Butadiene Basics

Butadiene (CH2=CH-CH=CH2) is

• The largest single use of butadiene is in the production of synthetic rubber (Styrene Butadiene Rubber or SBR and Polybutadiene Rubber or PBR). Non-rubber uses include hexamethylene diamine (HMDA) for nylon 6, 6 manufacture, Acrylonitrile Butadiene Styrene (ABS) resins, and Styrene-Butadiene (SB) Copolymer latexes
• End products such as tires, carpet backing, hoses, footwear, wetsuits, etc.
• Colorless gas, mildly aromatic
• A very reactive intermediate and, therefore, is involved in many chemical reactions
  • Polymerization for the production of polybutadiene and copolymers (like styrene and/or acrylonitrile)
  • Adiponitrile through hydrocyanation
  • Dimerization and trimerization through Diels-Alder reactions for the synthesis of cycloalkanes and cycloalkenes
• Potential carcinogen, flammable and irritative
• Butadiene industry originated leading up to the Second World War to reduce dependence on natural rubber

Butadiene manufacturing

• By-product of the thermal cracking process for ethylene production and is extracted from the mixed C4s cut
• On-purpose butadiene production via butane or butenes through non-oxidative dehydrogenation
• Oxidative dehydrogenation of butenes, limited industrial applications
• Was produced from ethanol in smaller quantities using catalysts, no longer used industrially
• Butanes/buttons non-oxidative dehydrogenation process
  • Reactor section – adiabatic fixed bed multi-reactor system at vacuum conditions, cyclic operation with catalysts regeneration
    • Once through conversion of butanes/butenes is claimed to be high under the selected operating conditions
    • Palladium-alumina based
  • Recovery Section
    • Including reactor effluent compressor, butadiene separation from lights, paraffin, and mono-olefins