Investigation of the properties of the solid residue of the pyrolysis of sewage sludge

Abstract

This article presents the results of the thermal processing of sludge from domestic wastewater under laboratory conditions. The pyrolysis process is carried out in a batch reactor with an original design. Gaseous and liquid forms of hydrocarbon compounds, as well as solid carbonaceous residue, were obtained after processing the sludge in a pyrolytic plant. It is established that during pyrolysis of sludge sewage sludge, the output of the process products depends on the heating rate of the raw material. The results of chromatographic, X-ray diff raction, spectroscopic studies of the composition, properties, and structure of pyrolysis products are presented in the following sections. This research  project involved the analysis of sludge sediment samples obtained from diff erent locations within the oil and gas fi eld of the West Kazakhstan region. The results of the chemical analysis of the initial sludge (pH of the water extract, cationic-anionic composition, determination of organic matter in the sample) selected from several points of the sludge site are presented. Diff erential thermal analysis of silt sediments has been carried out. The results of this study demonstrate that the pyrolysis of sludge leads to thermal sterilization and the production of gaseous, liquid, and solid carbonaceous residue, which exhibit potential as fuel sources or raw materials for petrochemical synthesis. In addition, heavy metals (such as mercury and cadmium) can be separated from the carbonaceous residue during pyrolysis. It is proposed to use the solid pyrolysis sludge as a sorbent for the collection of oil and petroleum products, as it is economically and environmentally benefi cial.

Keywords

• sewage sludge
• pyrolysis
• pyrolysis of sludge
• water absorption
• sorption capacity
• diff erential thermal analysis