Abstract of CEH report Linear and Branched Alkylbenzenes
Abstract
Linear alkylbenzene (LAB) is produced by
reacting benzene with alkyl groups containing ten to thirteen carbon atoms
that are derived from normal (i.e., straight-chain) paraffins or linear alpha-olefins.
LAB may also be called soft alkylate, detergent alkylate or dodecylbenzene.
Branched alkylbenzene (BAB) is produced by reacting benzene with alkyl groups
derived from polymerizing propylene (mainly propylene tetramer). BAB is sometimes
called hard alkylate but may also be referred to as detergent alkylate or dodecylbenzene.
Nearly all LAB is converted to linear alkylbenzene sulfonate (LAS) by sulfonation.
LAS is a major surfactant in household and industrial detergents. BAB is also
sulfonated to produce a branched alkylbenzene sulfonate (BAS, but often referred
to as ABS) that can be used in the same applications as LAS. However, BAS is
slow to biodegrade in waste treatment plants; consequently, it has been replaced
by LAS in household detergent applications in the more developed countries.
BAS continues to be used in some industrial applications in the developed nations
and in household detergent applications in many of the less developed countries.
However, LAS is increasingly replacing BAS in all but the poorest countries.
Total worldwide capacity for those LAB plants actually in operation in early
2006 is estimated at 3.44 million metric tons. North America, Western Europe
and Japan together account for only about 35% of total world capacity. This
share has continued to decline as more plants are built in the developing regions
of the world to meet the growing demand for synthetic detergents that contain
LAS. In most of these developing countries, the capacity growth in LAB reflects
its use in synthetic detergents that are gradually replacing soaps for laundry
and dishwashing applications. There are now only six plants that make BAB and
that might subsequently be converted to LAB production.
The following pie charts show capacity for linear (LAB) and branched (BAB)
alkylbenzenes in 2006:
World Capacity for Linear and Branched Alkylbenzenes—2006
Existing capacity in North America, Western Europe and Japan is adequate for
demand within these regions and for substantial exports to other world areas.
The South African company Sasol Ltd. (and its wholly owned affiliates) is the
world’s largest producer of LAB. It accounts for over 15% of worldwide
capacity and 50% of the total capacity in Western Europe and North America.
Compañía Española de Petróleos, S.A. is the second-largest
producer in the world. It accounted for almost 15% of worldwide LAB capacity
in 2005 and about 30% of the combined LAB capacity of Western Europe and North
America.
The worldwide capacity of BAB plants in operation during early 2006 is now
estimated at only about 280–285 thousand metric tons. There is only one
BAB plant in the three major developed regions. It is located in France and
accounts for about 35% of worldwide capacity for BAB. The last U.S. BAB plant
closed in late 1991; the last Japanese plant closed in 2003, and was subsequently
converted to production of LAB.
