32 results about "Andrussow process" patented technology

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.

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.