200results about "Hydrogen cyanide preparation/purification/separation" patented technology

Supported bis(phosphorus) ligands are disclosed for use in a variety of catalytic processes, including the isomerization, hydrogenation, hydroformylation, and hydrocyanation of unsaturated organic compounds. Catalysts are formed when the ligands are combined with a catalytically active metal, such as nickel.

The present invention relates to three-dimensional catalyst gauzes for gas reactions knitted in two or more layers from noble metal wires in which the meshes of the individual layers are joined to one another by pile threads. In these catalyst gauzes weft threads are inserted between the mesh layers. These catalyst gauzes have an increased catalytic activity and efficiency in gas reaction. These improvements enable operation with a lower total amount of noble metal employed, for example by reducing the number of gauzes and/or the length of the wire processed in the catalyst gauze and/or the wire thickness, without thereby having to accept disadvantages with respect to the yield and selectivity of the gas reaction, mechanical strength and service life of the gauzes or unavoidable loss of noble metal.

Disclosed are means for improving the service-life of indirect tubesheet type heat exchangers used in chemical reactors, particularly those exposed to reducing, nitridizing and/or carburizing environments. Such means include the use of certain ferrules within the heat exchange tubes and/or weld types used in construction of these heat exchangers.

The invention relates to a method for separating HCN and NH3 for reclamation or realizing standardized discharge from wastewater solution that contains CN<-> and NH3 or NH4<+>, particularly relates to a new technique of resource cyclic utilization of high-salt cyanide and ammonium bearing wastewater, which is represented by cyanuric chloride industry, thus opening a new way of resource cyclic utilization of the high-salt cyanide and ammonium bearing wastewater, which is represented by cyanuric chloride, and providing a totally new clean production technology with simple technique, investment-saving and low operation fee and resource cyclic used feature of the integrated utilization of wastewater that contains the CN<-> and NH3 or NH4<+>.

The invention belongs to the technical field of plasma chemical synthesis, and provides a metal supported catalyst and an HCN synthesis method. The metal supported catalyst comprises an active component and a carrier, the active component is one or two or above of non-noble metals, alkali metals, noble metals and rare earth metals, and the weight percentage of the active component in the catalyst is 0.4-50%; and a ratio of the equivalent diameter of carrier particles to the internal diameter of a reactor is 0.01-0.4. The retention time of methane and ammonia gas in a discharge zone is 0.01-100s, the reaction temperature is 200-650DEG C, the reaction pressure is -0.06 - 0.2 Mpa, and a molar ratio of methane to the ammonia gas in the reaction system is 0-10. The method has the advantages of mild reaction conditions, implementation at a low temperature under normal pressure, cheap and easily available raw materials comprising methane and ammonia gas, and realization of simple flow and environmental protection because the plasma catalytic synthesis method is a one-step direct synthesis method.

The invention provides an acid preparing method by coal gas wet oxidation and desulfurization, which comprises the following steps of: introducing sulfur-containing coal gas into an absorption section of a desulfurization regeneration tower from the bottom, and then introducing desulfurization barren solution into the absorption section from the upper part to contact the coal gas countercurrent; delivering desulfurization rich liquid from the bottom of the absorption section at the lower part of the desulfurization regeneration tower into a regeneration section at the top of the desulfurization regeneration tower; introducing regeneration air into the regeneration section to obtain the mixture of the desulfurization barren solution and sulfur foam; concentrating the sulfur foam into sulfur pulp to be delivered in a combustion furnace after being atomized by adopting compressed air through a nozzle and then delivered into a converter provided with vanadium catalyst to be converted to sulfur trioxide after the furnace gas is cooled, washed and dried; and delivering the sulfur trioxide into an absorption tower to be converted into product sulfuric acid with weight concentration of 94 percent to 98 percent. The method reduces exhaust emissions, does not emit liquid waste outwards, and has conversion rate of sulfur dioxide over 99.6 percent and good economic and social benefits.

Solid membranes comprising an intimate, gas-impervious, multi-phase mixture of an electronically-conductive material and an oxygen ion-conductive material and/or a mixed metal oxide of a perovskite structure are described. Electrochemical reactor components, such as reactor cells, and electrochemical reactors are also described for transporting oxygen from any oxygen-containing gas to any gas or mixture of gases that consume oxygen. The reactor cells generally comprise first and second zones separated by an element having a first surface capable of reducing oxygen to oxygen ions, a second surface capable of reacting oxygen ions with an oxygen-consuming gas, an electron-conductive path between the first and second surfaces and an oxygen ion-conductive path between the first and second surfaces. The element may further comprise (1) a porous substrate, (2) an electron-conductive metal, metal oxide or mixture thereof and/or (3) a catalyst. The reactor cell may further comprise a catalyst in the zone which comprises a passageway from an entrance end to an exit end of the element. Processes described which may be conducted with the disclosed reactor cells and reactors include, for example, the partial oxidation of methane to produce unsaturated compounds or synthesis gas, the partial oxidation of ethanes substitution of aromatic compounds, extraction of oxygen from oxygen-containing gases, including oxidized gases, ammoxidation of methane, etc. The extraction of oxygen from oxidized gases may be used for flue or exhaust gas cleanup.

