Concentrated sulfuric acid dries chlorine gas

When activated carbon filters are used under conditions of concentrated sulfuric acid, the requirements for the resin in the activated carbon become quite stringent. What I know is that graphite heat exchangers deteriorate quickly when used under conditions involving concentrated sulfuric acid; this is due to the resin.

Activated carbon must not be used for concentrated sulfuric acid mists, as concentrated sulfuric acid is a strong oxidizing agent with extremely high oxidizing properties; when it comes into contact with activated carbon, it causes the activated carbon to oxidize.

There are many options for filters; stainless steel sintered filter elements or PP ones (depending on the temperature) and PTFE pleated filter elements are all suitable. Using activated carbon not only poses oxidation issues, but also generates hazardous waste.

Magnetic sphere filter media can be used for filtration, or gravity sedimentation can be employed to remove impurities

This post was last edited by qqgd on 2026-2-1 at 14:32. The concentrated sulfuric acid used for drying chlorine gas has a very high concentration and strong oxidizing properties. If handled improperly, it can cause the temperature of the filter media to rise; under such circumstances, the concentrated sulfuric acid can easily react with activated carbon. There are many measures to deal with sulfuric acid mist. Using ceramic balls of appropriate particle size is both inexpensive and convenient; moreover, they can be reused. How great is that!

This post was last edited by pzhhuagong on 2025-6-2 at 15:36. 98% concentrated sulfuric acid is generally colorless and transparent, with very few impurities. Generally, protecting the metering pump at the pump inlet can be achieved by using a Y-type filter. An abnormal pressure difference in the acid mist collector is mostly caused by poor chlorine gas washing at the upstream stage and ineffective water mist scrubbers (e.g., gas short-circuiting, failure to perform self-purification). As a result, the humid chlorine gas entering the drying system contains a high level of salts, which combine with sulfuric acid to form sulfates. This possibility is higher.

Do you concentrate the sulfuric acid by yourselves? If so, the cause of the blockage might be the accumulation of salt on the filter element. All that’s needed is to clean the filter element annually and replace the sulfuric acid regularly

1. Regarding the use of activated carbon filters? Absolutely do not use it. Concentrated sulfuric acid is a strong oxidizing agent; it directly “digests” carbon, destroying the structure of activated carbon. As a result, its filtration function becomes ineffective instantly, and new impurities are introduced. 2. What is the root cause of the abnormal rise in the pressure difference across the acid mist collector? The increase in pressure difference across the acid mist collector is caused by impurities in the sulfuric acid clogging the collector’s filter element. These impurities can be broadly categorized into two types: one is solid particulate matter, such as inorganic particles like dust and rust. One type is organic and colloidal impurities: such as polymers peeled off from the inner walls of pipes, organic substances brought in by upstream raw materials, etc. Prolonged recycling of sulfuric acid or purchasing low-quality acid can both lead to the accumulation of impurities. 3. What should be used for filtering? Given that the root cause of the problem is impurities, the correct approach is to employ multi-stage physical interception. However, the material should not be chosen arbitrarily; it is recommended to opt for PTFE as the material of choice. Two-stage filtration can be considered; the first stage is pre-filtration: PTFE pleated filters or wire meshes, which trap large particles larger than 5μm (such as rust and sand). Secondary precision filtration: All-PTFE pleated/melt-blown filter elements; the pore size should be ≤5μm. This is the core component for protecting the trap; it traps fine impurities, thereby directly addressing the issue of increased pressure differential.

It’s much safer to have an extra clarification tank and clean it regularly than to rely on that filter. When filtering sulfuric acid with a filter, safety must be given careful consideration.

I haven’t used it yet. Later on, if there are any results, can I share my experiences?