Physical and chemical characterization of acid tar waste from crude benzol refining
The physical and chemical composition of acid tar waste is important in assessing and developing technological processing options for their subsequent utilization. In the present investigation gas chromatography/mass spectrometry (GC/MS), fourier transform infrared (FTIR), inductively coupled plasma/atomic emission spectrometry (ICP/AES), scanning electron microscopy with energy dispersive Xray (SEM/EDX) were mainly used to characterize the acid tar waste from crude benzol refining. The acid tar waste had a moisture content within the range 7-11%, pH values < 2.5 at a Liquid Solid (L/S) ratio of 20. Chemical analysis indicated the presence calcium, phosphorus and iron at 56.3, 15.7 and 11.3 ppm respectively with trace concentrations of lead, zinc, manganese and chromium. Organic analysis of the aromatic fraction of the acid tar waste by GC-MS revealed a wide range of compounds, including polycyclic aromatic hydrocarbons, furans, phenols, thiophenes and biphenyls. FTIR analysis was used to complement GC-MS. These results may be useful in the design and development of technological processes that can utilize acid tar waste.
Keywords: Acid tars; Analytical techniques; Hazardous waste; Hydrocarbons