Kinetic Model for the Remediation of Soils Contaminated with Hydrocarbons Using Low-Temperature Oxidation

Abstract

This paper presents a kinetic model for the remediation of soils contaminated with hydrocarbons by low-temperature oxidation (LTO). The oxidation of hydrocarbons, which consist of a mixture of straight chained, branched and ringed compounds follow a number of complex chain reactions. The investigations into the kinetics of the process are simplified by using pseudocomponents such as maltenes, asphaltenes, and coke. The mechanisms of LTO are divided into four groups: Original maltenes comprised of slow-reacting and volatile maltenes. Slow-reacting maltenes react with oxygen to produce asphaltenes and water. Asphaltenes undergo polymerization and dehydrogenation to form coke, product-volatile maltenes, and hydrogen; the volatile maltenes oxidize to form carbon oxides and water. These proposed mechanisms explain the experimental observations. The kinetic model in conjunction with a heat-transfer model can be used to determine the compositional changes when LTO is applied to remediate soils contaminated with hydrocarbons.