No abstract

No abstract

No abstract

No abstract

No abstract

No abstract

Oxidative desulfurisation is a method of removing sulfur from diesel fuel that has the potential to compete with conventional hydrodesulfurisation processes in refineries.Ultrasound has been shown to greatly increase peroxide oxidation rates of sulfur compounds and can thereby enhance the technology. Through the use of conceptual design modelling, this article critically assesses a range of novel process options. Calculations show that the rate enhancement achieved by ultrasound can translate into reduced process complexity and costs.By modelling various process options, the separation stage of the process is optimised to reveal that a solid adsorbent combined with a combustion regeneration method is the most economically viable. Although the process is limited to feeds with low sulfur content, it is competitive with conventional hydrotreater technology and superior to upgrading an ageing facility.

Water condensation is a possible cause of membrane wetting in the operation of membrane contactors, especially under high-temperature conditions. In this study, water condensation in pores of polytetrafluoroethylene (PTFE) hollow fiber membranes was investigated during high-pressure CO2 absorption around 70 °C. It was found that the liquid accumulation rate in the treated gas knock-out drum was constant during continuous operation for 24 h when all experimental conditions were fixed, indicating a stable degree of membrane wetting. However, as the operating parameters were changed, the equilibrium vapor pressure of water within membrane pores could change, which may result in a condensation-conducive environment. Water condensation in membrane pores was detected and proven indirectly through the increase in liquid accumulation rate in the treated gas knock-out drum. The Hagen–Poiseuille equation was used to correlate the liquid accumulation rate with the degree of membrane wetting. The degree of membrane wetting increased significantly from 1.8 × 10−15 m3 to 3.9 × 10−15 m3 when the feed gas flow rate was reduced from 1.45 kg/h to 0.40 kg/h in this study due to water condensation in membrane pores. The results of this study provide insights into potential operational limitations of membrane contactor for CO2 absorption under high-temperature conditions.