Characterization of tar deposits, extraction and sorption properties

Abstract

The major part of tars is created from the carbonization of coal. Tars are defined as a dangerous waste and removal or conversion of tar is considered to be a technologically very challenging problem. Tars can condense or polymerize into more complex structures (tar deposits), which may lead to clogging of pipes and heat exchangers. Nowadays tar deposits are mostly incinerated, and therefore the main goal of this paper was to characterize and find a useful solution for decomposition of tar deposits. For experimental part tar deposits, formed by polymerization and condensation reactions, from storage tank for tars were chosen. At first the initial analyzes of tar deposits (elemental, thermogravimetric and calorimetric analysis) were performed. Next step was in analyzation of ashes from tar deposits by X-ray fluorescence. After characterization the tar deposits were extracted in the Soxhlet extractor by acetone, toluene and quinolone and activated with potassium hydroxide. The final step of this work was by sorption characterization on 3Flex Surface Characterization Analyzer (Micromeritics). The specific surface area of the samples was evaluated using two methods single point measurement at p/p0=0.2 and BET method. Micropore and external surface areas were calculated based on the t-plot analysis (carbon black model).