is a catalyst system for heterogeneous reactions, which contains microfibre of a high-silica support and at least one active element, the active element being in form of either a MeOxHalv composite or a EwMezOxHaly composite, wherein the element Me in both composites is selected from a group which includes transition metals of groups 5-12 and periods 4 and 5, or elements of lanthanum or lanthanide groups or, preferably, ruthenium; element Hal is one of the halogens: fluorine, chlorine, bromine, iodine, but preferably chlorine; element E in the EwMezOxHaly composite is selected from a group which includes alkali, alkali-earth elements, or hydrogen, and indices w, z, x and y are weight fractions of elements in given composites and can vary in the following ranges: z - from 0.12 to 0.80, x - from 0.013 to 0.34, y - from 0.14 to 0.74, w - from 0 to 0.50.
EFFECT: method enables to achieve high degree of conversion of starting reactants and high selectivity of formation of alcohols.
4 cl, 15 ex
SUBSTANCE: invention relates to method of obtaining carbonyl compounds, namely ketones and aldehydes C2-C4, which find different application as valuable semi-products of FINE and basic organic synthesis, as well as are widely applied as solvents. Method is carried out in gas phase by interaction of nitrous oxide with mixture of aliphatic C2-C4 olefins and alkanes at temperature 300-550°C and pressure 1-100 atm.
EFFECT: method makes it possible to obtain valuable target products with high productivity and high total selectivity with explosion safety of work.
12 cl, 4 tbl, 30 ex