Linear alkylbenzene (LAB) is an organic compound with the formula C6H5CnH2n+1, where n is typically between 11 and 12. LAB is used almost wholly as an intermediate in the production of linear alkylbenzene sulphonate (LAS), which is a surfactant. In the past five decades, LAB has emerged as an important feedstock for producing biodegradable detergents and other cleaners.
Normal paraffin (n-paraffin) and benzene are the main feedstocks for LAB. High-purity n-paraffin is obtained by hydrotreating jet kerosene. This is then dehydrogenated to form linear olefins, which are then exposed to benzene in the presence of a catalyst to produce LAB.
There are three types of catalysts used in producing LAB. Hydrogen fluoride (HF) is the major catalyst used. The second type of catalyst used is aluminium chloride (AlCl3), but it is getting phased out. The HF process, in particular, was seen to be the most commercially viable. However, because of environmental concerns around the use of HF, it has been replaced since 1995 by a fixed bed catalyst system – for example, the DETAL process, which does not use HF.
Surfactant LAS, also known as linear alkylbenzene sulphonic acid (LABSA), is typically sold at a 96% minimum purity level in liquid state. LAS is used widely in the manufacture of detergents for household and industrial use. The common use form is as a sodium salt.
One tonne of LAS uses around 0.77 tonnes of LAB.
ICIS quotes LAB and LAS prices in Asia/Middle East.
To find out more Linear Alkylbenzene Methodology December 2012