The invention provides an industrial production method of acrylonitrile, which comprises that the air, propylene and ammonia are subjected to ammoxidation inside a reactor and generate a reaction gas containing the acrylonitrile; the reaction gas enters a first tower and shock cooling, neutralization and cooling are achieved; the reaction gas which is subjected to shock cooling, neutralization and cooling enters a second tower and the water absorbs organic materials contained in the reaction gas; the water absorbing liquid enters a third tower, the acrylonitrile, hydrocyanic acid and water vapor steamed out by the third tower are subjected to condensation, and then separation of an aqueous phase and an organic phase is achieved in a quantizer of the third tower; the water phase inside the quantizer of the third tower are delivered to the third tower; the water phase introduced from a last piece of tower plates of a tower kettle of the third tower is subjected to heat exchange and then serves as absorbing water of the second tower; a gas phase containing acetonitrile is extracted from the side lines of the third tower and sent into a fourth tower and a rough acetonitrile product is obtained; and the organic phase in the quantizer of the third tower enters a fifth tower and a sixth tower sequentially and hydrocyanic acid and a acrylonitrile product are respectively obtained. According to the method, the reliability of a device is improved and the energy utilization is high.

The invention includes an apparatus and process for the catalytic production of HCN from a feed gas of ammonia and a hydrocarbon gas by means of heat tubes supplying heat to the feed gas stream and heat tubes for removal of heat from the products. The invention further includes a process for N₂O abatement comprising transferring heat from an exothermic N₂O degradation reaction through a heat pipe.

The invention relates to a method for preparing hydrogen cyanide according to andrussow process, which is carried out by reacting methane gas, ammonia gas and oxygen-containing gas at rising temperature on catalyst. Oxygen has a volume proportion (O<2>/(O<2>+N<2>) of 0.2 to 1.0 corresponding to total volume of nitrogen and oxygen, and the reaction is carried out by adopting mixture of incombustible reactant gas.

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.

A process and a device for reducing the nitrous oxide which is formed during the catalytic combustion of ammonia and oxygen to form nitrogen oxides. A catalyst system including at least one first catalyst mesh element and at least one second catalyst mesh element is used for the catalytic combustion of ammonia and oxygen to form nitrogen oxides, where the minimum of one first catalyst mesh element is a platinum-rhodium mesh and the minimum of one second, downstream catalyst mesh element is a palladium-rhodium mesh with 2-4 wt. % of rhodium.

A reactor system for carrying out an endothermic reaction of a feed gas, including: a structured catalyst arranged for catalyzing the endothermic reaction of a feed gas, the structured catalyst including a macroscopic structure of electrically conductive material, the macroscopic structure supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; a pressure shell housing the structured catalyst; heat insulation layer between the structured catalyst and the pressure shell; at least two conductors electrically connected to the electrically conductive material and to an electrical power supply placed outside the pressure shell, wherein the electrical power supply is dimensioned to heat at least part of said structured catalyst to a temperature of at least 200° C. by passing an electrical current through the electrically conductive material. Also, a process for performing an endothermic reaction of a feed gas.

The invention discloses a catalyst for preparing hydrocyanic acid by adopting methanol ammonia oxidization as well as a preparation method and application of the catalyst for preparing the hydrocyanic acid by adopting the methanol ammonia oxidization. Most existing catalysts for preparing the hydrocyanic acid by adopting the methanol ammonia oxidization are complicated in structure, inconvenient to prepare and non-ideal in yield. The catalyst disclosed by the invention consists of elements such as molybdenum, bismuth and an oxide of X; the experimental form of the catalyst is MoaBibXcOd, wherein X is one of Fe, K, Ca and Zn; a, b and c are atomic ratios; when a is equal to 1, b is equal to a number from 1 to 2.5, c is equal to a number from 1 to 5, and d is a total number of oxygen atoms in a corresponding oxide generated by chemical combination of catalyst components. The catalyst disclosed by the invention is simple in constituent, high in catalysis activity and stability and convenient to prepare; when the catalyst is applied to preparation of the hydrocyanic acid by adopting the ammonia oxidization, the ammonia oxygen amount is greatly reduced.

A static mixer is disclosed for a hydrogen cyanide reaction process that thoroughly mixes the reactant gases to form a ternary gas mixture that has a coefficient of variation of less than 0.1 across the diameter of the catalyst bed. The static mixer comprises tabs that are inserted through non-continuous slots in the conduit and the tabs are secured to the external wall of the conduit.

The present invention provides a method for producing a high-purity liquid hydrogen cyanide for hydrogen cyanide gas obtained by ammoxidation. The liquid hydrogen cyanide of a low water content is obtained by absorption of low-temperature water in an absorbing tower and operation of a three-stage distillation tower and a gas-liquid separator. The process and method have the beneficial effects that by virtue of adoption by low-temperature water, the absorption efficiency of HCN gas is improved, the load on subsequent exhaust gas processing facilitates is alleviated, and the environmental protection pressure is relieved. Refined by the process disclosed by the invention, the content of a finished product hydrogen cyanide water can reach below 50 ppm, thereby sufficiently satisfying the using requirements on downstream users; the leakage risk of the hydrogen cyanide is effectively avoided, thereby more facilitating the safe production; and self-polymerization of hydrogen cyanide can be further slowed, so that production is more smooth and the production efficiency is improved.

This invention relates to gas-impermeable, solid state materials fabricated into membranes for use in catalytic membrane reactors. This invention particularly relates to solid state oxygen anion- and electron-mediating membranes for use in catalytic membrane reactors for promoting partial or full oxidation of different chemical species, for decomposition of oxygen-containing species, and for separation of oxygen from other gases. Solid state materials for use in the membranes of this invention include mixed metal oxide compounds having the brownmillerite crystal structure.

A fixed bed containing a particulate catalyst or sorbent material (10) subject to operation at high temperature having a shaped boundary member (16) inclined to the direction of fluid flow through the bed that maintains the depth of said catalyst or sorbent at the boundary of the bed through a series of thermal expansion-thermal contraction cycles is described. By maintaining bed depth, the shaped boundary member (16) can prevent bypass of, e.g. ammonia through a bed of particulate ammonia oxidation catalyst.