In the alkylation unit, light olefins such as butylene, pentene, and propylene are combined with isobutane to create high octane alkylates.  This reaction most commonly occurs in the presence of concentrated sulfuric acid or hydrofluoric acid which acts as a catalyst. Alkylate is an important blending components for gasoline, and so is a critical unit in maintaining overall refinery gasoline production rates.  Failure to remove water and contamination from the feedstocks hinders catalyst performance and results in a reduction in alkylate quality and production. 

Free water in the alkylation unit olefin feedstocks is extremely costly to the alkylation process, as the water results in greatly accelerated rates of acid spend, as the acid dilution must be counterbalanced with replacement with fresh acid.  A rule of thum is that for every 1 kg (or lb.) of free water, 10 kg (or lb.) of acid must be replaced.  Another issue with free water intrusion is that dilution of the acid catalyst decreases the efficiency of reaction which directly results in a lower quality alkylate output.

Pall’s advanced filtration solutions for the alkylation process deliver superior contaminant and water removal for a refining process that is more efficient and produces higher quality alkylates while minimizing required maintenance and downtime.

Featuring a large diameter, coreless design, the Pall Ultipleat High Flow filter utilizes crescent-shaped pleat geometry and proprietary filter media to deliver optimal solids removal that improve the efficiency of the alkylation process.  The high storage capacity ensures extended filter life to reduce the frequency of filter changeouts.  With a flow path from inside to outside, the Ultipleat high flow filters capture contaminants and keep them inside the filter for improved filtration performance and ease of filter changeout.

Pall’s Marksman XLD high flow series filter elements deliver enhanced solids removal performance to improve feedstock and alkylate output quality as well as preserve the life of process equipment.  Featuring the proprietary Poly-Fine Extended Life Depth (XLD) media, the Pall Marksman series filters provide consistent, high performance filtration.  The large cartridge geometry and high flow capacity extend filter life and reduce the frequency of costly scheduled maintenance activities.  Furthermore, its inside to outside flow design ensures that captured particulates are trapped inside the filter element for improved filter performance and a fast, clean changeout procedure.

Pall Profile Coreless filter elements utilize proven depth filter technology to deliver cost effective high flow filter performance.  The long-lasting Profile Coreless filters require fewer changeouts while providing effective solids removal with a low pressure differential.  Along with a simple installation procedure and reduced operating costs, the Pall Profile Coreless Filters offer an economical solids removal solution for high flow applications.

The Pall AquaSep XS Liquid/Liquid Coalescer delivers optimal water removal to improve feedstock quality, acid utilization, and alkylate quality.  With enhanced liquid removal capability, the Pall AquaSep coalescer prevents the excess spend of costly acid catalysts during the alkylation process.  Also providing superior reliability, the AquaSep coalescer reduces the frequency of scheduled maintenance operations for a streamlined refining process.

In the alkylation process, downstream of the catalytic reaction, a caustic wash is typically done on the alkylate to remove any remaining acid.  This may result in trace spent caustic passing downstream, contributing to off-sec alkylate.  Use of particulate prefilter and compatible liquid/liquid coalescer will effectively and reliably remove the spent caustic.

For prefiltration prior to the liquid/liquid coalescer, Nylon Profile® filters deliver efficient removal of solids. Nylon Profile® filters are constructed from Nylon. In some cored configurations, the Nylon core may also contain glass fibers for reinforcement.  Different configurations such as Profile coreless or Profile II elements are available to suit your flow requirements.  The elements contain an absolute-rated downstream section, and a continuously graded pore size upstream section, which increases service life. Since the fibers in Profile filters are continuous and are “bonded” by intertwining during the manufacturing process, the filters show no media migration and have fixed pore construction that provides consistent downstream fluid quality.

High efficiency PhaseSep liquid/liquid coalescers reliably remove spent caustic / high pH water to meet ‘clear and bright’ product specification and sodium levels downstream. These coalescers remove caustic carryover from alkylate to assure the highest quality and prevent downstream unit downtime from caustic contamination of catalytic processes.

Pall high flow filter and liquid removal solutions utilize advanced technology to deliver enhanced and reliable performance for improved efficiency and alkylate quality in the alkylation process.  Contact our team of filtration experts to learn more.