Gas Chromatographic Determination of 1,4-Dioxane in Benzene

Abstract

The term ‘petrochemicals’ implies the basic chemicals derived from refinery petroleum cuts. They are produced by the separation of the byproducts from the cracking of hydrocarbon streams. The basic petrochemicals, which are produced in large volumes, are divided into two classes, olefins and aromatics. Olefins include ethylene, propylene and 1,3-butadiene. Aromatics such as benzene, toluene and xylenes are obtained from refinery and petrochemical light naphtha streams. Aromatics are produced in the reforming process and in stream cracking. Extraction or various extractive distillation processes are used to isolate

and separate aromatics from the naphtha streams. Typical extraction processes are based on tetra- ethylene glycol, sulpholane, <i>N,N’-</i>methyl pyrrolidone or morpholine. They produce a mixture of aromatics that are subsequently separated by distillation. Glycols used in extraction processes contain small amounts of 1,4-dioxane, which gets distilled over with benzene when aromatics are separated by distillation. In view of the hazardous properties, it is necessary to determine the levels of 1,4-dioxane in glycols and benzene. Determination of 1,4-dioxane in glycols at low p p m levels has already been reported. The detailed studies

carried out for the gas chromatographic determination of 1,4-dioxane in benzene including column selection and linearity are reported in the present communication.