To produce high-purity butene-1 that is suitable for copolymers in LLDPE production via the Alphabutol ethylene dimerization process developed by IFP/Axens in cooperation with SABIC.
Polymer-grade ethylene is oligomerized in a liquid-phase reactor (1) with a homogeneous liquid system that has high activity and selectivity.
Liquid effluent and spent catalyst are then separated (2); the liquid is distilled (3) for recycling of unreacted ethylene to the reactor, and fractionated (4) in order to produce high-purity butene-1. Spent catalyst is treated to remove volatile hydrocarbons before safe disposal.
The Alphabutol process features are: simple processing, high turndown, ease of operation, low operating pressure and temperature, liquid-phase operation and carbon steel equipment. The technology has advantages over other production or supply sources: uniformly highquality product, low impurities, reliable feedstock source, low capital costs, high turndown and ease of production.
Yields: LLDPE copolymer grade butene-1 is produced with a purity exceeding 99.5 wt%. Typical product specification is:
Other C4s (butenes + butanes) < 0.3 wt% Ethane < 0.15 wt% Ethylene < 0.05 wt% C6 olefins < 100 ppmw Ethers (as DME) < 2 ppmw Sulfur, chlorine < 1 ppmw Dienes, acetylenes < 5 ppmw each CO, CO2, O2, H2O, MeOH < 5 ppmw each Licensor: Axens