Iranian Journal of Oil and Gas Science and Technology

Abstract Burning fuel oil presents a significant problem due to the harmful release of sulfur dioxide gases, which contribute to acid rain and environmental damage. Fuel oil contains a sulfur-rich asphaltene component, but the issues associated with burning this fuel oil can be mitigated through solvent deasphalting. This method isolates a portion of the asphaltene, thereby reducing the problems related to fuel oil combustion. In this study, the introduction of Nano-Fe2O3 into the fuel oil improved the efficiency of the solvent deasphalting process by up to 51% under optimal conditions (with a solvent-to-fuel oil ratio of 10 and a 5% weight percentage of Nano-Fe2O3). As a result, the sulfur content in fuel oil decreased from 3.5% to 2.71% by weight, reflecting a 22.5% reduction. Various analyses, including XRD, BET, FESEM, and FTIR, were used to examine the Nano-Fe2O3. Additionally, the Response Surface Method from Design Expert software was employed for statistical analysis and optimization. The experimental design included two numerical variables: the percentage of Nano-Fe2O3 (ranging from 1 to 5% by weight) and the solvent-to-fuel oil ratio (ranging from 5 to 10). The remaining sulfur in fuel oil and the efficiency of the asphaltene separation process were the dependent variables under investigation. Mathematical models were introduced to analyze these output variables, showing a high level of significance in predicting their behavior based on the independent variables, with predicted R2 values of 0.8218 and 0.9843, respectively.

Abstract In Iran, power plants use liquid fuels such as heavy fuel oil (HFO) or mazut to prevent disruption in power generation. The high percentage of sulfur compounds in HFO and the lack of efforts to remove it, causing significant damage to the environment. The purpose of this research is performing a techno-economic analysis on the Hydrodesulfurization (HDS) process of HFO. The results showed that for removing 85% of sulfur compounds from HFO with a volume flow rate of 250 m3/h that includes 3.5% wt sulfur compounds, the total capital investment and the net production cost are 308.9 million US$ and 114.5 million US$/year, respectively. Besides, the sensitivity analysis indicates that with a 100% increase in the catalyst loading, the mass percentage of sulfur compounds in the HFO will be decreased by 15% more. Also, 6.4% and 32% will add to the total capital investment and net production cost, respectively. With a 100% increase in the gas to oil ratio, the mass percentage of sulfur compounds in the HFO will be decreased by 15.3% more. Also, 43.8% and 6% will be added to the total capital investment and net production cost, respectively. With a 100% increase in the pressure of the HDS process, the mass percentage of sulfur compounds in the HFO will be reduced by 20.75% more. Also, 43% and 6.75% will be added to the total capital investment and net production cost, respectively. Ultimately, with a 100% increase in the inlet temperature of beds, the mass percentage of sulfur compounds in the HFO will be reduced by 5% more. Among the effective operational parameters, hydrogen consumption has the greatest impact on net production cost and payback period, and the pressure of the Hydrodesulfurization process has the greatest impact on increasing the total capital investment of the process.