32 results about "Andrussow process" patented technology

The present invention relates to a system and a process for producing hydrogen cyanide and more particularly, to a process for controlling operational stability of the system and process by blanketing the system with inert gas. More particularly, the present invention relates to the flushing of the system with an inert gas when a crude hydrogen cyanide product exceeds a threshold of oxygen, such as greater than 0.4 vol.% oxygen.

An improved method of igniting a catalyzed gas phase chemical reaction involving the act of providing a reactor vessel (10), wherein the gaseous reactant, continuously passing through the reactor, makes contact with a solid phase metallic catalyst media (18), with an inductive coil (14) within the reactor (10) on the inlet side of the catalyst and a porous thermal, spark and radiation barrier (17) between the induction coil (14) and solid catalyst (18). According to the improved method of ignition, the metallic catalyst media (18) is inductively heated in order to ignite the chemical reaction and after ignition the inductive heating is suspended and the exotherm of the chemical reaction is thereafter relied upon to sustain the reaction temperature. Such a reactor and method of operation is particularly useful for continuous production of hydrogen cyanide by the Andrussow process.

The invention is directed at the field of chemical engineering and provides a cheap preparation method for high purity D,L-methionine. The preparation method comprises the following steps: preparing a hydrocyanic acid gas mixture by using an Andrussow process; fully reacting the hydrocyanic acid gas mixture with methylthiopropionaldehyde under the catalysis of base so as to prepare a 2-hydroxy-4-methylthiobutyronityile system; reacting the 2-hydroxy-4-methylthiobutyronityile system with ammonia under the conditions of heating and pressurization and carrying out pressure reduction and deamination so as to obtain 2-amino-4-methylthiobutyronityile; and subjecting 2-amino-4-methylthiobutyronityile to acidolysis with inorganic acid so as to obtain D,L-methionine. According to the invention, raw materials used in the method are cheap and easily available, the intermediate 2-hydroxy-4-methylthiobutyronityile has stable properties, prepared 2-amino-4-methylthiobutyronityile has high yield and high purity, and D,L-methionine obtained after continued production has the advantages of high yield, high purity, great bulk density and low total production cost.

The invention is directed at the field of chemical engineering and provides a preparation method for calcium D,L-2-hydroxy-4-methylthiobutyrate. The preparation method comprises the following steps: preparing a hydrocyanic acid gas mixture by using an Andrussow process; preparing a 2-hydroxy-4-methylthiobutyronityile system with the hydrocyanic acid gas mixture and methylthiopropionaldehyde as starting raw materials; hydrolyzing the 2-hydroxy-4-methylthiobutyronityile system with inorganic base so as to obtain D,L-2-hydroxy-4-methylthiobutyrate; and chelating D,L-2-hydroxy-4-methylthiobutyrate with a soluble calcium salt so as to produce calcium D,L-2-hydroxy-4-methylthiobutyrate. The method has the advantages of a few processing step, cheap and easily available raw materials, stable intermediate properties and low total production cost. Prepared calcium D,L-2-hydroxy-4-methylthiobutyrate has the advantages of high yield, high purity, a powder crystal form and great bulk density, can be used as an animal feed additive for effective mixing with a feed so as to supplement trace elements and amino acid in daily ration and improve production performance and immune performance of animals and can also be used as a medicine reagent.

The present invention relates to a process for the production of hydrogen cyanide, more particularly to a process for the production of crude hydrogen cyanide comprising 0.05-1% by volume of methane. The invention also relates to a reactor for the production of crude hydrogen cyanide product, said reactor having a catalyst bed supported by an annular support providing a passage zone having an area of ​​at least 90% of the cross-sectional area of ​​the reactor, and wherein The annular support substantially prevents catalyst bed bypass. The invention also relates to a crude hydrogen cyanide comprising 0.05-1% by volume of methane.

The invention provides a production system and a production method for synthesizing hydrocyanic acid by an Andrussow process. The production system comprises a natural gas conveying system, an air conveying system, an ammonia gas conveying system and mixed reaction equipment, wherein an outlet of the air conveying system and an outlet of the ammonia gas conveying system are joined at one place and communicated with an inlet of the mixed reaction equipment; an outlet of the natural gas conveying system is communicated with an inlet of the mixed reaction equipment. The production method comprises the following steps: mixing air and ammonia gas; mixing the mixed gas with natural gas; and introducing the mixture into a reactor for reaction through a flame arrester. According to the production system and production method provided by the invention, hot ammonia gas and hot air are mixed on an air pipeline, three materials are separately preheated respectively, the burst points of the three gases can be avoided in a large range, the process route and process equipment are simplified, the reaction efficiency is improved, the energy consumption is reduced, the raw material natural gas can be saved by 10-15%, and 5-5.5 million yuan can be saved per year.

