Process development and techno-economic analysis of microwave-assisted demetallization and desulfurization of crude petroleum oil

Abstract

Metals and sulfur, if not efficiently eliminated from crude petroleum oil during refining, may have severe detrimental impacts in refinery processes such as fluid catalytic cracking and hydrotreating units. Recently, the lab-scale microwave-assisted demetallization and desulfurization (MW-DMDS) of crude oil using Bis(2-ethylhexyle) phosphoric acid (D2EHPA) have shown several advantages such as high removal efficiency, being environmentally green, and lower energy requirements. This paper presents a comprehensive industrial process scheme for MW-DMDS by designing the required processing units. In addition, an effective methodology to regenerate D2EHPA using sulfuric acid and sodium hydroxide (NaOH) aqueous solutions was developed and experimentally validated. A Techno-economic investigation was carried out by adopting the ASPEN Plus process simulator to estimate the upscaling feasibility of the process to treat 50,000 barrels per stream day (BPSD) of crude oil. Total capital costs (CAPEX) and total annual operating costs (OPEX) were estimated at 6.77 MUSD and 4.23 MUSD (0.24 $/bbl), respectively. The results indicated the economic superiority of the proposed process compared to the existing technologies, like hydrodemetallization (HDM) and hydrodesulfurization (HDS) due to the remarkably lower CAPEX and OPEX costs. Sensitivity analysis by changing the primary design parameters demonstrated that the required microwave power and the corresponding purchase costs of the microwave generators have the highest share of the estimated CAPEX costs. Moreover, the annual operating costs seem to strongly depend on the reagent consumption and regeneration process effectiveness.

Keywords

• Techno-economic analysis
• Microwave heating
• Process design
• Demetallization
• Desulfurization
• Crude oil