High capacity solid filtration media

Abstract

A high capacity filtration media, method of preparing the media, and method of treating a fluid stream with the media are provided. The media contain a porous substrate impregnated with high concentrations of a permanganate. Preferably, the media includes a porous substrate impregnated with at least about 8% permanganate by weight. The media can optionally contain sodium bicarbonate. Improved capacity for the removal of undesirable compounds such as ethylene, formaldehyde, hydrogen sulfide and methyl mercaptan are achieved.

Description

TECHNICAL FIELD [0001] The present invention relates generally to a composition and method for the removal of compounds having disagreeable odors, toxic properties or corrosive properties from gaseous streams. The invention more particularly relates to the use in filter beds of a high capacity solid filtration media containing a substrate impregnated with a permanganate. BACKGROUND OF THE INVENTION [0002] The removal of toxic, corrosive and odorous gases can be accomplished by a number of techniques. These may include wet scrubbing, incineration, and removal via gas-phase air filtration using a variety of dry scrubbing adsorptive, absorptive, and / or chemically impregnated media. As opposed to these other methods, gas-phase air filtration does not require the consumption of large quantities water or fuel. Dry-scrubbing media can be engineered from a number of common adsorbent materials with or without chemical additives for the control of a broad spectrum of gases or tailored for spe...

AI Technical Summary

Benefits of technology

[0020] High capacity solid filtration media, methods of preparing the same and methods of treating a fluid stream with the solid filtration media are provided. The solid filtration media described herein are useful for removing or reducing undesirable contaminants from a gaseous fluid stream.

[0021] Generally described, the high capacity solid filtration media include a porous, impregnated substrate having high levels of impregnate. The impregnate is a permanganate, preferably a permanganate salt having high water solubility, such as sodium permanganate or lithium permanganate. A gas-evolving or gas-producing material such as sodium bicarbonate may also be included in the media. In contrast to presently available filtration media, the high capacity solid filtration media described herein contain levels of permanganate approximately 8% or higher, thereby providing an increased efficiency for removing undesirable gaseous compounds from a fluid stream, particularly compounds such as ethylene, formaldehyde and methyl mercaptan from gaseous streams by exhibiting a higher capacity for contaminant. For example, when used to remove ethylene from a gaseous stream, the media described herein utilizing sodium permanganate have an ethylene capacity of approximately 9%, whereas currently available potassium permanganate-impregnated media exhibit a maximum ethylene capacity of only approximately 3%.

[0022] The present invention addresses an existing need in the industry by providing a high capacity, low flammability permanganate-impregnated substrate for the removal of undesirable contaminants from gas streams. The permanganate-impregnated substrate provides a long lasting filtration media that can be replaced less frequently, thereby minimizing maintenance and replacement costs. Due to its high capacity, the impregnated substrate described herein may be used in small filter beds, thereby allowing the treatment of fluid streams where significant space limitations exist. The filtration media described herein yield an equivalent or superior capacity over activated carbon adsorbents and are much less expensive and considerably less flammable than activated carbon adsorbents.

Problems solved by technology

Furthermore, H2S is flammable.

At lower levels, in combination with moisture, chlorine has a corrosive effect on electronic circuitry, stainless steel and the like.

Nitrogen dioxide, however, is a deadly poison.

Inhalation of the vapor is known to irritate the respiratory tract.

Furthermore, exposure to high concentrations of isopropyl alcohol can have a narcotic effect, producing symptoms of dizziness, drowsiness, headache, staggering, unconsciousness and possibly death.

Control of this compound prolongs the marketable life of such items.

The airborne compounds described above can have a detrimental effect on the local environment.

For example, acidification is caused by emissions of sulfur dioxide and nitrogen compounds (nitrogen oxides and ammonia), which in turn cause acid rain.

In addition to causing environmental damage, ozone poses a health hazard, particularly for children, the elderly and individuals with asthma or lung disease.

Although a variety of permanganate-impregnated substrates are known for removing undesirable contaminants from fluid streams, these known impregnated substrates all demonstrate a limited capacity and, therefore, a low efficiency for the removal of undesirable compounds from the streams.

These limitations arise to a large extent from an insufficient porosity of the solid filtration media or a clogging of pores with byproducts formed by reactions of the impregnate with the contaminant.

This results in the currently available media not meeting the needs of various industries.