Linear α-olefins (LAOs) are used in a wide range of applications in the chemical industry. Back in the 1990s, Linde Engineering and the Saudi Basic Industries Corporation (SABIC) joined forces to develop α-SABLIN® technology. The first commercial plant to use α-SABLIN® technology went on-stream in Saudi Arabia in 2009 and has been working consistently above full design capacity since then. Linde and SABIC are continuing their successful partnership with the development of an on-purpose route to 1-hexene (LAO OP).
The key characteristics and features of the α-SABLIN® process include:
Moderate reaction conditions
Single-step, homogeneous catalytic reaction
Runaway-safe reaction system
Highly flexible product distribution
High selectivities and high product purities without superfractionation
Available for licensing
α-SABLIN® plants comprise three main units: a reaction section, a catalyst quench and a separation section.
The α-SABLIN® process uses a Zr(IV) carboxylate as a catalyst and special aluminium alkyl components as a co-catalyst.
The oligomerisation of ethylene into LAOs takes place in a bubble column reactor at 20 to 35 bar and between 50 and 100°C. The solvent toluene and the dissolved catalyst components are fed into the liquid phase.
Ethylene is introduced to the bottom section of the reactor via a gas distribution system. The heavy liquid LAOs are removed from the lower section together with the solvent and the catalyst.
The LAO reaction is highly exothermic. Any heat exchanger surfaces in the reaction area, however, would be subject to heavy fouling. The α-SABLIN® process solves this problem by removing heat with ethylene. Using ethylene as a coolant in the LAO reactor is a unique feature of α-SABLIN® technology.
Separation section:α-SABLIN® product separation
The LAO products and solvent are separated downstream of the reaction section in the product separation section. The separation train only applies to standard distillation technology. Due to the high selectivity of the catalyst system, there is no need to install sophisticated superfractionation steps for removal of by-products and impurities.