Shell Oil Comapny

David A Weingaertner

Paul C Johnson

Arnold R Marsden, Jr

Lynton W Dicks

Arthur L Otermat

Lynn Henry Slaugh

Charles C Chou

Stephen Merle Stearns

Dallas Lea Byers

George M Deeley

Harvey B Wilde

James D Colthart

A system for in situ decontamination of contaminated soil in a contaminated zone comprising:

Enhanced deep soil vapor extraction process and apparatus utilizing

An Enhanced Deep Soil Vapor Extraction Process and Apparatus utilizes heaters placed into the soil at least to the depth of contamination and a vapor/condensate extraction system that withdraws volatilized contaminant vapors from the subsurface and any condensate that collects in the extraction well. Depending on the rate of formation of condensate in the well, a second conduit may be placed inside the well for the collection and removal of condensate by a downhole pump or a suction device located at ground surface. The process is directed towards contaminants trapped in or below the normal groundwater level. Groundwater extraction wells are also employed to create a 'cone of depression', or local draw-down of the groundwater to expose those soils that are normally water saturated and thereby permit decontamination of such soils. Conduits may be placed within the groundwater extraction wells for the purpose of extracting groundwater.

Enhanced deep soil vapor extraction process and apparatus for removing

A heater blanket for use in soil remediation utilizes a rigid construction which isolates the heater elements from air, water, and contaminant vapors which could act to oxidize, embrittle or otherwise degrade the integrity of the electrical heaters. A rigid structural frame is constructed from a support frame of parallel members which are rigidly connected to a series of support tubes perpendicular thereto. The support tubes enclose and protect the heater elements. One or more heater modules thus constructed may be easily transported to a selected site.

Modified heater for in situ soil heating

A soil heater assembly (SHA) utilizes for example, two or more, 5 ft by 10 ft heating sections rigidly bolted together. Each section contains three NICHROME heating elements encased in ceramic beads which are floatingly pinned to a 4-inch thick ceramic fiber insulation encased in NEXTEL cloth. The heating elements run across the entire length and width of the SHA, spaced approximately three inches apart. The heating sections are pinned to their respective 5 ft by 10 ft stainless steel support frame, which is made out of structural angles and flat bars, with pins running through the four-inch ceramic fiber insulation. Since the insulation is somewhat compressible and the pins are slideable therethrough, i.e. not fixed, the heater elements can move or 'float' vertically to accommodate surface irregularities of the soil. Both heating sections and support frames are then positioned side-by-side on the ground, bolted together, and covered by another four inches of fiber insulation. All of the insulation packages are surrounded by NEXTEL or a silica-based cloth for ease of handling and retaining their integrity. The entire assembly may be lifted by a crane and moved to another site, or it may be fitted with wheels and towed.

Heater blanket for in-situ soil heating

An in-situ thermal desorption system utilizes perforated or slotted pipe buried in the soil below the depth of contamination in the soil. The surface of the soil is covered with a layer of permeable insulation (to conserve heat and to provide a gas migration path on top of the soil) and a layer of impermeable material above the insulation. A vapor recovery/treatment system consists of a method of inducing a vacuum between the impermeable layer and the soil surface (e.g., a vacuum pump or an induced draft fan) and a treatment system for the contaminated vapor (e.g., a cold trap, carbon adsorption, or incineration). Fuel and compressed air are fed to a pressurized combustion chamber and combusted, the combustion products flow into the buried pipe and are distributed through the contaminated soil. Heat from the pressurized combustion products causes the organic contaminants within the soil to vaporize, pyrolyze, decompose, or react with oxygen. Contaminants and their by-products are swept away by the combustion products into the vapor recovery/treatment system.

In-situ thermal desorption of contaminated surface soil

An improved in-situ soil decontamination heating process utilizes a submerged vapor recovery system comprising perforated or slotted pipes buried in the contaminated soil or below the depth of contamination. The pipes may be buried in a manifold arrangement and may contain thermocouples to monitor temperature. A vapor recovery/treatment system is connected to the buried pipe network and includes a method of inducing a vacuum on the buried pipe network (e.g., a vacuum pump or an induced draft fan) and a treatment system for the contaminated vapor (e.g., a cold trap, carbon adsorption, or incineration). Heat is applied to the soil surface by a relatively flat, surface-conforming, resistance heater. When heat is applied to the soil, a vacuum is induced in the buried pipes. The heat causes the contaminants within the soil to vaporize, pyrolyze, decompose, or react with oxygen. The contaminants and their by-products are swept away by the air into the buried pipe network for further treatment or disposal.

In-situ soil decontamination process with sub-surface vapor recovery

An improved process for the remediation of soil contaminated by the presence therein of organic or semi-volatile inorganic contaminants which comprises (1) supplying thermal energy to the soil at one or more locations under the surface of the soil, (2) collecting the vapors resulting from contaminant vaporization or decomposition under the influence of the thermal energy, after passage horizontally through the soil, at one or more locations under the surface of the soil and separating from the collected vapors the environmentally undesirable components thereof.

Soil decontamination

This invention relates to a process for extracting styrene from a styrene-containing hydrocarbon feedstock by:

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Houston, TX, United States of America

David A Weingaertner