Hydrotreating is a catalytic chemical process to remove Sulfur (S), Nitrogen (N), Oxygen (O), and metals from straight run and cracked products. This “clean-up” also saturates olefins to yield easier-to-process intermediates. Removing the S reduces SOx emissions when fuels are combusted. Sulfur also poisons downstream noble metal reformer catalysts and must be removed from reformer feeds (<0.5 ppm S is a typical naphtha feed spec).
The reaction is carried out in a hydrogen rich environment over a fixed catalyst bed. The process replaces sulfur or nitrogen contaminants in the hydrocarbon chains with hydrogen, making the process a consumer of hydrogen. Protection of the catalyst beds from fouling is critical to maintaining long term hydrotreating efficiency.
Treated products are then stabilized with heat to remove H2S and light ends. Use of direct steam injection is common, especially on diesel.
- Achieve production quotas of low sulfur gasolines and diesels via reliable hydrotreatment of straight run and cracked products that otherwise become a bottleneck
- Provide consistent transportation fuel quality
- Protect against fouling of the feed/effluent heat exchanger
- Protect against premature loss of catalyst activity
- Meet steadily increasing clean fuels specifications
Production Challenge / Pall Solution
Reduced catalyst bed activity and shortened life between shutdowns due to bed fouling and associated channeling
Improve refinery productivity and extend hydrotreater bed life by removing solids from the feed to protect the feed/effluent heat exchanger and/or catalyst bed.
- A range of absolute and nominal rated filter elements is available to reduce suspended solids levels in the feed, to protect the exchanger and/or catalyst bed from fouling
Products failing to meet specifications due to solids and water carryover from direct injection steam stripping
Improve product quality making it easier to meet ‘clear and bright’ clean fuels standards by removal of water and solids carried over from steam stripper.
- A range of absolute and nominal rated filter elements is available to reduce suspended solids to <5 ppmw, and extend the coalescer life.
- High efficiency AquaSep® Plus liquid/liquid coalescers reliably meet the ‘clear and bright’ product specification and/or reduce the cost for downstream dehydration.
Hydrogen recycle and makeup gas compressors requiring excessive maintenance (rebuilds and downtime) due to liquid and solid carryover from separator causing severe fouling and erosion of compressor internals
Reduced maintenance of the recycle and make-up gas compressors by removal of liquids and solids in the hydrogen recycle stream from separator.
- KO pots, mesh pads, cyclonic devices and conventional filter-separators may not effectively remove aerosol-sized liquid hydrocarbon droplets or fine solids.
- High efficiency SepraSol™ Plus liquid/gas coalescers and Medallion™ HP liquid/gas coalescers provide 99.999% removal at 0.3 microns per the DOP test and 1 ppb downstream per the modified ANSI/CAGI-400-1999 test procedure. Both provide excellent compressor protection
Catalyst Bed Protection
Use of hydrotreating and hydrocracking to removesulfur, nitrogen, oxygen, and metals from hydrocarbons is an important step in the refinement process. Removing these contaminants requires the use of catalysts, which need to be maintained at a high level of purity in order to work at the highest level of efficiency and effectiveness. Particulate fouling, water fouling, or deactivators dissolved in incoming water will contribute to catalyst deactivation, rise in catalyst bed differential pressure, or heat exchanger fouling and efficiency loss, all contributing to shortened campaign length. The result is unscheduled production loss and downtime costs to skim and wash or replace catalyst. Pall filters are designed to ensure the continued efficacy of these catalysts and heat exchangers.
Ultipleat High Flow filters effectively control fouling of the catalyst bed and heat exchanger. The Ultipleat® High Flow filter is a large diameter, coreless, single open ended, pleated cartridge with an inside-to-outside flow pattern. The filter's unique crescent-shaped pleat geometry, combined with its large 152.4 mm (6 inch) diameter and proprietary range of available Pall filter media, allows the use of significantly fewer filters and smaller housings for high flow rate applications. Systems can handle up to 115,443 lpm (30,500 gpm).
The Ultipleat® High Flow Filter offers many benefits, including a smaller filter system with up to 40 times fewer elements to change out vs. 2.5” O.D. commodity filter element designs by providing higher flow rates per filter cartridge – up to 1900 lpm (500 gpm)Elements are available in 508 mm (20 inch), 1016 mm (40 inch), 1524 mm (60 inch) and 2032 mm (80 inch) lengths. Coreless, all plastic construction minimizes waste disposal, and absolute rated filter media provide reproducible performance. The in-to-out filter flow configuration means all debris stays within the filter. High filtration efficiency, reproducible performance, easy change out of filter elements , and long filter service life are key features of this superior filter.
If free water or dissolved contaminants are causing catalyst fouling issues, installation of a high efficiency liquid/liquid coalescer is recommended. Pall AquaSep® XS Coalescer filters efficiently separate water and solids contaminants from hydrocarbons. Due to the ability of each coalescer element to process a higher flow in a higher solids environment while still providing superior effluent quality, the AquaSep XS liquid/liquid coalesce system is a cost-effective way to separate the water and solids from hydrocarbon fluids before reaching the catalysts.
Hydrotreated Steam Stripped Diesel Dewatering
Following hydrotreating, diesel streams are stabilized by application of heat to drive off lighter ends. Use of direct injection steam has become commonplace. The challenge is that the steam condenses as very fine droplets that are difficult to remove with commodity glass fiber coalescers, ESPs or other legacy separation equipment, creating hazy fuel that contaminates downstream final blending, or creates high loads on water removal equipment such as salt beds or desiccant dryers. Use of AquaSep XS coalescers protected by Ultipleat Flow filters will ensure clear and bright steam-stripped diesel, improving final product quality and reducing salt or desiccant dryer operating costs.
Hydrogen Recycle Compressor Protection
During hydrotreating or hydrocracking, large volumes of hydrogen is used to ensure adequate hydrogenation of the hydrocarbon feeds is achieved. Excess hydrogen is separated, boosted in pressure via compression and recycled to the front of the process. Because of their high operating pressure, these hydrogen recycle compressors are prone to attack from hydrocarbon liquids and from fine solids in the gas. Installation of high efficiency SepraSel Plus or Medallion HP L/G coalescrs upstream of the compressors has been proven to unsure compressor reliability so they can run between scheduled campaign lengths without the need for unscheduled downtime or maintenance overhauls.
High efficiency SepraSolTM Plus liquid/gas coalescers and MedallionTM HP liquid/gas coalescers provide 99.999% removal at 0.3 microns per the DOP test and 1 ppb downstream per the modified ANSI/CAGI-400-1999 test procedure.
Ultipleat® High Flow Filters and AquaSep® XS Coalescers, help ensure the highest quality catalysts and best hydrotreated diesel quality, free from particulate and water contamination. SepraSol Plus or Medallion HP L/G coalescers offer superior compressor protection. For more information on how this system works and can be installed, click here to see purchase information or talk to a Pall expert.
Contact our team of filtration experts to address your needs
As the industry leader in innovative filtration technology, We offer premium filtration solutions for refining applications that maximize contaminant removal.
Let’s find the right solution, together.
Let’s connect. We want to share our innovative filtration solutions with you today. Contact our knowledgeable subject matter experts for information on how we can help. Thank you and we look forward to assisting you shortly.