45 results about "Hydrogen cyanide gas" patented technology

The invention discloses an ammonia recovery method from the mixing gas produced in the process of hydrogen cyanide production, comprising ammonia absorption process, decyanation process, desorption process and rectifying process for solving the technical problem. The invention is characterized in that decyanation process is set separately to recovery hydrogen cyanide gas, avoiding the loss of hydrogen cyanide caused by a large amount of acid gas like hydrocyanic acid contained in the ammonium phosphate solution directly steamed in Versum method, reducing production cost of hydrogen cyanide, reducing the emission of the harmful acid gas like hydrogen cyanide, and avoiding the serious pollution of peripheral enviroment. Besides, the ammonium phosphate solution contains a much smaller amout of hydrocyanic acid after hydrogen cyanide is recovered, which can not influence production process and make the production process more safety.

Spent potliner from an aluminum reduction cell is subject to an acid digest and the digest may be adjusted to produce a first gas component comprised of at least one material selected from the group consisting of silicon tetrafluoride, hydrogen fluoride, hydrogen cyanide gas and water vapor, and a slurry component comprised of at least one material selected from the group consisting of carbon, silica, alumina, and sodium, iron, calcium and magnesium compounds. The first gas component is removed from the digester and heated to a temperature sufficiently high to convert said silicon tetrafluoride to fumed silica and hydrogen fluoride. Thereafter, the fumed silica is separated from the hydrogen fluoride to recover fumed silica from spent potliner material.

The invention relates to a nano sensitive material for monitoring hydrogen cyanide. The nano sensitive material is characterized by consisting of the following components in percentage by weight: 25 to 35 percent of NiO, 30 to 40 percent of V2O5 and 32 to 42 percent of Al2O3 nano powder. The particle size of the nano sensitive material is between 25 and 40nm. A hydrogen cyanide air sensor made of the nano sensitive material has the advantages of wide linear range, high selectivity and high sensitivity, and can monitor a trace amount of hydrogen cyanide on line without being influenced by coexisting substances.

The compositions and methods relate to an organic polymer-inorganic particle sensor material for detecting analytes. Interactions between the polymer and the particles are affected by the presence of analyte, which displaces the polymer and increases its free volume. This change in free volume can be detected, e.g., using an embedded piezoresistive microcantilever (EPM) sensor. Analytes that can be detected include noxious substances, such as hydrogen cyanide gas and carbon monoxide.

The invention discloses a reactor used for preparing gas-phase hydrogen cyanide. The reactor used for preparing gas-phase hydrogen cyanide comprises an upper sealing head, a lower sealing head, a shell side and reaction tubes, wherein the reaction tubes are arranged in the shell side; the upper sealing head and the lower sealing head are respectively and correspondingly mounted at the upper end and the lower end of the shell side; the reactor used for preparing gas-phase hydrogen cyanide also comprises a feed gas distribution device, a temperature monitoring device, a heat-transfer medium flow guide device and a hollow flow guide cylinder; the feed gas distribution device is mounted in the top end of a main body structure of the tubular reactor; the temperature monitoring device is inserted from the top end of the main body structure of the tubular reactor; the heat-transfer medium flow guide device is mounted on the outer part of the shell side; flow guide holes are formed in an inner wall surface, being in contact with the heat-transfer medium flow guide device, of the shell side; the hollow flow guide cylinder and the reaction tubes are mounted in the shell side in a mixing manner. The reactor used for preparing gas-phase hydrogen cyanide has the beneficial effects of being capable of generating easily-separated hydrogen cyanide gas and stably and effectively dissipating reaction heat, an accurate reaction temperature monitoring system is arranged, the feed gas distribution effect is good, the reaction conversion rate is high; a catalyst is low in loss during use and long in service life.

The invention discloses a detection apparatus and detection method for hydrogen cyanide in a research lab. The detection apparatus comprises a controller, a memory, a base plate, a rectangular cross section equipped air chamber and a support frame arranged on the base plate, and a guide structure and a cross lead screw arranged on the support frame. The inner wall top of the air chamber is provided with an ultrasonic generator and several fans for blowing down, the inner side wall of the air chamber is equipped with a gas sensitive film, a metal net composed by heating wires and for supporting the gas sensitive film, a horizontal separator plate that is located below the metal net and separating the inside of the air chamber into an upper part and a lower part from top down in order, and the air chamber is internally provided with an ultrasonic receiver, a support plate, a detection head and a track spirally distributed along the upper surface of the support plate. The detection apparatus provided by the invention has the characteristics of high sensitivity, good stability and short response time, good selectivity to hydrogen cyanide, and ability to detect lower concentration trace hydrogen cyanide gas, thus effectively guaranteeing people good health.

