Ashland Project: Precision HCl Filtration System for Specialty Chemical Lines
Project Background:
Ashland is a leading global specialty chemical company whose products are widely used in pharmaceuticals, personal care, and architectural coatings. In the production of a high- performance intermediate, large quantities of industrial hydrochloric acid (HCl) are used as a reaction reagent. However, raw HCl often contains trace amounts of rust, pipe debris, and insoluble impurities from transportation and storage. If these particles enter the reactor, they can cause catalyst poisoning or degrade the color and purity of the final product. Consequently, Ashland introduced Unite's highly corrosion- resistant precision filtration units.
Core Challenges:
Extreme Chemical Corrosion: Hydrochloric acid (HCl) is extremely aggressive; traditional 304 or 316L stainless steel can be penetrated in a short time, demanding ultimate corrosion resistance from equipment materials.
Strict Cleanliness Standards: Specialty chemicals are extremely sensitive to impurities, requiring filters to stably intercept fine particles larger than 1-5μm.
Zero- Leakage Safety: Due to the volatility and toxicity of HCl, the filtration system must operate with 100% hermetic integrity to prevent leaks that could lead to safety or environmental incidents.
Maintenance Convenience: Given the chemical risks, the replacement process for filter elements or bags must be quick and simple to minimize operator exposure to strong acids.
Our Solution:
Tailored to Ashland's strong acid conditions, we provided a fully PTFE- lined precision filtration integrated solution:
Specialty PTFE/PFA Lined Structure: Filter vessels are constructed of high- strength carbon steel lined with thick PTFE or PFA. All wetted parts are non- metallic, completely eliminating metal ion contamination and equipment corrosion.
High- Performance Non- Metallic Elements: Equipped with precision depth filter elements (or bags) made of Polypropylene (PP) or PTFE, offering excellent chemical compatibility and high impurity retention rates.
Hermetic Leak- Proof Design: Utilizing flanged lids with specialty perfluoroelastomer (FFKM) or encapsulated O- rings to ensure absolute airtightness under pressurized operation.
Modular Anti- Corrosive Skid: The filtration unit integrates acid- resistant diaphragm pressure gauges and corrosive- resistant sampling valves, with overall anti- corrosion coating protection for rapid on- site connection and extended service life.
Customer Value & Results:
Since the commissioning of the HCI filtration system at Ashland, its performance has been exceptionally stable. Testing shows that the acid particulate indicators improved by two grades, significantly reducing reactor fouling and catalyst loss downstream. The fully PTFE- lined design ensures zero corrosion leakage during years of operation, drastically lowering environmental O&M costs. Ashland highly commended Unite's expertise in handling highly corrosive fluids, and this project provides a key reference for upgrading similar production lines within their global network.
