Basis of this process is a new zeolite catalyst developed by TU München and Südchemie. The catalyst is suspended in liquid isobutane. The reaction takes place in a new developed reaction system.
The reactor is a reaction column, where the trays are functioning as reactor. Rising isobutane vapour and the boiling liquid on the trays are supporting the mixing of the reaction components. This secures the best possible dilution of the reactants. Reaction mixture is isobutane and butene which is fed to each reaction tray via separate ports.
After the reaction the mixture is transported to a separation column where isobutane, alkylate and the high boiling fraction including catalyst are separated. The catalyst is sent back to the reaction column.
The regeneration of the catalyst takes place in a new developed kind of hydrocracking process where the high boiling components are converted into valuable products. This new regeneration is a cooperation with the university in Stuttgart. This moderate regeneration method allows to high recycling rates of the catalyst.
Worldwide the demand for unleaded gasoline is growing. Several countries are banning or have already banned the lead as additive. The substitutes of lead, aromatics and MTBE are still under discussion. Aromatics must be reduced and the usage of MTBE is limited. Therefore the only octane-buster left for safe use are high octane aliphatic components.
A additional demand of alkylates will come from the oncoming specifications for road transport fuels being introduced in 2005. Also the political pressure from local governments or the European parliament to reduce the CO2-emissions which comes from the ratification of the Kyoto protocol will force refineries to look to an alternative fuel production.
Alkylate is an ideal blendstock for production of high octane fuel. It has negligible amounts of toxics and ozone precursors. It has high RON and MON values. In addition blending more alkylate into gasoline helps lower the benzene, aromatics, and sulfur levels trough dilution and can also help replace the octane lost due to reduction of aromatics. Alkylation offers several key advantages to refiners including the highest average quality of all components available to the gasoline pool, increased amounts of gasoline per volume of crude oil and high heats of combustion.
The alkylation process entails contacting light olefins -propylene, butylenes, and amylenes- with isobutane in the presence of a strong acid catalyst to form an alkylate product, consisted of branched paraffins having a low RVP and high octane number.
Commercial alkylation plants use either sulfuric acid (H2SO4) or hydrogen fluoride (HF) as catalysts.
Although H2SO4 alkylation generally is viewed as less hazardous than HF processing, it requires BLOCK 2 - - FORUM 9 213 LURGI