10 results about "Methyl nitrate" patented technology

The invention discloses a method for preparing methyl nitrite through nitric acid reduction, belongs to the technical field of methyl nitrite preparation, and aims to solve the technical problem that the nitric acid conversion rate and the reaction selectivity of the methyl nitrite prepared through nitric acid reduction in the prior art need to be further improved. The preparation method specifically comprises the following steps: roasting and activating a mixed catalyst, and uniformly stirring to obtain an activated catalyst. Through preparation of the active catalyst, construction of a composite network, optimization of a pore structure and metal dispersion through hydrothermal treatment and calcination in the preparation process, and rapid generation of NO < + > at a copper site in the reaction process, the preparation process is simple, and the preparation process is convenient. The catalyst diffuses to tin sites and performs nucleophilic substitution with methanol to generate methyl nitrite, proton feedback drives NO < + > to be continuously generated, efficient mass transfer is ensured by utilizing regular pore channels, the conversion rate of nitric acid and the selectivity of methyl nitrite are remarkably improved through the synergistic effect of Cu-Sn, side reactions are reduced, and the catalyst is suitable for industrial production.

The invention discloses a catalytic synthesis method of methyl nitrite, belongs to the technical field of methyl nitrite synthesis, and is used for solving the technical problem that the selectivity of catalytic synthesis of methyl nitrite in the prior art needs to be further improved. The catalytic synthesis method specifically comprises the following steps: adding lanthanum nitrate, copper nitrate, palladium chloride and deionized water into a beaker; the preparation method comprises the following steps: adding amino graphene and aluminum silica gel into a reaction kettle, stirring at room temperature for 10-20 minutes, adding ethylene glycol, continuously stirring for 15-30 minutes, adding a composite carrier into a system, adjusting the pH value to 3-4 by using saturated dilute nitric acid, heating to 50 DEG C, reacting for 12-15 hours, and performing post-treatment to obtain the modified catalyst. The reaction conversion rate, selectivity and catalyst stability are improved.

The present invention provides a method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene, which uses acetylene, carbon monoxide and methyl nitrite as raw materials, and reacts them under the action of a supported palladium catalyst at a temperature of 60-200°C. o C. Under conditions of pressure of 0.1 to 6 MPa, acetylene is subjected to a double carbonylation reaction for 0.5 to 48 hours to obtain dimethyl fumarate and dimethyl maleate compounds. The present invention replaces methanol with methyl nitrite and employs a supported palladium catalyst, eliminating the need for any auxiliary agents and the direct use of O2. This avoids the problems of explosion limits, the use of corrosive auxiliary agents, and the separation and recycling of catalysts in the current double carbonylation of acetylene, overcoming the technical pain points of the prior art. Furthermore, the reaction has the advantages of high atomic utilization, mild reaction conditions, and high product yields. The byproduct, NO, can be recycled, making it suitable for industrial production and promising broad application prospects.

The invention discloses a mass correction factor-based soluble methyl nitrite content determination method and a mass correction factor-based soluble methyl nitrite content determination system, and belongs to the technical field of methyl nitrite content determination. According to the method, an alcohol substance is adopted as a reference substance, a reliable bridge is provided for indirect quantification, and the problems that a conventional reference substance is poor in compatibility and prone to volatilization or hydrolysis are solved; secondly, an indirect quantitative system of the gaseous correction factor and the liquid reference content is established, the content of the methyl nitrite can be accurately measured without a dissolved methyl nitrite standard sample for the first time, and the technical problem that direct quantification is difficult due to lack of a special liquid standard substance in the prior art is solved.

The invention discloses a method for preparing methyl nitrite through a reaction of NO and methanol, belongs to the technical field of methyl nitrite, and aims to solve the technical problems that in the process of preparing methyl nitrite through a reaction of NO and methanol in the prior art, the conversion rate, the selectivity and the purity of converting NO into methyl nitrite need to be further improved. The method specifically comprises the following steps: filling a catalyst in a catalytic section of a reaction tower protected by nitrogen, raising the temperature of the catalytic section of the reaction tower to 50-60 DEG C, and raising the pressure of the reaction tower to 0.1-0.2 MPa; according to the method, reaction parameters in the process of preparing the methyl nitrite through the reaction of the NO and the methanol are optimized, so that the conversion rate and the selectivity of converting the NO into the methyl nitrite are effectively improved, the by-product process is reduced, the content of water, nitric acid and other impurities in the prepared methyl nitrite is extremely low, and the method is suitable for industrial production. The catalyst can be directly suitable for reacting with CO to prepare dimethyl carbonate.

