Published October 2014
Polybutadiene is the second largest volume elastomer worldwide. The primary end use is automobile tires, followed by industrial applications such as belts and hoses, and consumer items such as golf balls. It is almost entirely produced by solution polymerization of butadiene, using catalysts based on rare earth metals such as neodymium, as well as cobalt, nickel and lithium. The microstructure and physical properties of the polymer are determined largely by the catalyst system used to produce it. Neodymium has emerged as the catalyst of choice in recent years for the high-cis variety of polybutadiene. The reactor effluent contains elastomer dissolved in a large excess of solvent. It is typically coagulated and separated from the solvent using steam stripping. The solvent is recycled to the reactors and the elastomer undergoes various polymer processing operations.
In this PEP review, we primarily focus on the solution polymerization of butadiene using a neodymium catalyst. We review developments since the publication of our 1996 PEP review on this subject. The process economics are presented for producing 50,000 MT/yr of polybutadiene product at a US Gulf Coast location. An iPEP Navigator module is attached with the electronic version of this review to allow a quick conversion of process economics in three other major regions: Germany, Japan and China. With the selection of each competing process, the module also allows production economics to be reported in each region in English or metric units.
While the processes are PEP’s independent interpretation of the companies’ patent literature and may not reflect in whole or in part the actual plant configuration, we do believe that they are sufficiently representative of the processes to estimate the plant economics within the range of accuracy for economic evaluations of the conceptual process designs.