Determination of Sulphur Dioxide (SO<sub>2</sub>) Air Emission of Refined Petroleum Products by Emission Factor Approach for Air Pollution Control

Abstract

Air pollution control is a safe method for achieving a sustainable environment and can be accomplished by adequately monitoring pollutants that pose significant environmental risks. The combustion of sulfur-containing petroleum products has been a major concern for several decades. Therefore, this study was aimed at determining sulfur levels in refined petroleum products such as Premium Motor Spirit (PMS), Automotive Gas Oil (AGO), and Dual-Purpose Kerosene (DPK). It also investigated the air quality implications of sulfur levels and estimated the contribution of the refinery’s products to sulfur dioxide air emission. Fuel samples were collected from the Warri Refining and Petrochemical Company (WRPC) in Nigeria and analyzed using Ultraviolet-visible spectrophotometer (UV-Vis) and Energy-Dispersive X-ray Fluorescence (EDXRF). Sulfur levels were determined at 425 nm wavelength, and sulfur dioxide air emission were estimated for seven consecutive years from 2010 to 2016 using the emission factor approach. The densities of PMS, AGO, and DPK were 0.77 kg/l, 0.832 kg/l, and 0.82 kg/l respectively. The levels of sulfur in PMS, AGO, and DPK were 2.007 x 10<sup>-4</sup> %, 6.970 x 10<sup>-5</sup> wt%, and 4.233 x 10<sup>-5</sup> wt% respectively from UV-Vis technique and 0.016, 0.087 and 0.029% respectively for EDXRF technique were found below the sulfur limit of 0.015 %, 0.005 % and 0.015 % for PMS, AGO and DPK respectively specified by Standard Organization of Nigeria (SON) specifications of 0.1, 0.5 and 0.15wt% for PMS, AGO and DPK respectively. The annual sulfur dioxide emissions were obtained for seven consecutive years from 2010 to 2016. The results from UV-VIS were observed to have the highest SO<sub>2</sub> emission of 0.1718 tons for PMS in 2011, 0.2593 tons in 2010 for AGO, and 0.0974 tons for DPK in 2010, while the lowest emission was observed to be 0.029 tons for PMS in 2015, 0.0362 tons in 2015 for AGO and 0.0181 tons for DPK also in 2015. The results from EDXRF technique were observed to have the highest SO<sub>2</sub> emission of 13.6939 tons for PMS in 2012, 323.6881 tons for AGO in 2010, and 66.7147 tons for DPK also in 2010, while the lowest emissions for PMS, AGO and DPK were all observed in 2015 to be 2.3122, 45.1872, and 12.4182 tons respectively. The study concluded that the refinery complied with the set requirements.