Article | REF: J3984 V1

Soil treatment by conventional thermal desorption

Authors: Jan HAEMERS, Marie-Odile SIMONNOT

Publication date: May 10, 2018

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


Overview

Français

ABSTRACT

Conventional thermal desorption is a clean-up technology for excavated soils based on vaporizing pollutants. This article describes the principle and history of the process, and then the treatments of soil matrices (heating in rotary kilns to vaporize pollutants) and gases (destruction of pollutants at high temperature, dust capture and neutralization). The pollutants that can be treated by thermal desorption are then presented, mainly organic compounds and some inorganic ones including mercury, and the safety conditions related to the risk of fire and explosion. The article is illustrated with a concrete example of treatment.

Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.

Read the article

AUTHORS

  • Jan HAEMERS: Managing Director - Haemers Technologies SA (Brussels – Belgium)

  • Marie-Odile SIMONNOT: Professor of Process Engineering - University of Lorraine (Nancy – France)

 INTRODUCTION

Conventional thermal desorption is an ex situ physical technique for treating polluted soils. It involves heating the excavated polluted soil in a rotary kiln, in order to vaporize the pollutants and physically separate them from the matrix. The matrix is then cooled by mixing with water and recycled. The resulting gases containing the pollutants are treated in a plant, where they are oxidized, filtered, neutralized and sometimes even adsorbed before being released into the atmosphere, in compliance with regulations.

The main advantage of the technique lies in its robustness and its application to any type of soil and any type of organic pollutant, including mixtures. Heating ensures that very low or even non-detectable residual levels of the pollutants concerned are reached, enabling the soil to be reused to a very large extent and the pollution to be eliminated once and for all.

The main drawback of this technology, apart from its sometimes high cost due to high energy consumption, is its difficulty of acceptance due to the size of the plants, their continuous operation and the nuisance it can cause during the actual treatment.

Two types of plant are used: fixed plants in industrial environments, where nuisances are well controlled, operating like a waste treatment center, and mobile plants. The latter are set up on industrial sites to be remediated, generally large-scale and far from the population, where the quantities of soil to be treated are significant (several tens or even hundreds of thousands of tonnes) and where the treated soil is returned to the place from which it was excavated.

The main problems covered by conventional thermal desorption are related to coking and gas plants, as well as large-scale chemical sites. The oil industry also makes extensive use of this technique, which was originally developed for refineries, depots and service stations. Today, conventional thermal desorption is mainly applied to oil sites (crude oil), petrochemical sites (refineries), coking and gas plants (coal industry) and large chemical complexes (fertilizers, explosives, pesticides).

The aim of this article is to present the basics of thermal desorption, describe the different types of rotary kilns and gas treatment systems, and outline the limits of use and application for each in relation to the types of soil and pollutants that can be treated.

You do not have access to this resource.

Exclusive to subscribers. 97% yet to be discovered!

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


The Ultimate Scientific and Technical Reference

A Comprehensive Knowledge Base, with over 1,200 authors and 100 scientific advisors
+ More than 10,000 articles and 1,000 how-to sheets, over 800 new or updated articles every year
From design to prototyping, right through to industrialization, the reference for securing the development of your industrial projects

KEYWORDS

heating   |   rotary kiln   |   soil treatment   |   remediation


This article is included in

Environment

This offer includes:

Knowledge Base

Updated and enriched with articles validated by our scientific committees

Services

A set of exclusive tools to complement the resources

Practical Path

Operational and didactic, to guarantee the acquisition of transversal skills

Doc & Quiz

Interactive articles with quizzes, for constructive reading

Subscribe now!

Ongoing reading
Soil treatment by conventional thermal desorption