The invention provides a technological method for jointly preparing liquid hydrogen cyanide and hydroxynitrile. The technological method comprises the steps that a light oil cracking hydrogen cyanide gas mixture is used as a raw material and undergoes an ammonia removal process and a cryogenic process to obtain liquid hydrogen cyanide, wherein in the ammonia removal process, the hydrogen cyanide gas mixture is absorbed with a sulfuric acid aqueous solution; in the cryogenic process, the hydrogen cyanide gas mixture is cooled to minus 10-minus 20 DEG C, after the hydrogen cyanide gas mixture is cooled, a part of the hydrogen cyanide gas becomes liquid to obtain liquid hydrogen cyanide, and the other part of the hydrogen cyanide gas is the tail gas containing hydrogen cyanide; the tail gas containing hydrogen cyanide, which undergoes cryogenic treatment, is absorbed with a formaldehyde aqueous solution containing a catalyst to prepare a hydroxynitrile aqueous solution, and the tail gas absorbed with the formaldehyde aqueous solution directly enters an incinerator to be incinerated. By adopting the technological method, the purification efficiency and the utilization efficiency of hydrogen cyanide can be obviously improved, meanwhile, the energy consumption in the hydrogen cyanide purification process is greatly reduced and can be reduced by 90% at most, and the utilization rate of hydrogen cyanide is more than 99.9%.

The invention relates to the technical field of organic synthesis, in particular to a method of continuously preparing a substituted benzyl cyanide compound by using a microchannel reactor, and discloses a preparation method of substituted benzyl cyanide. The preparation method comprises the steps of preheating accurately metered raw materials, namely substituted benzyl halide and hydrogen cyanide gas separately, allowing the raw materials to enter a microchannel reactor after mixing for nucleophilic substitution reaction at 150.0-250.0 DEG C and pressure of 1.0-10.0MPa to generate substituted benzyl cyanide and hydrogen halide, keeping reaction retention time for 10-300s, then cooling for quenching reaction, and post-treating a reaction material to form substituted benzyl cyanide. The method has the advantages of low cost, high production efficiency, continuous production and clean production.

An electrochemical hydrogen cyanide sensor (1) comprises a housing (10) comprising an opening (2) allowing gas to enter the sensor (1); an electrolyte disposed within the housing (10); a plurality ofelectrodes in contact with the electrolyte within the housing (10), wherein the plurality of electrodes comprise a working electrode (5) and a counter electrode (7), and wherein the electrodes comprise a metal catalytic material; and a filter (3) operable to cover the opening (2) of the housing (10), and prevent hydrogen sulfide from reaching the electrodes, wherein the filter (3) comprises silversulfate layered onto a polytetrafluoroethylene support material.

The invention relates to a high-quality cyanide solution continuous production process and a production system of the high-quality cyanide solution, and belongs to the technical field of cyanide production. The production system comprises a metering pump, a mass flowmeter, a static mixer 7, a tube reactor 8, a gas-liquid separator 11, and pipeline valves and auto control instruments of the production system. A sampling valve 9 and a pressure auto control system 10 are arranged on a pipeline; a demister is installed inside the gas-liquid separator 11; a reaction tail gas discharging opening 12 having auto pressure control is arranged on the top of the gas-liquid separator; and a material discharging pipe and a circulating returning pipeline are arranged at the bottom of the gas-liquid separator. The method is simple; continuous production can be realize; the reaction time is short; the gas-liquid contact has no dead angle; the mass and heat transfer effects are good; the absorption rate of a raw material hydrogen cyanide is close to 100%; the aggregation discoloration caused by partial aggregation of the hydrogen cyanide gas is avoided particularly; the periodic equipment cleaning process in conventional arts is avoided especially; the labor intensity of workers is decreased; the labor force is saved; the product quality is notably improved as well; the cost is reduced by a certain degree; and accordingly the production process and the production system provided by the invention have good economic and social benefits.

The invention relates to an electrochemical hydrogen cyanide gas sensor. The sensor comprises a shell, electrolyte, as well as a working electrode, a reference electrode and a counter electrode, whichare used for forming an ionic conduction in the electrolyte; each of the working electrode, the reference electrode and the counter electrode comprises an electrode membrane and a mixture adsorbed onthe electrode membrane; the mixture on the working electrode includes a first nanometer material and polytetrafluoroethylene particles; the mixture on the reference electrode includes a second nanometer material and the polytetrafluoroethylene particles; the mixture on the counter electrode includes a third nanometer material and the polytetrafluoroethylene particles; the electrolyte is the propylene carbonate solution; and, the lithium perchlorate and the triethanolamine are dissolved in the propylene carbonate solution. The gas sensor provided by the technical scheme of the invention precisely and quickly measures the concentration of the hydrogen cyanide gas, and monitors the concentration of the hydrogen cyanide gas in real time.

The invention discloses a method of treating a vacuum potassium carbonate desulfurization waste liquid through an acidic separation-out/oxidization process. In the invention, the vacuum potassium carbonate desulfurization waste liquid is added by an acid to perform acid-out, wherein the separated hydrogen sulfide and hydrogen cyanide gases are mixed with acidic gas come out from a vacuum potassium carbonate desulfurization and regeneration column. The mixed gas is fed into a Claus furnace to recycle sulfur. The waste liquid after the acidic separation is added with an oxidizing agent to remove the residual sulfides and cyanides in the waste liquid. The treated waste liquid, after pH regulation, is discharged into a coking phenolic and cyanide wastewater bio-chemical treatment system to perform bio-chemical treatment. The method utilizes a vacuum system arranged on the top of the original vacuum potassium carbonate desulfurization and regeneration column. The method is short in technical process and less in equipment. By means of the process of firstly acid-out and then oxidization, the consumption of the oxidizing agent is less, so that the method is low in operation cost.