Hydrogenation to products with IV below 1

Abstract

AbstractThe hydrogenation of fatty acids (FA) or fatty acid methyl esters (FAME) is a fundamental process to manufacture basic oleochemicals, like stabilizers and surfactants. These kinds of oleochemicals are used in downstream processes, to obtain products which are easily bio‐degradable, non‐irritant to the skin, and equipped with other favourable characteristics. In principle the FA or FAME are hydrogenated in a reactor under pressure, higher temperature and in the presence of a metallic catalyst, such as nickel or palladium. The process can be controlled in a desired direction by appropriate choice of these parameters to get a product with different degrees of saturation, melting properties and colour. The commonly used process nowadays is a batch process. The hydrogenation reaction is carried out in a loop or stirred reactor, in the presence of a suspended catalyst. After the reaction the catalyst must be removed from the product by an elaborate and time‐consuming filtration. This leads to higher consumption of catalyst. Another concern is that Ni‐soaps can be formed during the process leading to deactivation of catalyst and the presence of nickel in the final product. Therefore the fixed bed method was developed to eliminate these disadvantages. A pilot plant was constructed in which the catalyst is fixed on a carrier matrix and filled into the reactor and a test run was carried out with FA from tallow and FAME from palm oil. The iodine value of < 0.1 in hydrogenated FAME was achieved as required by the industry for the production of surfactants. In the fixed bed hydrogenation for ME nickel catalyst and for FA a palladium catalyst is used. Furthermore catalyst is reused, its consumption is reduced and the formation of byproducts is minimized. The process is characterized by a high reliability, feed flexibility, easy control and high yield.