Alkyfining – Hydroisomerisation 1-butene to 2-butene
Alkyfining® is the market leader for upgrading HF alkylation plant feeds. In contrast to H2SO4 plants, 1-Butene will negatively affect the octane of the alkylate produced by HF Alkylation. By converting butadiene to butenes and isomerizing 1-butene to 2-butenes (for higher alkylate octane), Alkyfining greatly enhances HF alkylation plant performance.
Butadiene produces unwanted high boiling oligomers often called sludge or Acid-Soluble Oil (ASO). When ASO is removed, significant amounts of alkylation catalyst are lost with it. ASO is hazardous and difficult to dispose of properly; its very presence signifies yield and catalyst loss.
Alkyfining solves these problems and delivers some remarkable results; it is distinguished by:
The treatment of the olefin cut in the liquid state, reducing the operating cost to a minimum.
The use of a family of palladium catalysts on a special alumina carrier. These catalysts are continually being improved in order to meet specific client objectives.
Optimized reactor design to ensure good fluid distribution maximizes olefin yield and the catalyst cycle.
The isomerization without loss of total olefins through over-hydrogenation to alkanes.
Accurate distribution is of paramount importance to selectively hydrogenate dienes and to isomerize butene-1 into butene-2 without saturating olefins. Axens’ proprietary internal (such as Hy-UpTM distributor tray) now proposed in the Alkyfining technology allows full advantage to be taken of the high intrinsic activity and selectivity of Axens catalysts. In addition to providing high turndown capabilities (40% of normal flow), this design eradicates the potential for channeling and hot spots which result in lower olefin yield and a shorter catalyst life.
Particular attention is given to the presence of contaminants in cracked feedstock from FCC and coker units. Axens catalysts have particularly high resistance to sulfur, and if catalyst activity is reduced by temporary poisons, it is restored quickly using simple procedures. Full catalyst regeneration can be carried out in situ or off site. Cycles over three years and service lives in excess of six years are typical.