Stručni rad
ENVIRONMENTALLY SAFE REMEDIAL OF ACID SLUDGE BY INCINERATION
Filip Kokalj
Niko Samec
Branko Perdija
Sažetak
Abstract
Acid sludge or gudron is oily waste that forms in the process of acid rafination inter products of crude oil or waste oil with concentrated sulphur acid. There are several old dump sites for acid gudron in Slovenia. Recently was made a decision to start the remedial process of these old unsolved ecological problems. After the recent investigation of some other remedial processes, a decision was made to investigate the incineration of acid sludge. In order to conduct the investigation, chemical analyses of acid sludge from two biggest dump sites in area of the city of Maribor, located in the city suburbs of Studenci and Pesnica was made. These two locations and several smaller will be in remedial process in the course of next years. Gudron was transported there more then 20 years ago. It was produced while processing old oils with the process of rafination with sulphur acid. With this process the unsaturated hydrocarbons, metal parts and carbon chlorides are removed. The amount of waste material in such a process is between 3 and 10 percent of input quantity. There is a difference between the two samples, especially in concentration of chlorine, zinc and lead. Calorific value and concentration of sulphur are similar and they are the most influential in the process of combustion and formation of combustion products.
In the very beginning, the theoretical-technical study of possible and environmentally safe processes of incineration of unprocessed acid sludge was conducted. Due to specific chemical composition and physical properties of acid sludge the decision was made to perform test incineration of acid sludge by using two different technologies with variety of flue gas treatment systems, which are indispensably necessary for reaching the flue gas emission levels set by the European Community Directive.
Appropriate planning of all test trials with correct selection of incineration technology and technology of flue gas treatment together with precise execution of tests shows, that it is possible to incinerate acid sludge with very good results. The concentration of SO2 was the hardest to get under the legislative value. The SO2 concentration in raw gases was around 10 g/Nm3, showing that all sulphur has been burnt and has left the primary combustion chamber with flue gases. The reduction of its concentration was undertaken in two or in three steps. The concentration of heavy metals in slag shows, that only smaller part of them has left the primary chamber, adding to the eased work of flue gas treatment devices.
Ključne riječi
acid sludge; waste incineration plant viewpoint of environmental hazards restitution of threatened natural resources
Hrčak ID:
7368
URI
Datum izdavanja:
29.8.2003.
Posjeta: 4.310 *