Abstract: 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.

Abstract: A batch method and apparatus provides controlled release of gaseous air contaminants into the atmosphere through catalytic oxidation while minimizing both the energy required and the volume of waste gas exhausted into the atmosphere. The device has a recirculating gas stream driven by a recirculation fan which moves gas, normally and naturally present at start-up, through a bed of granular catalyst, in an oxidizer and into contact with the surface of a process-gas heater and back to the recirculation fan. The gaseous contaminants may be drawn into this system using a vacuum pump. Control of catalyst temperature is achieved based upon the novel system configuration, and without the introduction of dilution air, and the contaminant gas is introduced without controlling either flow rate or temperature.