The progressive reduction of the permitted content of 1,4-dioxane in ethoxy sulphates presents an increased challenge for surfactant producers. This article discusses technical solutions that can be put in place based on the chemistry of the 1,4-dioxane molecule and its formation mechanism during surfactant production. Desmet Ballestra’s “ultra-low dioxane technology” is discussed in detail, with emphasis on the technical features, advantages, and achievable quality. Technologies for 1,4-dioxane degradation and disposal into water effluent streams are also illustrated.
The n-hexane transformations over alumina-supported platinum have been investigated in order to understand the influence of metal dispersion on the catalytic processes. To obtain reproducible behavior of the catalysts a set of pretreatments was necessary. Hydrogenolysis and dehydrocyclization rates increase with dispersion while the isomerization rate does not change. The ratios among the isomerization products (2-methylpentane and 3methylpentane) remain constant for the examined catalysts. This finding suggests the preeminence of a mechanism which occurs through a cyclic intermediate.
the surface is an important factor for the meso-and macroporous materials. Generally the sulfur adsorption and activity are low as in the case of SiCL, MgO, and carbon blacks. The presence of Lewis acid sites of the surface of ALO;s and TiCL may enhance sulfur adsorption and thereby the activity. These acid sites can be poisoned with Lewis bases such as water or pyridine.Iron oxide shows exceptional behavior, because it combines a high activity with a very low selectivity. An oxidation-reduction mechanism involving the iron ion is very likely. Other investigators (Cook and Ross, 1973;Ross and Jeanes, 1974) found that the oxides of Co, Mo, Ni, and W also promote the direct conversion of HL> S in SCL.
Anionic Surfactants, and Sulphonates in particular, will continue to keep their important rule in Detergents formulation for generations to come.The sulphonation Reactor is the key-tool to generate Sulphonated Molecules for Detergent application, therefore the efforts in improving the specific technology are focused on the best possible design and search for optimum operation of the same.The limits of the present technology are discussed and the peculiarity and advantages of the latest generation of Multi Tube Falling Film Reactor are valued by highlighting:Design basisConstruction accuracyOperating conditions and savingsAchievable products quality
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