The invention discloses a method and a device for efficiently producing methyl nitrite. The method comprises the following steps: carrying out a reaction for generating methyl nitrite in a reaction chamber A to obtain a liquid-phase material, and transferring nitric acid out of the liquid-phase material in the reaction chamber A through an acid transfer concentration device; wherein the liquid-phase material after the nitric acid is transferred serves as a reaction raw material and is reused in the reaction chamber A; transferring the transferred nitric acid into a reaction chamber B; when the mass concentration of the nitric acid in the reaction chamber B is larger than or equal to a first set value, the reaction of converting the nitric acid into methyl nitrite is carried out in the reaction chamber B; when the mass concentration of the nitric acid in the reaction chamber B is less than or equal to a second set value, stopping the reaction for generating the methyl nitrite; the first set value is greater than the second set value. According to the device and the method, oxidative esterification and nitric acid conversion reaction can be simultaneously carried out, methyl nitrite is efficiently produced, the total space-time yield of the product is improved, and the process energy consumption and cost are reduced.

The invention discloses a Pd / M-CeO2 single-site catalyst, a preparation method thereof and application of the Pd / M-CeO2 single-site catalyst in preparation of dimethyl carbonate through CO esterification, and belongs to the field of catalysts. The catalyst comprises an active component Pd and a CeO2 carrier doped with metal M, m is selected from at least one of rare earth lanthanide elements and IIIA main group elements. When the catalyst is applied to preparation of dimethyl carbonate through CO esterification, decomposition of methyl nitrite can be reduced, and the catalyst has high dimethyl carbonate selectivity which can reach 92%.

This invention discloses a method for determining the concentration of soluble methyl nitrite based on a mass correction factor, belonging to the field of analytical chemistry. Using an organic compound that can be prepared as both a gaseous and liquid standard as a reference substance, the concentration of soluble methyl nitrite in the alcohol-containing liquid sample is obtained by measuring the relative mass correction factor of gaseous methyl nitrite with respect to the gaseous reference substance and combining this with the measured concentration of the liquid reference substance in the sample. This method can accurately determine the concentration of soluble methyl nitrite without requiring a standard sample, is simple to operate, has good repeatability, and provides accurate and stable results. It solves the problems of poor compatibility between conventional reference substances and alcohol-containing liquid sample matrices, as well as their volatility or hydrolysis, which lead to inaccurate quantification. This method enables the direct and accurate determination of the concentration of soluble methyl nitrite and can be used for the precise analysis of soluble methyl nitrite in alcohol-containing liquid systems in chemical production.

The invention discloses a methyl nitrite regeneration tower based on a gas circulation supply mechanism, relates to the technical field of methyl nitrite regeneration, and aims to solve the problems that an emergency supply mechanism is lacked, the reaction in the tower is difficult to stably control and the nitric acid conversion rate is low due to insufficient gas-liquid contact when gas and a pump are stopped. On one hand, a gas circulation mechanism is matched with a gas-liquid countercurrent horizontal pushing composite effect, stable gas-liquid mixing in the methyl nitrite regeneration process is achieved, heat is taken away through circulation gas, meanwhile, heat is absorbed through spraying gasification of a methanol solution, and the temperature is cooperatively controlled; rapid methanol solution compensation is carried out in cooperation with spraying immediately, and dangerous accidents caused by the fact that the methanol concentration exceeds the standard are prevented; and on the other hand, through the gas-liquid mass transfer effect of variable-pitch and rotatable inlet circulating synthesis gas, turbulent flow changes of the transmission rate and the transmission direction of the synthesis gas can be carried out during secondary gas supply, and finally, the regeneration efficiency of methyl nitrite is improved.

The application discloses a preparation method of chlorophthalic acid, which comprises the following steps: contacting a raw material liquid containing chloro-o-xylene with an oxidant and an oxidation reaction catalyst, and generating an oxidation reaction to prepare the chlorophthalic acid; wherein the oxidant comprises methyl nitrite and oxygen. The method can fully utilize methyl nitrite, which is an important intermediate in a coal-to-ethylene glycol process. The methyl nitrite and the oxygen are used as the oxidant, so that the chloro-o-xylene can be efficiently oxidized to prepare the chlorophthalic acid under mild conditions.