Aromatic substituted nonionic surfactants in soil prevention, reduction or removal in treatment zones

Abstract

Disclosed is a process for the treatment of a plant gaseous stream containing odor compounds including hydrogen sulfide, an alkyl mercaptan or an alkyl thiol and mixtures thereof by contacting the plant stream with an oxidizing agent that reduces the odor but forms elemental sulfur. The elemental sulfur, and other inorganic, scales that form, or deposit, can be suppressed or removed using a specific aromatic substituted nonionic surfactant material. The use of such a process produces a significant improvement in odor quality while maintaining a clean process facility and low operating pressure drop.

Description

[0001] The invention relates to the use of specific aromatic nonionic surfactant materials to prevent the formation of or remove soils such as an inorganic soil. The material can be used to remove soils from a variety of surfaces, (i.e.) from reaction zones, treatment zones or other soil accumulation areas. The compounds of the invention are useful in removing elemental sulfur in simple or complex soils from soiled surfaces. More particularly, the aromatic nonionic surfactant materials can be used in columns or scrubbers used in a gas treatment for the prevention of the formation of or removal of inorganic soils such as elemental sulfur or carbon soils, phosphate soils carbonate, silicate soils or other soils of complex mixture. The aromatic surfactants are used to remove sulfur, in an elemental form commonly found in combination with other soils from surfaces within the gas treatment equipment. The invention relates to the maintenance of or the restoration of substantial pressure d...

AI Technical Summary

Benefits of technology

[0030] Surprisingly, neither the aromatic nonionic surfactant material, the peroxyacid, nor the essential oils are destroyed by the processing conditions at a rate that interferes with oxidative odor reduction or soil removal. Using a combination of a peroxyacid and an essential oil, surprisingly, allows the essential oil to behave as both a masking agent and an odor chemical reactant that augments the oxidative capacity of the peroxyacid; especially towards sulfur containing malodorous compounds. Accordingly, the invention can be found in a process for removing an inorganic or organic soil, scale, or sediment from a pre-soiled atmosphere treatment device, such as an air scrubber. The process comprising contacting the atmosphere treating system with an aqueous solution of the aromatic nonionic surfactant; and removing at least a portion of the used treatment. In the process soil residues can be prevented or routinely removed from a scrubber system.

[0032] Further, the invention may also be found in a process for removing an odor from a liquid effluent, the process comprising contacting the liquid effluent comprising an odor component with an aqueous peroxyacid treatment composition combined with the aromatic nonionic surfactant composition and optionally one or more essential oils, forming a combined effluent and aqueous treatment composition having reduced odor; and removing at least a portion of the combined composition.

[0035] Further, not only does the peroxyacid (such as peroxyacetic acid) material result in the oxidation of odor components into freely soluble or dispersable materials that remain in the aqueous phase, we have found that the use of such an acidic material results in the absorption of organic bases such as ammonia and amines resulting in the effective scrubbing of these compounds from the atmospheric effluent material. Additionally, it is now shown that the combinations of peroxyacids, aromatic nonionic surfactant, and essential oils allows for simultaneous masking and enhanced malodor removal. In large part the process is designed to favor the mass transfer of odor compounds into the aqueous treatment.

Problems solved by technology

The formation of or accumulation of soils on hard surfaces or in a treatment zone is undesirable for both esthetic and operational reasons.

Sulfur soils can be unsightly.

Further, such soils can often reduce the efficiency of the chemical treatment for the overall treatment efficiency of a treatment zone.

Inorganic soils can be particularly troublesome.

Further, industrial plants, agricultural installations, hospitals, kitchens, etc. that handle large quantities of organic material such as hog farms, dairy farms, chicken farms, meat packing plants, animal rendering plants, composting plants, paper mills, sewage treatment plants and other similar installations can generate large quantities of odors that typically exit the facility in an odor contaminated atmospheric effluent flume or other effluents.

An atmospheric effluent having one or more of such compounds can have a strong odor and can be highly objectionable within the plant to plant personnel and outside the plant to plant neighbors.

Such plugging reduces the volume of gas that can be treated, increases the pressure drop within the equipment and increases the cost of operating the gas transport device.

With a low threshold a small amount of these and similar odors common in plant effluent are serious olfactory problems.

These odor sources are not capable forming elemental sulfur deposits however they can no big a part of the deposit and can in certain circumstances in proved a the tendency of a sulfur to form deposits.

While chlorine dioxide has had some success, chlorine dioxide is highly toxic, difficult to handle and must be generated on site.

Such difficulties lead to substantial resistance to its use.

Hydrogen peroxide by itself is not effective against a broad range of odor constituents without additional treatment materials.

However, the application of oxidative technologies including ozone, hydrogen peroxide, chlorine dioxide and other oxidants have had some limited success.

Such materials have not been seriously considered as odor reducing materials because of the nature of its odor.

Images