The invention is a closed-loop, thermal process for remediating soil contaminated with hydrocarbon chemicals; it is particularly well suited for the remediation of soils containing hydrocarbons with relatively high boiling points and for the remediation of soils which contain clays or silts. The process uses a combination of at least one extraction well which is used to withdraw vapors from contaminated soil and at least one injection well, called a "fire" well which is used to burn both a source of hydrocarbon fuel and all of the hydrocarbons present in the recovered vapors and then inject the combustion gases into contaminated soil. The heat in the combustion gases is used to raise the temperature of the contaminated soil and volatilize hydrocarbons in the soil. Dielectric heating can be used to supplement the heating performed by the combustion gases.

Vapor-extraction system for removing hydrocarbons from soil

Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.

Method and system for accessing subterranean deposits from the surface

According to one embodiment, a system for accessing a subterranean zone from the surface includes a well bore extending from the surface to the subterranean zone, and a well bore pattern connected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.

Method and system for accessing subterranean deposits from the surface and tools therefor

Volatile contaminants are removed from the vadose zone of contaminated ground by pumping volatilized contaminants from the vadose zone using one or more vacuum extraction wells.

Removal of volatile contaminants from the vadose zone of contaminated ground

A system for removing volatile contaminants from a subsurface plume of contamination comprising two sets of wells, a well for injecting a fluid into a saturated zone on one side of the plume and an extracting well for collecting the fluid together with volatilized contaminants from the plume on the other side of the plume. The fluid enables the volatile contaminants to be volatilized and carried therewith through the ground to the extracting well. Injecting and extracting wells are preferably horizontal wells positioned below the plume in the saturated zone and above the plume in the vadose zone, respectively. The fluid may be air or other gas or a gas and liquid mixture depending on the type of contaminant to be removed and may be preheated to facilitate volatilization. Treatment of the volatilized contamination may be by filtration, incineration, atmospheric dispersion or the like.

In-situ remediation system and method for contaminated groundwater

The present invention provides a multistage process for the removal of tar, water and particulate contaminants from a hot product gas resulting from the in-situ gasification of an underground coal deposit, which comprises passing the hot product gas through a first heat exchange zone in indirect heat exchange relationship with a gasification gas to thereby sufficiently reduce the temperature of the product gas so as to separate the tar present in the product gas and provide a substantially tar-free product gas. Thereafter, the tar-free product gas is withdrawn from the first heat exchange zone and passed through at least one subsequent heat exchange zone in indirect or direct heat exchange relationship with a heat exchange material which has a lower temperature than the product gas. A major portion of the water originally present in the hot product gas is removed in the subsequent heat exchange zone. The gasification gas, used to cool the hot product stream by means of indirect heat exchange, is passed to an underground coal deposit and utilized therein to gasify the same. A fluidized bed heat exchanger may be used in the first heat exchange zone in order to substantially completely remove tar and particulate contaminants.

Multistage clean-up of product gas from underground coal gasification

Indene is separated from close boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, indene is separated from trans-β-methylstyrene, and from 2-, 3- and 4-methylstyrene by extractive distillation using 1-methyl-2-pyrrolidone as the extracting agent.

Separating indene from unsaturated alkylaromatics

Vinyltoluene is separated from close-boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, vinyltoluene is separated from cis-β-methylstyrene, and from α-methylstyrene by extractive distillation using γ-butyrolactone as the extracting agent.

John C. Montagna

Papers

Multistage clean-up of product gas from underground coal gasification

Separating indene from unsaturated alkylaromatics

Separating vinyltoluene from other alkenylaromatics