Clean technique for producing nitrilotriacetic acid

The invention relates to a method for producing a chelator nitrilotriacetic acid from conveniently and readily accessible raw materials, belonging to the technical field of organic chemistry synthesis. Ammonia water, sodium hydroxide and hydroxyacetonitrile are utilized as raw materials to synthesize the nitrilotriacetic acid. The method specifically comprises the following steps: gradually and dropwisely adding the hydroxyacetonitrile into the mixed solution of ammonia water and sodium hydroxide; and hydrolyzing under heating conditions to obtain an aqueous solution of sodium nitrilotriacetate. The byproduct ammonia gas is absorbed by a falling film absorption column to prepare ammonia water for cyclic use. The invention has the advantages of accessible raw materials and simple technological process, and the byproduct can be effectively recycled and reutilized.