REDUCTION OF ORGANONITRILE IMPURITY LEVELS IN HCN FROM AN OXYGEN ANDRUSSOW PROCESS

摘要

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 provide an 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.