Processes and systems for the production of hydrogen cyanide via the Andrussow process are described. A reaction zone, wherein oxygen, ammonia, and methane can be allowed to react in the presence of a catalyst comprising platinum to provide hydrogen cyanide. A desulfurization zone, wherein a feed stream comprising sulfur and at least one of the oxygen, the ammonia, and the methane can be contacted with a desulfurization material to produce a sulfur- reduced feed stream that is provided to the reaction zone. In an example, the desulfurization material includes zinc oxide.

The present application provides devices and methods for hydrogen recovery in the Andrussow process. The present disclosure relates to hydrogen recovery for the Andrussow process for the production of hydrogen cyanide (HCN) from methane, ammonia and oxygen. The method comprises (a) conditioning a reaction mixture comprising methane, ammonia, and oxygen to provide sufficient oxygen to the reaction mixture to produce a gaseous waste product having at least 40% hydrogen after removal of ammonia and recovery of hydrogen cyanide stream; and (b) removing components from said gaseous waste stream to produce recycled hydrogen. The device includes a reactor and a hydrogen recovery system. The present invention safely solves the problem of wasteful losses of hydrogen from oxygen-enriched or oxygen Andrussow process product streams through the use of the hydrogen recovery methods and systems described herein.

A method for producing hydrogen cyanide comprising: feeding a reaction mixture feed comprising gaseous ammonia, methane and oxygen to a plurality of main reactors each comprising a platinum-containing catalyst bed; determining the whether the percent yield of hydrogen cyanide in any one of the plurality of primary reactors is at or below a threshold; when the percent yield of hydrogen cyanide in any one of the plurality of primary reactors is at or below at said threshold, identifying one or more suboptimal reactors among said plurality of primary reactors; and when said one or more suboptimal reactors are identified, supplementing said reaction mixture feed Feed to one or more supplementary reactors, wherein each of the one or more supplementary reactors includes a platinum-containing catalyst bed. The supplemental feeding may be performed in place of the feed of the reaction mixture to the one or more suboptimal reactors, or in addition to the feed of the reaction mixture to the one or more suboptimal reactors In addition to the feed, the supplementary feed is also carried out. The overall process is sufficient to maintain the total measured hydrogen cyanide production rate in the one or more supplementary reactors and the main reactor within a desired total hydrogen cyanide production rate range.

The invention aims at the chemical industry field, and relates to a preparation method of a D,L-2-hydroxy-4-methylthiobutyric acid-trace element chelate. The method comprises the following steps: preparing a hydrocyanic acid mixed gas by adopting an Andrussow process, and reacting the hydrocyanic acid mixed gas with methylthiopropionaldehyde to obtain a 2-hydroxy-4-methylthiobutyronityile system, hydrolyzing the 2-hydroxy-4-methylthiobutyronityile system by an inorganic alkali to obtain D,L-2-hydroxy-4-methylthiobutyrate, and chelating the D,L-2-hydroxy-4-methylthiobutyrate with a trace metal element salt to generate the D,L-2-hydroxy-4-methylthiobutyric acid-trace element chelate. The method has the advantages of few technological steps, cheap and easily available raw materials, stable properties of the above intermediate, and low total production cost; the obtained D,L-2-hydroxy-4-methylthiobutyric acid-trace element chelate has the advantages of high yield, high purity and large bulk density; and the D,L-2-hydroxy-4-methylthiobutyric acid-trace element chelate can be effectively mixed with feeds as an animal feed additive to supplement trace elements and amino acids in the daily ration and improve the endozoic production and immunity performances, and can also be used as a medicinal reagent.

The invention provides an oxygen Andrussow process for production of hydrogen cyanide from a methane-containing feedstock such as natural gas in the presence of oxygen and ammonia over a platinum catalyst, wherein the production of byproduct organonitrile impurities, such as acrylonitrile, is reduced. Limiting the content of C2+ hydrocarbons in the methane feedstock in the oxygen Andrussow process, in contrast to the air Andrussow process, has been found to reduce formation of organonitriles, such as acrylonitrile. The organonitrile impurities can require additional processing for removal, cause fouling of equipment, and can also contribute to hydrogen cyanide polymerization. Reduction of C2+ hydrocarbon levels to less than 2 wt%, or 1 wt%, or less than 0.1 wt%, in the methane can providean improved yield of higher purity HCN. Reduction of C2+ hydrocarbon levels also solves the problem of polymer buildup in process equipment, reducing downtime required for cleaning when higher C2+ hydrocarbon levels are present in the reaction feed.