Equation 1 can be used for easy calculation without going through tiresome graphical interpretation steps
Pressure level 90-760 mmHg 21-89 mmHg 3.1-20 mmHg
a
b
0.1779 0.1460 0.1010 0.0469 0.0196
0.6758 0.6667 0.6637 0.6719 0.6962
1-3 mmHg <1 mmHg
All from one Source!
Table 4
two-stage VDs demonstrate comparable operational per- formance and reliability. However, while two-stage dryers involve higher capital expenditures, single-stage dryers slightly increase operational costs due to higher utility require- ments. Considering both Capex and Opex, the single-stage VD stands out as the overall better option. Additionally, the integration of a pre-condenser is highly recommended as it significantly reduces the steam consumption of ejectors and cooling water circulation for after-cooler, thereby lowering operational expenses. The use of a multi-diameter VD can further optimise tower sizing and substantially reduce Capex. However, the place- ment of a coalescer upstream of the VD is generally not pre- ferred due to the additional Capex and Opex involved. This study also highlighted the need for adopting higher-grade metallurgy in vacuum overhead systems to prevent corrosion. Benchmarking across various facilities has reinforced the preference for simpler, cost-effective configurations, with a notable trend towards single-stage VDs in newly com- missioned facilities. This alignment with industry practices ensures not only compliance with stringent water con- tent specifications but also operational sustainability and cost-effectiveness. References 1 Evaluation of ULSD Fuel Haze Resulting from Water Content, CRC Project No. DP-06-20. 2 Brown R L, Wines T H, Improve suspended water removal from fuels, Hydrocarbon Processing , December 1993. 3 AFPM Conference, 2010. 4 Standards for Steam Jet Vacuum Systems , 5th edition, HEI. 5 ASTM D4176-22 – Standard Test Method for Free Water and Particulate Contamination in Distillate Fuels (Visual Inspection Procedures). 6 ASTM D8148-22 – Standard Test Method for Spectroscopic Determination of Haze in Fuels. 7 Nelakanti D M, Patel K, Gadhvi S, Experimental study on ULSD fuel haziness, Catalysis PTQ 2024 . Rajib Talukder is a chemical engineer in the Global Manufacturing Excellence department at Aramco. Throughout his career, he has worked on numerous projects around the world employed by various engineering companies. He graduated from NIT Tiruchirappalli, India. Email: rajib.talukder@aramco.com Prabhas K Mandal is an Operations Engineer Specialist at Aramco. He has more than 30 years of experience in petroleum refining, and sup - ports front end design development for capital projects. He holds a B.Tech in chemical engineering and a M.Tech in petroleum engineering. Email: prabhas.mandal@aramco.com
Duranit ® Catalyst Support Material
Support Plates/ Grids
Droplet Separators / Demisters
Feed Devices: Gas / Liquids
Liquid distributors / Collectors
Random Packings - Ceramic
- Metall - Plastic
Software and Consulting
Get in touch: info@vff.com
Check out: Image Movie VFF
Vereinigte Füllkörper-Fabriken GmbH & Co.KG, P. O. Box 552, 56225 Ransbach-Baumbach, Germany, +49 26 23 / 895 - 0
www.digitalrefining.com
Powered by FlippingBook